diff --git a/Api/CategoryRepositoryInterface.php b/Api/CategoryRepositoryInterface.php
new file mode 100644
index 0000000..48d8b29
--- /dev/null
+++ b/Api/CategoryRepositoryInterface.php
@@ -0,0 +1,57 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api;
+
+
+interface CategoryRepositoryInterface
+{
+
+
+    /**
+     * Save Category
+     * @param \DevStone\UsageCalculator\Api\Data\CategoryInterface $usage
+     * @return \DevStone\UsageCalculator\Api\Data\CategoryInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function save(
+        \DevStone\UsageCalculator\Api\Data\CategoryInterface $usage
+    );
+
+    /**
+     * Retrieve Category
+     * @param string $usageId
+     * @return \DevStone\UsageCalculator\Api\Data\CategoryInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getById($usageId);
+
+    /**
+     * Retrieve Category matching the specified criteria.
+     * @param \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+     * @return \DevStone\UsageCalculator\Api\Data\CategorySearchResultsInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+    );
+
+    /**
+     * Delete Category
+     * @param \DevStone\UsageCalculator\Api\Data\CategoryInterface $usage
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function delete(
+        \DevStone\UsageCalculator\Api\Data\CategoryInterface $usage
+    );
+
+    /**
+     * Delete Category by ID
+     * @param string $usageId
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\NoSuchEntityException
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function deleteById($usageId);
+}
diff --git a/Api/Data/CategoryInterface.php b/Api/Data/CategoryInterface.php
new file mode 100644
index 0000000..7e45cc4
--- /dev/null
+++ b/Api/Data/CategoryInterface.php
@@ -0,0 +1,37 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface CategoryInterface
+{
+    const NAME = 'name';
+
+    /**
+     * Get usage_id
+     * @return string|null
+     */
+    public function getId();
+
+    /**
+     * Set usage_id
+     * @param string $usage_id
+     * @return \DevStone\UsageCalculator\Api\Data\CategoryInterface
+     */
+    public function setId($usageId);
+
+    /**
+     * Get name
+     * @return string|null
+     */
+    public function getName();
+
+    /**
+     * Set name
+     * @param string $name
+     * @return \DevStone\UsageCalculator\Api\Data\CategoryInterface
+     */
+    public function setName($name);
+
+    
+}
diff --git a/Api/Data/CategorySearchResultsInterface.php b/Api/Data/CategorySearchResultsInterface.php
new file mode 100644
index 0000000..ac15cf1
--- /dev/null
+++ b/Api/Data/CategorySearchResultsInterface.php
@@ -0,0 +1,22 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface CategorySearchResultsInterface extends \Magento\Framework\Api\SearchResultsInterface
+{
+
+
+    /**
+     * Get Usage list.
+     * @return \DevStone\UsageCalculator\Api\Data\CategoryInterface[]
+     */
+    public function getItems();
+
+    /**
+     * Set name list.
+     * @param \DevStone\UsageCalculator\Api\Data\CategoryInterface[] $items
+     * @return $this
+     */
+    public function setItems(array $items);
+}
diff --git a/Api/Data/CustomOptionInterface.php b/Api/Data/CustomOptionInterface.php
new file mode 100644
index 0000000..1b4735a
--- /dev/null
+++ b/Api/Data/CustomOptionInterface.php
@@ -0,0 +1,65 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+/**
+ * Interface CustomOptionInterface
+ * @api
+ * @since 100.0.2
+ */
+interface CustomOptionInterface extends \Magento\Framework\Api\ExtensibleDataInterface
+{
+    /**#@+
+     * Constants
+     */
+    const OPTION_ID = 'option_id';
+    const OPTION_VALUE = 'option_value';
+    /**#@-*/
+
+    /**
+     * Get option id
+     *
+     * @return string
+     */
+    public function getOptionId();
+
+    /**
+     * Set option id
+     *
+     * @param string $value
+     * @return bool
+     */
+    public function setOptionId($value);
+
+    /**
+     * Get option value
+     *
+     * @return string
+     */
+    public function getOptionValue();
+
+    /**
+     * Set option value
+     *
+     * @param string $value
+     * @return bool
+     */
+    public function setOptionValue($value);
+
+    /**
+     * Retrieve existing extension attributes object or create a new one.
+     *
+     * @return \Magento\Catalog\Api\Data\CustomOptionExtensionInterface|null
+     */
+    public function getExtensionAttributes();
+
+    /**
+     * Set an extension attributes object.
+     *
+     * @param \Magento\Catalog\Api\Data\CustomOptionExtensionInterface|null $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+        \Magento\Catalog\Api\Data\CustomOptionExtensionInterface $extensionAttributes
+    );
+}
diff --git a/Api/Data/SizeInterface.php b/Api/Data/SizeInterface.php
new file mode 100644
index 0000000..640cf81
--- /dev/null
+++ b/Api/Data/SizeInterface.php
@@ -0,0 +1,36 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface SizeInterface
+{
+    const NAME = 'name';
+
+    /**
+     * Get usage_id
+     * @return string|null
+     */
+    public function getId();
+
+    /**
+     * Set usage_id
+     * @param string $usage_id
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface
+     */
+    public function setId($usageId);
+
+    /**
+     * Get name
+     * @return string|null
+     */
+    public function getName();
+
+    /**
+     * Set name
+     * @param string $name
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface
+     */
+    public function setName($name);
+
+}
diff --git a/Api/Data/SizeSearchResultsInterface.php b/Api/Data/SizeSearchResultsInterface.php
new file mode 100644
index 0000000..8344344
--- /dev/null
+++ b/Api/Data/SizeSearchResultsInterface.php
@@ -0,0 +1,22 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface SizeSearchResultsInterface extends \Magento\Framework\Api\SearchResultsInterface
+{
+
+
+    /**
+     * Get Usage list.
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface[]
+     */
+    public function getItems();
+
+    /**
+     * Set name list.
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface[] $items
+     * @return $this
+     */
+    public function setItems(array $items);
+}
diff --git a/Api/Data/UsageCustomOptionInterface.php b/Api/Data/UsageCustomOptionInterface.php
new file mode 100644
index 0000000..935003a
--- /dev/null
+++ b/Api/Data/UsageCustomOptionInterface.php
@@ -0,0 +1,227 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+/**
+ * @api
+ * @since 100.0.2
+ */
+interface UsageCustomOptionInterface extends \Magento\Framework\Api\ExtensibleDataInterface
+{
+    /**
+     * Product text options group.
+     */
+    const OPTION_GROUP_TEXT = 'text';
+
+    /**
+     * Usage file options group.
+     */
+    const OPTION_GROUP_FILE = 'file';
+
+    /**
+     * Usage select options group.
+     */
+    const OPTION_GROUP_SELECT = 'select';
+
+    /**
+     * Usage date options group.
+     */
+    const OPTION_GROUP_DATE = 'date';
+
+    /**
+     * Usage field option type.
+     */
+    const OPTION_TYPE_FIELD = 'field';
+
+    /**
+     * Usage area option type.
+     */
+    const OPTION_TYPE_AREA = 'area';
+
+    /**
+     * Usage file option type.
+     */
+    const OPTION_TYPE_FILE = 'file';
+
+    /**
+     * Usage drop-down option type.
+     */
+    const OPTION_TYPE_DROP_DOWN = 'drop_down';
+
+    /**
+     * Usage radio option type.
+     */
+    const OPTION_TYPE_RADIO = 'radio';
+
+    /**
+     * Usage checkbox option type.
+     */
+    const OPTION_TYPE_CHECKBOX = 'checkbox';
+
+    /**
+     * Usage multiple option type.
+     */
+    const OPTION_TYPE_MULTIPLE = 'multiple';
+
+    /**
+     * Usage date option type.
+     */
+    const OPTION_TYPE_DATE = 'date';
+
+    /**
+     * Usage datetime option type.
+     */
+    const OPTION_TYPE_DATE_TIME = 'date_time';
+
+    /**
+     * Usage time option type.
+     */
+    const OPTION_TYPE_TIME = 'time';
+
+    /**
+     * Get option id
+     *
+     * @return int|null
+     */
+    public function getOptionId();
+
+    /**
+     * Set option id
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function setOptionId($optionId);
+
+    /**
+     * Get option title
+     *
+     * @return string
+     */
+    public function getTitle();
+
+    /**
+     * Set option title
+     *
+     * @param string $title
+     * @return $this
+     */
+    public function setTitle($title);
+
+    /**
+     * Get option type
+     *
+     * @return string
+     */
+    public function getType();
+
+    /**
+     * Set option type
+     *
+     * @param string $type
+     * @return $this
+     */
+    public function setType($type);
+
+    /**
+     * Get sort order
+     *
+     * @return int
+     */
+    public function getSortOrder();
+
+    /**
+     * Set sort order
+     *
+     * @param int $sortOrder
+     * @return $this
+     */
+    public function setSortOrder($sortOrder);
+
+    /**
+     * Get is require
+     *
+     * @return bool
+     * @SuppressWarnings(PHPMD.BooleanGetMethodName)
+     */
+    public function getIsRequire();
+
+    /**
+     * Set is require
+     *
+     * @param bool $isRequired
+     * @return $this
+     */
+    public function setIsRequire($isRequired);
+
+    /**
+     * Get price
+     *
+     * @return float|null
+     */
+    public function getPrice();
+
+    /**
+     * Set price
+     *
+     * @param float $price
+     * @return $this
+     */
+    public function setPrice($price);
+
+    /**
+     * Get price type
+     *
+     * @return string|null
+     */
+    public function getPriceType();
+
+    /**
+     * Set price type
+     *
+     * @param string $priceType
+     * @return $this
+     */
+    public function setPriceType($priceType);
+
+
+    /**
+     * @param string $help
+     * @return $this
+     */
+    public function setHelp($help);
+
+    /**
+     * @return string|null
+     */
+    public function getHelp();
+
+
+    /**
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface[]|null
+     */
+    public function getValues();
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface[] $values
+     * @return $this
+     */
+    public function setValues(array $values = null);
+
+    /**
+     * Retrieve existing extension attributes object or create a new one.
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface|null
+     */
+    public function getExtensionAttributes();
+
+    /**
+     * Set an extension attributes object.
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+        \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface $extensionAttributes
+    );
+}
diff --git a/Api/Data/UsageCustomOptionTypeInterface.php b/Api/Data/UsageCustomOptionTypeInterface.php
new file mode 100644
index 0000000..c8a5d10
--- /dev/null
+++ b/Api/Data/UsageCustomOptionTypeInterface.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+use Magento\Framework\Api\ExtensibleDataInterface;
+
+/**
+ * @api
+ * @since 100.0.2
+ */
+interface UsageCustomOptionTypeInterface extends ExtensibleDataInterface
+{
+    /**
+     * Get option type label
+     *
+     * @return string
+     */
+    public function getLabel();
+
+    /**
+     * Set option type label
+     *
+     * @param string $label
+     * @return $this
+     */
+    public function setLabel($label);
+
+    /**
+     * Get option type code
+     *
+     * @return string
+     */
+    public function getCode();
+
+    /**
+     * Set option type code
+     *
+     * @param string $code
+     * @return $this
+     */
+    public function setCode($code);
+
+    /**
+     * Get option type group
+     *
+     * @return string
+     */
+    public function getGroup();
+
+    /**
+     * Set option type group
+     *
+     * @param string $group
+     * @return $this
+     */
+    public function setGroup($group);
+
+    /**
+     * Retrieve existing extension attributes object.
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface|null
+     */
+    public function getExtensionAttributes();
+
+    /**
+     * Set an extension attributes object.
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+        \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface $extensionAttributes
+    );
+}
diff --git a/Api/Data/UsageCustomOptionValuesInterface.php b/Api/Data/UsageCustomOptionValuesInterface.php
new file mode 100644
index 0000000..3512738
--- /dev/null
+++ b/Api/Data/UsageCustomOptionValuesInterface.php
@@ -0,0 +1,84 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+/**
+ * @api
+ */
+interface UsageCustomOptionValuesInterface
+{
+    /**
+     * Get option title
+     *
+     * @return string
+     */
+    public function getTitle();
+
+    /**
+     * Set option title
+     *
+     * @param string $title
+     * @return $this
+     */
+    public function setTitle($title);
+
+    /**
+     * Get sort order
+     *
+     * @return int
+     */
+    public function getSortOrder();
+
+    /**
+     * Set sort order
+     *
+     * @param int $sortOrder
+     * @return $this
+     */
+    public function setSortOrder($sortOrder);
+
+    /**
+     * Get price
+     *
+     * @return float
+     */
+    public function getPrice();
+
+    /**
+     * Set price
+     *
+     * @param float $price
+     * @return $this
+     */
+    public function setPrice($price);
+
+    /**
+     * Get price type
+     *
+     * @return string
+     */
+    public function getPriceType();
+
+    /**
+     * Set price type
+     *
+     * @param string $priceType
+     * @return $this
+     */
+    public function setPriceType($priceType);
+
+    /**
+     * Get Option type id
+     *
+     * @return int|null
+     */
+    public function getOptionTypeId();
+
+    /**
+     * Set Option type id
+     *
+     * @param int $optionTypeId
+     * @return int|null
+     */
+    public function setOptionTypeId($optionTypeId);
+}
diff --git a/Api/Data/UsageInterface.php b/Api/Data/UsageInterface.php
new file mode 100644
index 0000000..183695e
--- /dev/null
+++ b/Api/Data/UsageInterface.php
@@ -0,0 +1,38 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface UsageInterface
+{
+    const NAME = 'name';
+
+    /**
+     * Get usage_id
+     * @return string|null
+     */
+    public function getId();
+
+    /**
+     * Set usage_id
+     * @param string $usage_id
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface
+     */
+    public function setId($usageId);
+    
+    /**
+     * Get list of product options
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[]|null
+     */
+    public function getOptions();
+
+    /**
+     * Set list of product options
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[] $options
+     * @return $this
+     */
+    public function setOptions(array $options = null);
+
+}
diff --git a/Api/Data/UsageOptionInterface.php b/Api/Data/UsageOptionInterface.php
new file mode 100644
index 0000000..a59459c
--- /dev/null
+++ b/Api/Data/UsageOptionInterface.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+use Magento\Framework\Api\ExtensibleDataInterface;
+
+/**
+ * Usage option interface
+ * @api
+ */
+interface UsageOptionInterface extends ExtensibleDataInterface
+{
+    /**
+     * Retrieve existing extension attributes object or create a new one.
+     *
+     * @return \Magento\Catalog\Api\Data\ProductOptionExtensionInterface|null
+     */
+    public function getExtensionAttributes();
+
+    /**
+     * Set an extension attributes object.
+     *
+     * @param \Magento\Catalog\Api\Data\ProductOptionExtensionInterface $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+        \Magento\Catalog\Api\Data\ProductOptionExtensionInterface $extensionAttributes
+    );
+}
diff --git a/Api/Data/UsageSearchResultsInterface.php b/Api/Data/UsageSearchResultsInterface.php
new file mode 100644
index 0000000..6e0df92
--- /dev/null
+++ b/Api/Data/UsageSearchResultsInterface.php
@@ -0,0 +1,22 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api\Data;
+
+interface UsageSearchResultsInterface extends \Magento\Framework\Api\SearchResultsInterface
+{
+
+
+    /**
+     * Get Usage list.
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface[]
+     */
+    public function getItems();
+
+    /**
+     * Set name list.
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface[] $items
+     * @return $this
+     */
+    public function setItems(array $items);
+}
diff --git a/Api/SizeRepositoryInterface.php b/Api/SizeRepositoryInterface.php
new file mode 100644
index 0000000..a7aa734
--- /dev/null
+++ b/Api/SizeRepositoryInterface.php
@@ -0,0 +1,57 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api;
+
+
+interface SizeRepositoryInterface
+{
+
+
+    /**
+     * Save Size
+     * @param \DevStone\SizeCalculator\Api\Data\SizeInterface $size
+     * @return \DevStone\SizeCalculator\Api\Data\SizeInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function save(
+        \DevStone\UsageCalculator\Api\Data\SizeInterface $size
+    );
+
+    /**
+     * Retrieve Size
+     * @param string $sizeId
+     * @return \DevStone\SizeCalculator\Api\Data\SizeInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getById($sizeId);
+
+    /**
+     * Retrieve Size matching the specified criteria.
+     * @param \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+     * @return \DevStone\SizeCalculator\Api\Data\SizeSearchResultsInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+    );
+
+    /**
+     * Delete Size
+     * @param \DevStone\SizeCalculator\Api\Data\SizeInterface $size
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function delete(
+        \DevStone\UsageCalculator\Api\Data\SizeInterface $size
+    );
+
+    /**
+     * Delete Size by ID
+     * @param string $sizeId
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\NoSuchEntityException
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function deleteById($sizeId);
+}
diff --git a/Api/UsageCustomOptionRepositoryInterface.php b/Api/UsageCustomOptionRepositoryInterface.php
new file mode 100644
index 0000000..3442b27
--- /dev/null
+++ b/Api/UsageCustomOptionRepositoryInterface.php
@@ -0,0 +1,72 @@
+<?php
+
+namespace DevStone\UsageCalculator\Api;
+
+/**
+ * @api
+ */
+interface UsageCustomOptionRepositoryInterface
+{
+    /**
+     * Get the list of custom options for a specific usage
+     *
+     * @param string $sku
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[]
+     */
+    public function getList($sku);
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+     * @param bool $requiredOnly
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[]
+     */
+    public function getUsageOptions(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $usage,
+        $requiredOnly = false
+    );
+
+    /**
+     * Get custom option for a specific usage
+     *
+     * @param string $sku
+     * @param int $optionId
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface
+     */
+    public function get($sku, $optionId);
+
+    /**
+     * Delete custom option from usage
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface $option
+     * @return bool
+     */
+    public function delete(\DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface $option);
+
+    /**
+     * Duplicate product options
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface $product
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface $duplicate
+     * @return mixed
+     * @since 101.0.0
+     */
+    public function duplicate(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $product,
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $duplicate
+    );
+
+    /**
+     * Save Custom Option
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface $option
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface
+     */
+    public function save(\DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface $option);
+
+    /**
+     * @param string $sku
+     * @param int $optionId
+     * @return bool
+     */
+    public function deleteByIdentifier($sku, $optionId);
+}
diff --git a/Api/UsageCustomOptionTypeListInterface.php b/Api/UsageCustomOptionTypeListInterface.php
new file mode 100644
index 0000000..2f8be80
--- /dev/null
+++ b/Api/UsageCustomOptionTypeListInterface.php
@@ -0,0 +1,21 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Api;
+
+/**
+ * @api
+ * @since 100.0.2
+ */
+interface UsageCustomOptionTypeListInterface
+{
+    /**
+     * Get custom option types
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeInterface[]
+     */
+    public function getItems();
+}
diff --git a/Api/UsageRepositoryInterface.php b/Api/UsageRepositoryInterface.php
new file mode 100644
index 0000000..8be5ae3
--- /dev/null
+++ b/Api/UsageRepositoryInterface.php
@@ -0,0 +1,57 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Api;
+
+
+interface UsageRepositoryInterface
+{
+
+
+    /**
+     * Save Usage
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function save(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+    );
+
+    /**
+     * Retrieve Usage
+     * @param string $usageId
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getById($usageId);
+
+    /**
+     * Retrieve Usage matching the specified criteria.
+     * @param \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+     * @return \DevStone\UsageCalculator\Api\Data\UsageSearchResultsInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $searchCriteria
+    );
+
+    /**
+     * Delete Usage
+     * @param \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function delete(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+    );
+
+    /**
+     * Delete Usage by ID
+     * @param string $usageId
+     * @return bool true on success
+     * @throws \Magento\Framework\Exception\NoSuchEntityException
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function deleteById($usageId);
+}
diff --git a/Block/Adminhtml/Category/Edit/BackButton.php b/Block/Adminhtml/Category/Edit/BackButton.php
new file mode 100644
index 0000000..b445581
--- /dev/null
+++ b/Block/Adminhtml/Category/Edit/BackButton.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * BackButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Category\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class BackButton
+ */
+class BackButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     */
+    public function __construct(Context $context)
+    {
+        $this->urlBuilder = $context->getUrlBuilder();
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        return [
+            'label' => __('Back'),
+            'on_click' => sprintf("location.href = '%s';", $this->getBackUrl()),
+            'class' => 'back',
+            'sort_order' => 10
+        ];
+    }
+
+    /**
+     * Get URL for back (reset) button
+     *
+     * @return string
+     */
+    public function getBackUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/');
+    }
+}
diff --git a/Block/Adminhtml/Category/Edit/DeleteButton.php b/Block/Adminhtml/Category/Edit/DeleteButton.php
new file mode 100644
index 0000000..db9c50c
--- /dev/null
+++ b/Block/Adminhtml/Category/Edit/DeleteButton.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * DeleteButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Category\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class DeleteButton
+ */
+class DeleteButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Registry
+     *
+     * @var Registry
+     */
+    protected $registry;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     * @param Registry $registry
+     */
+    public function __construct(
+        Context $context,
+        Registry $registry
+    ) {
+        $this->urlBuilder = $context->getUrlBuilder();
+        $this->registry = $registry;
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Delete'),
+            'class' => 'delete',
+            'id' => 'category-edit-delete-button',
+            'data_attribute' => [
+                'url' => $this->getDeleteUrl()
+            ],
+            'on_click' => 'deleteConfirm(\'' . __("Are you sure you want to do this?") . '\', \'' . $this->getDeleteUrl() . '\')',
+            'sort_order' => 20,
+        ];
+        return $data;
+    }
+
+    /**
+     * @return string
+     */
+    public function getDeleteUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/delete', ['entity_id' => $this->registry->registry('entity_id')]);
+    }
+}
diff --git a/Block/Adminhtml/Category/Edit/SaveAndContinueButton.php b/Block/Adminhtml/Category/Edit/SaveAndContinueButton.php
new file mode 100644
index 0000000..aa2c0b6
--- /dev/null
+++ b/Block/Adminhtml/Category/Edit/SaveAndContinueButton.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * SaveAndContinueButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Category\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveAndContinueButton
+ */
+class SaveAndContinueButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save and Continue Edit'),
+            'class' => 'save',
+            'data_attribute' => [
+                'mage-init' => [
+                    'button' => ['event' => 'saveAndContinueEdit'],
+                ],
+            ],
+            'sort_order' => 80,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Adminhtml/Category/Edit/SaveButton.php b/Block/Adminhtml/Category/Edit/SaveButton.php
new file mode 100644
index 0000000..b361e0d
--- /dev/null
+++ b/Block/Adminhtml/Category/Edit/SaveButton.php
@@ -0,0 +1,34 @@
+<?php
+/**
+ * SaveButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Category\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveButton
+ */
+class SaveButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save'),
+            'class' => 'save primary',
+            'data_attribute' => [
+                'mage-init' => ['button' => ['event' => 'save']],
+                'form-role' => 'save',
+            ],
+            'sort_order' => 90,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Adminhtml/Size/Edit/BackButton.php b/Block/Adminhtml/Size/Edit/BackButton.php
new file mode 100644
index 0000000..89d0ffd
--- /dev/null
+++ b/Block/Adminhtml/Size/Edit/BackButton.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * BackButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Size\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class BackButton
+ */
+class BackButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     */
+    public function __construct(Context $context)
+    {
+        $this->urlBuilder = $context->getUrlBuilder();
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        return [
+            'label' => __('Back'),
+            'on_click' => sprintf("location.href = '%s';", $this->getBackUrl()),
+            'class' => 'back',
+            'sort_order' => 10
+        ];
+    }
+
+    /**
+     * Get URL for back (reset) button
+     *
+     * @return string
+     */
+    public function getBackUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/');
+    }
+}
diff --git a/Block/Adminhtml/Size/Edit/DeleteButton.php b/Block/Adminhtml/Size/Edit/DeleteButton.php
new file mode 100644
index 0000000..5fcbdd8
--- /dev/null
+++ b/Block/Adminhtml/Size/Edit/DeleteButton.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * DeleteButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Size\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class DeleteButton
+ */
+class DeleteButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Registry
+     *
+     * @var Registry
+     */
+    protected $registry;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     * @param Registry $registry
+     */
+    public function __construct(
+        Context $context,
+        Registry $registry
+    ) {
+        $this->urlBuilder = $context->getUrlBuilder();
+        $this->registry = $registry;
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Delete'),
+            'class' => 'delete',
+            'id' => 'size-edit-delete-button',
+            'data_attribute' => [
+                'url' => $this->getDeleteUrl()
+            ],
+            'on_click' => 'deleteConfirm(\'' . __("Are you sure you want to do this?") . '\', \'' . $this->getDeleteUrl() . '\')',
+            'sort_order' => 20,
+        ];
+        return $data;
+    }
+
+    /**
+     * @return string
+     */
+    public function getDeleteUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/delete', ['entity_id' => $this->registry->registry('entity_id')]);
+    }
+}
diff --git a/Block/Adminhtml/Size/Edit/SaveAndContinueButton.php b/Block/Adminhtml/Size/Edit/SaveAndContinueButton.php
new file mode 100644
index 0000000..e24ef0d
--- /dev/null
+++ b/Block/Adminhtml/Size/Edit/SaveAndContinueButton.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * SaveAndContinueButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Size\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveAndContinueButton
+ */
+class SaveAndContinueButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save and Continue Edit'),
+            'class' => 'save',
+            'data_attribute' => [
+                'mage-init' => [
+                    'button' => ['event' => 'saveAndContinueEdit'],
+                ],
+            ],
+            'sort_order' => 80,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Adminhtml/Size/Edit/SaveButton.php b/Block/Adminhtml/Size/Edit/SaveButton.php
new file mode 100644
index 0000000..8475e2d
--- /dev/null
+++ b/Block/Adminhtml/Size/Edit/SaveButton.php
@@ -0,0 +1,34 @@
+<?php
+/**
+ * SaveButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Size\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveButton
+ */
+class SaveButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save'),
+            'class' => 'save primary',
+            'data_attribute' => [
+                'mage-init' => ['button' => ['event' => 'save']],
+                'form-role' => 'save',
+            ],
+            'sort_order' => 90,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Adminhtml/Usage/Edit/BackButton.php b/Block/Adminhtml/Usage/Edit/BackButton.php
new file mode 100644
index 0000000..e7bc612
--- /dev/null
+++ b/Block/Adminhtml/Usage/Edit/BackButton.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * BackButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class BackButton
+ */
+class BackButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     */
+    public function __construct(Context $context)
+    {
+        $this->urlBuilder = $context->getUrlBuilder();
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        return [
+            'label' => __('Back'),
+            'on_click' => sprintf("location.href = '%s';", $this->getBackUrl()),
+            'class' => 'back',
+            'sort_order' => 10
+        ];
+    }
+
+    /**
+     * Get URL for back (reset) button
+     *
+     * @return string
+     */
+    public function getBackUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/');
+    }
+}
diff --git a/Block/Adminhtml/Usage/Edit/DeleteButton.php b/Block/Adminhtml/Usage/Edit/DeleteButton.php
new file mode 100644
index 0000000..a343bbb
--- /dev/null
+++ b/Block/Adminhtml/Usage/Edit/DeleteButton.php
@@ -0,0 +1,73 @@
+<?php
+/**
+ * DeleteButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit;
+
+use Magento\Backend\Block\Widget\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class DeleteButton
+ */
+class DeleteButton implements ButtonProviderInterface
+{
+    /**
+     * Url Builder
+     *
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Registry
+     *
+     * @var Registry
+     */
+    protected $registry;
+
+    /**
+     * Constructor
+     *
+     * @param Context $context
+     * @param Registry $registry
+     */
+    public function __construct(
+        Context $context,
+        Registry $registry
+    ) {
+        $this->urlBuilder = $context->getUrlBuilder();
+        $this->registry = $registry;
+    }
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Delete'),
+            'class' => 'delete',
+            'id' => 'usage-edit-delete-button',
+            'data_attribute' => [
+                'url' => $this->getDeleteUrl()
+            ],
+            'on_click' =>
+                'deleteConfirm(\'' . __("Are you sure you want to do this?") . '\', \'' . $this->getDeleteUrl() . '\')',
+            'sort_order' => 20,
+        ];
+        return $data;
+    }
+
+    /**
+     * @return string
+     */
+    public function getDeleteUrl()
+    {
+        return $this->urlBuilder->getUrl('*/*/delete', ['entity_id' => $this->registry->registry('entity_id')]);
+    }
+}
diff --git a/Block/Adminhtml/Usage/Edit/SaveAndContinueButton.php b/Block/Adminhtml/Usage/Edit/SaveAndContinueButton.php
new file mode 100644
index 0000000..63a4d1b
--- /dev/null
+++ b/Block/Adminhtml/Usage/Edit/SaveAndContinueButton.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * SaveAndContinueButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveAndContinueButton
+ */
+class SaveAndContinueButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save and Continue Edit'),
+            'class' => 'save',
+            'data_attribute' => [
+                'mage-init' => [
+                    'button' => ['event' => 'saveAndContinueEdit'],
+                ],
+            ],
+            'sort_order' => 80,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Adminhtml/Usage/Edit/SaveButton.php b/Block/Adminhtml/Usage/Edit/SaveButton.php
new file mode 100644
index 0000000..42bb2bb
--- /dev/null
+++ b/Block/Adminhtml/Usage/Edit/SaveButton.php
@@ -0,0 +1,34 @@
+<?php
+/**
+ * SaveButton
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit;
+
+use Magento\Framework\View\Element\UiComponent\Control\ButtonProviderInterface;
+
+/**
+ * Class SaveButton
+ */
+class SaveButton implements ButtonProviderInterface
+{
+
+    /**
+     * @return array
+     */
+    public function getButtonData()
+    {
+        $data = [
+            'label' => __('Save'),
+            'class' => 'save primary',
+            'data_attribute' => [
+                'mage-init' => ['button' => ['event' => 'save']],
+                'form-role' => 'save',
+            ],
+            'sort_order' => 90,
+        ];
+        return $data;
+    }
+}
diff --git a/Block/Catalog/Product/Usage.php b/Block/Catalog/Product/Usage.php
new file mode 100644
index 0000000..8a8b527
--- /dev/null
+++ b/Block/Catalog/Product/Usage.php
@@ -0,0 +1,374 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Block\Catalog\Product;
+
+use Magento\Catalog\Pricing\Price\FinalPrice;
+use Magento\Downloadable\Model\Link;
+use Magento\Downloadable\Pricing\Price\LinkPrice;
+use Magento\Framework\Json\EncoderInterface;
+
+/**
+ * Downloadable Product Links part block
+ *
+ * @api
+ * @since 100.0.2
+ */
+class Usage extends \Magento\Catalog\Block\Product\AbstractProduct
+{
+    /**
+     * @var \Magento\Framework\Pricing\Helper\Data
+     */
+    protected $pricingHelper;
+
+    /**
+     * @var EncoderInterface
+     */
+    protected $encoder;
+    
+    /**
+     * @var \Magento\Framework\Api\SearchCriteriaBuilder
+     */
+    protected $searchCriteriaBuilder;
+
+    /**
+     * @var UsageRepositoryInterface
+     */
+    protected $usageRepository;
+    
+    /**
+     * @var CategoryRepositoryInterface
+     */
+    protected $categoryRepository;
+    
+    /**
+     *
+     * @var \DevStone\UsageCalculator\Model\Category[] 
+     */
+    private $categories;
+    
+    /**
+     *
+     * @var \DevStone\UsageCalculator\Model\Usage[] 
+     */
+    private $usages;
+
+    /**
+     * @param \Magento\Catalog\Block\Product\Context $context
+     * @param \Magento\Framework\Pricing\Helper\Data $pricingHelper
+     * @param EncoderInterface $encoder
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Catalog\Block\Product\Context $context,
+        \Magento\Framework\Pricing\Helper\Data $pricingHelper,
+        EncoderInterface $encoder,
+        \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder,
+        \DevStone\UsageCalculator\Api\UsageRepositoryInterface $usageRepository,
+        \DevStone\UsageCalculator\Api\CategoryRepositoryInterface $categoryRepository,
+        \DevStone\UsageCalculator\Model\Usage\Option $option,
+        array $data = []
+    ) {
+        $this->pricingHelper = $pricingHelper;
+        $this->encoder = $encoder;
+        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
+        $this->usageRepository = $usageRepository;
+        $this->categoryRepository = $categoryRepository;
+        $this->optionModel = $option;
+        parent::__construct($context, $data);
+    }
+
+    /**
+     *
+     * @return boolean
+     */
+    public function getLinksPurchasedSeparately()
+    {
+        return $this->getProduct()->getLinksPurchasedSeparately();
+    }
+
+    /**
+     * @return boolean
+     */
+    public function getLinkSelectionRequired()
+    {
+        return $this->getProduct()->getTypeInstance()->getLinkSelectionRequired($this->getProduct());
+    }
+
+    /**
+     * @return boolean
+     */
+    public function hasLinks()
+    {
+        return $this->getProduct()->getTypeInstance()->hasLinks($this->getProduct());
+    }
+
+    /**
+     * @return array
+     */
+    public function getLinks()
+    {
+        return $this->getProduct()->getTypeInstance()->getLinks($this->getProduct());
+    }
+    
+    /**
+     * @return array
+     */
+    public function getUsages($category = null)
+    {
+        if (empty($this->usages)) {
+            $searchCriteria = $this->searchCriteriaBuilder->create();
+            $items = $this->usageRepository->getList($searchCriteria)->getItems();
+
+            $this->usages = [];
+            foreach($items as $item) {
+                $item->afterLoad();
+                $this->usages[$item->getCategoryId()][] = $item;
+            }
+        }
+        if ($category) {
+            if( isset($this->usages[$category->getId()])) { 
+                return $this->usages[$category->getId()];
+            } else {
+                return [];
+            }
+        }
+        if ($this->usages) {
+            return call_user_func_array('array_merge', $this->usages);
+        } else { 
+            return $this->usages;
+        }
+    }
+    
+    
+    public function getCategories()
+    {
+        $searchCriteria = $this->searchCriteriaBuilder->create();
+        $list = $this->categoryRepository->getList($searchCriteria)->getItems();
+        return $list;
+    }
+    
+    public function getUsagesSelectHtml($usages, $category)
+    {
+		$store = $this->getProduct()->getStore();
+        
+        $extraParams = '';
+        $select = $this->getLayout()->createBlock(
+            \Magento\Framework\View\Element\Html\Select::class
+        )->setData(
+            [
+                'id' => 'usage_'.$category->getId().'_usages',
+                'class' => 'required product-custom-option admin__control-select usage-select-box'
+            ]
+        );
+        
+        $select->setName('usage_id['.$category->getId().']')->addOption('', __('-- Please Select --'));
+        
+        foreach ($usages as $usage) {
+
+            $select->addOption(
+                $usage->getId(),
+                $usage->getName(),
+				[
+					'price' => $this->pricingHelper->currencyByStore($usage->getPrice(), $store, false),
+					'data-terms' => $usage->getTerms(),
+				]
+            );
+			
+        }
+        $extraParams .= ' data-selector="' . $select->getName() . '"';
+        $select->setExtraParams($extraParams);
+
+        return $select->getHtml();
+    }
+    
+    public function getCategoriesSelectHtml()
+    {        
+        $extraParams = '';
+        $select = $this->getLayout()->createBlock(
+            \Magento\Framework\View\Element\Html\Select::class
+        )->setData(
+            [
+                'id' => 'usage_category',
+                'class' => 'required product-custom-option admin__control-select'
+            ]
+        );
+        
+        $select->setName('usage_category')->addOption('', __('-- Please Select --'));
+        
+        foreach ($this->getCategories() as $category) {
+
+            $select->addOption(
+                $category->getId(),
+                $category->getName() 
+            );
+        }
+        $extraParams .= ' data-selector="' . $select->getName() . '"';
+        $select->setExtraParams($extraParams);
+
+        return $select->getHtml();
+    }
+    
+    /**
+     * Returns price converted to current currency rate
+     *
+     * @param float $price
+     * @return float
+     */
+    public function getCurrencyPrice($price)
+    {
+        $store = $this->getProduct()->getStore();
+        return $this->pricingHelper->currencyByStore($price, $store, false);
+    }
+
+    /**
+     * @return string
+     */
+    public function getJsonConfig()
+    {
+        $finalPrice = $this->getProduct()->getPriceInfo()
+            ->getPrice(FinalPrice::PRICE_CODE);
+
+        $linksConfig = [];
+        foreach ($this->getUsages() as $usage) {
+
+            $amount = $finalPrice->getCustomAmount($usage->getPrice());
+            $linksConfig[$usage->getId()] = [
+                'finalPrice' => $amount->getValue(),
+                'basePrice' => $amount->getBaseAmount()
+            ];
+        }
+
+        return $this->encoder->encode(['links' => $linksConfig]);
+    }
+
+    /**
+     * @param Link $link
+     * @return string
+     */
+    public function getLinkSampleUrl($link)
+    {
+        $store = $this->getProduct()->getStore();
+        return $store->getUrl('downloadable/download/linkSample', ['link_id' => $link->getId()]);
+    }
+
+    /**
+     * Return title of links section
+     *
+     * @return string
+     */
+    public function getLinksTitle()
+    {
+        if ($this->getProduct()->getLinksTitle()) {
+            return $this->getProduct()->getLinksTitle();
+        }
+        return $this->_scopeConfig->getValue(
+            \Magento\Downloadable\Model\Link::XML_PATH_LINKS_TITLE,
+            \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+        );
+    }
+
+    /**
+     * Return true if target of link new window
+     *
+     * @return bool
+     * @SuppressWarnings(PHPMD.BooleanGetMethodName)
+     */
+    public function getIsOpenInNewWindow()
+    {
+        return $this->_scopeConfig->isSetFlag(
+            \Magento\Downloadable\Model\Link::XML_PATH_TARGET_NEW_WINDOW,
+            \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+        );
+    }
+
+    /**
+     * Returns whether link checked by default or not
+     *
+     * @param Link $link
+     * @return bool
+     * @SuppressWarnings(PHPMD.BooleanGetMethodName)
+     */
+    public function getIsLinkChecked($link)
+    {
+        $configValue = $this->getProduct()->getPreconfiguredValues()->getLinks();
+        if (!$configValue || !is_array($configValue)) {
+            return false;
+        }
+
+        return $configValue && in_array($link->getId(), $configValue);
+    }
+
+    /**
+     * Returns value for link's input checkbox - either 'checked' or ''
+     *
+     * @param Link $link
+     * @return string
+     */
+    public function getLinkCheckedValue($link)
+    {
+        return $this->getIsLinkChecked($link) ? 'checked' : '';
+    }
+
+    /**
+     * @param Link $link
+     * @return \Magento\Framework\Pricing\Amount\AmountInterface
+     */
+    protected function getLinkAmount($link)
+    {
+        return $this->getPriceType()->getLinkAmount($link);
+    }
+
+    /**
+     * @param Link $link
+     * @return string
+     */
+    public function getLinkPrice(Link $link)
+    {
+        return $this->getLayout()->getBlock('product.price.render.default')->renderAmount(
+            $this->getLinkAmount($link),
+            $this->getPriceType(),
+            $this->getProduct()
+        );
+    }
+
+    /**
+     * Get LinkPrice Type
+     *
+     * @return \Magento\Framework\Pricing\Price\PriceInterface
+     */
+    protected function getPriceType()
+    {
+        return $this->getProduct()->getPriceInfo()->getPrice(LinkPrice::PRICE_CODE);
+    }
+    
+    
+    /**
+     * Get option html block
+     *
+     * @param \DevStone\UsageCalculator\Model\Usage\Option $option
+     * @return string
+     */
+    public function getOptionHtml(\DevStone\UsageCalculator\Model\Usage\Option $option)
+    {
+        $type = $this->getGroupOfOption($option->getType());
+        $renderer = $this->getChildBlock($type);
+
+        $renderer->setProduct($this->getProduct())->setOption($option);
+
+        return $this->getChildHtml($type, false);
+    }
+    
+    /**
+     * @param string $type
+     * @return string
+     */
+    public function getGroupOfOption($type)
+    {
+        $group = $this->optionModel->getGroupByType($type);
+
+        return $group == '' ? 'default' : $group;
+    }
+}
diff --git a/Block/Usage/View/Options.php b/Block/Usage/View/Options.php
new file mode 100644
index 0000000..c750e4f
--- /dev/null
+++ b/Block/Usage/View/Options.php
@@ -0,0 +1,311 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View;
+
+use Magento\Catalog\Model\Product;
+
+/**
+ * @api
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class Options extends \Magento\Framework\View\Element\Template
+{
+    /**
+     * @var Product
+     */
+    protected $_product;
+
+    /**
+     * Usage option
+     *
+     * @var \DevStone\UsageCalculator\Model\Usage\Option
+     */
+    protected $_option;
+
+    /**
+     * Core registry
+     *
+     * @var \Magento\Framework\Registry
+     */
+    protected $_registry = null;
+
+    /**
+     * Catalog product
+     *
+     * @var Product
+     */
+    protected $_catalogProduct;
+
+    /**
+     * @var \Magento\Framework\Json\EncoderInterface
+     */
+    protected $_jsonEncoder;
+
+    /**
+     * @var \Magento\Framework\Pricing\Helper\Data
+     */
+    protected $pricingHelper;
+
+    /**
+     * @var \Magento\Catalog\Helper\Data
+     */
+    protected $_catalogData;
+
+    /**
+     * @param \Magento\Framework\View\Element\Template\Context $context
+     * @param \Magento\Framework\Pricing\Helper\Data $pricingHelper
+     * @param \Magento\Catalog\Helper\Data $catalogData
+     * @param \Magento\Framework\Json\EncoderInterface $jsonEncoder
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @param \Magento\Framework\Registry $registry
+     * @param \Magento\Framework\Stdlib\ArrayUtils $arrayUtils
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Framework\View\Element\Template\Context $context,
+        \Magento\Framework\Pricing\Helper\Data $pricingHelper,
+        \Magento\Catalog\Helper\Data $catalogData,
+        \Magento\Framework\Json\EncoderInterface $jsonEncoder,
+        \DevStone\UsageCalculator\Model\Usage\Option $option,
+        \Magento\Framework\Registry $registry,
+        \Magento\Framework\Stdlib\ArrayUtils $arrayUtils,
+        \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder,
+        \DevStone\UsageCalculator\Api\UsageRepositoryInterface $usageRepository,
+        array $data = []
+    ) {
+        $this->pricingHelper = $pricingHelper;
+        $this->_catalogData = $catalogData;
+        $this->_jsonEncoder = $jsonEncoder;
+        $this->_registry = $registry;
+        $this->_option = $option;
+        $this->arrayUtils = $arrayUtils;
+        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
+        $this->usageRepository = $usageRepository;
+        parent::__construct($context, $data);
+    }
+
+    /**
+     * Retrieve product object
+     *
+     * @return Product
+     * @throws \LogicExceptions
+     */
+    public function getProduct()
+    {
+        if (!$this->_product) {
+            if ($this->_registry->registry('current_product')) {
+                $this->_product = $this->_registry->registry('current_product');
+            } else {
+                throw new \LogicException('Product is not defined');
+            }
+        }
+        return $this->_product;
+    }
+
+    /**
+     * Set product object
+     *
+     * @param Product $product
+     * @return \Magento\Catalog\Block\Product\View\Options
+     */
+    public function setProduct(Product $product = null)
+    {
+        $this->_product = $product;
+        return $this;
+    }
+    
+    public function getUsage()
+    {
+        $searchCriteria = $this->searchCriteriaBuilder->create();
+        $list = $this->usageRepository->getList($searchCriteria)->getItems();
+        return current($list);
+    }
+    
+    public function getCategories()
+    {
+        $searchCriteria = $this->searchCriteriaBuilder->create();
+        $list = $this->usageRepository->getList($searchCriteria)->getItems();
+        return current($list);
+    }
+    
+    public function getCategoriesSelectHtml()
+    {
+        $this->getCategories();
+        
+        $extraParams = '';
+        $select = $this->getLayout()->createBlock(
+            \Magento\Framework\View\Element\Html\Select::class
+        )->setData(
+            [
+                'id' => 'usage_category',
+                'class' => 'required product-custom-option admin__control-select'
+            ]
+        );
+        
+        $select->setName('usage_category')->addOption('', __('-- Please Select --'));
+        
+        foreach ($this->getCategories() as $category) {
+
+            $select->addOption(
+                $category->getId(),
+                $category->getName() 
+            );
+        }
+        if (!$this->getSkipJsReloadPrice()) {
+            $extraParams .= ' onchange="opConfig.reloadPrice()"';
+        }
+        $extraParams .= ' data-selector="' . $select->getName() . '"';
+        $select->setExtraParams($extraParams);
+
+        if ($configValue) {
+            $select->setValue($configValue);
+        }
+
+        return $select->getHtml();
+    }
+
+    /**
+     * @param string $type
+     * @return string
+     */
+    public function getGroupOfOption($type)
+    {
+        $group = $this->_option->getGroupByType($type);
+
+        return $group == '' ? 'default' : $group;
+    }
+
+    /**
+     * Get product options
+     *
+     * @return array
+     */
+    public function getOptions()
+    {
+        return $this->getUsage()->getOptions();
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasOptions()
+    {
+        if ($this->getOptions()) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Get price configuration
+     *
+     * @param \Magento\Catalog\Model\Product\Option\Value|\Magento\Catalog\Model\Product\Option $option
+     * @return array
+     */
+    protected function _getPriceConfiguration($option)
+    {
+        $optionPrice = $this->pricingHelper->currency($option->getPrice(true), false, false);
+        $data = [
+            'prices' => [
+                'oldPrice' => [
+                    'amount' => $this->pricingHelper->currency($option->getRegularPrice(), false, false),
+                    'adjustments' => [],
+                ],
+                'basePrice' => [
+                    'amount' => $this->_catalogData->getTaxPrice(
+                        $option->getProduct(),
+                        $optionPrice,
+                        false,
+                        null,
+                        null,
+                        null,
+                        null,
+                        null,
+                        false
+                    ),
+                ],
+                'finalPrice' => [
+                    'amount' => $this->_catalogData->getTaxPrice(
+                        $option->getProduct(),
+                        $optionPrice,
+                        true,
+                        null,
+                        null,
+                        null,
+                        null,
+                        null,
+                        false
+                    ),
+                ],
+            ],
+            'type' => $option->getPriceType(),
+            'name' => $option->getTitle()
+        ];
+        return $data;
+    }
+
+    /**
+     * Get json representation of
+     *
+     * @return string
+     */
+    public function getJsonConfig()
+    {
+        $config = [];
+        foreach ($this->getOptions() as $option) {
+            /* @var $option \Magento\Catalog\Model\Product\Option */
+            if ($option->hasValues()) {
+                $tmpPriceValues = [];
+                foreach ($option->getValues() as $valueId => $value) {
+                    $tmpPriceValues[$valueId] = $this->_getPriceConfiguration($value);
+                }
+                $priceValue = $tmpPriceValues;
+            } else {
+                $priceValue = $this->_getPriceConfiguration($option);
+            }
+            $config[$option->getId()] = $priceValue;
+        }
+
+        $configObj = new \Magento\Framework\DataObject(
+            [
+                'config' => $config,
+            ]
+        );
+
+        //pass the return array encapsulated in an object for the other modules to be able to alter it eg: weee
+        $this->_eventManager->dispatch('catalog_product_option_price_configuration_after', ['configObj' => $configObj]);
+
+        $config=$configObj->getConfig();
+
+        return $this->_jsonEncoder->encode($config);
+    }
+
+    /**
+     * Get option html block
+     *
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @return string
+     */
+    public function getOptionHtml(\Magento\Catalog\Model\Product\Option $option)
+    {
+        $type = $this->getGroupOfOption($option->getType());
+        $renderer = $this->getChildBlock($type);
+
+        $renderer->setProduct($this->getProduct())->setOption($option);
+
+        return $this->getChildHtml($type, false);
+    }
+
+    /**
+     * Decorate a plain array of arrays or objects
+     *
+     * @param array $array
+     * @param string $prefix
+     * @param bool $forceSetAll
+     * @return array
+     */
+    public function decorateArray($array, $prefix = 'decorated_', $forceSetAll = false)
+    {
+        return $this->arrayUtils->decorateArray($array, $prefix, $forceSetAll);
+    }
+}
diff --git a/Block/Usage/View/Options/AbstractOptions.php b/Block/Usage/View/Options/AbstractOptions.php
new file mode 100644
index 0000000..f1964dd
--- /dev/null
+++ b/Block/Usage/View/Options/AbstractOptions.php
@@ -0,0 +1,178 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View\Options;
+
+use Magento\Catalog\Pricing\Price\CustomOptionPriceInterface;
+
+/**
+ * @api
+ */
+abstract class AbstractOptions extends \Magento\Framework\View\Element\Template
+{
+    /**
+     * Product object
+     *
+     * @var \Magento\Catalog\Model\Product
+     */
+    protected $_product;
+
+    /**
+     * Product option object
+     *
+     * @var \Magento\Catalog\Model\Product\Option
+     */
+    protected $_option;
+
+    /**
+     * @var \Magento\Framework\Pricing\Helper\Data
+     */
+    protected $pricingHelper;
+
+    /**
+     * @var \Magento\Catalog\Helper\Data
+     */
+    protected $_catalogHelper;
+
+    /**
+     * @param \Magento\Framework\View\Element\Template\Context $context
+     * @param \Magento\Framework\Pricing\Helper\Data $pricingHelper
+     * @param \Magento\Catalog\Helper\Data $catalogData,
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Framework\View\Element\Template\Context $context,
+        \Magento\Framework\Pricing\Helper\Data $pricingHelper,
+        \Magento\Catalog\Helper\Data $catalogData,
+        array $data = []
+    ) {
+        $this->pricingHelper = $pricingHelper;
+        $this->_catalogHelper = $catalogData;
+        parent::__construct($context, $data);
+    }
+
+    /**
+     * Set Product object
+     *
+     * @param \Magento\Catalog\Model\Product $product
+     * @return \Magento\Catalog\Block\Product\View\Options\AbstractOptions
+     */
+    public function setProduct(\Magento\Catalog\Model\Product $product = null)
+    {
+        $this->_product = $product;
+        return $this;
+    }
+
+    /**
+     * Retrieve Product object
+     *
+     * @return \Magento\Catalog\Model\Product
+     */
+    public function getProduct()
+    {
+        return $this->_product;
+    }
+
+    /**
+     * Set option
+     *
+     * @param \DevStone\UsageCalculator\Model\Usage\Option $option
+     * @return \Magento\Catalog\Block\Product\View\Options\AbstractOptions
+     */
+    public function setOption(\DevStone\UsageCalculator\Model\Usage\Option $option)
+    {
+        $this->_option = $option;
+        return $this;
+    }
+
+    /**
+     * Get option
+     *
+     * @return \DevStone\UsageCalculator\Model\Usage\Option
+     */
+    public function getOption()
+    {
+        return $this->_option;
+    }
+
+    /**
+     * @return string
+     */
+    public function getFormatedPrice()
+    {
+        if ($option = $this->getOption()) {
+            return $this->_formatPrice(
+                [
+                    'is_percent' => $option->getPriceType() == 'percent',
+                    'pricing_value' => $option->getPrice($option->getPriceType() == 'percent'),
+                ]
+            );
+        }
+        return '';
+    }
+
+    /**
+     * Return formated price
+     *
+     * @param array $value
+     * @param bool $flag
+     * @return string
+     */
+    protected function _formatPrice($value, $flag = true)
+    {
+        if ($value['pricing_value'] == 0) {
+            return '';
+        }
+
+        $sign = '+';
+        if ($value['pricing_value'] < 0) {
+            $sign = '-';
+            $value['pricing_value'] = 0 - $value['pricing_value'];
+        }
+
+        $priceStr = $sign;
+
+        $customOptionPrice = $this->getProduct()->getPriceInfo()->getPrice('custom_option_price');
+        $context = [CustomOptionPriceInterface::CONFIGURATION_OPTION_FLAG => true];
+        $optionAmount = $customOptionPrice->getCustomAmount($value['pricing_value'], null, $context);
+        $priceStr .= $this->getLayout()->getBlock('product.price.render.default')->renderAmount(
+            $optionAmount,
+            $customOptionPrice,
+            $this->getProduct()
+        );
+
+        if ($flag) {
+            $priceStr = '<span class="price-notice">' . $priceStr . '</span>';
+        }
+
+        return $priceStr;
+    }
+
+    /**
+     * Get price with including/excluding tax
+     *
+     * @param float $price
+     * @param bool $includingTax
+     * @return float
+     */
+    public function getPrice($price, $includingTax = null)
+    {
+        if ($includingTax !== null) {
+            $price = $this->_catalogHelper->getTaxPrice($this->getProduct(), $price, true);
+        } else {
+            $price = $this->_catalogHelper->getTaxPrice($this->getProduct(), $price);
+        }
+        return $price;
+    }
+
+    /**
+     * Returns price converted to current currency rate
+     *
+     * @param float $price
+     * @return float
+     */
+    public function getCurrencyPrice($price)
+    {
+        $store = $this->getProduct()->getStore();
+        return $this->pricingHelper->currencyByStore($price, $store, false);
+    }
+}
diff --git a/Block/Usage/View/Options/Type/Date.php b/Block/Usage/View/Options/Type/Date.php
new file mode 100644
index 0000000..d0a9d68
--- /dev/null
+++ b/Block/Usage/View/Options/Type/Date.php
@@ -0,0 +1,233 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View\Options\Type;
+
+/**
+ * Product options text type block
+ *
+ * @api
+ * @since 100.0.2
+ */
+class Date extends \DevStone\UsageCalculator\Block\Usage\View\Options\AbstractOptions
+{
+    /**
+     * Fill date and time options with leading zeros or not
+     *
+     * @var boolean
+     */
+    protected $_fillLeadingZeros = true;
+
+    /**
+     * Catalog product option type date
+     *
+     * @var \Magento\Catalog\Model\Product\Option\Type\Date
+     */
+    protected $_catalogProductOptionTypeDate;
+
+    /**
+     * @param \Magento\Framework\View\Element\Template\Context $context
+     * @param \Magento\Framework\Pricing\Helper\Data $pricingHelper
+     * @param \Magento\Catalog\Helper\Data $catalogData
+     * @param \Magento\Catalog\Model\Product\Option\Type\Date $catalogProductOptionTypeDate
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Framework\View\Element\Template\Context $context,
+        \Magento\Framework\Pricing\Helper\Data $pricingHelper,
+        \Magento\Catalog\Helper\Data $catalogData,
+        \Magento\Catalog\Model\Product\Option\Type\Date $catalogProductOptionTypeDate,
+        array $data = []
+    ) {
+        $this->_catalogProductOptionTypeDate = $catalogProductOptionTypeDate;
+        parent::__construct($context, $pricingHelper, $catalogData, $data);
+    }
+
+    /**
+     * Use JS calendar settings
+     *
+     * @return boolean
+     */
+    public function useCalendar()
+    {
+        return $this->_catalogProductOptionTypeDate->useCalendar();
+    }
+
+    /**
+     * Date input
+     *
+     * @return string Formatted Html
+     */
+    public function getDateHtml()
+    {
+        if ($this->useCalendar()) {
+            return $this->getCalendarDateHtml();
+        } else {
+            return $this->getDropDownsDateHtml();
+        }
+    }
+
+    /**
+     * JS Calendar html
+     *
+     * @return string Formatted Html
+     */
+    public function getCalendarDateHtml()
+    {
+        $option = $this->getOption();
+        $value = $this->getProduct()->getPreconfiguredValues()->getData('options/' . $option->getId() . '/date');
+
+        $yearStart = $this->_catalogProductOptionTypeDate->getYearStart();
+        $yearEnd = $this->_catalogProductOptionTypeDate->getYearEnd();
+
+        $dateFormat = $this->_localeDate->getDateFormat(\IntlDateFormatter::SHORT);
+        /** Escape RTL characters which are present in some locales and corrupt formatting */
+        $escapedDateFormat = preg_replace('/[^MmDdYy\/\.\-]/', '', $dateFormat);
+        $calendar = $this->getLayout()->createBlock(
+            \Magento\Framework\View\Element\Html\Date::class
+        )->setId(
+            'options_' . $this->getOption()->getId() . '_date'
+        )->setName(
+            'options[' . $this->getOption()->getId() . '][date]'
+        )->setClass(
+            'product-custom-option datetime-picker input-text'
+        )->setImage(
+            $this->getViewFileUrl('Magento_Theme::calendar.png')
+        )->setDateFormat(
+            $escapedDateFormat
+        )->setValue(
+            $value
+        )->setYearsRange(
+            $yearStart . ':' . $yearEnd
+        );
+
+        return $calendar->getHtml();
+    }
+
+    /**
+     * Date (dd/mm/yyyy) html drop-downs
+     *
+     * @return string Formatted Html
+     */
+    public function getDropDownsDateHtml()
+    {
+        $fieldsSeparator = '&nbsp;';
+        $fieldsOrder = $this->_catalogProductOptionTypeDate->getConfigData('date_fields_order');
+        $fieldsOrder = str_replace(',', $fieldsSeparator, $fieldsOrder);
+
+        $monthsHtml = $this->_getSelectFromToHtml('month', 1, 12);
+        $daysHtml = $this->_getSelectFromToHtml('day', 1, 31);
+
+        $yearStart = $this->_catalogProductOptionTypeDate->getYearStart();
+        $yearEnd = $this->_catalogProductOptionTypeDate->getYearEnd();
+        $yearsHtml = $this->_getSelectFromToHtml('year', $yearStart, $yearEnd);
+
+        $translations = ['d' => $daysHtml, 'm' => $monthsHtml, 'y' => $yearsHtml];
+        return strtr($fieldsOrder, $translations);
+    }
+
+    /**
+     * Time (hh:mm am/pm) html drop-downs
+     *
+     * @return string Formatted Html
+     */
+    public function getTimeHtml()
+    {
+        if ($this->_catalogProductOptionTypeDate->is24hTimeFormat()) {
+            $hourStart = 0;
+            $hourEnd = 23;
+            $dayPartHtml = '';
+        } else {
+            $hourStart = 1;
+            $hourEnd = 12;
+            $dayPartHtml = $this->_getHtmlSelect(
+                'day_part'
+            )->setOptions(
+                ['am' => __('AM'), 'pm' => __('PM')]
+            )->getHtml();
+        }
+        $hoursHtml = $this->_getSelectFromToHtml('hour', $hourStart, $hourEnd);
+        $minutesHtml = $this->_getSelectFromToHtml('minute', 0, 59);
+
+        return $hoursHtml . '&nbsp;<b>:</b>&nbsp;' . $minutesHtml . '&nbsp;' . $dayPartHtml;
+    }
+
+    /**
+     * Return drop-down html with range of values
+     *
+     * @param string $name Id/name of html select element
+     * @param int $from  Start position
+     * @param int $to    End position
+     * @param int|null $value Value selected
+     * @return string Formatted Html
+     */
+    protected function _getSelectFromToHtml($name, $from, $to, $value = null)
+    {
+        $options = [['value' => '', 'label' => '-']];
+        for ($i = $from; $i <= $to; $i++) {
+            $options[] = ['value' => $i, 'label' => $this->_getValueWithLeadingZeros($i)];
+        }
+        return $this->_getHtmlSelect($name, $value)->setOptions($options)->getHtml();
+    }
+
+    /**
+     * HTML select element
+     *
+     * @param string $name Id/name of html select element
+     * @param int|null $value
+     * @return mixed
+     */
+    protected function _getHtmlSelect($name, $value = null)
+    {
+        $option = $this->getOption();
+
+        $this->setSkipJsReloadPrice(1);
+
+        // $require = $this->getOption()->getIsRequire() ? ' required-entry' : '';
+        $require = '';
+        $select = $this->getLayout()->createBlock(
+            \Magento\Framework\View\Element\Html\Select::class
+        )->setId(
+            'options_' . $this->getOption()->getId() . '_' . $name
+        )->setClass(
+            'product-custom-option admin__control-select datetime-picker' . $require
+        )->setExtraParams()->setName(
+            'options[' . $option->getId() . '][' . $name . ']'
+        );
+
+        $extraParams = 'style="width:auto"';
+        if (!$this->getSkipJsReloadPrice()) {
+            $extraParams .= ' onchange="opConfig.reloadPrice()"';
+        }
+        $extraParams .= ' data-role="calendar-dropdown" data-calendar-role="' . $name . '"';
+        $extraParams .= ' data-selector="' . $select->getName() . '"';
+        if ($this->getOption()->getIsRequire()) {
+            $extraParams .= ' data-validate=\'{"datetime-validation": true}\'';
+        }
+
+        $select->setExtraParams($extraParams);
+        if ($value === null) {
+            $value = $this->getProduct()->getPreconfiguredValues()->getData(
+                'options/' . $option->getId() . '/' . $name
+            );
+        }
+        if ($value !== null) {
+            $select->setValue($value);
+        }
+
+        return $select;
+    }
+
+    /**
+     * Add Leading Zeros to number less than 10
+     *
+     * @param int $value
+     * @return string|int
+     */
+    protected function _getValueWithLeadingZeros($value)
+    {
+        if (!$this->_fillLeadingZeros) {
+            return $value;
+        }
+        return $value < 10 ? '0' . $value : $value;
+    }
+}
diff --git a/Block/Usage/View/Options/Type/DefaultType.php b/Block/Usage/View/Options/Type/DefaultType.php
new file mode 100644
index 0000000..1720b76
--- /dev/null
+++ b/Block/Usage/View/Options/Type/DefaultType.php
@@ -0,0 +1,16 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Block\Usage\View\Options\Type;
+
+/**
+ * Product options default type block
+ *
+ * @api
+ * @since 100.0.2
+ */
+class DefaultType extends \DevStone\UsageCalculator\Block\Usage\View\Options\AbstractOptions
+{
+}
diff --git a/Block/Usage/View/Options/Type/File.php b/Block/Usage/View/Options/Type/File.php
new file mode 100644
index 0000000..270b5e1
--- /dev/null
+++ b/Block/Usage/View/Options/Type/File.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View\Options\Type;
+
+/**
+ * Product options text type block
+ *
+ * @api
+ * @since 100.0.2
+ */
+class File extends \DevStone\UsageCalculator\Block\Usage\View\Options\AbstractOptions
+{
+    /**
+     * Returns info of file
+     *
+     * @return string
+     */
+    public function getFileInfo()
+    {
+        $info = $this->getProduct()->getPreconfiguredValues()->getData('options/' . $this->getOption()->getId());
+        if (empty($info)) {
+            $info = new \Magento\Framework\DataObject();
+        } elseif (is_array($info)) {
+            $info = new \Magento\Framework\DataObject($info);
+        }
+        return $info;
+    }
+}
diff --git a/Block/Usage/View/Options/Type/Select.php b/Block/Usage/View/Options/Type/Select.php
new file mode 100644
index 0000000..34fb13c
--- /dev/null
+++ b/Block/Usage/View/Options/Type/Select.php
@@ -0,0 +1,164 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View\Options\Type;
+
+/**
+ * Product options text type block
+ *
+ * @api
+ * @since 100.0.2
+ */
+class Select extends \DevStone\UsageCalculator\Block\Usage\View\Options\AbstractOptions
+{
+    /**
+     * Return html for control element
+     *
+     * @return string
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    public function getValuesHtml()
+    {
+        $_option = $this->getOption();
+        $configValue = $this->getProduct()->getPreconfiguredValues()->getData('options/' . $_option->getId());
+        $store = $this->getProduct()->getStore();
+
+        $this->setSkipJsReloadPrice(1);
+        // Remove inline prototype onclick and onchange events
+
+        if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DROP_DOWN ||
+            $_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_MULTIPLE
+        ) {
+            $require = $_option->getIsRequire() ? ' required' : '';
+            $extraParams = '';
+            $select = $this->getLayout()->createBlock(
+                \Magento\Framework\View\Element\Html\Select::class
+            )->setData(
+                [
+                    'id' => 'select_' . $_option->getId(),
+                    'class' => $require . ' product-custom-option admin__control-select',
+					'title' => $_option->getTitle(),
+                ]
+            );
+            if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DROP_DOWN) {
+                $select->setName('options[' . $_option->getid() . ']')->addOption('', __('-- Please Select --'));
+            } else {
+                $select->setName('options[' . $_option->getid() . '][]');
+                $select->setClass('multiselect admin__control-multiselect' . $require . ' product-custom-option');
+            }
+            foreach ($_option->getValues() as $_value) {
+                $select->addOption(
+                    $_value->getOptionTypeId(),
+                    $_value->getTitle(),
+                    ['price' => $this->pricingHelper->currencyByStore($_value->getPrice(), $store, false)]
+                );
+            }
+            if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_MULTIPLE) {
+                $extraParams = ' multiple="multiple"';
+            }
+            if (!$this->getSkipJsReloadPrice()) {
+                $extraParams .= ' onchange="opConfig.reloadPrice()"';
+            }
+            $extraParams .= ' data-selector="' . $select->getName() . '"';
+            $select->setExtraParams($extraParams);
+
+            if ($configValue) {
+                $select->setValue($configValue);
+            }
+
+            return $select->getHtml();
+        }
+
+        if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_RADIO ||
+            $_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_CHECKBOX
+        ) {
+            $selectHtml = '<div class="options-list nested" id="options-' . $_option->getId() . '-list">';
+            $require = $_option->getIsRequire() ? ' required' : '';
+            $arraySign = '';
+            switch ($_option->getType()) {
+                case \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_RADIO:
+                    $type = 'radio';
+                    $class = 'radio admin__control-radio';
+                    if (!$_option->getIsRequire()) {
+                        $selectHtml .= '<div class="field choice admin__field admin__field-option">' .
+                            '<input type="radio" id="options_' .
+                            $_option->getId() .
+                            '" class="' .
+                            $class .
+                            ' product-custom-option " name="options[' .
+                            $_option->getId() .
+                            ']"' .
+                            ' data-selector="options[' . $_option->getId() . ']"' .
+                            ($this->getSkipJsReloadPrice() ? '' : ' onclick="opConfig.reloadPrice()"') .
+                            ' value="" checked="checked" /><label class="label admin__field-label" for="options_' .
+                            $_option->getId() .
+                            '"><span>' .
+                            __('None') . '</span></label></div>';
+                    }
+                    break;
+                case \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_CHECKBOX:
+                    $type = 'checkbox';
+                    $class = 'checkbox admin__control-checkbox';
+                    $arraySign = '[]';
+                    break;
+            }
+            $count = 1;
+            foreach ($_option->getValues() as $_value) {
+                $count++;
+
+                $htmlValue = $_value->getOptionTypeId();
+                if ($arraySign) {
+                    $checked = is_array($configValue) && in_array($htmlValue, $configValue) ? 'checked' : '';
+                } else {
+                    $checked = $configValue == $htmlValue ? 'checked' : '';
+                }
+
+                $dataSelector = 'options[' . $_option->getId() . ']';
+                if ($arraySign) {
+                    $dataSelector .= '[' . $htmlValue . ']';
+                }
+
+                $selectHtml .= '<div class="field choice admin__field admin__field-option' .
+                    $require .
+                    '">' .
+                    '<input type="' .
+                    $type .
+                    '" class="' .
+                    $class .
+                    ' ' .
+                    $require .
+                    ' product-custom-option"' .
+                    ($this->getSkipJsReloadPrice() ? '' : ' onclick="opConfig.reloadPrice()"') .
+                    ' name="options[' .
+                    $_option->getId() .
+                    ']' .
+                    $arraySign .
+                    '" id="options_' .
+                    $_option->getId() .
+                    '_' .
+                    $count .
+                    '" value="' .
+                    $htmlValue .
+                    '" ' .
+                    $checked .
+                    ' data-selector="' . $dataSelector . '"' .
+                    ' price="' .
+                    $this->pricingHelper->currencyByStore($_value->getPrice(true), $store, false) .
+                    '" />' .
+                    '<label class="label admin__field-label" for="options_' .
+                    $_option->getId() .
+                    '_' .
+                    $count .
+                    '"><span>' .
+                    $_value->getTitle() .
+                    '</span> ' .
+                    '</label>';
+                $selectHtml .= '</div>';
+            }
+            $selectHtml .= '</div>';
+
+            return $selectHtml;
+        }
+    }
+}
diff --git a/Block/Usage/View/Options/Type/Text.php b/Block/Usage/View/Options/Type/Text.php
new file mode 100644
index 0000000..a358934
--- /dev/null
+++ b/Block/Usage/View/Options/Type/Text.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace DevStone\UsageCalculator\Block\Usage\View\Options\Type;
+
+/**
+ * Product options text type block
+ *
+ * @api
+ */
+class Text extends \DevStone\UsageCalculator\Block\Usage\View\Options\AbstractOptions
+{
+    /**
+     * Returns default value to show in text input
+     *
+     * @return string
+     */
+    public function getDefaultValue()
+    {
+        return $this->getProduct()->getPreconfiguredValues()->getData('options/' . $this->getOption()->getId());
+    }
+}
diff --git a/Controller/Adminhtml/Category/Delete.php b/Controller/Adminhtml/Category/Delete.php
new file mode 100644
index 0000000..827f310
--- /dev/null
+++ b/Controller/Adminhtml/Category/Delete.php
@@ -0,0 +1,63 @@
+<?php
+/**
+ * Delete
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\CategoryFactory;
+
+class Delete extends Action
+{
+    /** @var categoryFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param CategoryFactory $objectFactory
+     */
+    public function __construct(
+    Context $context,
+    CategoryFactory $objectFactory
+    ) {
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::category');
+    }
+
+    /**
+     * Delete action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $resultRedirect = $this->resultRedirectFactory->create();
+        $id = $this->getRequest()->getParam('entity_id', null);
+
+        try {
+            $objectInstance = $this->objectFactory->create()->load($id);
+            if ($objectInstance->getId()) {
+                $objectInstance->delete();
+                $this->messageManager->addSuccessMessage(__('You deleted the record.'));
+            } else {
+                $this->messageManager->addErrorMessage(__('Record does not exist.'));
+            }
+        } catch (\Exception $exception) {
+            $this->messageManager->addErrorMessage($exception->getMessage());
+        }
+        
+        return $resultRedirect->setPath('*/*');
+    }
+}
diff --git a/Controller/Adminhtml/Category/Edit.php b/Controller/Adminhtml/Category/Edit.php
new file mode 100644
index 0000000..9c6d3dd
--- /dev/null
+++ b/Controller/Adminhtml/Category/Edit.php
@@ -0,0 +1,100 @@
+<?php
+/**
+ * Edit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Result\PageFactory;
+use DevStone\UsageCalculator\Model\CategoryFactory;
+
+class Edit extends Action
+{
+    /**
+     * Core registry
+     *
+     * @var Registry
+     */
+    protected $_coreRegistry = null;
+
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /** @var categoryFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     * @param Registry $registry
+     * @param CategoryFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory,
+        Registry $registry,
+        CategoryFactory $objectFactory
+    ) {
+        $this->resultPageFactory = $resultPageFactory;
+        $this->_coreRegistry = $registry;
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::category');
+    }
+
+    /**
+     * Edit
+     *
+     * @return \Magento\Backend\Model\View\Result\Page|\Magento\Backend\Model\View\Result\Redirect
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     */
+    public function execute()
+    {
+        // 1. Get ID
+        $id = $this->getRequest()->getParam('entity_id');
+        $objectInstance = $this->objectFactory->create();
+
+        // 2. Initial checking
+        if ($id) {
+            $objectInstance->load($id);
+            if (!$objectInstance->getId()) {
+                $this->messageManager->addErrorMessage(__('This record no longer exists.'));
+                /** \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+                $resultRedirect = $this->resultRedirectFactory->create();
+
+                return $resultRedirect->setPath('*/*/');
+            }
+        }
+
+        // 3. Set entered data if was error when we do save
+        $data = $this->_session->getFormData(true);
+        if (!empty($data)) {
+            $objectInstance->addData($data);
+        }
+
+        // 4. Register model to use later in blocks
+        $this->_coreRegistry->register('entity_id', $id);
+
+        // 5. Build edit form
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::category');
+        $resultPage->getConfig()->getTitle()->prepend(__('Category Edit'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Category/Index.php b/Controller/Adminhtml/Category/Index.php
new file mode 100644
index 0000000..d88abc2
--- /dev/null
+++ b/Controller/Adminhtml/Category/Index.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * index.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\View\Result\PageFactory;
+
+class Index extends Action
+{
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory
+    ) {
+        parent::__construct($context);
+        $this->resultPageFactory = $resultPageFactory;
+    }
+    
+    /**
+     * Check the permission to run it
+     *
+     * @return boolean
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::category');
+    }
+
+    /**
+     * Index action
+     *
+     * @return \Magento\Backend\Model\View\Result\Page
+     */
+    public function execute()
+    {
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::category');
+        $resultPage->getConfig()->getTitle()->prepend(__('Category'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Category/InlineEdit.php b/Controller/Adminhtml/Category/InlineEdit.php
new file mode 100644
index 0000000..89966c3
--- /dev/null
+++ b/Controller/Adminhtml/Category/InlineEdit.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * InlineEdit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Category\Collection;
+
+/**
+ * Grid inline edit controller
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class InlineEdit extends Action
+{
+
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /**
+     * @var Collection
+     */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Collection $objectCollection
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        Collection $objectCollection,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->objectCollection = $objectCollection;
+    }
+
+    /**
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        /** @var \Magento\Framework\Controller\Result\Json $resultJson */
+        $resultJson = $this->jsonFactory->create();
+        $error = false;
+        $messages = [];
+
+        $postItems = $this->getRequest()->getParam('items', []);
+        if (!($this->getRequest()->getParam('isAjax') && count($postItems))) {
+            return $resultJson->setData([
+                'messages' => [__('Please correct the data sent.')],
+                'error' => true,
+            ]);
+        }
+
+        try {
+            $this->objectCollection
+                ->addFieldToFilter('entity_id', array('in' => array_keys($postItems)))
+                ->walk('saveCollection', array($postItems));
+        } catch (\Exception $e) {
+            $messages[] = __('There was an error saving the data: ') . $e->getMessage();
+            $error = true;
+        }
+
+        return $resultJson->setData([
+            'messages' => $messages,
+            'error' => $error
+        ]);
+    }
+}
diff --git a/Controller/Adminhtml/Category/MassDelete.php b/Controller/Adminhtml/Category/MassDelete.php
new file mode 100644
index 0000000..bd76e89
--- /dev/null
+++ b/Controller/Adminhtml/Category/MassDelete.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * MassDelete.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Ui\Component\MassAction\Filter;
+use Magento\Framework\Controller\ResultFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Category\Collection;
+
+/**
+ * Class MassDelete
+ */
+class MassDelete extends Action
+{
+    /**
+     * @var Filter
+     */
+    protected $filter;
+
+    /** @var Collection $objectCollection */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Filter $filter
+     * @param Collection $objectCollection
+     */
+    public function __construct(Context $context, Filter $filter, Collection $objectCollection)
+    {
+        $this->filter = $filter;
+        $this->objectCollection = $objectCollection;
+        parent::__construct($context);
+    }
+
+    /**
+     * Execute action
+     *
+     * @return \Magento\Backend\Model\View\Result\Redirect
+     * @throws \Magento\Framework\Exception\LocalizedException|\Exception
+     */
+    public function execute()
+    {
+        $collection = $this->filter->getCollection($this->objectCollection);
+        $collectionSize = $collection->getSize();
+        $collection->walk('delete');
+
+        $this->messageManager->addSuccessMessage(__('A total of %1 record(s) have been deleted.', $collectionSize));
+
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
+        return $resultRedirect->setPath('*/*/');
+    }
+}
diff --git a/Controller/Adminhtml/Category/Save.php b/Controller/Adminhtml/Category/Save.php
new file mode 100644
index 0000000..6f6ae28
--- /dev/null
+++ b/Controller/Adminhtml/Category/Save.php
@@ -0,0 +1,85 @@
+<?php
+/**
+ * Save
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\CategoryFactory;
+
+class Save extends Action
+{
+    /** @var CategoryFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param CategoryFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        CategoryFactory $objectFactory
+    ) {
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::category');
+    }
+
+    /**
+     * Save action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $data = $this->getRequest()->getParams();
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultRedirectFactory->create();
+        if ($data) {
+            $params = [];
+            $objectInstance = $this->objectFactory->create();
+            $idField = $objectInstance->getIdFieldName();
+            if (empty($data[$idField])) {
+                $data[$idField] = null;
+            } else {
+                $objectInstance->load($data[$idField]);
+                $params[$idField] = $data[$idField];
+            }
+            $objectInstance->addData($data);
+
+            $this->_eventManager->dispatch(
+                'devstone_usagecalculator_category_prepare_save',
+                ['object' => $this->objectFactory, 'request' => $this->getRequest()]
+            );
+
+            try {
+                $objectInstance->save();
+                $this->messageManager->addSuccessMessage(__('You saved this record.'));
+                $this->_getSession()->setFormData(false);
+                if ($this->getRequest()->getParam('back')) {
+                    $params = [$idField => $objectInstance->getId(), '_current' => true];
+                    return $resultRedirect->setPath('*/*/edit', $params);
+                }
+                return $resultRedirect->setPath('*/*/');
+            } catch (\Exception $e) {
+                $this->messageManager->addErrorMessage($e->getMessage());
+                $this->messageManager->addExceptionMessage($e, __('Something went wrong while saving the record.'));
+            }
+
+            $this->_getSession()->setFormData($this->getRequest()->getPostValue());
+            return $resultRedirect->setPath('*/*/edit', $params);
+        }
+        return $resultRedirect->setPath('*/*/');
+    }
+}
diff --git a/Controller/Adminhtml/Category/Validate.php b/Controller/Adminhtml/Category/Validate.php
new file mode 100644
index 0000000..6d16b06
--- /dev/null
+++ b/Controller/Adminhtml/Category/Validate.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * Validate
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Category;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+
+class Validate extends Action
+{
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /** @var  \Magento\Framework\DataObject $response */
+    protected $response;
+
+    /**
+     * @param Context $context
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->response = new \Magento\Framework\DataObject();
+    }
+
+    /**
+     * Check if required fields is not empty
+     *
+     * @param array $data
+     */
+    public function validateRequireEntries(array $data)
+    {
+        $requiredFields = [
+            'identifier' => __('Category Identifier'),
+        ];
+        foreach ($data as $field => $value) {
+            if (in_array($field, array_keys($requiredFields)) && $value == '') {
+                $this->_addErrorMessage(
+                    __('To apply changes you should fill in required "%1" field', $requiredFields[$field])
+                );
+            }
+        }
+    }
+
+    /**
+     * Add error message validation
+     *
+     * @param $message
+     */
+    protected function _addErrorMessage($message)
+    {
+        $this->response->setError(true);
+        if (!is_array($this->response->getMessages())) {
+            $this->response->setMessages([]);
+        }
+        $messages = $this->response->getMessages();
+        $messages[] = $message;
+        $this->response->setMessages($messages);
+    }
+
+    /**
+     * AJAX customer validation action
+     *
+     * @return \Magento\Framework\Controller\Result\Json
+     */
+    public function execute()
+    {
+        $this->response->setError(0);
+
+        $this->validateRequireEntries($this->getRequest()->getParams());
+
+        $resultJson = $this->jsonFactory->create()->setData($this->response);
+        return $resultJson;
+    }
+}
diff --git a/Controller/Adminhtml/Size/Delete.php b/Controller/Adminhtml/Size/Delete.php
new file mode 100644
index 0000000..b6aa9f1
--- /dev/null
+++ b/Controller/Adminhtml/Size/Delete.php
@@ -0,0 +1,63 @@
+<?php
+/**
+ * Delete
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\SizeFactory;
+
+class Delete extends Action
+{
+    /** @var sizeFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param SizeFactory $objectFactory
+     */
+    public function __construct(
+    Context $context,
+    SizeFactory $objectFactory
+    ) {
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::size');
+    }
+
+    /**
+     * Delete action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $resultRedirect = $this->resultRedirectFactory->create();
+        $id = $this->getRequest()->getParam('entity_id', null);
+
+        try {
+            $objectInstance = $this->objectFactory->create()->load($id);
+            if ($objectInstance->getId()) {
+                $objectInstance->delete();
+                $this->messageManager->addSuccessMessage(__('You deleted the record.'));
+            } else {
+                $this->messageManager->addErrorMessage(__('Record does not exist.'));
+            }
+        } catch (\Exception $exception) {
+            $this->messageManager->addErrorMessage($exception->getMessage());
+        }
+        
+        return $resultRedirect->setPath('*/*');
+    }
+}
diff --git a/Controller/Adminhtml/Size/Edit.php b/Controller/Adminhtml/Size/Edit.php
new file mode 100644
index 0000000..6ff8562
--- /dev/null
+++ b/Controller/Adminhtml/Size/Edit.php
@@ -0,0 +1,101 @@
+<?php
+/**
+ * Edit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Result\PageFactory;
+use DevStone\UsageCalculator\Model\SizeFactory;
+
+class Edit extends Action
+{
+    /**
+     * Core registry
+     *
+     * @var Registry
+     */
+    protected $_coreRegistry = null;
+
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /** @var sizeFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     * @param Registry $registry
+     * @param SizeFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory,
+        Registry $registry,
+        SizeFactory $objectFactory
+    ) {
+        $this->resultPageFactory = $resultPageFactory;
+        $this->_coreRegistry = $registry;
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::size');
+    }
+
+    /**
+     * Edit
+     *
+     * @return \Magento\Backend\Model\View\Result\Page|\Magento\Backend\Model\View\Result\Redirect
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     */
+    public function execute()
+    {
+        // 1. Get ID
+        $id = $this->getRequest()->getParam('entity_id');
+        $objectInstance = $this->objectFactory->create();
+
+        // 2. Initial checking
+        if ($id) {
+            $objectInstance->load($id);
+            if (!$objectInstance->getId()) {
+                $this->messageManager->addErrorMessage(__('This record no longer exists.'));
+                /** \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+                $resultRedirect = $this->resultRedirectFactory->create();
+
+                return $resultRedirect->setPath('*/*/');
+            }
+        }
+
+        // 3. Set entered data if was error when we do save
+        $data = $this->_session->getFormData(true);
+        if (!empty($data)) {
+            $objectInstance->addData($data);
+        }
+
+        // 4. Register model to use later in blocks
+        $this->_coreRegistry->register('entity_id', $id);
+
+
+        // 5. Build edit form
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::size');
+        $resultPage->getConfig()->getTitle()->prepend(__('Size Edit'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Size/Index.php b/Controller/Adminhtml/Size/Index.php
new file mode 100644
index 0000000..8f0dfcf
--- /dev/null
+++ b/Controller/Adminhtml/Size/Index.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * index.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\View\Result\PageFactory;
+
+class Index extends Action
+{
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory
+    ) {
+        parent::__construct($context);
+        $this->resultPageFactory = $resultPageFactory;
+    }
+    
+    /**
+     * Check the permission to run it
+     *
+     * @return boolean
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::size');
+    }
+
+    /**
+     * Index action
+     *
+     * @return \Magento\Backend\Model\View\Result\Page
+     */
+    public function execute()
+    {
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::size');
+        $resultPage->getConfig()->getTitle()->prepend(__('Size'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Size/InlineEdit.php b/Controller/Adminhtml/Size/InlineEdit.php
new file mode 100644
index 0000000..5a65c3b
--- /dev/null
+++ b/Controller/Adminhtml/Size/InlineEdit.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * InlineEdit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Size\Collection;
+
+/**
+ * Grid inline edit controller
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class InlineEdit extends Action
+{
+
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /**
+     * @var Collection
+     */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Collection $objectCollection
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        Collection $objectCollection,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->objectCollection = $objectCollection;
+    }
+
+    /**
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        /** @var \Magento\Framework\Controller\Result\Json $resultJson */
+        $resultJson = $this->jsonFactory->create();
+        $error = false;
+        $messages = [];
+
+        $postItems = $this->getRequest()->getParam('items', []);
+        if (!($this->getRequest()->getParam('isAjax') && count($postItems))) {
+            return $resultJson->setData([
+                'messages' => [__('Please correct the data sent.')],
+                'error' => true,
+            ]);
+        }
+
+        try {
+            $this->objectCollection
+                ->addFieldToFilter('entity_id', array('in' => array_keys($postItems)))
+                ->walk('saveCollection', array($postItems));
+        } catch (\Exception $e) {
+            $messages[] = __('There was an error saving the data: ') . $e->getMessage();
+            $error = true;
+        }
+
+        return $resultJson->setData([
+            'messages' => $messages,
+            'error' => $error
+        ]);
+    }
+}
diff --git a/Controller/Adminhtml/Size/MassDelete.php b/Controller/Adminhtml/Size/MassDelete.php
new file mode 100644
index 0000000..c1ac1b5
--- /dev/null
+++ b/Controller/Adminhtml/Size/MassDelete.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * MassDelete.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Ui\Component\MassAction\Filter;
+use Magento\Framework\Controller\ResultFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Size\Collection;
+
+/**
+ * Class MassDelete
+ */
+class MassDelete extends Action
+{
+    /**
+     * @var Filter
+     */
+    protected $filter;
+
+    /** @var Collection $objectCollection */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Filter $filter
+     * @param Collection $objectCollection
+     */
+    public function __construct(Context $context, Filter $filter, Collection $objectCollection)
+    {
+        $this->filter = $filter;
+        $this->objectCollection = $objectCollection;
+        parent::__construct($context);
+    }
+
+    /**
+     * Execute action
+     *
+     * @return \Magento\Backend\Model\View\Result\Redirect
+     * @throws \Magento\Framework\Exception\LocalizedException|\Exception
+     */
+    public function execute()
+    {
+        $collection = $this->filter->getCollection($this->objectCollection);
+        $collectionSize = $collection->getSize();
+        $collection->walk('delete');
+
+        $this->messageManager->addSuccessMessage(__('A total of %1 record(s) have been deleted.', $collectionSize));
+
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
+        return $resultRedirect->setPath('*/*/');
+    }
+}
diff --git a/Controller/Adminhtml/Size/Save.php b/Controller/Adminhtml/Size/Save.php
new file mode 100644
index 0000000..15f190e
--- /dev/null
+++ b/Controller/Adminhtml/Size/Save.php
@@ -0,0 +1,85 @@
+<?php
+/**
+ * Save
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\SizeFactory;
+
+class Save extends Action
+{
+    /** @var SizeFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param SizeFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        SizeFactory $objectFactory
+    ) {
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::size');
+    }
+
+    /**
+     * Save action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $data = $this->getRequest()->getParams();
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultRedirectFactory->create();
+        if ($data) {
+            $params = [];
+            $objectInstance = $this->objectFactory->create();
+            $idField = $objectInstance->getIdFieldName();
+            if (empty($data[$idField])) {
+                $data[$idField] = null;
+            } else {
+                $objectInstance->load($data[$idField]);
+                $params[$idField] = $data[$idField];
+            }
+            $objectInstance->addData($data);
+
+            $this->_eventManager->dispatch(
+                'devstone_usagecalculator_size_prepare_save',
+                ['object' => $this->objectFactory, 'request' => $this->getRequest()]
+            );
+
+            try {
+                $objectInstance->save();
+                $this->messageManager->addSuccessMessage(__('You saved this record.'));
+                $this->_getSession()->setFormData(false);
+                if ($this->getRequest()->getParam('back')) {
+                    $params = [$idField => $objectInstance->getId(), '_current' => true];
+                    return $resultRedirect->setPath('*/*/edit', $params);
+                }
+                return $resultRedirect->setPath('*/*/');
+            } catch (\Exception $e) {
+                $this->messageManager->addErrorMessage($e->getMessage());
+                $this->messageManager->addExceptionMessage($e, __('Something went wrong while saving the record.'));
+            }
+
+            $this->_getSession()->setFormData($this->getRequest()->getPostValue());
+            return $resultRedirect->setPath('*/*/edit', $params);
+        }
+        return $resultRedirect->setPath('*/*/');
+    }
+}
diff --git a/Controller/Adminhtml/Size/Validate.php b/Controller/Adminhtml/Size/Validate.php
new file mode 100644
index 0000000..3e2ab8a
--- /dev/null
+++ b/Controller/Adminhtml/Size/Validate.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * Validate
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Size;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+
+class Validate extends Action
+{
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /** @var  \Magento\Framework\DataObject $response */
+    protected $response;
+
+    /**
+     * @param Context $context
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->response = new \Magento\Framework\DataObject();
+    }
+
+    /**
+     * Check if required fields is not empty
+     *
+     * @param array $data
+     */
+    public function validateRequireEntries(array $data)
+    {
+        $requiredFields = [
+            'identifier' => __('Size Identifier'),
+        ];
+        foreach ($data as $field => $value) {
+            if (in_array($field, array_keys($requiredFields)) && $value == '') {
+                $this->_addErrorMessage(
+                    __('To apply changes you should fill in required "%1" field', $requiredFields[$field])
+                );
+            }
+        }
+    }
+
+    /**
+     * Add error message validation
+     *
+     * @param $message
+     */
+    protected function _addErrorMessage($message)
+    {
+        $this->response->setError(true);
+        if (!is_array($this->response->getMessages())) {
+            $this->response->setMessages([]);
+        }
+        $messages = $this->response->getMessages();
+        $messages[] = $message;
+        $this->response->setMessages($messages);
+    }
+
+    /**
+     * AJAX customer validation action
+     *
+     * @return \Magento\Framework\Controller\Result\Json
+     */
+    public function execute()
+    {
+        $this->response->setError(0);
+
+        $this->validateRequireEntries($this->getRequest()->getParams());
+
+        $resultJson = $this->jsonFactory->create()->setData($this->response);
+        return $resultJson;
+    }
+}
diff --git a/Controller/Adminhtml/Usage/Delete.php b/Controller/Adminhtml/Usage/Delete.php
new file mode 100644
index 0000000..f9d0ea6
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Delete.php
@@ -0,0 +1,63 @@
+<?php
+/**
+ * Delete
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\UsageFactory;
+
+class Delete extends Action
+{
+    /** @var usageFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param UsageFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        UsageFactory $objectFactory
+    ) {
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::usage');
+    }
+
+    /**
+     * Delete action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $resultRedirect = $this->resultRedirectFactory->create();
+        $id = $this->getRequest()->getParam('entity_id', null);
+
+        try {
+            $objectInstance = $this->objectFactory->create()->load($id);
+            if ($objectInstance->getId()) {
+                $objectInstance->delete();
+                $this->messageManager->addSuccessMessage(__('You deleted the record.'));
+            } else {
+                $this->messageManager->addErrorMessage(__('Record does not exist.'));
+            }
+        } catch (\Exception $exception) {
+            $this->messageManager->addErrorMessage($exception->getMessage());
+        }
+        
+        return $resultRedirect->setPath('*/*');
+    }
+}
diff --git a/Controller/Adminhtml/Usage/Edit.php b/Controller/Adminhtml/Usage/Edit.php
new file mode 100644
index 0000000..efc36db
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Edit.php
@@ -0,0 +1,100 @@
+<?php
+/**
+ * Edit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Registry;
+use Magento\Framework\View\Result\PageFactory;
+use DevStone\UsageCalculator\Model\UsageFactory;
+
+class Edit extends Action
+{
+    /**
+     * Core registry
+     *
+     * @var Registry
+     */
+    protected $_coreRegistry = null;
+
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /** @var usageFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     * @param Registry $registry
+     * @param UsageFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory,
+        Registry $registry,
+        UsageFactory $objectFactory
+    ) {
+        $this->resultPageFactory = $resultPageFactory;
+        $this->_coreRegistry = $registry;
+        $this->objectFactory = $objectFactory;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::usage');
+    }
+
+    /**
+     * Edit
+     *
+     * @return \Magento\Backend\Model\View\Result\Page|\Magento\Backend\Model\View\Result\Redirect
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     */
+    public function execute()
+    {
+        // 1. Get ID
+        $id = $this->getRequest()->getParam('entity_id');
+        $objectInstance = $this->objectFactory->create();
+
+        // 2. Initial checking
+        if ($id) {
+            $objectInstance->load($id);
+            if (!$objectInstance->getId()) {
+                $this->messageManager->addErrorMessage(__('This record no longer exists.'));
+                /** \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+                $resultRedirect = $this->resultRedirectFactory->create();
+
+                return $resultRedirect->setPath('*/*/');
+            }
+        }
+
+        // 3. Set entered data if was error when we do save
+        $data = $this->_session->getFormData(true);
+        if (!empty($data)) {
+            $objectInstance->addData($data);
+        }
+
+        // 4. Register model to use later in blocks
+        $this->_coreRegistry->register('entity_id', $id);
+
+        // 5. Build edit form
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::usage');
+        $resultPage->getConfig()->getTitle()->prepend(__('Usage Edit'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Usage/Index.php b/Controller/Adminhtml/Usage/Index.php
new file mode 100644
index 0000000..c786b05
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Index.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * index.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\View\Result\PageFactory;
+
+class Index extends Action
+{
+    /**
+     * @var PageFactory
+     */
+    protected $resultPageFactory;
+
+    /**
+     * @param Context $context
+     * @param PageFactory $resultPageFactory
+     */
+    public function __construct(
+        Context $context,
+        PageFactory $resultPageFactory
+    ) {
+        parent::__construct($context);
+        $this->resultPageFactory = $resultPageFactory;
+    }
+    
+    /**
+     * Check the permission to run it
+     *
+     * @return boolean
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::usage');
+    }
+
+    /**
+     * Index action
+     *
+     * @return \Magento\Backend\Model\View\Result\Page
+     */
+    public function execute()
+    {
+        /** @var \Magento\Backend\Model\View\Result\Page $resultPage */
+        $resultPage = $this->resultPageFactory->create();
+        $resultPage->setActiveMenu('DevStone_UsageCalculator::usage');
+        $resultPage->getConfig()->getTitle()->prepend(__('Usage'));
+
+        return $resultPage;
+    }
+}
diff --git a/Controller/Adminhtml/Usage/Initialization/Helper.php b/Controller/Adminhtml/Usage/Initialization/Helper.php
new file mode 100644
index 0000000..1e938af
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Initialization/Helper.php
@@ -0,0 +1,217 @@
+<?php
+
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage\Initialization;
+
+use Magento\Catalog\Api\Data\ProductCustomOptionInterfaceFactory as CustomOptionFactory;
+
+class Helper
+{
+    /**
+     * @var \Magento\Framework\App\RequestInterface
+     */
+    protected $request;
+
+
+
+
+    /**
+     * @var CustomOptionFactory
+     */
+    protected $customOptionFactory;
+
+    /**
+     * Constructor
+     *
+     * @param \Magento\Framework\App\RequestInterface $request
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterfaceFactory $customOptionFactory
+     */
+    public function __construct(
+        \Magento\Framework\App\RequestInterface $request,
+        \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterfaceFactory $customOptionFactory
+    ) {
+        $this->request = $request;
+        $this->customOptionFactory = $customOptionFactory;        
+    }
+
+    /**
+     * Initialize usage from data
+     *
+     * @param \DevStone\UsageCalculator\Model\Usage $usage
+     * @param array $usageData
+     * @return \DevStone\UsageCalculator\Model\Usage
+     */
+    public function initializeFromData(
+            \DevStone\UsageCalculator\Model\Usage $usage, 
+            array $usageData
+    ) {
+        
+
+//        $usageData = $this->normalize($usageData);
+
+        if (isset($usageData['options'])) {
+            $usageOptions = $usageData['options'];
+            unset($usageData['options']);
+        } else {
+            $usageOptions = [];
+        }
+        
+
+        $usage = $this->fillProductOptions($usage, $usageOptions);
+
+        $usage->setCanSaveCustomOptions(
+            !empty($usageData['affect_usage_custom_options']) && !$usage->getOptionsReadonly()
+        );
+
+        return $usage;
+    }
+
+    /**
+     * Initialize usage before saving
+     *
+     * @param \DevStone\UsageCalculator\Model\Usage $usage
+     * @return \DevStone\UsageCalculator\Model\Usage
+     */
+    public function initialize( \DevStone\UsageCalculator\Model\Usage $usage)
+    {
+        $usageData = $this->request->getPost('usage', []);
+        return $this->initializeFromData($usage, $usageData);
+    }
+
+    /**
+     * Internal normalization
+     *
+     * @param array $productData
+     * @return array
+     * @todo Remove this method
+     * @since 101.0.0
+     */
+    protected function normalize(array $productData)
+    {
+        foreach ($productData as $key => $value) {
+            if (is_scalar($value)) {
+                if ($value === 'true') {
+                    $productData[$key] = '1';
+                } elseif ($value === 'false') {
+                    $productData[$key] = '0';
+                }
+            } elseif (is_array($value)) {
+                $productData[$key] = $this->normalize($value);
+            }
+        }
+
+        return $productData;
+    }
+
+    /**
+     * Merge product and default options for product
+     *
+     * @param array $productOptions product options
+     * @param array $overwriteOptions default value options
+     * @return array
+     */
+    public function mergeProductOptions($productOptions, $overwriteOptions)
+    {
+        if (!is_array($productOptions)) {
+            return [];
+        }
+
+        if (!is_array($overwriteOptions)) {
+            return $productOptions;
+        }
+
+        foreach ($productOptions as $optionIndex => $option) {
+            $optionId = $option['option_id'];
+            $option = $this->overwriteValue($optionId, $option, $overwriteOptions);
+
+            if (isset($option['values']) && isset($overwriteOptions[$optionId]['values'])) {
+                foreach ($option['values'] as $valueIndex => $value) {
+                    if (isset($value['option_type_id'])) {
+                        $valueId = $value['option_type_id'];
+                        $value = $this->overwriteValue($valueId, $value, $overwriteOptions[$optionId]['values']);
+                        $option['values'][$valueIndex] = $value;
+                    }
+                }
+            }
+
+            $productOptions[$optionIndex] = $option;
+        }
+
+        return $productOptions;
+    }
+
+    /**
+     * Overwrite values of fields to default, if there are option id and field name in array overwriteOptions
+     *
+     * @param int $optionId
+     * @param array $option
+     * @param array $overwriteOptions
+     * @return array
+     */
+    private function overwriteValue($optionId, $option, $overwriteOptions)
+    {
+        if (isset($overwriteOptions[$optionId])) {
+            foreach ($overwriteOptions[$optionId] as $fieldName => $overwrite) {
+                if ($overwrite && isset($option[$fieldName]) && isset($option['default_' . $fieldName])) {
+                    $option[$fieldName] = $option['default_' . $fieldName];
+                    if ('title' == $fieldName) {
+                        $option['is_delete_store_title'] = 1;
+                    }
+					if ('help' == $fieldName) {
+                        $option['is_delete_store_help'] = 1;
+                    }
+                }
+            }
+        }
+
+        return $option;
+    }
+
+
+    /**
+     * Fills $product with options from $productOptions array
+     *
+     * @param \DevStone\UsageCalculator\Model\Usage $usage
+     * @param array $usageOptions
+     * @return \DevStone\UsageCalculator\Model\Usage
+     */
+    private function fillProductOptions(
+        \DevStone\UsageCalculator\Model\Usage $usage, 
+        array $usageOptions
+    ) {
+        if ($usage->getOptionsReadonly()) {
+            return $product;
+        }
+
+        if (empty($usageOptions)) {
+            return $usage->setOptions([]);
+        }
+
+        // mark custom options that should to fall back to default value
+        $options = $this->mergeProductOptions(
+            $usageOptions,
+            $this->request->getPost('options_use_default')
+        );
+        $customOptions = [];
+        foreach ($options as $customOptionData) {
+            if (!empty($customOptionData['is_delete'])) {
+                continue;
+            }
+
+            if (empty($customOptionData['option_id'])) {
+                $customOptionData['option_id'] = null;
+            }
+
+            if (isset($customOptionData['values'])) {
+                $customOptionData['values'] = array_filter($customOptionData['values'], function ($valueData) {
+                    return empty($valueData['is_delete']);
+                });
+            }
+
+            $customOption = $this->customOptionFactory->create(['data' => $customOptionData]);
+            $customOption->setUsageId($usage->getId());
+            $customOptions[] = $customOption;
+        }
+
+        return $usage->setOptions($customOptions);
+    }
+}
diff --git a/Controller/Adminhtml/Usage/InlineEdit.php b/Controller/Adminhtml/Usage/InlineEdit.php
new file mode 100644
index 0000000..0debeeb
--- /dev/null
+++ b/Controller/Adminhtml/Usage/InlineEdit.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * InlineEdit.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\Collection;
+
+/**
+ * Grid inline edit controller
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class InlineEdit extends Action
+{
+
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /**
+     * @var Collection
+     */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Collection $objectCollection
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        Collection $objectCollection,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->objectCollection = $objectCollection;
+    }
+
+    /**
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        /** @var \Magento\Framework\Controller\Result\Json $resultJson */
+        $resultJson = $this->jsonFactory->create();
+        $error = false;
+        $messages = [];
+
+        $postItems = $this->getRequest()->getParam('items', []);
+        if (!($this->getRequest()->getParam('isAjax') && count($postItems))) {
+            return $resultJson->setData([
+                'messages' => [__('Please correct the data sent.')],
+                'error' => true,
+            ]);
+        }
+
+        try {
+            $this->objectCollection
+                ->setStoreId($this->getRequest()->getParam('store', 0))
+                ->addFieldToFilter('entity_id', ['in' => array_keys($postItems)])
+                ->walk('saveCollection', [$postItems]);
+        } catch (\Exception $e) {
+            $messages[] = __('There was an error saving the data: ') . $e->getMessage();
+            $error = true;
+        }
+
+        return $resultJson->setData([
+            'messages' => $messages,
+            'error' => $error
+        ]);
+    }
+}
diff --git a/Controller/Adminhtml/Usage/MassDelete.php b/Controller/Adminhtml/Usage/MassDelete.php
new file mode 100644
index 0000000..486ac4f
--- /dev/null
+++ b/Controller/Adminhtml/Usage/MassDelete.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * MassDelete.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Ui\Component\MassAction\Filter;
+use Magento\Framework\Controller\ResultFactory;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\Collection;
+
+/**
+ * Class MassDelete
+ */
+class MassDelete extends Action
+{
+    /**
+     * @var Filter
+     */
+    protected $filter;
+
+    /** @var Collection $objectCollection */
+    protected $objectCollection;
+
+    /**
+     * @param Context $context
+     * @param Filter $filter
+     * @param Collection $objectCollection
+     */
+    public function __construct(Context $context, Filter $filter, Collection $objectCollection)
+    {
+        $this->filter = $filter;
+        $this->objectCollection = $objectCollection;
+        parent::__construct($context);
+    }
+
+    /**
+     * Execute action
+     *
+     * @return \Magento\Backend\Model\View\Result\Redirect
+     * @throws \Magento\Framework\Exception\LocalizedException|\Exception
+     */
+    public function execute()
+    {
+        $collection = $this->filter->getCollection($this->objectCollection);
+        $collectionSize = $collection->getSize();
+        $collection->walk('delete');
+
+        $this->messageManager->addSuccessMessage(__('A total of %1 record(s) have been deleted.', $collectionSize));
+
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
+        return $resultRedirect->setPath('*/*/');
+    }
+}
diff --git a/Controller/Adminhtml/Usage/Save.php b/Controller/Adminhtml/Usage/Save.php
new file mode 100644
index 0000000..e8aa06c
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Save.php
@@ -0,0 +1,98 @@
+<?php
+/**
+ * Save
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use DevStone\UsageCalculator\Model\UsageFactory;
+
+class Save extends Action
+{
+    /** @var UsageFactory $objectFactory */
+    protected $objectFactory;
+
+    /**
+     * @var Initialization\Helper $helper
+     */
+    protected $helper;
+    
+    /**
+     * @param Context $context
+     * @param UsageFactory $objectFactory
+     */
+    public function __construct(
+        Context $context,
+        UsageFactory $objectFactory,
+        Initialization\Helper $helper
+    ) {
+        $this->objectFactory = $objectFactory;
+        $this->helper = $helper;
+        parent::__construct($context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _isAllowed()
+    {
+        return $this->_authorization->isAllowed('DevStone_UsageCalculator::usage');
+    }
+
+    /**
+     * Save action
+     *
+     * @return \Magento\Framework\Controller\ResultInterface
+     */
+    public function execute()
+    {
+        $storeId = (int)$this->getRequest()->getParam('store_id');
+        $data = $this->getRequest()->getParams();        
+        /** @var \Magento\Backend\Model\View\Result\Redirect $resultRedirect */
+        $resultRedirect = $this->resultRedirectFactory->create();
+        if ($data) {
+            $params = [];
+            $objectInstance = $this->objectFactory->create();
+            $objectInstance->setStoreId($storeId);
+            $params['store'] = $storeId;
+            if (empty($data['entity_id'])) {
+                $data['entity_id'] = null;
+            } else {
+                $objectInstance->load($data['entity_id']);
+                $params['entity_id'] = $data['entity_id'];
+            }
+            $objectInstance->addData($data);
+
+            $this->_eventManager->dispatch(
+                'devstone_usagecalculator_usage_prepare_save',
+                ['object' => $this->objectFactory, 'request' => $this->getRequest()]
+            );
+            
+            $objectInstance = $this->helper->initialize($objectInstance);
+
+            try {
+                $objectInstance->save();
+                $this->messageManager->addSuccessMessage(__('You saved this record.'));
+                $this->_getSession()->setFormData(false);
+                if ($this->getRequest()->getParam('back')) {
+                    $params['entity_id'] = $objectInstance->getId();
+                    $params['_current'] = true;
+                    return $resultRedirect->setPath('*/*/edit', $params);
+                }
+                return $resultRedirect->setPath('*/*/');
+            } catch (\Exception $e) {
+                $this->messageManager->addErrorMessage($e->getMessage());
+                $this->messageManager->addExceptionMessage($e, __('Something went wrong while saving the record.'));
+            }
+
+            $this->_getSession()->setFormData($this->getRequest()->getPostValue());
+            return $resultRedirect->setPath('*/*/edit', $params);
+        }
+        return $resultRedirect->setPath('*/*/');
+    }
+
+}
diff --git a/Controller/Adminhtml/Usage/Validate.php b/Controller/Adminhtml/Usage/Validate.php
new file mode 100644
index 0000000..093550b
--- /dev/null
+++ b/Controller/Adminhtml/Usage/Validate.php
@@ -0,0 +1,84 @@
+<?php
+/**
+ * Validate
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Controller\Adminhtml\Usage;
+
+use Magento\Backend\App\Action;
+use Magento\Backend\App\Action\Context;
+use Magento\Framework\Controller\Result\JsonFactory;
+
+class Validate extends Action
+{
+    /** @var JsonFactory $jsonFactory */
+    protected $jsonFactory;
+
+    /** @var  \Magento\Framework\DataObject $response */
+    protected $response;
+
+    /**
+     * @param Context $context
+     * @param JsonFactory $jsonFactory
+     */
+    public function __construct(
+        Context $context,
+        JsonFactory $jsonFactory
+    ) {
+        parent::__construct($context);
+        $this->jsonFactory = $jsonFactory;
+        $this->response = new \Magento\Framework\DataObject();
+    }
+
+    /**
+     * Check if required fields is not empty
+     *
+     * @param array $data
+     */
+    public function validateRequireEntries(array $data)
+    {
+        $requiredFields = [
+            'identifier' => __('Usage Identifier'),
+        ];
+        foreach ($data as $field => $value) {
+            if (in_array($field, array_keys($requiredFields)) && $value == '') {
+                $this->_addErrorMessage(
+                    __('To apply changes you should fill in required "%1" field', $requiredFields[$field])
+                );
+            }
+        }
+    }
+
+    /**
+     * Add error message validation
+     *
+     * @param $message
+     */
+    protected function _addErrorMessage($message)
+    {
+        $this->response->setError(true);
+        if (!is_array($this->response->getMessages())) {
+            $this->response->setMessages([]);
+        }
+        $messages = $this->response->getMessages();
+        $messages[] = $message;
+        $this->response->setMessages($messages);
+    }
+
+    /**
+     * AJAX customer validation action
+     *
+     * @return \Magento\Framework\Controller\Result\Json
+     */
+    public function execute()
+    {
+        $this->response->setError(0);
+
+        $this->validateRequireEntries($this->getRequest()->getParams());
+
+        $resultJson = $this->jsonFactory->create()->setData($this->response);
+        return $resultJson;
+    }
+}
diff --git a/Model/Category.php b/Model/Category.php
new file mode 100644
index 0000000..fcf1334
--- /dev/null
+++ b/Model/Category.php
@@ -0,0 +1,79 @@
+<?php
+
+/**
+ * Category.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\DataObject\IdentityInterface;
+use Magento\Framework\Model\AbstractModel;
+
+class Category extends AbstractModel implements IdentityInterface, \DevStone\UsageCalculator\Api\Data\CategoryInterface
+{
+    /**
+     * CMS page cache tag
+     */
+    const CACHE_TAG = 'devstone_usagecalculator_category';
+
+    /**
+     * @var string
+     */
+    protected $_cacheTag = 'devstone_usagecalculator_category';
+
+    /**
+     * Prefix of model events names
+     *
+     * @var string
+     */
+    protected $_eventPrefix = 'devstone_usagecalculator_category';
+
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        parent::_construct();
+        $this->_init(\DevStone\UsageCalculator\Model\ResourceModel\Category::class);
+    }
+    
+    /**
+     * Get identities
+     *
+     * @return array
+     */
+    public function getIdentities()
+    {
+        return [self::CACHE_TAG . '_' . $this->getId()];
+    }
+
+    /**
+     * Save from collection data
+     *
+     * @param array $data
+     * @return $this|bool
+     */
+    public function saveCollection(array $data)
+    {
+        if (isset($data[$this->getId()])) {
+            $this->addData($data[$this->getId()]);
+            $this->getResource()->save($this);
+        }
+        return $this;
+    }
+    
+    public function setName($name) {
+        $this->setData(self::NAME, $name);
+        return $this;
+    }
+    
+    public function getName()
+    {
+        return $this->getData(self::NAME);
+    }
+}
diff --git a/Model/CategoryRepository.php b/Model/CategoryRepository.php
new file mode 100644
index 0000000..9ca3f31
--- /dev/null
+++ b/Model/CategoryRepository.php
@@ -0,0 +1,197 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\Exception\CouldNotDeleteException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\Exception\CouldNotSaveException;
+use DevStone\UsageCalculator\Api\Data\CategorySearchResultsInterfaceFactory;
+use Magento\Framework\Reflection\DataObjectProcessor;
+use DevStone\UsageCalculator\Model\ResourceModel\Category as ResourceCategory;
+use DevStone\UsageCalculator\Model\ResourceModel\Category\CollectionFactory as CategoryCollectionFactory;
+use Magento\Framework\Api\SortOrder;
+use DevStone\UsageCalculator\Api\CategoryRepositoryInterface;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Framework\Api\DataObjectHelper;
+use DevStone\UsageCalculator\Api\Data\CategoryInterfaceFactory;
+use DevStone\UsageCalculator\Api\Data\CategoryInterface;
+
+class CategoryRepository implements CategoryRepositoryInterface
+{
+
+    protected $dataObjectProcessor;
+
+    protected $categoryFactory;
+
+    protected $dataObjectHelper;
+
+    protected $categoryCollectionFactory;
+
+    protected $searchResultsFactory;
+
+    protected $resource;
+
+    private $storeManager;
+    /**
+     * @param ResourceCategory $resource
+     * @param CategoryFactory $categoryFactory
+     * @param CategoryCollectionFactory $categoryCollectionFactory
+     * @param CategorySearchResultsInterfaceFactory $searchResultsFactory
+     * @param DataObjectHelper $dataObjectHelper
+     * @param DataObjectProcessor $dataObjectProcessor
+     * @param StoreManagerInterface $storeManager
+     */
+    public function __construct(
+        ResourceCategory $resource,
+        CategoryFactory $categoryFactory,
+        CategoryInterfaceFactory $dataSizeFactory,
+        CategoryCollectionFactory $categoryCollectionFactory,
+        CategorySearchResultsInterfaceFactory $searchResultsFactory,
+        DataObjectHelper $dataObjectHelper,
+        DataObjectProcessor $dataObjectProcessor,
+        StoreManagerInterface $storeManager
+    ) {
+        $this->resource = $resource;
+        $this->categoryFactory = $categoryFactory;
+        $this->categoryCollectionFactory = $categoryCollectionFactory;
+        $this->searchResultsFactory = $searchResultsFactory;
+        $this->dataObjectHelper = $dataObjectHelper;
+        $this->dataObjectProcessor = $dataObjectProcessor;
+        $this->storeManager = $storeManager;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function save(
+        CategoryInterface $category
+    ) {
+        /* if (empty($category->getStoreId())) {
+            $storeId = $this->storeManager->getStore()->getId();
+            $category->setStoreId($storeId);
+        } */
+        try {
+            $category->getResource()->save($category);
+        } catch (\Exception $exception) {
+            throw new CouldNotSaveException(__(
+                'Could not save the category: %1',
+                $exception->getMessage()
+            ));
+        }
+        return $category;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getById($categoryId)
+    {
+        $category = $this->categoryFactory->create();
+        $category->getResource()->load($category, $categoryId);
+        if (!$category->getId()) {
+            throw new NoSuchEntityException(__('Category with id "%1" does not exist.', $categoryId));
+        }
+        return $category;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $criteria
+    ) {
+        $collection = $this->categoryCollectionFactory->create();
+        
+        foreach ($criteria->getFilterGroups() as $filterGroup) {
+            foreach ($filterGroup->getFilters() as $filter) {
+                if ($filter->getField() === 'store_id') {
+                    $collection->addStoreFilter($filter->getValue(), false);
+                    continue;
+                }
+                $condition = $filter->getConditionType() ?: 'eq';
+                $collection->addFieldToFilter($filter->getField(), [$condition => $filter->getValue()]);
+            }
+        }
+        
+        $sortOrders = $criteria->getSortOrders();
+        if ($sortOrders) {
+            /** @var SortOrder $sortOrder */
+            foreach ($sortOrders as $sortOrder) {
+                $collection->addOrder(
+                    $sortOrder->getField(),
+                    ($sortOrder->getDirection() == SortOrder::SORT_ASC) ? 'ASC' : 'DESC'
+                );
+            }
+        }
+        $collection->setCurPage($criteria->getCurrentPage());
+        $collection->setPageSize($criteria->getPageSize());
+        
+        $searchResults = $this->searchResultsFactory->create();
+        $searchResults->setSearchCriteria($criteria);
+        $searchResults->setTotalCount($collection->getSize());
+        $searchResults->setItems($collection->getItems());
+        return $searchResults;
+        
+//        
+//        $searchResults = $this->searchResultsFactory->create();
+//        $searchResults->setSearchCriteria($searchCriteria);
+//        /** @var \Magento\Customer\Model\ResourceModel\Customer\Collection $collection */
+//        $collection = $this->customerFactory->create()->getCollection();
+//        $this->extensionAttributesJoinProcessor->process(
+//            $collection,
+//            \Magento\Customer\Api\Data\CustomerInterface::class
+//        );
+//        // This is needed to make sure all the attributes are properly loaded
+//        foreach ($this->customerMetadata->getAllAttributesMetadata() as $metadata) {
+//            $collection->addAttributeToSelect($metadata->getAttributeCode());
+//        }
+//        // Needed to enable filtering on name as a whole
+//        $collection->addNameToSelect();
+//        // Needed to enable filtering based on billing address attributes
+//        $collection->joinAttribute('billing_postcode', 'customer_address/postcode', 'default_billing', null, 'left')
+//            ->joinAttribute('billing_city', 'customer_address/city', 'default_billing', null, 'left')
+//            ->joinAttribute('billing_telephone', 'customer_address/telephone', 'default_billing', null, 'left')
+//            ->joinAttribute('billing_region', 'customer_address/region', 'default_billing', null, 'left')
+//            ->joinAttribute('billing_country_id', 'customer_address/country_id', 'default_billing', null, 'left')
+//            ->joinAttribute('company', 'customer_address/company', 'default_billing', null, 'left');
+//
+//        $this->collectionProcessor->process($searchCriteria, $collection);
+//
+//        $searchResults->setTotalCount($collection->getSize());
+//
+//        $customers = [];
+//        /** @var \Magento\Customer\Model\Customer $customerModel */
+//        foreach ($collection as $customerModel) {
+//            $customers[] = $customerModel->getDataModel();
+//        }
+//        $searchResults->setItems($customers);
+//        return $searchResults;
+        
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete(
+        CategoryInterface $category
+    ) {
+        try {
+            $category->getResource()->delete($category);
+        } catch (\Exception $exception) {
+            throw new CouldNotDeleteException(__(
+                'Could not delete the Category: %1',
+                $exception->getMessage()
+            ));
+        }
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function deleteById($categoryId)
+    {
+        return $this->delete($this->getById($categoryId));
+    }
+}
diff --git a/Model/Metadata/UsageCachedMetadata.php b/Model/Metadata/UsageCachedMetadata.php
new file mode 100644
index 0000000..2525e37
--- /dev/null
+++ b/Model/Metadata/UsageCachedMetadata.php
@@ -0,0 +1,31 @@
+<?php
+
+//namespace DevStone\UsageCalculator\Model\Metadata;
+//
+//use Magento\Customer\Api\CustomerMetadataInterface;
+//use Magento\Customer\Model\Metadata\CachedMetadata;
+//
+//
+///**
+// * Cached customer attribute metadata service
+// */
+//class UsageCachedMetadata extends CachedMetadata
+//{
+//    /**
+//     * @var string
+//     */
+//    protected $entityType = 'usage';
+//
+//    /**
+//     * Constructor
+//     *
+//     * @param CustomerMetadata $metadata
+//     * @param AttributeMetadataCache|null $attributeMetadataCache
+//     */
+//    public function __construct(
+//        CustomerMetadata $metadata,
+//        AttributeMetadataCache $attributeMetadataCache = null
+//    ) {
+//        parent::__construct($metadata, $attributeMetadataCache);
+//    }
+//}
diff --git a/Model/ResourceModel/Attribute.php b/Model/ResourceModel/Attribute.php
new file mode 100644
index 0000000..de761c5
--- /dev/null
+++ b/Model/ResourceModel/Attribute.php
@@ -0,0 +1,135 @@
+<?php
+/**
+ * Attribute.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Model\ResourceModel;
+
+use DevStone\UsageCalculator\Setup\CategorySetup;
+use Magento\Eav\Model\Config;
+use Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface;
+use Magento\Eav\Model\ResourceModel\Entity\Attribute as EavAttribute;
+use Magento\Eav\Model\ResourceModel\Entity\Type;
+use Magento\Framework\Model\AbstractModel;
+use Magento\Framework\Model\ResourceModel\Db\Context;
+use Magento\Store\Model\StoreManagerInterface;
+
+class Attribute extends EavAttribute
+{
+    /**
+     * Eav config
+     *
+     * @var Config
+     */
+    protected $_eavConfig;
+
+    /**
+     * @param Context $context
+     * @param StoreManagerInterface $storeManager
+     * @param Type $eavEntityType
+     * @param Config $eavConfig
+     * @param string $connectionName
+     */
+    public function __construct(
+        Context $context,
+        StoreManagerInterface $storeManager,
+        Type $eavEntityType,
+        Config $eavConfig,
+        $connectionName = null
+    ) {
+        $this->_eavConfig = $eavConfig;
+        parent::__construct($context, $storeManager, $eavEntityType, $connectionName);
+    }
+
+    /**
+     * Perform actions after object save
+     *
+     * @param AbstractModel $object
+     * @return $this
+     */
+    protected function _afterSave(AbstractModel $object)
+    {
+        $this->_clearUselessAttributeValues($object);
+        return parent::_afterSave($object);
+    }
+
+    /**
+     * Clear useless attribute values
+     *
+     * @param  AbstractModel $object
+     * @return $this
+     */
+    protected function _clearUselessAttributeValues(AbstractModel $object)
+    {
+        $origData = $object->getOrigData();
+
+        if ($object->isScopeGlobal() && isset(
+                $origData['is_global']
+            ) && ScopedAttributeInterface::SCOPE_GLOBAL != $origData['is_global']
+        ) {
+            $attributeStoreIds = array_keys($this->_storeManager->getStores());
+            if (!empty($attributeStoreIds)) {
+                $delCondition = [
+                    'attribute_id = ?' => $object->getId(),
+                    'store_id IN(?)' => $attributeStoreIds,
+                ];
+                $this->getConnection()->delete($object->getBackendTable(), $delCondition);
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Delete entity
+     *
+     * @param AbstractModel $object
+     * @return $this
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function deleteEntity(AbstractModel $object)
+    {
+        if (!$object->getEntityAttributeId()) {
+            return $this;
+        }
+
+        $select = $this->getConnection()->select()->from(
+            $this->getTable('eav_entity_attribute')
+        )->where(
+            'entity_attribute_id = ?',
+            (int)$object->getEntityAttributeId()
+        );
+        $result = $this->getConnection()->fetchRow($select);
+
+        if ($result) {
+            $attribute = $this->_eavConfig->getAttribute(
+                CategorySetup::ENTITY_TYPE_CODE,
+                $result['attribute_id']
+            );
+
+            $backendTable = $attribute->getBackend()->getTable();
+            if ($backendTable) {
+                $select = $this->getConnection()->select()->from(
+                    $attribute->getEntity()->getEntityTable(),
+                    'entity_id'
+                )->where(
+                    'attribute_set_id = ?',
+                    $result['attribute_set_id']
+                );
+
+                $clearCondition = [
+                    'attribute_id =?' => $attribute->getId(),
+                    'entity_id IN (?)' => $select,
+                ];
+                $this->getConnection()->delete($backendTable, $clearCondition);
+            }
+        }
+
+        $condition = ['entity_attribute_id = ?' => $object->getEntityAttributeId()];
+        $this->getConnection()->delete($this->getTable('eav_entity_attribute'), $condition);
+
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Attribute/Collection.php b/Model/ResourceModel/Attribute/Collection.php
new file mode 100644
index 0000000..a8f4ffa
--- /dev/null
+++ b/Model/ResourceModel/Attribute/Collection.php
@@ -0,0 +1,104 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Attribute;
+
+use DevStone\UsageCalculator\Setup\UsageSetup;
+use Magento\Eav\Model\Config;
+use Magento\Eav\Model\EntityFactory as EavEntityFactory;
+use Magento\Eav\Model\ResourceModel\Entity\Attribute\Collection as EavCollection;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactory;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+use Psr\Log\LoggerInterface;
+
+class Collection extends EavCollection
+{
+    /**
+     * Entity factory
+     *
+     * @var EavEntityFactory
+     */
+    protected $_eavEntityFactory;
+
+    /**
+     * @param EntityFactory $entityFactory
+     * @param LoggerInterface $logger
+     * @param FetchStrategyInterface $fetchStrategy
+     * @param ManagerInterface $eventManager
+     * @param EavEntityFactory $eavEntityFactory
+     * @param Config $eavConfig
+     * @param AdapterInterface $connection
+     * @param AbstractDb $resource
+     */
+    public function __construct(
+        EntityFactory $entityFactory,
+        LoggerInterface $logger,
+        FetchStrategyInterface $fetchStrategy,
+        ManagerInterface $eventManager,
+        Config $eavConfig,
+        EavEntityFactory $eavEntityFactory,
+        AdapterInterface $connection = null,
+        AbstractDb $resource = null
+    ) {
+        $this->_eavEntityFactory = $eavEntityFactory;
+        parent::__construct($entityFactory, $logger, $fetchStrategy, $eventManager, $eavConfig, $connection, $resource);
+    }
+
+    /**
+     * Main select object initialization.
+     *
+     * @return $this
+     */
+    protected function _initSelect()
+    {
+        $this->getSelect()->from(
+            ['main_table' => $this->getResource()->getMainTable()]
+        )->where(
+            'main_table.entity_type_id=?',
+            $this->_eavEntityFactory->create()->setType(UsageSetup::ENTITY_TYPE_CODE)->getTypeId()
+        )->join(
+            ['additional_table' => $this->getTable(UsageSetup::ENTITY_TYPE_CODE . '_eav_attribute')],
+            'additional_table.attribute_id = main_table.attribute_id'
+        );
+        return $this;
+    }
+
+    /**
+     * @return $this
+     */
+    public function getFilterAttributesOnly()
+    {
+        $this->getSelect()->where('additional_table.is_filterable', 1);
+        return $this;
+    }
+
+    /**
+     * @param int $status
+     * @return $this
+     */
+    public function addVisibilityFilter($status = 1)
+    {
+        $this->getSelect()->where('additional_table.is_visible', $status);
+        return $this;
+    }
+
+    /**
+     * Specify attribute entity type filter
+     *
+     * @param int $typeId
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setEntityTypeFilter($typeId)
+    {
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Category.php b/Model/ResourceModel/Category.php
new file mode 100644
index 0000000..cb4c258
--- /dev/null
+++ b/Model/ResourceModel/Category.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * Category.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Model\ResourceModel;
+
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+
+class Category extends AbstractDb
+{
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init('devstone_usage_category', 'entity_id');
+    }
+}
diff --git a/Model/ResourceModel/Category/Collection.php b/Model/ResourceModel/Category/Collection.php
new file mode 100644
index 0000000..01cdca2
--- /dev/null
+++ b/Model/ResourceModel/Category/Collection.php
@@ -0,0 +1,31 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Model\ResourceModel\Category;
+
+use Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection;
+
+class Collection extends AbstractCollection
+{
+    /**
+     * @var string
+     */
+    protected $_idFieldName = 'entity_id';
+
+    /**
+     * Define resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(
+            \DevStone\UsageCalculator\Model\Category::class, 
+            \DevStone\UsageCalculator\Model\ResourceModel\Category::class
+        );
+    }
+}
diff --git a/Model/ResourceModel/Category/Grid/Collection.php b/Model/ResourceModel/Category/Grid/Collection.php
new file mode 100644
index 0000000..05b9027
--- /dev/null
+++ b/Model/ResourceModel/Category/Grid/Collection.php
@@ -0,0 +1,160 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Category\Grid;
+
+use Magento\Framework\Api\Search\SearchResultInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactoryInterface;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+use Magento\Framework\Search\AggregationInterface;
+use Psr\Log\LoggerInterface;
+use DevStone\UsageCalculator\Model\ResourceModel\Category\Collection as CategoryCollection;
+
+/**
+ * Class Collection
+ * Collection for displaying grid
+ */
+class Collection extends CategoryCollection implements SearchResultInterface
+{
+    /**
+     * @var AggregationInterface
+     */
+    protected $aggregations;
+
+    /**
+     * @param EntityFactoryInterface $entityFactory
+     * @param LoggerInterface $logger
+     * @param FetchStrategyInterface $fetchStrategy
+     * @param ManagerInterface $eventManager
+     * @param mixed|null $mainTable
+     * @param AbstractDb $eventPrefix
+     * @param mixed $eventObject
+     * @param mixed $resourceModel
+     * @param string $model
+     * @param null $connection
+     * @param AbstractDb|null $resource
+     * 
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        EntityFactoryInterface $entityFactory,
+        LoggerInterface $logger,
+        FetchStrategyInterface $fetchStrategy,
+        ManagerInterface $eventManager,
+        $mainTable,
+        $eventPrefix,
+        $eventObject,
+        $resourceModel,
+        $model = 'Magento\Framework\View\Element\UiComponent\DataProvider\Document',
+        $connection = null,
+        AbstractDb $resource = null
+    ) {
+        parent::__construct(
+            $entityFactory,
+            $logger,
+            $fetchStrategy,
+            $eventManager,
+            $connection,
+            $resource
+        );
+        $this->_eventPrefix = $eventPrefix;
+        $this->_eventObject = $eventObject;
+        $this->_init($model, $resourceModel);
+        $this->setMainTable($mainTable);
+    }
+
+    /**
+     * @return AggregationInterface
+     */
+    public function getAggregations()
+    {
+        return $this->aggregations;
+    }
+
+    /**
+     * @param AggregationInterface $aggregations
+     * @return $this
+     */
+    public function setAggregations($aggregations)
+    {
+        $this->aggregations = $aggregations;
+    }
+
+
+    /**
+     * Retrieve all ids for collection
+     * Backward compatibility with EAV collection
+     *
+     * @param int $limit
+     * @param int $offset
+     * @return array
+     */
+    public function getAllIds($limit = null, $offset = null)
+    {
+        return $this->getConnection()->fetchCol($this->_getAllIdsSelect($limit, $offset), $this->_bindParams);
+    }
+
+    /**
+     * Get search criteria.
+     *
+     * @return SearchCriteriaInterface|null
+     */
+    public function getSearchCriteria()
+    {
+        return null;
+    }
+
+    /**
+     * Set search criteria.
+     *
+     * @param SearchCriteriaInterface $searchCriteria
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setSearchCriteria(SearchCriteriaInterface $searchCriteria = null)
+    {
+        return $this;
+    }
+
+    /**
+     * Get total count.
+     *
+     * @return int
+     */
+    public function getTotalCount()
+    {
+        return $this->getSize();
+    }
+
+    /**
+     * Set total count.
+     *
+     * @param int $totalCount
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setTotalCount($totalCount)
+    {
+        return $this;
+    }
+
+    /**
+     * Set items list.
+     *
+     * @param \Magento\Framework\Api\ExtensibleDataInterface[] $items
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setItems(array $items = null)
+    {
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Eav/Attribute.php b/Model/ResourceModel/Eav/Attribute.php
new file mode 100644
index 0000000..6be7960
--- /dev/null
+++ b/Model/ResourceModel/Eav/Attribute.php
@@ -0,0 +1,180 @@
+<?php
+/**
+ * Attribute.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Eav;
+
+use DevStone\UsageCalculator\Setup\UsageSetup;
+use Magento\Eav\Model\Entity\Attribute as EavAttribute;
+use Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface;
+
+/**
+ * Class Attribute
+ * @package Staempfli\Employee\Model\ResourceModel\Eav
+ */
+class Attribute extends EavAttribute implements ScopedAttributeInterface
+{
+    /**
+     * Constants
+     */
+    const MODULE_NAME = 'DevStone_Usage';
+    const KEY_IS_GLOBAL = 'is_global';
+    const KEY_IS_STATIC = 'static';
+
+    /**
+     * Event object name
+     *
+     * @var string
+     */
+    protected $_eventObject = 'attribute';
+
+    /**
+     * Array with labels
+     *
+     * @var array
+     */
+    protected static $_labels = null;
+
+    /**
+     * Event prefix
+     *
+     * @var string
+     */
+    protected $_eventPrefix = UsageSetup::ENTITY_TYPE_CODE . '_entity_attribute';
+
+    /**
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init('DevStone\UsageCalculator\Model\ResourceModel\Attribute');
+    }
+
+    /**
+     * Processing object before save data
+     *
+     * @return \Magento\Framework\Model\AbstractModel
+     * @throws LocalizedException
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     */
+    public function beforeSave() //@codingStandardsIgnoreLine
+    {
+        $this->setData('modulePrefix', self::MODULE_NAME);
+        if (isset($this->_origData[self::KEY_IS_GLOBAL])) {
+            if (!isset($this->_data[self::KEY_IS_GLOBAL])) {
+                $this->_data[self::KEY_IS_GLOBAL] = self::SCOPE_GLOBAL;
+            }
+        }
+        return parent::beforeSave();
+    }
+
+    /**
+     * Processing object after save data
+     *
+     * @return \Magento\Framework\Model\AbstractModel
+     */
+    public function afterSave() //@codingStandardsIgnoreLine
+    {
+        /**
+         * Fix saving attribute in admin
+         */
+        $this->_eavConfig->clear();
+        return parent::afterSave();
+    }
+
+    /**
+     * Return is attribute global
+     *
+     * @return integer
+     */
+    public function getIsGlobal()
+    {
+        if ($this->getBackendType() === self::KEY_IS_STATIC) {
+            return true;
+        }
+        return $this->_getData(self::KEY_IS_GLOBAL);
+    }
+
+    /**
+     * Retrieve attribute is global scope flag
+     *
+     * @return bool
+     */
+    public function isScopeGlobal()
+    {
+        return $this->getIsGlobal() == self::SCOPE_GLOBAL;
+    }
+
+    /**
+     * Retrieve attribute is website scope website
+     *
+     * @return bool
+     */
+    public function isScopeWebsite()
+    {
+        return $this->getIsGlobal() == self::SCOPE_WEBSITE;
+    }
+
+    /**
+     * Retrieve attribute is store scope flag
+     *
+     * @return bool
+     */
+    public function isScopeStore()
+    {
+        return !$this->isScopeGlobal() && !$this->isScopeWebsite();
+    }
+
+    /**
+     * Retrieve store id
+     *
+     * @return int
+     */
+    public function getStoreId()
+    {
+        $dataObject = $this->getDataObject();
+        if ($dataObject) {
+            return $dataObject->getStoreId();
+        }
+        return $this->getData('store_id');
+    }
+
+    /**
+     * Retrieve source model
+     *
+     * @return \Magento\Eav\Model\Entity\Attribute\Source\AbstractSource
+     */
+    public function getSourceModel()
+    {
+        $model = $this->getData('source_model');
+        if (empty($model)) {
+            if ($this->getBackendType() == 'int' && $this->getFrontendInput() == 'select') {
+                return $this->_getDefaultSourceModel();
+            }
+        }
+        return $model;
+    }
+
+    /**
+     * Get default attribute source model
+     *
+     * @return string
+     */
+    public function _getDefaultSourceModel()
+    {
+        return 'Magento\Eav\Model\Entity\Attribute\Source\Table';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function afterDelete() //@codingStandardsIgnoreLine
+    {
+        $this->_eavConfig->clear();
+        return parent::afterDelete();
+    }
+}
diff --git a/Model/ResourceModel/Size.php b/Model/ResourceModel/Size.php
new file mode 100644
index 0000000..d603e31
--- /dev/null
+++ b/Model/ResourceModel/Size.php
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * Size.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Model\ResourceModel;
+
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+
+class Size extends AbstractDb
+{
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init('devstone_downloadable_image_size', 'entity_id');
+    }
+}
diff --git a/Model/ResourceModel/Size/Collection.php b/Model/ResourceModel/Size/Collection.php
new file mode 100644
index 0000000..8526272
--- /dev/null
+++ b/Model/ResourceModel/Size/Collection.php
@@ -0,0 +1,28 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Model\ResourceModel\Size;
+
+use Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection;
+
+class Collection extends AbstractCollection
+{
+    /**
+     * @var string
+     */
+    protected $_idFieldName = 'entity_id';
+
+    /**
+     * Define resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Model\Size::class, \DevStone\UsageCalculator\Model\ResourceModel\Size::class);
+    }
+}
diff --git a/Model/ResourceModel/Size/Grid/Collection.php b/Model/ResourceModel/Size/Grid/Collection.php
new file mode 100644
index 0000000..2066140
--- /dev/null
+++ b/Model/ResourceModel/Size/Grid/Collection.php
@@ -0,0 +1,160 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Size\Grid;
+
+use Magento\Framework\Api\Search\SearchResultInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactoryInterface;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+use Magento\Framework\Search\AggregationInterface;
+use Psr\Log\LoggerInterface;
+use DevStone\UsageCalculator\Model\ResourceModel\Size\Collection as SizeCollection;
+
+/**
+ * Class Collection
+ * Collection for displaying grid
+ */
+class Collection extends SizeCollection implements SearchResultInterface
+{
+    /**
+     * @var AggregationInterface
+     */
+    protected $aggregations;
+
+    /**
+     * @param EntityFactoryInterface $entityFactory
+     * @param LoggerInterface $logger
+     * @param FetchStrategyInterface $fetchStrategy
+     * @param ManagerInterface $eventManager
+     * @param mixed|null $mainTable
+     * @param AbstractDb $eventPrefix
+     * @param mixed $eventObject
+     * @param mixed $resourceModel
+     * @param string $model
+     * @param null $connection
+     * @param AbstractDb|null $resource
+     * 
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        EntityFactoryInterface $entityFactory,
+        LoggerInterface $logger,
+        FetchStrategyInterface $fetchStrategy,
+        ManagerInterface $eventManager,
+        $mainTable,
+        $eventPrefix,
+        $eventObject,
+        $resourceModel,
+        $model = 'Magento\Framework\View\Element\UiComponent\DataProvider\Document',
+        $connection = null,
+        AbstractDb $resource = null
+    ) {
+        parent::__construct(
+            $entityFactory,
+            $logger,
+            $fetchStrategy,
+            $eventManager,
+            $connection,
+            $resource
+        );
+        $this->_eventPrefix = $eventPrefix;
+        $this->_eventObject = $eventObject;
+        $this->_init($model, $resourceModel);
+        $this->setMainTable($mainTable);
+    }
+
+    /**
+     * @return AggregationInterface
+     */
+    public function getAggregations()
+    {
+        return $this->aggregations;
+    }
+
+    /**
+     * @param AggregationInterface $aggregations
+     * @return $this
+     */
+    public function setAggregations($aggregations)
+    {
+        $this->aggregations = $aggregations;
+    }
+
+
+    /**
+     * Retrieve all ids for collection
+     * Backward compatibility with EAV collection
+     *
+     * @param int $limit
+     * @param int $offset
+     * @return array
+     */
+    public function getAllIds($limit = null, $offset = null)
+    {
+        return $this->getConnection()->fetchCol($this->_getAllIdsSelect($limit, $offset), $this->_bindParams);
+    }
+
+    /**
+     * Get search criteria.
+     *
+     * @return SearchCriteriaInterface|null
+     */
+    public function getSearchCriteria()
+    {
+        return null;
+    }
+
+    /**
+     * Set search criteria.
+     *
+     * @param SearchCriteriaInterface $searchCriteria
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setSearchCriteria(SearchCriteriaInterface $searchCriteria = null)
+    {
+        return $this;
+    }
+
+    /**
+     * Get total count.
+     *
+     * @return int
+     */
+    public function getTotalCount()
+    {
+        return $this->getSize();
+    }
+
+    /**
+     * Set total count.
+     *
+     * @param int $totalCount
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setTotalCount($totalCount)
+    {
+        return $this;
+    }
+
+    /**
+     * Set items list.
+     *
+     * @param \Magento\Framework\Api\ExtensibleDataInterface[] $items
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setItems(array $items = null)
+    {
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Usage.php b/Model/ResourceModel/Usage.php
new file mode 100644
index 0000000..33845b6
--- /dev/null
+++ b/Model/ResourceModel/Usage.php
@@ -0,0 +1,141 @@
+<?php
+
+/**
+ * Usage.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel;
+
+use Magento\Eav\Model\Entity\AbstractEntity;
+use Magento\Eav\Model\Entity\Context;
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManagerInterface;
+use DevStone\UsageCalculator\Setup\UsageSetup;
+
+class Usage extends AbstractEntity
+{
+    /**
+     * Store id
+     *
+     * @var int
+     */
+    protected $_storeId = null;
+
+    /**
+     * @var StoreManagerInterface
+     */
+    protected $_storeManager;
+
+    /**
+     * Usage constructor.
+     * @param Context $context
+     * @param StoreManagerInterface $storeManager
+     * @param array $data
+     */
+    public function __construct(
+        Context $context,
+        StoreManagerInterface $storeManager,
+        array $data = []
+    ) {
+        parent::__construct($context, $data);
+        $this->setType(UsageSetup::ENTITY_TYPE_CODE);
+        $this->setConnection(UsageSetup::ENTITY_TYPE_CODE . '_read', UsageSetup::ENTITY_TYPE_CODE . '_write');
+        $this->_storeManager = $storeManager;
+    }
+
+    /**
+     * Retrieve employee entity default attributes
+     *
+     * @return string[]
+     */
+    protected function _getDefaultAttributes()
+    {
+        return [
+            'created_at',
+            'updated_at',
+            'size_id',
+            'category_id',
+        ];
+    }
+
+    /**
+     * Set store Id
+     *
+     * @param integer $storeId
+     * @return $this
+     */
+    public function setStoreId($storeId)
+    {
+        $this->_storeId = $storeId;
+        return $this;
+    }
+
+    /**
+     * Return store id
+     *
+     * @return integer
+     */
+    public function getStoreId()
+    {
+        if ($this->_storeId === null) {
+            return $this->_storeManager->getStore()->getId();
+        }
+        return $this->_storeId;
+    }
+
+    /**
+     * Set Attribute values to be saved
+     *
+     * @param \Magento\Framework\Model\AbstractModel $object
+     * @param \Magento\Eav\Model\Entity\Attribute\AbstractAttribute $attribute
+     * @param mixed $value
+     * @return $this
+     */
+    protected function _saveAttribute($object, $attribute, $value)
+    {
+        $table = $attribute->getBackend()->getTable();
+        if (!isset($this->_attributeValuesToSave[$table])) {
+            $this->_attributeValuesToSave[$table] = [];
+        }
+
+        $entityIdField = $attribute->getBackend()->getEntityIdField();
+        $storeId = $object->getStoreId()?:Store::DEFAULT_STORE_ID;
+        $data = [
+            $entityIdField => $object->getId(),
+            'attribute_id' => $attribute->getId(),
+            'value' => $this->_prepareValueForSave($value, $attribute),
+            'store_id' => $storeId,
+        ];
+
+        if (!$this->getEntityTable() || $this->getEntityTable() == \Magento\Eav\Model\Entity::DEFAULT_ENTITY_TABLE) {
+            $data['entity_type_id'] = $object->getEntityTypeId();
+        }
+
+        if ($attribute->isScopeStore()) {
+            /**
+             * Update attribute value for store
+             */
+            $this->_attributeValuesToSave[$table][] = $data;
+        } elseif ($attribute->isScopeWebsite() && $storeId != Store::DEFAULT_STORE_ID) {
+            /**
+             * Update attribute value for website
+             */
+            $storeIds = $this->_storeManager->getStore($storeId)->getWebsite()->getStoreIds(true);
+            foreach ($storeIds as $storeId) {
+                $data['store_id'] = (int)$storeId;
+                $this->_attributeValuesToSave[$table][] = $data;
+            }
+        } else {
+            /**
+             * Update global attribute value
+             */
+            $data['store_id'] = Store::DEFAULT_STORE_ID;
+            $this->_attributeValuesToSave[$table][] = $data;
+        }
+
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Usage/Collection.php b/Model/ResourceModel/Usage/Collection.php
new file mode 100644
index 0000000..b578e34
--- /dev/null
+++ b/Model/ResourceModel/Usage/Collection.php
@@ -0,0 +1,302 @@
+<?php
+
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage;
+
+use Magento\Eav\Model\Config;
+use Magento\Eav\Model\Entity\Collection\AbstractCollection;
+use Magento\Eav\Model\EntityFactory as EavEntityFactory;
+use Magento\Eav\Model\ResourceModel\Helper;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactory;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Validator\UniversalFactory;
+use Magento\Store\Model\StoreManagerInterface;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Class Collection
+ * @package DevStone\UsageCalculator\Model\ResourceModel\Usage
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class Collection extends AbstractCollection
+{
+    /**
+     * @var string
+     */
+    protected $_idFieldName = 'entity_id';
+
+    /**
+     * @var $_storeId
+     */
+    protected $_storeId;
+
+    /**
+     * @var StoreManagerInterface
+     */
+    protected $_storeManager;
+
+    /**
+     * @param EntityFactory $entityFactory
+     * @param LoggerInterface $logger
+     * @param FetchStrategyInterface $fetchStrategy
+     * @param ManagerInterface $eventManager
+     * @param Config $eavConfig
+     * @param ResourceConnection $resource
+     * @param EavEntityFactory $eavEntityFactory
+     * @param Helper $resourceHelper
+     * @param UniversalFactory $universalFactory
+     * @param StoreManagerInterface $storeManager
+     * @param AdapterInterface $connection
+     *
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        EntityFactory $entityFactory,
+        LoggerInterface $logger,
+        FetchStrategyInterface $fetchStrategy,
+        ManagerInterface $eventManager,
+        Config $eavConfig,
+        ResourceConnection $resource,
+        EavEntityFactory $eavEntityFactory,
+        Helper $resourceHelper,
+        UniversalFactory $universalFactory,
+        StoreManagerInterface $storeManager,
+        AdapterInterface $connection = null
+    ) {
+        $this->_storeManager = $storeManager;
+        parent::__construct(
+            $entityFactory,
+            $logger,
+            $fetchStrategy,
+            $eventManager,
+            $eavConfig,
+            $resource,
+            $eavEntityFactory,
+            $resourceHelper,
+            $universalFactory,
+            $connection
+        );
+    }
+
+    /**
+     * Define resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Model\Usage::class, \DevStone\UsageCalculator\Model\ResourceModel\Usage::class);
+    }
+
+    /**
+     * Set store scope
+     *
+     * @param int|string|\Magento\Store\Model\Store $store
+     * @return $this
+     */
+    public function setStore($store)
+    {
+        $this->setStoreId($this->_storeManager->getStore($store)->getId());
+        return $this;
+    }
+
+    /**
+     * Set store scope
+     *
+     * @param int|string|\Magento\Store\Api\Data\StoreInterface $storeId
+     * @return $this
+     */
+    public function setStoreId($storeId)
+    {
+        if ($storeId instanceof \Magento\Store\Api\Data\StoreInterface) {
+            $storeId = $storeId->getId();
+        }
+        $this->_storeId = (int)$storeId;
+        return $this;
+    }
+
+    /**
+     * Return current store id
+     *
+     * @return int
+     */
+    public function getStoreId()
+    {
+        if ($this->_storeId === null) {
+            $this->setStoreId($this->_storeManager->getStore()->getId());
+        }
+        return $this->_storeId;
+    }
+
+    /**
+     * Retrieve default store id
+     *
+     * @return int
+     */
+    public function getDefaultStoreId()
+    {
+        return \Magento\Store\Model\Store::DEFAULT_STORE_ID;
+    }
+
+    /**
+     * Retrieve attributes load select
+     *
+     * @param string $table
+     * @param array|int $attributeIds
+     * @return \Magento\Eav\Model\Entity\Collection\AbstractCollection
+     */
+    protected function _getLoadAttributesSelect($table, $attributeIds = [])
+    {
+        if (empty($attributeIds)) {
+            $attributeIds = $this->_selectAttributes;
+        }
+        $storeId = $this->getStoreId();
+        $connection = $this->getConnection();
+
+        $entityTable = $this->getEntity()->getEntityTable();
+        $indexList = $connection->getIndexList($entityTable);
+        $entityIdField = $indexList[$connection->getPrimaryKeyName($entityTable)]['COLUMNS_LIST'][0];
+
+        if ($storeId) {
+            $joinCondition = [
+                't_s.attribute_id = t_d.attribute_id',
+                "t_s.{$entityIdField} = t_d.{$entityIdField}",
+                $connection->quoteInto('t_s.store_id = ?', $storeId),
+            ];
+
+            $select = $connection->select()->from(
+                ['t_d' => $table],
+                ['attribute_id']
+            )->join(
+                ['e' => $entityTable],
+                "e.{$entityIdField} = t_d.{$entityIdField}",
+                ['e.entity_id']
+            )->where(
+                "e.entity_id IN (?)",
+                array_keys($this->_itemsById)
+            )->where(
+                't_d.attribute_id IN (?)',
+                $attributeIds
+            )->joinLeft(
+                ['t_s' => $table],
+                implode(' AND ', $joinCondition),
+                []
+            )->where(
+                't_d.store_id = ?',
+                $connection->getIfNullSql('t_s.store_id', \Magento\Store\Model\Store::DEFAULT_STORE_ID)
+            );
+        } else {
+            $select = $connection->select()->from(
+                ['t_d' => $table],
+                ['attribute_id']
+            )->join(
+                ['e' => $entityTable],
+                "e.{$entityIdField} = t_d.{$entityIdField}",
+                ['e.entity_id']
+            )->where(
+                "e.entity_id IN (?)",
+                array_keys($this->_itemsById)
+            )->where(
+                'attribute_id IN (?)',
+                $attributeIds
+            )->where(
+                'store_id = ?',
+                $this->getDefaultStoreId()
+            );
+        }
+        return $select;
+    }
+
+    /**
+     * @param \Magento\Framework\DB\Select $select
+     * @param string $table
+     * @param string $type
+     * @return \Magento\Framework\DB\Select
+     */
+    protected function _addLoadAttributesSelectValues($select, $table, $type)
+    {
+        $storeId = $this->getStoreId();
+        if ($storeId) {
+            $connection = $this->getConnection();
+            $valueExpr = $connection->getCheckSql('t_s.value_id IS NULL', 't_d.value', 't_s.value');
+
+            $select->columns(
+                ['default_value' => 't_d.value', 'store_value' => 't_s.value', 'value' => $valueExpr]
+            );
+        } else {
+            $select = parent::_addLoadAttributesSelectValues($select, $table, $type);
+        }
+        return $select;
+    }
+
+    /**
+     * Adding join statement to collection select instance
+     *
+     * @param string $method
+     * @param object $attribute
+     * @param string $tableAlias
+     * @param array $condition
+     * @param string $fieldCode
+     * @param string $fieldAlias
+     * @return \Magento\Eav\Model\Entity\Collection\AbstractCollection
+     */
+    protected function _joinAttributeToSelect($method, $attribute, $tableAlias, $condition, $fieldCode, $fieldAlias)
+    {
+        if (isset($this->_joinAttributes[$fieldCode]['store_id'])) {
+            $storeId = $this->_joinAttributes[$fieldCode]['store_id'];
+        } else {
+            $storeId = $this->getStoreId();
+        }
+
+        $connection = $this->getConnection();
+
+        if ($storeId != $this->getDefaultStoreId() && !$attribute->isScopeGlobal()) {
+            /**
+             * Add joining default value for not default store
+             * if value for store is null - we use default value
+             */
+            $defCondition = '(' . implode(') AND (', $condition) . ')';
+            $defAlias = $tableAlias . '_default';
+            $defAlias = $this->getConnection()->getTableName($defAlias);
+            $defFieldAlias = str_replace($tableAlias, $defAlias, $fieldAlias);
+            $tableAlias = $this->getConnection()->getTableName($tableAlias);
+
+            $defCondition = str_replace($tableAlias, $defAlias, $defCondition);
+            $defCondition .= $connection->quoteInto(
+                " AND " . $connection->quoteColumnAs("{$defAlias}.store_id", null) . " = ?",
+                $this->getDefaultStoreId()
+            );
+
+            $this->getSelect()->{$method}(
+                [$defAlias => $attribute->getBackend()->getTable()],
+                $defCondition,
+                []
+            );
+
+            $method = 'joinLeft';
+            $fieldAlias = $this->getConnection()->getCheckSql(
+                "{$tableAlias}.value_id > 0",
+                $fieldAlias,
+                $defFieldAlias
+            );
+            $this->_joinAttributes[$fieldCode]['condition_alias'] = $fieldAlias;
+            $this->_joinAttributes[$fieldCode]['attribute'] = $attribute;
+        } else {
+            $storeId = $this->getDefaultStoreId();
+        }
+        $condition[] = $connection->quoteInto(
+            $connection->quoteColumnAs("{$tableAlias}.store_id", null) . ' = ?',
+            $storeId
+        );
+        return parent::_joinAttributeToSelect($method, $attribute, $tableAlias, $condition, $fieldCode, $fieldAlias);
+    }
+}
diff --git a/Model/ResourceModel/Usage/Grid/Collection.php b/Model/ResourceModel/Usage/Grid/Collection.php
new file mode 100644
index 0000000..e563c5e
--- /dev/null
+++ b/Model/ResourceModel/Usage/Grid/Collection.php
@@ -0,0 +1,178 @@
+<?php
+/**
+ * Collection.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage\Grid;
+
+use Magento\Framework\Api\Search\SearchResultInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\Collection as UsageCollection;
+use Magento\Eav\Model\Config;
+use Magento\Eav\Model\EntityFactory as EavEntityFactory;
+use Magento\Eav\Model\ResourceModel\Helper;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactory;
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Validator\UniversalFactory;
+use Magento\Store\Model\StoreManagerInterface;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Class Collection
+ * @package DevStone\UsageCalculator\Model\ResourceModel\Usage\Grid
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class Collection extends UsageCollection implements SearchResultInterface
+{
+    /**
+     * @var AggregationInterface
+     */
+    protected $aggregations;
+
+    /**
+     * Collection constructor.
+     * @param EntityFactory $entityFactory
+     * @param LoggerInterface $logger
+     * @param FetchStrategyInterface $fetchStrategy
+     * @param ManagerInterface $eventManager
+     * @param Config $eavConfig
+     * @param ResourceConnection $resource
+     * @param EavEntityFactory $eavEntityFactory
+     * @param Helper $resourceHelper
+     * @param UniversalFactory $universalFactory
+     * @param StoreManagerInterface $eventPrefix
+     * @param $eventObject
+     * @param $resourceModel
+     * @param string $model
+     * @param StoreManagerInterface $storeManager
+     * @param AdapterInterface|null $connection
+     *
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        EntityFactory $entityFactory,
+        LoggerInterface $logger,
+        FetchStrategyInterface $fetchStrategy,
+        ManagerInterface $eventManager,
+        Config $eavConfig,
+        ResourceConnection $resource,
+        EavEntityFactory $eavEntityFactory,
+        Helper $resourceHelper,
+        UniversalFactory $universalFactory,
+        StoreManagerInterface $storeManager,
+        $eventPrefix,
+        $eventObject,
+        $resourceModel,
+        $model = 'DevStone\UsageCalculator\Ui\Component\Listing\DataProvider\Document',
+        AdapterInterface $connection = null
+    ) {
+        parent::__construct(
+            $entityFactory,
+            $logger,
+            $fetchStrategy,
+            $eventManager,
+            $eavConfig,
+            $resource,
+            $eavEntityFactory,
+            $resourceHelper,
+            $universalFactory,
+            $storeManager,
+            $connection
+        );
+        $this->_eventPrefix = $eventPrefix;
+        $this->_eventObject = $eventObject;
+        $this->_init($model, $resourceModel);
+    }
+
+    /**
+     * @return AggregationInterface
+     */
+    public function getAggregations()
+    {
+        return $this->aggregations;
+    }
+
+    /**
+     * @param AggregationInterface $aggregations
+     * @return $this
+     */
+    public function setAggregations($aggregations)
+    {
+        $this->aggregations = $aggregations;
+    }
+
+    /**
+     * Retrieve all ids for collection
+     * Backward compatibility with EAV collection
+     *
+     * @param int $limit
+     * @param int $offset
+     * @return array
+     */
+    public function getAllIds($limit = null, $offset = null)
+    {
+        return $this->getConnection()->fetchCol($this->_getAllIdsSelect($limit, $offset), $this->_bindParams);
+    }
+
+    /**
+     * Get search criteria.
+     *
+     * @return SearchCriteriaInterface|null
+     */
+    public function getSearchCriteria()
+    {
+        return null;
+    }
+
+    /**
+     * Set search criteria.
+     *
+     * @param SearchCriteriaInterface $searchCriteria
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setSearchCriteria(SearchCriteriaInterface $searchCriteria = null)
+    {
+        return $this;
+    }
+
+    /**
+     * Get total count.
+     *
+     * @return int
+     */
+    public function getTotalCount()
+    {
+        return $this->getSize();
+    }
+
+    /**
+     * Set total count.
+     *
+     * @param int $totalCount
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setTotalCount($totalCount)
+    {
+        return $this;
+    }
+
+    /**
+     * Set items list.
+     *
+     * @param \Magento\Framework\Api\ExtensibleDataInterface[] $items
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function setItems(array $items = null)
+    {
+        return $this;
+    }
+}
diff --git a/Model/ResourceModel/Usage/Option.php b/Model/ResourceModel/Usage/Option.php
new file mode 100644
index 0000000..d53ec24
--- /dev/null
+++ b/Model/ResourceModel/Usage/Option.php
@@ -0,0 +1,569 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage;
+
+/**
+ * Usage custom option resource model
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class Option extends \Magento\Framework\Model\ResourceModel\Db\AbstractDb
+{
+
+    /**
+     * Store manager
+     *
+     * @var \Magento\Store\Model\StoreManagerInterface
+     */
+    protected $_storeManager;
+
+    /**
+     * Currency factory
+     *
+     * @var \Magento\Directory\Model\CurrencyFactory
+     */
+    protected $_currencyFactory;
+
+    /**
+     * Core config model
+     *
+     * @var \Magento\Framework\App\Config\ScopeConfigInterface
+     */
+    protected $_config;
+
+    /**
+     * Class constructor
+     *
+     * @param \Magento\Framework\Model\ResourceModel\Db\Context $context
+     * @param \Magento\Directory\Model\CurrencyFactory $currencyFactory
+     * @param \Magento\Store\Model\StoreManagerInterface $storeManager
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $config
+     * @param string $connectionName
+     */
+    public function __construct(
+        \Magento\Framework\Model\ResourceModel\Db\Context $context,
+        \Magento\Directory\Model\CurrencyFactory $currencyFactory,
+        \Magento\Store\Model\StoreManagerInterface $storeManager,
+        \Magento\Framework\App\Config\ScopeConfigInterface $config,
+        $connectionName = null
+    ) {
+        $this->_currencyFactory = $currencyFactory;
+        $this->_storeManager = $storeManager;
+        $this->_config = $config;
+        parent::__construct($context, $connectionName);
+    }
+
+    /**
+     * Define main table and initialize connection
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option', 'option_id');
+    }
+
+    /**
+     * Save options store data
+     *
+     * @param \Magento\Framework\Model\AbstractModel $object
+     * @return \Magento\Framework\Model\ResourceModel\Db\AbstractDb
+     */
+    protected function _afterSave(\Magento\Framework\Model\AbstractModel $object)
+    {
+        $this->_saveValuePrices($object);
+        $this->_saveValueTitles($object);
+		$this->_saveValueHelps($object);
+
+        return parent::_afterSave($object);
+    }
+
+    /**
+     * Save value prices
+     *
+     * @param \Magento\Framework\Model\AbstractModel $object
+     * @return $this
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    protected function _saveValuePrices(\Magento\Framework\Model\AbstractModel $object)
+    {
+        $priceTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_price');
+        $connection = $this->getConnection();
+
+        /*
+         * Better to check param 'price' and 'price_type' for saving.
+         * If there is not price skip saving price
+         */
+
+        if (in_array($object->getType(), $this->getPriceTypes())) {
+            //save for store_id = 0
+            if (!$object->getData('scope', 'price')) {
+                $statement = $connection->select()->from(
+                    $priceTable,
+                    'option_id'
+                )->where(
+                    'option_id = ?',
+                    $object->getId()
+                )->where(
+                    'store_id = ?',
+                    \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                );
+                $optionId = $connection->fetchOne($statement);
+
+                if ($optionId) {
+                    $data = $this->_prepareDataForTable(
+                        new \Magento\Framework\DataObject(
+                            ['price' => $object->getPrice(), 'price_type' => $object->getPriceType()]
+                        ),
+                        $priceTable
+                    );
+
+                    $connection->update(
+                        $priceTable,
+                        $data,
+                        [
+                            'option_id = ?' => $object->getId(),
+                            'store_id  = ?' => \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                        ]
+                    );
+                } else {
+                    $data = $this->_prepareDataForTable(
+                        new \Magento\Framework\DataObject(
+                            [
+                                'option_id' => $object->getId(),
+                                'store_id' => \Magento\Store\Model\Store::DEFAULT_STORE_ID,
+                                'price' => $object->getPrice(),
+                                'price_type' => $object->getPriceType(),
+                            ]
+                        ),
+                        $priceTable
+                    );
+                    $connection->insert($priceTable, $data);
+                }
+            }
+
+            $scope = (int)$this->_config->getValue(
+                \Magento\Store\Model\Store::XML_PATH_PRICE_SCOPE,
+                \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+            );
+
+            if ($object->getStoreId() != '0' && $scope == \Magento\Store\Model\Store::PRICE_SCOPE_WEBSITE) {
+                $baseCurrency = $this->_config->getValue(
+                    \Magento\Directory\Model\Currency::XML_PATH_CURRENCY_BASE,
+                    'default'
+                );
+
+                $storeIds = $this->_storeManager->getStore($object->getStoreId())->getWebsite()->getStoreIds();
+                if (is_array($storeIds)) {
+                    foreach ($storeIds as $storeId) {
+                        if ($object->getPriceType() == 'fixed') {
+                            $storeCurrency = $this->_storeManager->getStore($storeId)->getBaseCurrencyCode();
+                            $rate = $this->_currencyFactory->create()->load($baseCurrency)->getRate($storeCurrency);
+                            if (!$rate) {
+                                $rate = 1;
+                            }
+                            $newPrice = $object->getPrice() * $rate;
+                        } else {
+                            $newPrice = $object->getPrice();
+                        }
+
+                        $statement = $connection->select()->from(
+                            $priceTable
+                        )->where(
+                            'option_id = ?',
+                            $object->getId()
+                        )->where(
+                            'store_id  = ?',
+                            $storeId
+                        );
+
+                        if ($connection->fetchOne($statement)) {
+                            $data = $this->_prepareDataForTable(
+                                new \Magento\Framework\DataObject(
+                                    ['price' => $newPrice, 'price_type' => $object->getPriceType()]
+                                ),
+                                $priceTable
+                            );
+
+                            $connection->update(
+                                $priceTable,
+                                $data,
+                                ['option_id = ?' => $object->getId(), 'store_id  = ?' => $storeId]
+                            );
+                        } else {
+                            $data = $this->_prepareDataForTable(
+                                new \Magento\Framework\DataObject(
+                                    [
+                                        'option_id' => $object->getId(),
+                                        'store_id' => $storeId,
+                                        'price' => $newPrice,
+                                        'price_type' => $object->getPriceType(),
+                                    ]
+                                ),
+                                $priceTable
+                            );
+                            $connection->insert($priceTable, $data);
+                        }
+                    }
+                }
+            } elseif ($scope == \Magento\Store\Model\Store::PRICE_SCOPE_WEBSITE && $object->getData('scope', 'price')
+            ) {
+                $connection->delete(
+                    $priceTable,
+                    ['option_id = ?' => $object->getId(), 'store_id  = ?' => $object->getStoreId()]
+                );
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Save titles
+     *
+     * @param \Magento\Framework\Model\AbstractModel $object
+     * @return void
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     */
+    protected function _saveValueTitles(\Magento\Framework\Model\AbstractModel $object)
+    {
+        $connection = $this->getConnection();
+        $titleTableName = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_title');
+        foreach ([\Magento\Store\Model\Store::DEFAULT_STORE_ID, $object->getStoreId()] as $storeId) {
+            $existInCurrentStore = $this->getColFromOptionTable($titleTableName, (int)$object->getId(), (int)$storeId);
+            $existInDefaultStore = (int)$storeId == \Magento\Store\Model\Store::DEFAULT_STORE_ID ?
+                $existInCurrentStore :
+                $this->getColFromOptionTable(
+                    $titleTableName,
+                    (int)$object->getId(),
+                    \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                );
+
+            if ($object->getTitle()) {
+                $isDeleteStoreTitle = (bool)$object->getData('is_delete_store_title');
+                if ($existInCurrentStore) {
+                    if ($isDeleteStoreTitle && (int)$storeId != \Magento\Store\Model\Store::DEFAULT_STORE_ID) {
+                        $connection->delete($titleTableName, ['option_title_id = ?' => $existInCurrentStore]);
+                    } elseif ($object->getStoreId() == $storeId) {
+                        $data = $this->_prepareDataForTable(
+                            new \Magento\Framework\DataObject(['title' => $object->getTitle()]),
+                            $titleTableName
+                        );
+                        $connection->update(
+                            $titleTableName,
+                            $data,
+                            [
+                                'option_id = ?' => $object->getId(),
+                                'store_id  = ?' => $storeId,
+                            ]
+                        );
+                    }
+                } else {
+                    // we should insert record into not default store only of if it does not exist in default store
+                    if (($storeId == \Magento\Store\Model\Store::DEFAULT_STORE_ID && !$existInDefaultStore) ||
+                        (
+                            $storeId != \Magento\Store\Model\Store::DEFAULT_STORE_ID &&
+                            !$existInCurrentStore &&
+                            !$isDeleteStoreTitle
+                        )
+                    ) {
+                        $data = $this->_prepareDataForTable(
+                            new \Magento\Framework\DataObject(
+                                [
+                                    'option_id' => $object->getId(),
+                                    'store_id' => $storeId,
+                                    'title' => $object->getTitle(),
+                                ]
+                            ),
+                            $titleTableName
+                        );
+                        $connection->insert($titleTableName, $data);
+                    }
+                }
+            } else {
+                if ($object->getId() && $object->getStoreId() > \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                    && $storeId
+                ) {
+                    $connection->delete(
+                        $titleTableName,
+                        [
+                            'option_id = ?' => $object->getId(),
+                            'store_id  = ?' => $object->getStoreId(),
+                        ]
+                    );
+                }
+            }
+        }
+    }
+	
+    /**
+     * Save titles
+     *
+     * @param \Magento\Framework\Model\AbstractModel $object
+     * @return void
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     */
+    protected function _saveValueHelps(\Magento\Framework\Model\AbstractModel $object)
+    {
+        $connection = $this->getConnection();
+        $titleTableName = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_help');
+        foreach ([\Magento\Store\Model\Store::DEFAULT_STORE_ID, $object->getStoreId()] as $storeId) {
+            $existInCurrentStore = $this->getColFromOptionTable($titleTableName, (int)$object->getId(), (int)$storeId);
+            $existInDefaultStore = (int)$storeId == \Magento\Store\Model\Store::DEFAULT_STORE_ID ?
+                $existInCurrentStore :
+                $this->getColFromOptionTable(
+                    $titleTableName,
+                    (int)$object->getId(),
+                    \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                );
+
+            if ($object->getTitle()) {
+                $isDeleteStoreTitle = (bool)$object->getData('is_delete_store_help');
+                if ($existInCurrentStore) {
+                    if ($isDeleteStoreTitle && (int)$storeId != \Magento\Store\Model\Store::DEFAULT_STORE_ID) {
+                        $connection->delete($titleTableName, ['option_help_id = ?' => $existInCurrentStore]);
+                    } elseif ($object->getStoreId() == $storeId) {
+                        $data = $this->_prepareDataForTable(
+                            new \Magento\Framework\DataObject(['help' => $object->getHelp()]),
+                            $titleTableName
+                        );
+                        $connection->update(
+                            $titleTableName,
+                            $data,
+                            [
+                                'option_id = ?' => $object->getId(),
+                                'store_id  = ?' => $storeId,
+                            ]
+                        );
+                    }
+                } else {
+                    // we should insert record into not default store only of if it does not exist in default store
+                    if (($storeId == \Magento\Store\Model\Store::DEFAULT_STORE_ID && !$existInDefaultStore) ||
+                        (
+                            $storeId != \Magento\Store\Model\Store::DEFAULT_STORE_ID &&
+                            !$existInCurrentStore &&
+                            !$isDeleteStoreTitle
+                        )
+                    ) {
+                        $data = $this->_prepareDataForTable(
+                            new \Magento\Framework\DataObject(
+                                [
+                                    'option_id' => $object->getId(),
+                                    'store_id' => $storeId,
+                                    'help' => $object->getHelp(),
+                                ]
+                            ),
+                            $titleTableName
+                        );
+                        $connection->insert($titleTableName, $data);
+                    }
+                }
+            } else {
+                if ($object->getId() && $object->getStoreId() > \Magento\Store\Model\Store::DEFAULT_STORE_ID
+                    && $storeId
+                ) {
+                    $connection->delete(
+                        $titleTableName,
+                        [
+                            'option_id = ?' => $object->getId(),
+                            'store_id  = ?' => $object->getStoreId(),
+                        ]
+                    );
+                }
+            }
+        }
+    }
+
+    /**
+     * Get first col from from first row for option table
+     *
+     * @param string $tableName
+     * @param int $optionId
+     * @param int $storeId
+     * @return string
+     */
+    protected function getColFromOptionTable($tableName, $optionId, $storeId)
+    {
+        $connection = $this->getConnection();
+        $statement = $connection->select()->from(
+            $tableName
+        )->where(
+            'option_id = ?',
+            $optionId
+        )->where(
+            'store_id  = ?',
+            $storeId
+        );
+
+        return $connection->fetchOne($statement);
+    }
+
+    /**
+     * Delete prices
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deletePrices($optionId)
+    {
+        $this->getConnection()->delete(
+            $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_price'),
+            ['option_id = ?' => $optionId]
+        );
+
+        return $this;
+    }
+
+    /**
+     * Delete titles
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deleteTitles($optionId)
+    {
+        $this->getConnection()->delete(
+            $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_title'),
+            ['option_id = ?' => $optionId]
+        );
+
+        return $this;
+    }
+	
+	/**
+     * Delete helps
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deleteHelps($optionId)
+    {
+        $this->getConnection()->delete(
+            $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_help'),
+            ['option_id = ?' => $optionId]
+        );
+
+        return $this;
+    }
+
+    /**
+     * Duplicate custom options for product
+     *
+     * @param \Magento\Catalog\Model\Product\Option $object
+     * @param int $oldProductId
+     * @param int $newProductId
+     * @return \Magento\Catalog\Model\Product\Option
+     */
+    public function duplicate(\Magento\Catalog\Model\Product\Option $object, $oldProductId, $newProductId)
+    {
+        $connection = $this->getConnection();
+
+        $optionsCond = [];
+        $optionsData = [];
+
+        // read and prepare original product options
+        $select = $connection->select()->from(
+            $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option')
+        )->where(
+            'product_id = ?',
+            $oldProductId
+        );
+
+        $query = $connection->query($select);
+
+        while ($row = $query->fetch()) {
+            $optionsData[$row['option_id']] = $row;
+            $optionsData[$row['option_id']]['product_id'] = $newProductId;
+            unset($optionsData[$row['option_id']]['option_id']);
+        }
+
+        // insert options to duplicated product
+        foreach ($optionsData as $oId => $data) {
+            $connection->insert($this->getMainTable(), $data);
+            $optionsCond[$oId] = $connection->lastInsertId($this->getMainTable());
+        }
+
+        // copy options prefs
+        foreach ($optionsCond as $oldOptionId => $newOptionId) {
+            // title
+            $table = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_title');
+
+            $select = $this->getConnection()->select()->from(
+                $table,
+                [new \Zend_Db_Expr($newOptionId), 'store_id', 'title']
+            )->where(
+                'option_id = ?',
+                $oldOptionId
+            );
+
+            $insertSelect = $connection->insertFromSelect(
+                $select,
+                $table,
+                ['option_id', 'store_id', 'title'],
+                \Magento\Framework\DB\Adapter\AdapterInterface::INSERT_ON_DUPLICATE
+            );
+            $connection->query($insertSelect);
+			
+			// help
+            $table = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_help');
+
+            $select = $this->getConnection()->select()->from(
+                $table,
+                [new \Zend_Db_Expr($newOptionId), 'store_id', 'help']
+            )->where(
+                'option_id = ?',
+                $oldOptionId
+            );
+
+            $insertSelect = $connection->insertFromSelect(
+                $select,
+                $table,
+                ['option_id', 'store_id', 'help'],
+                \Magento\Framework\DB\Adapter\AdapterInterface::INSERT_ON_DUPLICATE
+            );
+            $connection->query($insertSelect);
+
+            // price
+            $table = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_price');
+
+            $select = $connection->select()->from(
+                $table,
+                [new \Zend_Db_Expr($newOptionId), 'store_id', 'price', 'price_type']
+            )->where(
+                'option_id = ?',
+                $oldOptionId
+            );
+
+            $insertSelect = $connection->insertFromSelect(
+                $select,
+                $table,
+                ['option_id', 'store_id', 'price', 'price_type'],
+                \Magento\Framework\DB\Adapter\AdapterInterface::INSERT_ON_DUPLICATE
+            );
+            $connection->query($insertSelect);
+
+            $object->getValueInstance()->duplicate($oldOptionId, $newOptionId);
+        }
+
+        return $object;
+    }
+
+    /**
+     * All Option Types that support price and price_type
+     *
+     * @return string[]
+     */
+    public function getPriceTypes()
+    {
+        return [
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_FIELD,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_AREA,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_FILE,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DATE,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_TIME,
+        ];
+    }
+
+}
diff --git a/Model/ResourceModel/Usage/Option/Collection.php b/Model/ResourceModel/Usage/Option/Collection.php
new file mode 100644
index 0000000..7385ea3
--- /dev/null
+++ b/Model/ResourceModel/Usage/Option/Collection.php
@@ -0,0 +1,372 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage\Option;
+
+use Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface;
+use Magento\Framework\EntityManager\MetadataPool;
+
+/**
+ * Usage options collection
+ *
+ * @api
+ * @SuppressWarnings(PHPMD.LongVariable)
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ * @since 100.0.2
+ */
+class Collection extends \Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection
+{
+    /**
+     * @var JoinProcessorInterface
+     * @since 101.0.0
+     */
+    protected $joinProcessor;
+
+    /**
+     * @var \Magento\Framework\EntityManager\MetadataPool
+     * @since 101.0.0
+     */
+    protected $metadataPool;
+
+    /**
+     * Store manager
+     *
+     * @var \Magento\Store\Model\StoreManagerInterface
+     */
+    protected $_storeManager;
+
+    /**
+     * Option value factory
+     *
+     * @var \Magento\Catalog\Model\ResourceModel\Product\Option\Value\CollectionFactory
+     */
+    protected $_optionValueCollectionFactory;
+
+    /**
+     * @param \Magento\Framework\Data\Collection\EntityFactory $entityFactory
+     * @param \Psr\Log\LoggerInterface $logger
+     * @param \Magento\Framework\Data\Collection\Db\FetchStrategyInterface $fetchStrategy
+     * @param \Magento\Framework\Event\ManagerInterface $eventManager
+     * @param \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\CollectionFactory $optionValueCollectionFactory
+     * @param \Magento\Store\Model\StoreManagerInterface $storeManager
+     * @param \Magento\Framework\DB\Adapter\AdapterInterface $connection
+     * @param \Magento\Framework\Model\ResourceModel\Db\AbstractDb $resource
+     * @param MetadataPool $metadataPool
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        \Magento\Framework\Data\Collection\EntityFactory $entityFactory,
+        \Psr\Log\LoggerInterface $logger,
+        \Magento\Framework\Data\Collection\Db\FetchStrategyInterface $fetchStrategy,
+        \Magento\Framework\Event\ManagerInterface $eventManager,
+        \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\CollectionFactory $optionValueCollectionFactory,
+        \Magento\Store\Model\StoreManagerInterface $storeManager,
+        \Magento\Framework\DB\Adapter\AdapterInterface $connection = null,
+        \Magento\Framework\Model\ResourceModel\Db\AbstractDb $resource = null,
+        MetadataPool $metadataPool = null
+    ) {
+        $this->_optionValueCollectionFactory = $optionValueCollectionFactory;
+        $this->_storeManager = $storeManager;
+        $this->metadataPool = $metadataPool ?: \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(\Magento\Framework\EntityManager\MetadataPool::class);
+        parent::__construct($entityFactory, $logger, $fetchStrategy, $eventManager, $connection, $resource);
+    }
+
+    /**
+     * Resource initialization
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(
+            \DevStone\UsageCalculator\Model\Usage\Option::class,
+            \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option::class
+        );
+    }
+
+    /**
+     * Adds title, price & price_type attributes to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function getOptions($storeId)
+    {
+        $this->addPriceToResult($storeId)->addTitleToResult($storeId)->addHelpToResult($storeId);
+
+        return $this;
+    }
+
+    /**
+     * Add title to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addTitleToResult($storeId)
+    {
+        $productOptionTitleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_title');
+        $connection = $this->getConnection();
+        $titleExpr = $connection->getCheckSql(
+            'store_option_title.title IS NULL',
+            'default_option_title.title',
+            'store_option_title.title'
+        );
+
+        $this->getSelect()->join(
+            ['default_option_title' => $productOptionTitleTable],
+            'default_option_title.option_id = main_table.option_id',
+            ['default_title' => 'title']
+        )->joinLeft(
+            ['store_option_title' => $productOptionTitleTable],
+            'store_option_title.option_id = main_table.option_id AND ' . $connection->quoteInto(
+                'store_option_title.store_id = ?',
+                $storeId
+            ),
+            ['store_title' => 'title', 'title' => $titleExpr]
+        )->where(
+            'default_option_title.store_id = ?',
+            \Magento\Store\Model\Store::DEFAULT_STORE_ID
+        );
+
+        return $this;
+    }
+	
+	/**
+     * Add help to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addHelpToResult($storeId)
+    {
+        $productOptionTitleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_help');
+        $connection = $this->getConnection();
+        $helpExpr = $connection->getCheckSql(
+            'store_option_help.help IS NULL',
+            'default_option_help.help',
+            'store_option_help.help'
+        );
+
+        $this->getSelect()->join(
+            ['default_option_help' => $productOptionTitleTable],
+            'default_option_help.option_id = main_table.option_id',
+            ['default_help' => 'help']
+        )->joinLeft(
+            ['store_option_help' => $productOptionTitleTable],
+            'store_option_help.option_id = main_table.option_id AND ' . $connection->quoteInto(
+                'store_option_help.store_id = ?',
+                $storeId
+            ),
+            ['store_help' => 'help', 'help' => $helpExpr]
+        )->where(
+            'default_option_help.store_id = ?',
+            \Magento\Store\Model\Store::DEFAULT_STORE_ID
+        );
+
+        return $this;
+    }
+
+    /**
+     * Add price to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addPriceToResult($storeId)
+    {
+        $productOptionPriceTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_price');
+        $connection = $this->getConnection();
+        $priceExpr = $connection->getCheckSql(
+            'store_option_price.price IS NULL',
+            'default_option_price.price',
+            'store_option_price.price'
+        );
+        $priceTypeExpr = $connection->getCheckSql(
+            'store_option_price.price_type IS NULL',
+            'default_option_price.price_type',
+            'store_option_price.price_type'
+        );
+
+        $this->getSelect()->joinLeft(
+            ['default_option_price' => $productOptionPriceTable],
+            'default_option_price.option_id = main_table.option_id AND ' . $connection->quoteInto(
+                'default_option_price.store_id = ?',
+                \Magento\Store\Model\Store::DEFAULT_STORE_ID
+            ),
+            ['default_price' => 'price', 'default_price_type' => 'price_type']
+        )->joinLeft(
+            ['store_option_price' => $productOptionPriceTable],
+            'store_option_price.option_id = main_table.option_id AND ' . $connection->quoteInto(
+                'store_option_price.store_id = ?',
+                $storeId
+            ),
+            [
+                'store_price' => 'price',
+                'store_price_type' => 'price_type',
+                'price' => $priceExpr,
+                'price_type' => $priceTypeExpr
+            ]
+        );
+
+        return $this;
+    }
+
+    /**
+     * Add value to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addValuesToResult($storeId = null)
+    {
+        if ($storeId === null) {
+            $storeId = $this->_storeManager->getStore()->getId();
+        }
+        $optionIds = [];
+        foreach ($this as $option) {
+            $optionIds[] = $option->getId();
+        }
+        if (!empty($optionIds)) {
+            /** @var \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\Collection $values */
+            $values = $this->_optionValueCollectionFactory->create();
+            $values->addTitleToResult(
+                $storeId
+            )->addPriceToResult(
+                $storeId
+            )->addOptionToFilter(
+                $optionIds
+            )->setOrder(
+                'sort_order',
+                self::SORT_ORDER_ASC
+            )->setOrder(
+                'title',
+                self::SORT_ORDER_ASC
+            );
+
+            foreach ($values as $value) {
+                $optionId = $value->getOptionId();
+                if ($this->getItemById($optionId)) {
+                    $this->getItemById($optionId)->addValue($value);
+                    $value->setOption($this->getItemById($optionId));
+                }
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Add usage_id filter to select
+     *
+     * @param array|\DevStone\UsageCalculator\Model\Usage|int $usage
+     * @return $this
+     */
+    public function addProductToFilter($usage)
+    {
+        if (empty($usage)) {
+            $this->addFieldToFilter('usage_id', '');
+        } elseif (is_array($usage)) {
+            $this->addFieldToFilter('usage_id', ['in' => $usage]);
+        } elseif ($usage instanceof \DevStone\UsageCalculator\Model\Usage) {
+            $this->addFieldToFilter('usage_id', $usage->getId());
+        } else {
+            $this->addFieldToFilter('usage_id', $usage);
+        }
+
+        return $this;
+    }
+
+    /**
+     * @return void
+     * @throws \Exception
+     * @since 101.0.0
+     */
+    protected function _initSelect()
+    {
+        parent::_initSelect();
+        $this->getSelect()->join(
+            ['cpe' => $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_entity')],
+            'cpe.entity_id = main_table.usage_id',
+            []
+        );
+    }
+
+    /**
+     * @param int $usageId
+     * @param int $storeId
+     * @param bool $requiredOnly
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[]
+     */
+    public function getUsageOptions($usageId, $storeId, $requiredOnly = false)
+    {
+        $collection = $this->addFieldToFilter(
+            'cpe.entity_id',
+            $usageId
+        )->addTitleToResult(
+            $storeId
+        )->addHelpToResult(
+			$storeId
+		)->addPriceToResult(
+            $storeId
+        )->setOrder(
+            'sort_order',
+            'asc'
+        )->setOrder(
+            'title',
+            'asc'
+        );
+        if ($requiredOnly) {
+            $collection->addRequiredFilter();
+        }
+        $collection->addValuesToResult($storeId);
+        $this->getJoinProcessor()->process($collection);
+        return $collection->getItems();
+    }
+
+    /**
+     * Add is_required filter to select
+     *
+     * @param bool $required
+     * @return $this
+     */
+    public function addRequiredFilter($required = true)
+    {
+        $this->addFieldToFilter('main_table.is_require', (int)$required);
+        return $this;
+    }
+
+    /**
+     * Add filtering by option ids
+     *
+     * @param string|array $optionIds
+     * @return $this
+     */
+    public function addIdsToFilter($optionIds)
+    {
+        $this->addFieldToFilter('main_table.option_id', $optionIds);
+        return $this;
+    }
+
+    /**
+     * Call of protected method reset
+     *
+     * @return $this
+     */
+    public function reset()
+    {
+        return $this->_reset();
+    }
+
+    /**
+     * @return JoinProcessorInterface
+     */
+    private function getJoinProcessor()
+    {
+        if (null === $this->joinProcessor) {
+            $this->joinProcessor = \Magento\Framework\App\ObjectManager::getInstance()
+                ->get(\Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface::class);
+        }
+        return $this->joinProcessor;
+    }
+}
diff --git a/Model/ResourceModel/Usage/Option/Value.php b/Model/ResourceModel/Usage/Option/Value.php
new file mode 100644
index 0000000..5cef80d
--- /dev/null
+++ b/Model/ResourceModel/Usage/Option/Value.php
@@ -0,0 +1,450 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage\Option;
+
+use Magento\Catalog\Model\Product\Option\Value as OptionValue;
+use Magento\Directory\Model\Currency;
+use Magento\Directory\Model\CurrencyFactory;
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\App\ObjectManager;
+use Magento\Framework\Locale\FormatInterface;
+use Magento\Framework\Model\AbstractModel;
+use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
+use Magento\Framework\Model\ResourceModel\Db\Context;
+use Magento\Store\Model\ScopeInterface;
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManagerInterface;
+
+/**
+ * Catalog product custom option resource model
+ *
+ * @author      Magento Core Team <core@magentocommerce.com>
+ */
+class Value extends AbstractDb
+{
+    /**
+     * Store manager
+     *
+     * @var StoreManagerInterface
+     */
+    protected $_storeManager;
+
+    /**
+     * Currency factory
+     *
+     * @var CurrencyFactory
+     */
+    protected $_currencyFactory;
+
+    /**
+     * Core config model
+     *
+     * @var ScopeConfigInterface
+     */
+    protected $_config;
+
+    /**
+     * @var FormatInterface
+     */
+    private $localeFormat;
+
+    /**
+     * Class constructor
+     *
+     * @param Context $context
+     * @param CurrencyFactory $currencyFactory
+     * @param StoreManagerInterface $storeManager
+     * @param ScopeConfigInterface $config
+     * @param string $connectionName
+     */
+    public function __construct(
+        Context $context,
+        CurrencyFactory $currencyFactory,
+        StoreManagerInterface $storeManager,
+        ScopeConfigInterface $config,
+        $connectionName = null
+    ) {
+        $this->_currencyFactory = $currencyFactory;
+        $this->_storeManager = $storeManager;
+        $this->_config = $config;
+        parent::__construct($context, $connectionName);
+    }
+
+    /**
+     * Define main table and initialize connection
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_value', 'option_type_id');
+    }
+
+    /**
+     * Proceed operations after object is saved
+     * Save options store data
+     *
+     * @param AbstractModel $object
+     * @return AbstractDb
+     */
+    protected function _afterSave(AbstractModel $object)
+    {
+        $this->_saveValuePrices($object);
+        $this->_saveValueTitles($object);
+
+        return parent::_afterSave($object);
+    }
+
+    /**
+     * Save option value price data
+     *
+     * @param AbstractModel $object
+     * @return void
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    protected function _saveValuePrices(AbstractModel $object)
+    {
+        $objectPrice = $object->getPrice();
+        $priceTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_price');
+        $formattedPrice = $this->getLocaleFormatter()->getNumber($objectPrice);
+
+        $price = (double)sprintf('%F', $formattedPrice);
+        $priceType = $object->getPriceType();
+
+        if (isset($objectPrice) && $priceType) {
+            //save for store_id = 0
+            $select = $this->getConnection()->select()->from(
+                $priceTable,
+                'option_type_id'
+            )->where(
+                'option_type_id = ?',
+                (int)$object->getId()
+            )->where(
+                'store_id = ?',
+                Store::DEFAULT_STORE_ID
+            );
+            $optionTypeId = $this->getConnection()->fetchOne($select);
+
+            if ($optionTypeId) {
+                if ($object->getStoreId() == '0') {
+                    $bind = ['price' => $price, 'price_type' => $priceType];
+                    $where = [
+                        'option_type_id = ?' => $optionTypeId,
+                        'store_id = ?' => Store::DEFAULT_STORE_ID,
+                    ];
+
+                    $this->getConnection()->update($priceTable, $bind, $where);
+                }
+            } else {
+                $bind = [
+                    'option_type_id' => (int)$object->getId(),
+                    'store_id' => Store::DEFAULT_STORE_ID,
+                    'price' => $price,
+                    'price_type' => $priceType,
+                ];
+                $this->getConnection()->insert($priceTable, $bind);
+            }
+        }
+
+        $scope = (int)$this->_config->getValue(
+            Store::XML_PATH_PRICE_SCOPE,
+            ScopeInterface::SCOPE_STORE
+        );
+
+        if ($scope == Store::PRICE_SCOPE_WEBSITE
+            && $priceType
+            && isset($objectPrice)
+            && $object->getStoreId() != Store::DEFAULT_STORE_ID
+        ) {
+            $baseCurrency = $this->_config->getValue(
+                Currency::XML_PATH_CURRENCY_BASE,
+                'default'
+            );
+
+            $storeIds = $this->_storeManager->getStore($object->getStoreId())->getWebsite()->getStoreIds();
+            if (is_array($storeIds)) {
+                foreach ($storeIds as $storeId) {
+                    if ($priceType == 'fixed') {
+                        $storeCurrency = $this->_storeManager->getStore($storeId)->getBaseCurrencyCode();
+                        /** @var $currencyModel Currency */
+                        $currencyModel = $this->_currencyFactory->create();
+                        $currencyModel->load($baseCurrency);
+                        $rate = $currencyModel->getRate($storeCurrency);
+                        if (!$rate) {
+                            $rate = 1;
+                        }
+                        $newPrice = $price * $rate;
+                    } else {
+                        $newPrice = $price;
+                    }
+
+                    $select = $this->getConnection()->select()->from(
+                        $priceTable,
+                        'option_type_id'
+                    )->where(
+                        'option_type_id = ?',
+                        (int)$object->getId()
+                    )->where(
+                        'store_id = ?',
+                        (int)$storeId
+                    );
+                    $optionTypeId = $this->getConnection()->fetchOne($select);
+
+                    if ($optionTypeId) {
+                        $bind = ['price' => $newPrice, 'price_type' => $priceType];
+                        $where = ['option_type_id = ?' => (int)$optionTypeId, 'store_id = ?' => (int)$storeId];
+
+                        $this->getConnection()->update($priceTable, $bind, $where);
+                    } else {
+                        $bind = [
+                            'option_type_id' => (int)$object->getId(),
+                            'store_id' => (int)$storeId,
+                            'price' => $newPrice,
+                            'price_type' => $priceType,
+                        ];
+
+                        $this->getConnection()->insert($priceTable, $bind);
+                    }
+                }
+            }
+        } else {
+            if ($scope == Store::PRICE_SCOPE_WEBSITE
+                && !isset($objectPrice)
+                && !$priceType
+            ) {
+                $storeIds = $this->_storeManager->getStore($object->getStoreId())->getWebsite()->getStoreIds();
+                foreach ($storeIds as $storeId) {
+                    $where = [
+                        'option_type_id = ?' => (int)$object->getId(),
+                        'store_id = ?' => $storeId,
+                    ];
+                    $this->getConnection()->delete($priceTable, $where);
+                }
+            }
+        }
+    }
+
+    /**
+     * Save option value title data
+     *
+     * @param AbstractModel $object
+     * @return void
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     */
+    protected function _saveValueTitles(AbstractModel $object)
+    {
+        foreach ([Store::DEFAULT_STORE_ID, $object->getStoreId()] as $storeId) {
+            $titleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_title');
+            $select = $this->getConnection()->select()->from(
+                $titleTable,
+                ['option_type_id']
+            )->where(
+                'option_type_id = ?',
+                (int)$object->getId()
+            )->where(
+                'store_id = ?',
+                (int)$storeId
+            );
+            $optionTypeId = $this->getConnection()->fetchOne($select);
+            $existInCurrentStore = $this->getOptionIdFromOptionTable($titleTable, (int)$object->getId(), (int)$storeId);
+
+            if ($storeId != Store::DEFAULT_STORE_ID && $object->getData('is_delete_store_title')) {
+                $object->unsetData('title');
+            }
+
+            if ($object->getTitle()) {
+                if ($existInCurrentStore) {
+                    if ($storeId == $object->getStoreId()) {
+                        $where = [
+                            'option_type_id = ?' => (int)$optionTypeId,
+                            'store_id = ?' => $storeId,
+                        ];
+                        $bind = ['title' => $object->getTitle()];
+                        $this->getConnection()->update($titleTable, $bind, $where);
+                    }
+                } else {
+                    $existInDefaultStore = $this->getOptionIdFromOptionTable(
+                        $titleTable,
+                        (int)$object->getId(),
+                        Store::DEFAULT_STORE_ID
+                    );
+                    // we should insert record into not default store only of if it does not exist in default store
+                    if (($storeId == Store::DEFAULT_STORE_ID && !$existInDefaultStore)
+                        || ($storeId != Store::DEFAULT_STORE_ID && !$existInCurrentStore)
+                    ) {
+                        $bind = [
+                            'option_type_id' => (int)$object->getId(),
+                            'store_id' => $storeId,
+                            'title' => $object->getTitle(),
+                        ];
+                        $this->getConnection()->insert($titleTable, $bind);
+                    }
+                }
+            } else {
+                if ($storeId
+                    && $optionTypeId
+                    && $object->getStoreId() > Store::DEFAULT_STORE_ID
+                ) {
+                    $where = [
+                        'option_type_id = ?' => (int)$optionTypeId,
+                        'store_id = ?' => $storeId,
+                    ];
+                    $this->getConnection()->delete($titleTable, $where);
+                }
+            }
+        }
+    }
+
+    /**
+     * Get first col from from first row for option table
+     *
+     * @param string $tableName
+     * @param int $optionId
+     * @param int $storeId
+     * @return string
+     */
+    protected function getOptionIdFromOptionTable($tableName, $optionId, $storeId)
+    {
+        $connection = $this->getConnection();
+        $select = $connection->select()->from(
+            $tableName,
+            ['option_type_id']
+        )->where(
+            'option_type_id = ?',
+            $optionId
+        )->where(
+            'store_id = ?',
+            (int)$storeId
+        );
+        return $connection->fetchOne($select);
+    }
+
+    /**
+     * Delete values by option id
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deleteValue($optionId)
+    {
+        $statement = $this->getConnection()->select()->from(
+            $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_value')
+        )->where(
+            'option_id = ?',
+            $optionId
+        );
+
+        $rowSet = $this->getConnection()->fetchAll($statement);
+
+        foreach ($rowSet as $optionType) {
+            $this->deleteValues($optionType['option_type_id']);
+        }
+
+        $this->getConnection()->delete($this->getMainTable(), ['option_id = ?' => $optionId]);
+
+        return $this;
+    }
+
+    /**
+     * Delete values by option type
+     *
+     * @param int $optionTypeId
+     * @return void
+     */
+    public function deleteValues($optionTypeId)
+    {
+        $condition = ['option_type_id = ?' => $optionTypeId];
+
+        $this->getConnection()->delete($this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_price'), $condition);
+
+        $this->getConnection()->delete($this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_title'), $condition);
+    }
+
+    /**
+     * Duplicate product options value
+     *
+     * @param OptionValue $object
+     * @param int $oldOptionId
+     * @param int $newOptionId
+     * @return OptionValue
+     */
+    public function duplicate(OptionValue $object, $oldOptionId, $newOptionId)
+    {
+        $connection = $this->getConnection();
+        $select = $connection->select()->from($this->getMainTable())->where('option_id = ?', $oldOptionId);
+        $valueData = $connection->fetchAll($select);
+
+        $valueCond = [];
+
+        foreach ($valueData as $data) {
+            $optionTypeId = $data[$this->getIdFieldName()];
+            unset($data[$this->getIdFieldName()]);
+            $data['option_id'] = $newOptionId;
+
+            $connection->insert($this->getMainTable(), $data);
+            $valueCond[$optionTypeId] = $connection->lastInsertId($this->getMainTable());
+        }
+
+        unset($valueData);
+
+        foreach ($valueCond as $oldTypeId => $newTypeId) {
+            // price
+            $priceTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_price');
+            $columns = [new \Zend_Db_Expr($newTypeId), 'store_id', 'price', 'price_type'];
+
+            $select = $connection->select()->from(
+                $priceTable,
+                []
+            )->where(
+                'option_type_id = ?',
+                $oldTypeId
+            )->columns(
+                $columns
+            );
+            $insertSelect = $connection->insertFromSelect(
+                $select,
+                $priceTable,
+                ['option_type_id', 'store_id', 'price', 'price_type']
+            );
+            $connection->query($insertSelect);
+
+            // title
+            $titleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_title');
+            $columns = [new \Zend_Db_Expr($newTypeId), 'store_id', 'title'];
+
+            $select = $this->getConnection()->select()->from(
+                $titleTable,
+                []
+            )->where(
+                'option_type_id = ?',
+                $oldTypeId
+            )->columns(
+                $columns
+            );
+            $insertSelect = $connection->insertFromSelect(
+                $select,
+                $titleTable,
+                ['option_type_id', 'store_id', 'title']
+            );
+            $connection->query($insertSelect);
+        }
+
+        return $object;
+    }
+
+    /**
+     * Get FormatInterface to convert price from string to number format
+     *
+     * @return FormatInterface
+     * @deprecated 101.0.8
+     */
+    private function getLocaleFormatter()
+    {
+        if ($this->localeFormat === null) {
+            $this->localeFormat = ObjectManager::getInstance()
+                ->get(FormatInterface::class);
+        }
+        return $this->localeFormat;
+    }
+}
diff --git a/Model/ResourceModel/Usage/Option/Value/Collection.php b/Model/ResourceModel/Usage/Option/Value/Collection.php
new file mode 100644
index 0000000..4d07819
--- /dev/null
+++ b/Model/ResourceModel/Usage/Option/Value/Collection.php
@@ -0,0 +1,219 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value;
+
+/**
+ * Usage option values collection
+ *
+ * @api
+ */
+class Collection extends \Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection
+{
+    /**
+     * Resource initialization
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(
+            \DevStone\UsageCalculator\Model\Usage\Option\Value::class,
+            \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value::class
+        );
+    }
+
+    /**
+     * Add price, title to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function getValues($storeId)
+    {
+        $this->addPriceToResult($storeId)->addTitleToResult($storeId);
+
+        return $this;
+    }
+
+    /**
+     * Add titles to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addTitlesToResult($storeId)
+    {
+        $connection = $this->getConnection();
+        $optionTypePriceTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_price');
+        $optionTitleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_title');
+        $priceExpr = $connection->getCheckSql(
+            'store_value_price.price IS NULL',
+            'default_value_price.price',
+            'store_value_price.price'
+        );
+        $priceTypeExpr = $connection->getCheckSql(
+            'store_value_price.price_type IS NULL',
+            'default_value_price.price_type',
+            'store_value_price.price_type'
+        );
+        $titleExpr = $connection->getCheckSql(
+            'store_value_title.title IS NULL',
+            'default_value_title.title',
+            'store_value_title.title'
+        );
+        $joinExprDefaultPrice = 'default_value_price.option_type_id = main_table.option_type_id AND ' .
+            $connection->quoteInto('default_value_price.store_id = ?', \Magento\Store\Model\Store::DEFAULT_STORE_ID);
+
+        $joinExprStorePrice = 'store_value_price.option_type_id = main_table.option_type_id AND ' .
+            $connection->quoteInto('store_value_price.store_id = ?', $storeId);
+
+        $joinExprTitle = 'store_value_title.option_type_id = main_table.option_type_id AND ' . $connection->quoteInto(
+            'store_value_title.store_id = ?',
+            $storeId
+        );
+
+        $this->getSelect()->joinLeft(
+            ['default_value_price' => $optionTypePriceTable],
+            $joinExprDefaultPrice,
+            ['default_price' => 'price', 'default_price_type' => 'price_type']
+        )->joinLeft(
+            ['store_value_price' => $optionTypePriceTable],
+            $joinExprStorePrice,
+            [
+                'store_price' => 'price',
+                'store_price_type' => 'price_type',
+                'price' => $priceExpr,
+                'price_type' => $priceTypeExpr
+            ]
+        )->join(
+            ['default_value_title' => $optionTitleTable],
+            'default_value_title.option_type_id = main_table.option_type_id',
+            ['default_title' => 'title']
+        )->joinLeft(
+            ['store_value_title' => $optionTitleTable],
+            $joinExprTitle,
+            ['store_title' => 'title', 'title' => $titleExpr]
+        )->where(
+            'default_value_title.store_id = ?',
+            \Magento\Store\Model\Store::DEFAULT_STORE_ID
+        );
+
+        return $this;
+    }
+
+    /**
+     * Add title result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addTitleToResult($storeId)
+    {
+        $optionTitleTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_title');
+        $titleExpr = $this->getConnection()->getCheckSql(
+            'store_value_title.title IS NULL',
+            'default_value_title.title',
+            'store_value_title.title'
+        );
+
+        $joinExpr = 'store_value_title.option_type_id = main_table.option_type_id AND ' .
+            $this->getConnection()->quoteInto('store_value_title.store_id = ?', $storeId);
+        $this->getSelect()->join(
+            ['default_value_title' => $optionTitleTable],
+            'default_value_title.option_type_id = main_table.option_type_id',
+            ['default_title' => 'title']
+        )->joinLeft(
+            ['store_value_title' => $optionTitleTable],
+            $joinExpr,
+            ['store_title' => 'title', 'title' => $titleExpr]
+        )->where(
+            'default_value_title.store_id = ?',
+            \Magento\Store\Model\Store::DEFAULT_STORE_ID
+        );
+
+        return $this;
+    }
+
+    /**
+     * Add price to result
+     *
+     * @param int $storeId
+     * @return $this
+     */
+    public function addPriceToResult($storeId)
+    {
+        $optionTypeTable = $this->getTable(\DevStone\UsageCalculator\Setup\UsageSetup::ENTITY_TYPE_CODE.'_option_type_price');
+        $priceExpr = $this->getConnection()->getCheckSql(
+            'store_value_price.price IS NULL',
+            'default_value_price.price',
+            'store_value_price.price'
+        );
+        $priceTypeExpr = $this->getConnection()->getCheckSql(
+            'store_value_price.price_type IS NULL',
+            'default_value_price.price_type',
+            'store_value_price.price_type'
+        );
+
+        $joinExprDefault = 'default_value_price.option_type_id = main_table.option_type_id AND ' .
+            $this->getConnection()->quoteInto(
+                'default_value_price.store_id = ?',
+                \Magento\Store\Model\Store::DEFAULT_STORE_ID
+            );
+        $joinExprStore = 'store_value_price.option_type_id = main_table.option_type_id AND ' .
+            $this->getConnection()->quoteInto('store_value_price.store_id = ?', $storeId);
+        $this->getSelect()->joinLeft(
+            ['default_value_price' => $optionTypeTable],
+            $joinExprDefault,
+            ['default_price' => 'price', 'default_price_type' => 'price_type']
+        )->joinLeft(
+            ['store_value_price' => $optionTypeTable],
+            $joinExprStore,
+            [
+                'store_price' => 'price',
+                'store_price_type' => 'price_type',
+                'price' => $priceExpr,
+                'price_type' => $priceTypeExpr
+            ]
+        );
+
+        return $this;
+    }
+
+    /**
+     * Add option filter
+     *
+     * @param array $optionIds
+     * @param int $storeId
+     * @return $this
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function getValuesByOption($optionIds, $storeId = null)
+    {
+        if (!is_array($optionIds)) {
+            $optionIds = [$optionIds];
+        }
+
+        return $this->addFieldToFilter('main_table.option_type_id', ['in' => $optionIds]);
+    }
+
+    /**
+     * Add option to filter
+     *
+     * @param array|\DevStone\UsageCalculator\Model\Usage\Option|int $option
+     * @return $this
+     */
+    public function addOptionToFilter($option)
+    {
+        if (empty($option)) {
+            $this->addFieldToFilter('option_id', '');
+        } elseif (is_array($option)) {
+            $this->addFieldToFilter('option_id', ['in' => $option]);
+        } elseif ($option instanceof \DevStone\UsageCalculator\Model\Usage\Option) {
+            $this->addFieldToFilter('option_id', $option->getId());
+        } else {
+            $this->addFieldToFilter('option_id', $option);
+        }
+
+        return $this;
+    }
+}
diff --git a/Model/Size.php b/Model/Size.php
new file mode 100644
index 0000000..ead0826
--- /dev/null
+++ b/Model/Size.php
@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * Size.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\DataObject\IdentityInterface;
+use Magento\Framework\Model\AbstractModel;
+
+class Size extends AbstractModel implements IdentityInterface
+{
+    /**
+     * CMS page cache tag
+     */
+    const CACHE_TAG = 'devstone_usagecalculator_size';
+
+    /**
+     * @var string
+     */
+    protected $_cacheTag = 'devstone_usagecalculator_size';
+
+    /**
+     * Prefix of model events names
+     *
+     * @var string
+     */
+    protected $_eventPrefix = 'devstone_usagecalculator_size';
+    
+    protected $_idFieldName = 'entity_id';
+
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        parent::_construct();
+        $this->_init('DevStone\UsageCalculator\Model\ResourceModel\Size');
+    }
+
+    /**
+     * Get identities
+     *
+     * @return array
+     */
+    public function getIdentities()
+    {
+        return [self::CACHE_TAG . '_' . $this->getId()];
+    }
+
+    /**
+     * Save from collection data
+     *
+     * @param array $data
+     * @return $this|bool
+     */
+    public function saveCollection(array $data)
+    {
+        if (isset($data[$this->getId()])) {
+            $this->addData($data[$this->getId()]);
+            $this->getResource()->save($this);
+        }
+        return $this;
+    }
+}
diff --git a/Model/SizeRepository.php b/Model/SizeRepository.php
new file mode 100644
index 0000000..a367c96
--- /dev/null
+++ b/Model/SizeRepository.php
@@ -0,0 +1,165 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\Exception\CouldNotDeleteException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\Exception\CouldNotSaveException;
+use DevStone\UsageCalculator\Api\Data\SizeSearchResultsInterfaceFactory;
+use Magento\Framework\Reflection\DataObjectProcessor;
+use DevStone\UsageCalculator\Model\ResourceModel\Size as ResourceSize;
+use DevStone\UsageCalculator\Model\ResourceModel\Size\CollectionFactory as SizeCollectionFactory;
+use Magento\Framework\Api\SortOrder;
+use DevStone\UsageCalculator\Api\SizeRepositoryInterface;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Framework\Api\DataObjectHelper;
+use DevStone\UsageCalculator\Api\Data\SizeInterfaceFactory;
+
+class SizeRepository implements SizeRepositoryInterface
+{
+
+    protected $dataSizeFactory;
+
+    protected $dataObjectProcessor;
+
+    protected $sizeFactory;
+
+    protected $dataObjectHelper;
+
+    protected $sizeCollectionFactory;
+
+    protected $searchResultsFactory;
+
+    protected $resource;
+
+    private $storeManager;
+
+
+    /**
+     * @param ResourceSize $resource
+     * @param SizeFactory $sizeFactory
+     * @param SizeInterfaceFactory $dataSizeFactory
+     * @param SizeCollectionFactory $sizeCollectionFactory
+     * @param SizeSearchResultsInterfaceFactory $searchResultsFactory
+     * @param DataObjectHelper $dataObjectHelper
+     * @param DataObjectProcessor $dataObjectProcessor
+     * @param StoreManagerInterface $storeManager
+     */
+    public function __construct(
+        ResourceSize $resource,
+        SizeFactory $sizeFactory,
+        SizeInterfaceFactory $dataSizeFactory,
+        SizeCollectionFactory $sizeCollectionFactory,
+        SizeSearchResultsInterfaceFactory $searchResultsFactory,
+        DataObjectHelper $dataObjectHelper,
+        DataObjectProcessor $dataObjectProcessor,
+        StoreManagerInterface $storeManager
+    ) {
+        $this->resource = $resource;
+        $this->sizeFactory = $sizeFactory;
+        $this->sizeCollectionFactory = $sizeCollectionFactory;
+        $this->searchResultsFactory = $searchResultsFactory;
+        $this->dataObjectHelper = $dataObjectHelper;
+        $this->dataSizeFactory = $dataSizeFactory;
+        $this->dataObjectProcessor = $dataObjectProcessor;
+        $this->storeManager = $storeManager;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function save(
+        \DevStone\UsageCalculator\Api\Data\SizeInterface $size
+    ) {
+        /* if (empty($size->getStoreId())) {
+            $storeId = $this->storeManager->getStore()->getId();
+            $size->setStoreId($storeId);
+        } */
+        try {
+            $size->getResource()->save($size);
+        } catch (\Exception $exception) {
+            throw new CouldNotSaveException(__(
+                'Could not save the size: %1',
+                $exception->getMessage()
+            ));
+        }
+        return $size;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getById($sizeId)
+    {
+        $size = $this->sizeFactory->create();
+        $size->getResource()->load($size, $sizeId);
+        if (!$size->getId()) {
+            throw new NoSuchEntityException(__('Size with id "%1" does not exist.', $sizeId));
+        }
+        return $size;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $criteria
+    ) {
+        $collection = $this->sizeCollectionFactory->create();
+        foreach ($criteria->getFilterGroups() as $filterGroup) {
+            foreach ($filterGroup->getFilters() as $filter) {
+                if ($filter->getField() === 'store_id') {
+                    $collection->addStoreFilter($filter->getValue(), false);
+                    continue;
+                }
+                $condition = $filter->getConditionType() ?: 'eq';
+                $collection->addFieldToFilter($filter->getField(), [$condition => $filter->getValue()]);
+            }
+        }
+        
+        $sortOrders = $criteria->getSortOrders();
+        if ($sortOrders) {
+            /** @var SortOrder $sortOrder */
+            foreach ($sortOrders as $sortOrder) {
+                $collection->addOrder(
+                    $sortOrder->getField(),
+                    ($sortOrder->getDirection() == SortOrder::SORT_ASC) ? 'ASC' : 'DESC'
+                );
+            }
+        }
+        $collection->setCurPage($criteria->getCurrentPage());
+        $collection->setPageSize($criteria->getPageSize());
+        
+        $searchResults = $this->searchResultsFactory->create();
+        $searchResults->setSearchCriteria($criteria);
+        $searchResults->setTotalCount($collection->getSize());
+        $searchResults->setItems($collection->getItems());
+        return $searchResults;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete(
+        \DevStone\UsageCalculator\Api\Data\SizeInterface $size
+    ) {
+        try {
+            $size->getResource()->delete($size);
+        } catch (\Exception $exception) {
+            throw new CouldNotDeleteException(__(
+                'Could not delete the Size: %1',
+                $exception->getMessage()
+            ));
+        }
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function deleteById($sizeId)
+    {
+        return $this->delete($this->getById($sizeId));
+    }
+}
diff --git a/Model/Usage.php b/Model/Usage.php
new file mode 100644
index 0000000..c12c983
--- /dev/null
+++ b/Model/Usage.php
@@ -0,0 +1,108 @@
+<?php
+
+/**
+ * Usage.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\DataObject\IdentityInterface;
+use Magento\Framework\Model\AbstractModel;
+
+class Usage extends AbstractModel implements IdentityInterface, \DevStone\UsageCalculator\Api\Data\UsageInterface
+{
+    /**
+     * CMS page cache tag
+     */
+    const CACHE_TAG = 'devstone_usagecalculator_usage';
+
+    /**
+     * @var string
+     */
+    protected $_cacheTag = 'devstone_usagecalculator_usage';
+
+    /**
+     * Prefix of model events names
+     *
+     * @var string
+     */
+    protected $_eventPrefix = 'devstone_usagecalculator_usage';
+
+    /**
+     * Initialize resource model
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        parent::_construct();
+        $this->_init('DevStone\UsageCalculator\Model\ResourceModel\Usage');
+    }
+
+    /**
+     * Get identities
+     *
+     * @return array
+     */
+    public function getIdentities()
+    {
+        return [self::CACHE_TAG . '_' . $this->getId()];
+    }
+
+    /**
+     * Save from collection data
+     *
+     * @param array $data
+     * @return $this|bool
+     */
+    public function saveCollection(array $data)
+    {
+        if (isset($data[$this->getId()])) {
+            $this->addData($data[$this->getId()]);
+            $this->getResource()->save($this);
+        }
+        return $this;
+    }
+    
+    /**
+     * Get all options of usage
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[]|null
+     */
+    public function getOptions()
+    {
+        return $this->getData('options');
+    }
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface[] $options
+     * @return $this
+     */
+    public function setOptions(array $options = null)
+    {
+        $this->setData('options', $options);
+        return $this;
+    }
+    
+    public function afterSave() 
+    {
+        parent::afterSave();
+        
+        $saveHandler = \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(\DevStone\UsageCalculator\Model\Usage\Option\SaveHandler::class);
+        
+        $saveHandler->execute($this);
+    }
+    
+    public function afterLoad() {
+        parent::afterLoad();
+        
+        $readHandler = \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(\DevStone\UsageCalculator\Model\Usage\Option\ReadHandler::class);
+        
+        $readHandler->execute($this);
+    }
+}
diff --git a/Model/Usage/CatagoriesOptionsProvider.php b/Model/Usage/CatagoriesOptionsProvider.php
new file mode 100644
index 0000000..939e163
--- /dev/null
+++ b/Model/Usage/CatagoriesOptionsProvider.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage;
+
+class CatagoriesOptionsProvider implements \Magento\Framework\Data\OptionSourceInterface
+{
+    /**
+     * @var \DevStone\UsageCalculator\Api\CategoryRepositoryInterface
+     */
+    private $categoryRepository;
+
+    /**
+     * @var \Magento\Framework\Api\SearchCriteriaBuilder
+     */
+    private $searchCriteriaBuilder;
+
+    /**
+     * @var \Magento\Framework\Convert\DataObject
+     */
+    private $objectConverter;
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\CategoryRepositoryInterface $categoryRepository
+     * @param \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder
+     * @param \Magento\Framework\Convert\DataObject $objectConverter
+     */
+    public function __construct(
+        \DevStone\UsageCalculator\Api\CategoryRepositoryInterface $categoryRepository,
+        \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder,
+        \Magento\Framework\Convert\DataObject $objectConverter
+    ) {
+        $this->categoryRepository = $categoryRepository;
+        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
+        $this->objectConverter = $objectConverter;
+    }
+
+    /**
+     * @return array
+     */
+    public function toOptionArray()
+    {
+        $catagories = $this->categoryRepository->getList(
+            $this->searchCriteriaBuilder->create()
+        )->getItems();
+        
+        return $this->objectConverter->toOptionArray($catagories, 'entity_id', 'name');
+    }
+}
diff --git a/Model/Usage/Option.php b/Model/Usage/Option.php
new file mode 100644
index 0000000..f00a7f3
--- /dev/null
+++ b/Model/Usage/Option.php
@@ -0,0 +1,797 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage;
+
+use DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface;
+use DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface;
+use DevStone\UsageCalculator\Model\Usage;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\Collection;
+use Magento\Catalog\Pricing\Price\BasePrice;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\Model\AbstractExtensibleModel;
+
+/**
+ * usage option model
+ *
+ * @api
+ * @method int getUsageId()
+ * @method \DevStone\UsageCalculator\Model\Usage\Option setUsageId(int $value)
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ * @SuppressWarnings(PHPMD.ExcessivePublicCount)
+ */
+class Option extends AbstractExtensibleModel implements UsageCustomOptionInterface
+{
+    /**
+     * @var Option\Repository
+     */
+    protected $optionRepository;
+
+    /**
+     * Option type percent
+     */
+    protected static $typePercent = 'percent';
+
+    /**#@+
+     * Constants
+     */
+    const KEY_PRODUCT_SKU = 'usage_id';
+    const KEY_OPTION_ID = 'option_id';
+    const KEY_TITLE = 'title';
+    const KEY_TYPE = 'type';
+    const KEY_SORT_ORDER = 'sort_order';
+    const KEY_IS_REQUIRE = 'is_require';
+    const KEY_PRICE = 'price';
+    const KEY_PRICE_TYPE = 'price_type';
+    const KEY_HELP = 'help';
+
+    /**#@-*/
+
+    /**#@-*/
+    protected $usage;
+
+    /**
+     * @var array
+     */
+    protected $options = [];
+
+    /**
+     * @var array
+     */
+    protected $values = null;
+
+    /**
+     * Catalog product option value
+     *
+     * @var Option\Value
+     */
+    protected $productOptionValue;
+
+    /**
+     * Product option factory
+     *
+     * @var \Magento\Catalog\Model\Product\Option\Type\Factory
+     */
+    protected $optionTypeFactory;
+
+    /**
+     * @var \Magento\Framework\Stdlib\StringUtils
+     */
+    protected $string;
+
+    /**
+     * @var Option\Validator\Pool
+     */
+    protected $validatorPool;
+
+    /**
+     * @param \Magento\Framework\Model\Context $context
+     * @param \Magento\Framework\Registry $registry
+     * @param \Magento\Framework\Api\ExtensionAttributesFactory $extensionFactory
+     * @param \Magento\Framework\Api\AttributeValueFactory $customAttributeFactory
+     * @param Option\Value $productOptionValue
+     * @param Option\Type\Factory $optionFactory
+     * @param \Magento\Framework\Stdlib\StringUtils $string
+     * @param Option\Validator\Pool $validatorPool
+     * @param \Magento\Framework\Model\ResourceModel\AbstractResource $resource
+     * @param \Magento\Framework\Data\Collection\AbstractDb $resourceCollection
+     * @param array $data
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        \Magento\Framework\Model\Context $context,
+        \Magento\Framework\Registry $registry,
+        \Magento\Framework\Api\ExtensionAttributesFactory $extensionFactory,
+        \Magento\Framework\Api\AttributeValueFactory $customAttributeFactory,
+        Option\Value $productOptionValue,
+        \DevStone\UsageCalculator\Model\Usage\Option\Type\Factory $optionFactory,
+        \Magento\Framework\Stdlib\StringUtils $string,
+        Option\Validator\Pool $validatorPool,
+        \Magento\Framework\Model\ResourceModel\AbstractResource $resource = null,
+        \Magento\Framework\Data\Collection\AbstractDb $resourceCollection = null,
+        array $data = []
+    ) {
+        $this->productOptionValue = $productOptionValue;
+        $this->optionTypeFactory = $optionFactory;
+        $this->validatorPool = $validatorPool;
+        $this->string = $string;
+        parent::__construct(
+            $context,
+            $registry,
+            $extensionFactory,
+            $customAttributeFactory,
+            $resource,
+            $resourceCollection,
+            $data
+        );
+    }
+
+    /**
+     * Get resource instance
+     *
+     * @return \Magento\Framework\Model\ResourceModel\Db\AbstractDb
+     * @deprecated 101.1.0 because resource models should be used directly
+     */
+    protected function _getResource()
+    {
+        return $this->_resource ?: parent::_getResource();
+    }
+
+    /**
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Model\ResourceModel\Usage\Option::class);
+        parent::_construct();
+    }
+
+    /**
+     * Add value of option to values array
+     *
+     * @param Option\Value $value
+     * @return $this
+     */
+    public function addValue(Option\Value $value)
+    {
+        $this->values[$value->getId()] = $value;
+        return $this;
+    }
+
+    /**
+     * Get value by given id
+     *
+     * @param int $valueId
+     * @return Option\Value|null
+     */
+    public function getValueById($valueId)
+    {
+        if (isset($this->values[$valueId])) {
+            return $this->values[$valueId];
+        }
+
+        return null;
+    }
+
+    /**
+     * Whether or not the option type contains sub-values
+     *
+     * @param string $type
+     * @return bool
+     * @since 101.1.0
+     */
+    public function hasValues($type = null)
+    {
+        return $this->getGroupByType($type) == self::OPTION_GROUP_SELECT;
+    }
+
+    /**
+     * @return ProductCustomOptionValuesInterface[]|null
+     */
+    public function getValues()
+    {
+        return $this->values;
+    }
+
+    /**
+     * Retrieve value instance
+     *
+     * @return Option\Value
+     */
+    public function getValueInstance()
+    {
+        return $this->productOptionValue;
+    }
+
+    /**
+     * Add option for save it
+     *
+     * @param array $option
+     * @return $this
+     */
+    public function addOption($option)
+    {
+        $this->options[] = $option;
+        return $this;
+    }
+
+    /**
+     * Get all options
+     *
+     * @return array
+     */
+    public function getOptions()
+    {
+        return $this->options;
+    }
+
+    /**
+     * Set options for array
+     *
+     * @param array $options
+     * @return $this
+     */
+    public function setOptions($options)
+    {
+        $this->options = $options;
+        return $this;
+    }
+
+    /**
+     * Set options to empty array
+     *
+     * @return $this
+     */
+    public function unsetOptions()
+    {
+        $this->options = [];
+        return $this;
+    }
+
+    /**
+     * Retrieve usage instance
+     *
+     * @return Usage
+     */
+    public function getUsage()
+    {
+        return $this->usage;
+    }
+
+    /**
+     * Set usage instance
+     *
+     * @param Usage $product
+     * @return $this
+     */
+    public function setUsage(Usage $usage = null)
+    {
+        $this->usage = $usage;
+        return $this;
+    }
+
+    /**
+     * Get group name of option by given option type
+     *
+     * @param string $type
+     * @return string
+     */
+    public function getGroupByType($type = null)
+    {
+        if ($type === null) {
+            $type = $this->getType();
+        }
+        $optionGroupsToTypes = [
+            self::OPTION_TYPE_FIELD => self::OPTION_GROUP_TEXT,
+            self::OPTION_TYPE_AREA => self::OPTION_GROUP_TEXT,
+            self::OPTION_TYPE_FILE => self::OPTION_GROUP_FILE,
+            self::OPTION_TYPE_DROP_DOWN => self::OPTION_GROUP_SELECT,
+            self::OPTION_TYPE_RADIO => self::OPTION_GROUP_SELECT,
+            self::OPTION_TYPE_CHECKBOX => self::OPTION_GROUP_SELECT,
+            self::OPTION_TYPE_MULTIPLE => self::OPTION_GROUP_SELECT,
+            self::OPTION_TYPE_DATE => self::OPTION_GROUP_DATE,
+            self::OPTION_TYPE_DATE_TIME => self::OPTION_GROUP_DATE,
+            self::OPTION_TYPE_TIME => self::OPTION_GROUP_DATE,
+        ];
+
+        return isset($optionGroupsToTypes[$type]) ? $optionGroupsToTypes[$type] : '';
+    }
+
+    /**
+     * Group model factory
+     *
+     * @param string $type Option type
+     * @return \Magento\Catalog\Model\Product\Option\Type\DefaultType
+     * @throws LocalizedException
+     */
+    public function groupFactory($type)
+    {
+        $group = $this->getGroupByType($type);
+        if (!empty($group)) {
+            return $this->optionTypeFactory->create(
+                'DevStone\UsageCalculator\Model\Usage\Option\Type\\' . $this->string->upperCaseWords($group)
+            );
+        }
+        throw new LocalizedException(__('The option type to get group instance is incorrect.'));
+    }
+
+    /**
+     * {@inheritdoc}
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @since 101.0.0
+     */
+    public function beforeSave()
+    {
+        parent::beforeSave();
+        if ($this->getData('previous_type') != '') {
+            $previousType = $this->getData('previous_type');
+
+            /**
+             * if previous option has different group from one is came now
+             * need to remove all data of previous group
+             */
+            if ($this->getGroupByType($previousType) != $this->getGroupByType($this->getData('type'))) {
+                switch ($this->getGroupByType($previousType)) {
+                    case self::OPTION_GROUP_SELECT:
+                        $this->unsetData('values');
+                        if ($this->getId()) {
+                            $this->getValueInstance()->deleteValue($this->getId());
+                        }
+                        break;
+                    case self::OPTION_GROUP_TEXT:
+                        break;
+                }
+                if ($this->getGroupByType($this->getData('type')) == self::OPTION_GROUP_SELECT) {
+                    $this->unsetData('price');
+                    $this->unsetData('price_type');
+                    if ($this->getId()) {
+                        $this->deletePrices($this->getId());
+                    }
+                }
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * @return \Magento\Framework\Model\AbstractModel
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function afterSave()
+    {
+        $this->getValueInstance()->unsetValues();
+        $values = $this->getValues() ?: $this->getData('values');
+        if (is_array($values)) {
+            foreach ($values as $value) {
+                if ($value instanceof \Magento\Catalog\Api\Data\ProductCustomOptionValuesInterface) {
+                    $data = $value->getData();
+                } else {
+                    $data = $value;
+                }
+                $this->getValueInstance()->addValue($data);
+            }
+
+            $this->getValueInstance()->setOption($this)->saveValues();
+        } elseif ($this->getGroupByType($this->getType()) == self::OPTION_GROUP_SELECT) {
+            throw new LocalizedException(__('Select type options required values rows.'));
+        }
+
+        return parent::afterSave();
+    }
+
+    /**
+     * Return price. If $flag is true and price is percent
+     *  return converted percent to price
+     *
+     * @param bool $flag
+     * @return float
+     */
+    public function getPrice($flag = false)
+    {
+        if ($flag && $this->getPriceType() == self::$typePercent) {
+            $basePrice = $this->getUsage()->getPrice();
+            $price = $basePrice * ($this->_getData(self::KEY_PRICE) / 100);
+            return $price;
+        }
+        return $this->_getData(self::KEY_PRICE);
+    }
+
+    /**
+     * Delete prices of option
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deletePrices($optionId)
+    {
+        $this->getResource()->deletePrices($optionId);
+        return $this;
+    }
+
+    /**
+     * Delete titles of option
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function deleteTitles($optionId)
+    {
+        $this->getResource()->deleteTitles($optionId);
+        return $this;
+    }
+
+    /**
+     * Get Usage Option Collection
+     *
+     * @param Usage $product
+     * @return \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Collection
+     */
+    public function getUsageOptions(Usage $product)
+    {
+        return $this->getOptionRepository()->getUsageOptions($product, $this->getAddRequiredFilter());
+    }
+
+    /**
+     * Get collection of values for current option
+     *
+     * @return Collection
+     */
+    public function getValuesCollection()
+    {
+        $collection = $this->getValueInstance()->getValuesCollection($this);
+
+        return $collection;
+    }
+
+    /**
+     * Get collection of values by given option ids
+     *
+     * @param array $optionIds
+     * @param int $storeId
+     * @return Collection
+     */
+    public function getOptionValuesByOptionId($optionIds, $storeId)
+    {
+        $collection = $this->productOptionValue->getValuesByOption($optionIds, $this->getId(), $storeId);
+
+        return $collection;
+    }
+
+    /**
+     * Duplicate options for product
+     *
+     * @param int $oldProductId
+     * @param int $newProductId
+     * @return $this
+     */
+    public function duplicate($oldProductId, $newProductId)
+    {
+        $this->getResource()->duplicate($this, $oldProductId, $newProductId);
+
+        return $this;
+    }
+
+    /**
+     * Retrieve option searchable data
+     *
+     * @param int $productId
+     * @param int $storeId
+     * @return array
+     */
+    public function getSearchableData($productId, $storeId)
+    {
+        return $this->_getResource()->getSearchableData($productId, $storeId);
+    }
+
+    /**
+     * Clearing object's data
+     *
+     * @return $this
+     */
+    protected function _clearData()
+    {
+        $this->_data = [];
+        $this->values = null;
+        return $this;
+    }
+
+    /**
+     * Clearing cyclic references
+     *
+     * @return $this
+     */
+    protected function _clearReferences()
+    {
+        if (!empty($this->values)) {
+            foreach ($this->values as $value) {
+                $value->unsetOption();
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function _getValidationRulesBeforeSave()
+    {
+        return $this->validatorPool->get($this->getType());
+    }
+
+    /**
+     * Get product SKU
+     *
+     * @return string
+     */
+    public function getProductSku()
+    {
+        $productSku = $this->_getData(self::KEY_PRODUCT_SKU);
+
+        return $productSku;
+    }
+
+    /**
+     * Get option id
+     *
+     * @return int|null
+     * @codeCoverageIgnoreStart
+     */
+    public function getOptionId()
+    {
+        return $this->_getData(self::KEY_OPTION_ID);
+    }
+
+    /**
+     * Get option title
+     *
+     * @return string
+     */
+    public function getTitle()
+    {
+        return $this->_getData(self::KEY_TITLE);
+    }
+	
+	/**
+     * Get help text
+     *
+     * @return string
+     */
+    public function getHelp()
+    {
+        return $this->_getData(self::KEY_HELP);
+    }
+
+    /**
+     * Get option type
+     *
+     * @return string
+     */
+    public function getType()
+    {
+        return $this->_getData(self::KEY_TYPE);
+    }
+
+    /**
+     * Get sort order
+     *
+     * @return int
+     */
+    public function getSortOrder()
+    {
+        return $this->_getData(self::KEY_SORT_ORDER);
+    }
+
+    /**
+     * Get is require
+     *
+     * @return bool
+     * @SuppressWarnings(PHPMD.BooleanGetMethodName)
+     */
+    public function getIsRequire()
+    {
+        return $this->_getData(self::KEY_IS_REQUIRE);
+    }
+
+    /**
+     * Get price type
+     *
+     * @return string|null
+     */
+    public function getPriceType()
+    {
+        return $this->_getData(self::KEY_PRICE_TYPE);
+    }
+
+    /**
+     * Set product SKU
+     *
+     * @param string $productSku
+     * @return $this
+     */
+    public function setProductSku($productSku)
+    {
+        return $this->setData(self::KEY_PRODUCT_SKU, $productSku);
+    }
+
+    /**
+     * Set option id
+     *
+     * @param int $optionId
+     * @return $this
+     */
+    public function setOptionId($optionId)
+    {
+        return $this->setData(self::KEY_OPTION_ID, $optionId);
+    }
+
+    /**
+     * Set option title
+     *
+     * @param string $title
+     * @return $this
+     */
+    public function setTitle($title)
+    {
+        return $this->setData(self::KEY_TITLE, $title);
+    }
+	
+	/**
+     * Set help text
+     *
+     * @param string $help
+     * @return $this
+     */
+    public function setHelp($help)
+    {
+        return $this->setData(self::KEY_HELP, $help);
+    }
+
+    /**
+     * Set option type
+     *
+     * @param string $type
+     * @return $this
+     */
+    public function setType($type)
+    {
+        return $this->setData(self::KEY_TYPE, $type);
+    }
+
+    /**
+     * Set sort order
+     *
+     * @param int $sortOrder
+     * @return $this
+     */
+    public function setSortOrder($sortOrder)
+    {
+        return $this->setData(self::KEY_SORT_ORDER, $sortOrder);
+    }
+
+    /**
+     * Set is require
+     *
+     * @param bool $isRequired
+     * @return $this
+     */
+    public function setIsRequire($isRequired)
+    {
+        return $this->setData(self::KEY_IS_REQUIRE, $isRequired);
+    }
+
+    /**
+     * Set price
+     *
+     * @param float $price
+     * @return $this
+     */
+    public function setPrice($price)
+    {
+        return $this->setData(self::KEY_PRICE, $price);
+    }
+
+    /**
+     * Set price type
+     *
+     * @param string $priceType
+     * @return $this
+     */
+    public function setPriceType($priceType)
+    {
+        return $this->setData(self::KEY_PRICE_TYPE, $priceType);
+    }
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface[] $values
+     * @return $this
+     */
+    public function setValues(array $values = null)
+    {
+        $this->values = $values;
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface|null
+     */
+    public function getExtensionAttributes()
+    {
+        return $this->_getExtensionAttributes();
+    }
+
+    /**
+     * Return regular price.
+     *
+     * @return float|int
+     * @since 101.0.0
+     */
+    public function getRegularPrice()
+    {
+        if ($this->getPriceType() == self::$typePercent) {
+            $basePrice = $this->getUsage()->getPrice();
+            $price = $basePrice * ($this->_getData(self::KEY_PRICE) / 100);
+            return $price;
+        }
+        return $this->_getData(self::KEY_PRICE);
+    }
+
+    /**
+     * @param Usage $usage
+     * @return \Magento\Framework\Model\ResourceModel\Db\Collection\AbstractCollection
+     */
+    public function getUsageOptionCollection(Usage $usage)
+    {
+        $collection = clone $this->getCollection();
+        $collection->addFieldToFilter(
+            'usage_id',
+            'entity_id'
+        )->addTitleToResult(
+            $usage->getStoreId()
+        )->addPriceToResult(
+            $usage->getStoreId()
+        )->addHelpToResult(
+            $usage->getStoreId()
+        )->setOrder(
+            'sort_order',
+            'asc'
+        )->setOrder(
+            'title',
+            'asc'
+        );
+
+        if ($this->getAddRequiredFilter()) {
+            $collection->addRequiredFilter($this->getAddRequiredFilterValue());
+        }
+
+        $collection->addValuesToResult($usage->getStoreId());
+        return $collection;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+            \DevStone\UsageCalculator\Api\Data\UsageCustomOptionExtensionInterface $extensionAttributes
+    ) {
+        return $this->_setExtensionAttributes($extensionAttributes);
+    }
+
+    /**
+     * @return Option\Repository
+     */
+    private function getOptionRepository()
+    {
+        if (null === $this->optionRepository) {
+            $this->optionRepository = \Magento\Framework\App\ObjectManager::getInstance()
+                ->get(\DevStone\UsageCalculator\Model\Usage\Option\Repository::class);
+        }
+        return $this->optionRepository;
+    }
+
+    //@codeCoverageIgnoreEnd
+}
diff --git a/Model/Usage/Option/Converter.php b/Model/Usage/Option/Converter.php
new file mode 100644
index 0000000..ff1060b
--- /dev/null
+++ b/Model/Usage/Option/Converter.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ *
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+class Converter
+{
+    /**
+     * Convert option data to array
+     * @param \Magento\Catalog\Api\Data\ProductCustomOptionInterface $option
+     * @return array
+     */
+    public function toArray(\Magento\Catalog\Api\Data\ProductCustomOptionInterface $option)
+    {
+        $optionData = $option->getData();
+        $values = $option->getValues();
+        $valuesData = [];
+        if (!empty($values)) {
+            foreach ($values as $key => $value) {
+                $valuesData[$key] = $value->getData();
+            }
+        }
+        $optionData['values'] = $valuesData;
+        return $optionData;
+    }
+}
diff --git a/Model/Usage/Option/ReadHandler.php b/Model/Usage/Option/ReadHandler.php
new file mode 100644
index 0000000..524fd56
--- /dev/null
+++ b/Model/Usage/Option/ReadHandler.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+use DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface;
+use Magento\Framework\EntityManager\Operation\ExtensionInterface;
+
+/**
+ * Class ReadHandler
+ */
+class ReadHandler implements ExtensionInterface
+{
+    /**
+     * @var UsageCustomOptionRepositoryInterface
+     */
+    protected $optionRepository;
+
+    /**
+     * @param UsageCustomOptionRepositoryInterface $optionRepository
+     */
+    public function __construct(
+        UsageCustomOptionRepositoryInterface $optionRepository
+    ) {
+        $this->optionRepository = $optionRepository;
+    }
+
+    /**
+     * @param object $entity
+     * @param array $arguments
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface|object
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function execute($entity, $arguments = [])
+    {
+        $options = [];
+        /** @var $entity \DevStone\UsageCalculator\Api\Data\UsageInterface */
+        foreach ($this->optionRepository->getUsageOptions($entity) as $option) {
+            $option->setUsage($entity);
+            $options[] = $option;
+        }
+        $entity->setOptions($options);
+        return $entity;
+    }
+}
diff --git a/Model/Usage/Option/Repository.php b/Model/Usage/Option/Repository.php
new file mode 100644
index 0000000..77f832f
--- /dev/null
+++ b/Model/Usage/Option/Repository.php
@@ -0,0 +1,248 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+use DevStone\UsageCalculator\Api\Data\UsageInterface;
+use DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface;
+
+use Magento\Framework\Exception\CouldNotSaveException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\EntityManager\MetadataPool;
+use Magento\Framework\EntityManager\HydratorPool;
+use Magento\Framework\App\ObjectManager;
+
+/**
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class Repository implements \DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface
+{
+    /**
+     * @var \DevStone\UsageCalculator\Model\ResourceModel\Product\Usage\CollectionFactory
+     */
+    protected $collectionFactory;
+
+    /**
+     * @var \DevStone\UsageCalculator\Model\Usage\OptionFactory
+     */
+    protected $optionFactory;
+
+    /**
+     * @var \DevStone\UsageCalculator\Api\UsageRepositoryInterface
+     */
+    protected $usageRepository;
+
+    /**
+     * @var \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option
+     */
+    protected $optionResource;
+
+    /**
+     * @var MetadataPool
+     */
+    protected $metadataPool;
+
+    /**
+     * @var HydratorPool
+     */
+    protected $hydratorPool;
+
+    /**
+     * @var Converter
+     */
+    protected $converter;
+
+    /**
+     * Constructor
+     *
+     * @param \DevStone\UsageCalculator\Api\UsageRepositoryInterface $usageRepository
+     * @param \Magento\Catalog\Model\ResourceModel\Product\Option $optionResource
+     * @param Converter $converter
+     * @param \Magento\Catalog\Model\ResourceModel\Product\Option\CollectionFactory|null $collectionFactory
+     * @param \Magento\Catalog\Model\Product\OptionFactory|null $optionFactory
+     * @param \Magento\Framework\EntityManager\MetadataPool|null $metadataPool
+     */
+    public function __construct(
+        \DevStone\UsageCalculator\Api\UsageRepositoryInterface $usageRepository,
+        \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option $optionResource,
+        \DevStone\UsageCalculator\Model\Usage\Option\Converter $converter,
+        \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\CollectionFactory $collectionFactory = null,
+        \DevStone\UsageCalculator\Model\Usage\OptionFactory $optionFactory = null,
+        \Magento\Framework\EntityManager\MetadataPool $metadataPool = null
+    ) {
+        $this->usageRepository = $usageRepository;
+        $this->optionResource = $optionResource;
+        $this->converter = $converter;
+        $this->collectionFactory = $collectionFactory ?: ObjectManager::getInstance()
+            ->get(\DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\CollectionFactory::class);
+        $this->optionFactory = $optionFactory ?: ObjectManager::getInstance()
+            ->get(\DevStone\UsageCalculator\Model\Usage\OptionFactory::class);
+        $this->metadataPool = $metadataPool ?: ObjectManager::getInstance()
+            ->get(\Magento\Framework\EntityManager\MetadataPool::class);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getList($id)
+    {
+        $usage = $this->usageRepository->getById($id);
+        return $usage->getOptions() ?: [];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getUsageOptions(UsageInterface $usage, $requiredOnly = false)
+    {
+        return $this->collectionFactory->create()->getUsageOptions(
+            $usage->getEntityId(),
+            $usage->getStoreId(),
+            $requiredOnly
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function get($sku, $optionId)
+    {
+        $product = $this->usageRepository->getById($sku);
+        $option = $product->getOptionById($optionId);
+        if ($option === null) {
+            throw NoSuchEntityException::singleField('optionId', $optionId);
+        }
+        return $option;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete(UsageCustomOptionInterface $entity)
+    {
+        $this->optionResource->delete($entity);
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function duplicate(
+        UsageInterface $product,
+        UsageInterface $duplicate
+    ) {
+        $hydrator = $this->getHydratorPool()->getHydrator(UsageInterface::class);
+        $metadata = $this->metadataPool->getMetadata(UsageInterface::class);
+        return $this->optionResource->duplicate(
+            $this->optionFactory->create([]),
+            $hydrator->extract($product)[$metadata->getLinkField()],
+            $hydrator->extract($duplicate)[$metadata->getLinkField()]
+        );
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function save(UsageCustomOptionInterface $option)
+    {
+        $usageId = $option->getUsageId();
+        if (!$usageId) {
+            throw new CouldNotSaveException(__('usage_id should be specified'));
+        }
+        /** @var \DevStone\UsageCalculator\Model\Usage $usage */
+        $usage = $this->usageRepository->getById($usageId);
+        $option->setData('usage_id', $usageId);
+        $option->setData('store_id', $usage->getStoreId());
+
+        if ($option->getOptionId()) {
+            $options = $usage->getOptions();
+            if (!$options) {
+                $options = $this->getUsageOptions($usage);
+            }
+
+            $persistedOption = array_filter($options, function ($iOption) use ($option) {
+                return $option->getOptionId() == $iOption->getOptionId();
+            });
+            $persistedOption = reset($persistedOption);
+
+            if (!$persistedOption) {
+                throw new NoSuchEntityException();
+            }
+            $originalValues = $persistedOption->getValues();
+            $newValues = $option->getData('values');
+            if ($newValues) {
+                if (isset($originalValues)) {
+                    $newValues = $this->markRemovedValues($newValues, $originalValues);
+                }
+                $option->setData('values', $newValues);
+            }
+        }
+        $option->save();
+        return $option;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function deleteByIdentifier($sku, $optionId)
+    {
+        $product = $this->usageRepository->getById($sku);
+        $options = $product->getOptions();
+        $option = $product->getOptionById($optionId);
+        if ($option === null) {
+            throw NoSuchEntityException::singleField('optionId', $optionId);
+        }
+        unset($options[$optionId]);
+        try {
+            $this->delete($option);
+            if (empty($options)) {
+                $this->usageRepository->save($product);
+            }
+        } catch (\Exception $e) {
+            throw new CouldNotSaveException(__('Could not remove custom option'));
+        }
+        return true;
+    }
+
+    /**
+     * Mark original values for removal if they are absent among new values
+     *
+     * @param $newValues array
+     * @param $originalValues \Magento\Catalog\Model\Product\Option\Value[]
+     * @return array
+     */
+    protected function markRemovedValues($newValues, $originalValues)
+    {
+        $existingValuesIds = [];
+
+        foreach ($newValues as $newValue) {
+            if (array_key_exists('option_type_id', $newValue)) {
+                $existingValuesIds[] = $newValue['option_type_id'];
+            }
+        }
+        /** @var $originalValue \Magento\Catalog\Model\Product\Option\Value */
+        foreach ($originalValues as $originalValue) {
+            if (!in_array($originalValue->getData('option_type_id'), $existingValuesIds)) {
+                $originalValue->setData('is_delete', 1);
+                $newValues[] = $originalValue->getData();
+            }
+        }
+
+        return $newValues;
+    }
+
+    /**
+     * @return \Magento\Framework\EntityManager\HydratorPool
+     * @deprecated 101.0.0
+     */
+    private function getHydratorPool()
+    {
+        if (null === $this->hydratorPool) {
+            $this->hydratorPool = \Magento\Framework\App\ObjectManager::getInstance()
+                ->get(\Magento\Framework\EntityManager\HydratorPool::class);
+        }
+        return $this->hydratorPool;
+    }
+}
diff --git a/Model/Usage/Option/SaveHandler.php b/Model/Usage/Option/SaveHandler.php
new file mode 100644
index 0000000..c6a6002
--- /dev/null
+++ b/Model/Usage/Option/SaveHandler.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+use DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface as OptionRepository;
+use Magento\Framework\EntityManager\Operation\ExtensionInterface;
+
+/**
+ * Class SaveHandler
+ */
+class SaveHandler implements ExtensionInterface
+{
+    /**
+     * @var OptionRepository
+     */
+    protected $optionRepository;
+
+    /**
+     * @param OptionRepository $optionRepository
+     */
+    public function __construct(
+        OptionRepository $optionRepository
+    ) {
+        $this->optionRepository = $optionRepository;
+    }
+
+    /**
+     * @param object $entity
+     * @param array $arguments
+     * @return \DevStone\UsageCalculator\Api\Data\UsageInterface|object
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function execute($entity, $arguments = [])
+    {
+        $options = $entity->getOptions();
+
+        $optionIds = [];
+
+        if ($options) {
+            $optionIds = array_map(function ($option) {
+                /** @var \DevStone\UsageCalculatorModel\Usage\Option $option */
+                return $option->getOptionId();
+            }, $options);
+        }
+
+        /** @var \DevStone\UsageCalculator\Api\Data\UsageInterface $entity */
+        foreach ($this->optionRepository->getUsageOptions($entity) as $option) {
+            if (!in_array($option->getOptionId(), $optionIds)) {
+                $this->optionRepository->delete($option);
+            }
+        }
+        if ($options) {
+            foreach ($options as $option) {
+                $option->setUsageId($entity->getId());
+                $this->optionRepository->save($option);
+            }
+        }
+
+        return $entity;
+    }
+}
diff --git a/Model/Usage/Option/Type.php b/Model/Usage/Option/Type.php
new file mode 100644
index 0000000..e9843c7
--- /dev/null
+++ b/Model/Usage/Option/Type.php
@@ -0,0 +1,103 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+/**
+ * @codeCoverageIgnore
+ */
+class Type extends \Magento\Framework\Model\AbstractExtensibleModel implements
+        \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeInterface
+{
+    /**#@+
+     * Constants
+     */
+    const KEY_LABEL = 'label';
+    const KEY_CODE = 'code';
+    const KEY_GROUP = 'group';
+    /**#@-*/
+
+    /**
+     * Get option type label
+     *
+     * @return string
+     */
+    public function getLabel()
+    {
+        return $this->getData(self::KEY_LABEL);
+    }
+
+    /**
+     * Get option type code
+     *
+     * @return string
+     */
+    public function getCode()
+    {
+        return $this->getData(self::KEY_CODE);
+    }
+
+    /**
+     * Get option type group
+     *
+     * @return string
+     */
+    public function getGroup()
+    {
+        return $this->getData(self::KEY_GROUP);
+    }
+
+    /**
+     * Set option type label
+     *
+     * @param string $label
+     * @return $this
+     */
+    public function setLabel($label)
+    {
+        return $this->setData(self::KEY_LABEL, $label);
+    }
+
+    /**
+     * Set option type code
+     *
+     * @param string $code
+     * @return $this
+     */
+    public function setCode($code)
+    {
+        return $this->setData(self::KEY_CODE, $code);
+    }
+
+    /**
+     * Set option type group
+     *
+     * @param string $group
+     * @return $this
+     */
+    public function setGroup($group)
+    {
+        return $this->setData(self::KEY_GROUP, $group);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface|null
+     */
+    public function getExtensionAttributes()
+    {
+        return $this->_getExtensionAttributes();
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface $extensionAttributes
+     * @return $this
+     */
+    public function setExtensionAttributes(
+        \DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeExtensionInterface $extensionAttributes
+    ) {
+        return $this->_setExtensionAttributes($extensionAttributes);
+    }
+}
diff --git a/Model/Usage/Option/Type/Date.php b/Model/Usage/Option/Type/Date.php
new file mode 100644
index 0000000..acd85b6
--- /dev/null
+++ b/Model/Usage/Option/Type/Date.php
@@ -0,0 +1,397 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+use Magento\Catalog\Api\Data\ProductCustomOptionInterface;
+
+/**
+ * Catalog product option date type
+ *
+ * @author     Magento Core Team <core@magentocommerce.com>
+ */
+class Date extends \Magento\Catalog\Model\Product\Option\Type\DefaultType
+{
+    /**
+     * @var string
+     */
+    protected $_formattedOptionValue = null;
+
+    /**
+     * @var \Magento\Framework\Stdlib\DateTime\TimezoneInterface
+     */
+    protected $_localeDate;
+
+    /**
+     * Serializer interface instance.
+     *
+     * @var \Magento\Framework\Serialize\Serializer\Json
+     */
+    private $serializer;
+
+    /**
+     * @param \Magento\Checkout\Model\Session $checkoutSession
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Stdlib\DateTime\TimezoneInterface $localeDate
+     * @param array $data
+     * @param \Magento\Framework\Serialize\Serializer\Json|null $serializer
+     */
+    public function __construct(
+        \Magento\Checkout\Model\Session $checkoutSession,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Stdlib\DateTime\TimezoneInterface $localeDate,
+        array $data = [],
+        \Magento\Framework\Serialize\Serializer\Json $serializer = null
+    ) {
+        $this->_localeDate = $localeDate;
+        $this->serializer = $serializer ?: \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(\Magento\Framework\Serialize\Serializer\Json::class);
+        parent::__construct($checkoutSession, $scopeConfig, $data);
+    }
+
+    /**
+     * Validate user input for option
+     *
+     * @param array $values All product option values, i.e. array (option_id => mixed, option_id => mixed...)
+     * @return $this
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     */
+    public function validateUserValue($values)
+    {
+        parent::validateUserValue($values);
+
+        $option = $this->getOption();
+        $value = $this->getUserValue();
+
+        $dateValid = true;
+        if ($this->_dateExists()) {
+            if ($this->useCalendar()) {
+                $dateValid = isset($value['date']) && preg_match('/^\d{1,4}.+\d{1,4}.+\d{1,4}$/', $value['date']);
+            } else {
+                $dateValid = isset(
+                    $value['day']
+                ) && isset(
+                    $value['month']
+                ) && isset(
+                    $value['year']
+                ) && $value['day'] > 0 && $value['month'] > 0 && $value['year'] > 0;
+            }
+        }
+
+        $timeValid = true;
+        if ($this->_timeExists()) {
+            $timeValid = isset(
+                $value['hour']
+            ) && isset(
+                $value['minute']
+            ) && is_numeric(
+                $value['hour']
+            ) && is_numeric(
+                $value['minute']
+            );
+        }
+
+        $isValid = $dateValid && $timeValid;
+
+        if ($isValid) {
+            $this->setUserValue(
+                [
+                    'date' => isset($value['date']) ? $value['date'] : '',
+                    'year' => isset($value['year']) ? intval($value['year']) : 0,
+                    'month' => isset($value['month']) ? intval($value['month']) : 0,
+                    'day' => isset($value['day']) ? intval($value['day']) : 0,
+                    'hour' => isset($value['hour']) ? intval($value['hour']) : 0,
+                    'minute' => isset($value['minute']) ? intval($value['minute']) : 0,
+                    'day_part' => isset($value['day_part']) ? $value['day_part'] : '',
+                    'date_internal' => isset($value['date_internal']) ? $value['date_internal'] : '',
+                ]
+            );
+        } elseif (!$isValid && $option->getIsRequire() && !$this->getSkipCheckRequiredOption()) {
+            $this->setIsValid(false);
+            if (!$dateValid) {
+                throw new \Magento\Framework\Exception\LocalizedException(
+                    __('Please specify date required option(s).')
+                );
+            } elseif (!$timeValid) {
+                throw new \Magento\Framework\Exception\LocalizedException(
+                    __('Please specify time required option(s).')
+                );
+            } else {
+                throw new \Magento\Framework\Exception\LocalizedException(
+                    __('Please specify product\'s required option(s).')
+                );
+            }
+        } else {
+            $this->setUserValue(null);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Prepare option value for cart
+     *
+     * @return string|null Prepared option value
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.UnusedLocalVariable)
+     */
+    public function prepareForCart()
+    {
+        if ($this->getIsValid() && $this->getUserValue() !== null) {
+            $option = $this->getOption();
+            $value = $this->getUserValue();
+
+            if (isset($value['date_internal']) && $value['date_internal'] != '') {
+                $this->_setInternalInRequest($value['date_internal']);
+                return $value['date_internal'];
+            }
+
+            $timestamp = 0;
+
+            if ($this->_dateExists()) {
+                if ($this->useCalendar()) {
+                    $timestamp += $this->_localeDate->date($value['date'], null, true, false)->getTimestamp();
+                } else {
+                    $timestamp += mktime(0, 0, 0, $value['month'], $value['day'], $value['year']);
+                }
+            } else {
+                $timestamp += mktime(0, 0, 0, date('m'), date('d'), date('Y'));
+            }
+
+            if ($this->_timeExists()) {
+                // 24hr hour conversion
+                if (!$this->is24hTimeFormat()) {
+                    $pmDayPart = 'pm' == strtolower($value['day_part']);
+                    if (12 == $value['hour']) {
+                        $value['hour'] = $pmDayPart ? 12 : 0;
+                    } elseif ($pmDayPart) {
+                        $value['hour'] += 12;
+                    }
+                }
+
+                $timestamp += 60 * 60 * $value['hour'] + 60 * $value['minute'];
+            }
+
+            $date = (new \DateTime())->setTimestamp($timestamp);
+            $result = $date->format('Y-m-d H:i:s');
+
+            // Save date in internal format to avoid locale date bugs
+            $this->_setInternalInRequest($result);
+
+            return $result;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Return formatted option value for quote option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     * @SuppressWarnings(PHPMD.UnusedLocalVariable)
+     */
+    public function getFormattedOptionValue($optionValue)
+    {
+        if ($this->_formattedOptionValue === null) {
+            if ($this->getOption()->getType() == ProductCustomOptionInterface::OPTION_TYPE_DATE) {
+                $result = $this->_localeDate->formatDateTime(
+                    new \DateTime($optionValue),
+                    \IntlDateFormatter::MEDIUM,
+                    \IntlDateFormatter::NONE,
+                    null,
+                    'UTC'
+                );
+            } elseif ($this->getOption()->getType() == ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME) {
+                $result = $this->_localeDate->formatDateTime(
+                    new \DateTime($optionValue),
+                    \IntlDateFormatter::SHORT,
+                    \IntlDateFormatter::SHORT,
+                    null,
+                    'UTC'
+                );
+            } elseif ($this->getOption()->getType() == ProductCustomOptionInterface::OPTION_TYPE_TIME) {
+                $result = $this->_localeDate->formatDateTime(
+                    new \DateTime($optionValue),
+                    \IntlDateFormatter::NONE,
+                    \IntlDateFormatter::SHORT,
+                    null,
+                    'UTC'
+                );
+            } else {
+                $result = $optionValue;
+            }
+            $this->_formattedOptionValue = $result;
+        }
+        return $this->_formattedOptionValue;
+    }
+
+    /**
+     * Return printable option value
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getPrintableOptionValue($optionValue)
+    {
+        return $this->getFormattedOptionValue($optionValue);
+    }
+
+    /**
+     * Return formatted option value ready to edit, ready to parse
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getEditableOptionValue($optionValue)
+    {
+        return $this->getFormattedOptionValue($optionValue);
+    }
+
+    /**
+     * Parse user input value and return cart prepared value
+     *
+     * @param string $optionValue
+     * @param array $productOptionValues Values for product option
+     * @return string|null
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function parseOptionValue($optionValue, $productOptionValues)
+    {
+        try {
+            $date = new \DateTime($optionValue);
+        } catch (\Exception $e) {
+            return null;
+        }
+        return $date->format('Y-m-d H:i:s');
+    }
+
+    /**
+     * Prepare option value for info buy request
+     *
+     * @param string $optionValue
+     * @return array
+     */
+    public function prepareOptionValueForRequest($optionValue)
+    {
+        $confItem = $this->getConfigurationItem();
+        $infoBuyRequest = $confItem->getOptionByCode('info_buyRequest');
+        try {
+            $value = $this->serializer->unserialize($infoBuyRequest->getValue());
+            if (is_array($value) && isset($value['options']) && isset($value['options'][$this->getOption()->getId()])
+            ) {
+                return $value['options'][$this->getOption()->getId()];
+            } else {
+                return ['date_internal' => $optionValue];
+            }
+        } catch (\Exception $e) {
+            return ['date_internal' => $optionValue];
+        }
+    }
+
+    /**
+     * Use Calendar on frontend or not
+     *
+     * @return boolean
+     */
+    public function useCalendar()
+    {
+        return (bool)$this->getConfigData('use_calendar');
+    }
+
+    /**
+     * Time Format
+     *
+     * @return boolean
+     */
+    public function is24hTimeFormat()
+    {
+        return (bool)($this->getConfigData('time_format') == '24h');
+    }
+
+    /**
+     * Year range start
+     *
+     * @return string|false
+     */
+    public function getYearStart()
+    {
+        $_range = explode(',', $this->getConfigData('year_range'));
+        if (isset($_range[0]) && !empty($_range[0])) {
+            return $_range[0];
+        } else {
+            return date('Y');
+        }
+    }
+
+    /**
+     * Year range end
+     *
+     * @return string|false
+     */
+    public function getYearEnd()
+    {
+        $_range = explode(',', $this->getConfigData('year_range'));
+        if (isset($_range[1]) && !empty($_range[1])) {
+            return $_range[1];
+        } else {
+            return date('Y');
+        }
+    }
+
+    /**
+     * Save internal value of option in infoBuy_request
+     *
+     * @param string $internalValue Datetime value in internal format
+     * @return void
+     */
+    protected function _setInternalInRequest($internalValue)
+    {
+        $requestOptions = $this->getRequest()->getOptions();
+        if (!isset($requestOptions[$this->getOption()->getId()])) {
+            $requestOptions[$this->getOption()->getId()] = [];
+        }
+        if (!is_array($requestOptions[$this->getOption()->getId()])) {
+            $requestOptions[$this->getOption()->getId()] = [];
+        }
+        $requestOptions[$this->getOption()->getId()]['date_internal'] = $internalValue;
+        $this->getRequest()->setOptions($requestOptions);
+    }
+
+    /**
+     * Does option have date?
+     *
+     * @return boolean
+     */
+    protected function _dateExists()
+    {
+        return in_array(
+            $this->getOption()->getType(),
+            [
+                ProductCustomOptionInterface::OPTION_TYPE_DATE,
+                ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME
+            ]
+        );
+    }
+
+    /**
+     * Does option have time?
+     *
+     * @return boolean
+     */
+    protected function _timeExists()
+    {
+        return in_array(
+            $this->getOption()->getType(),
+            [
+                ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME,
+                ProductCustomOptionInterface::OPTION_TYPE_TIME
+            ]
+        );
+    }
+}
diff --git a/Model/Usage/Option/Type/DefaultType.php b/Model/Usage/Option/Type/DefaultType.php
new file mode 100644
index 0000000..cef5cf6
--- /dev/null
+++ b/Model/Usage/Option/Type/DefaultType.php
@@ -0,0 +1,410 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Catalog\Api\Data\ProductCustomOptionInterface;
+
+/**
+ * Catalog product option default type
+ *
+ * @api
+ * @author     Magento Core Team <core@magentocommerce.com>
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ * @since 100.0.2
+ */
+class DefaultType extends \Magento\Framework\DataObject
+{
+    /**
+     * Option Instance
+     *
+     * @var \Magento\Catalog\Model\Product\Option
+     */
+    protected $_option;
+
+    /**
+     * Product Instance
+     *
+     * @var \Magento\Catalog\Model\Product
+     */
+    protected $_product;
+
+    /**
+     * TODO: Fill in description
+     *
+     * @var array
+     */
+    protected $_productOptions = [];
+
+    /**
+     * Core store config
+     *
+     * @var \Magento\Framework\App\Config\ScopeConfigInterface
+     */
+    protected $_scopeConfig;
+
+    /**
+     * Checkout session
+     *
+     * @var \Magento\Checkout\Model\Session
+     */
+    protected $_checkoutSession;
+
+    /**
+     * Construct
+     *
+     * @param \Magento\Checkout\Model\Session $checkoutSession
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Checkout\Model\Session $checkoutSession,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        array $data = []
+    ) {
+        $this->_checkoutSession = $checkoutSession;
+        parent::__construct($data);
+        $this->_scopeConfig = $scopeConfig;
+    }
+
+    /**
+     * Option Instance setter
+     *
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @return $this
+     */
+    public function setOption($option)
+    {
+        $this->_option = $option;
+        return $this;
+    }
+
+    /**
+     * Option Instance getter
+     *
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @return \Magento\Catalog\Model\Product\Option
+     */
+    public function getOption()
+    {
+        if ($this->_option instanceof \Magento\Catalog\Model\Product\Option) {
+            return $this->_option;
+        }
+        throw new LocalizedException(__('The option instance type in options group is incorrect.'));
+    }
+
+    /**
+     * Product Instance setter
+     *
+     * @param \Magento\Catalog\Model\Product $product
+     * @return $this
+     */
+    public function setProduct($product)
+    {
+        $this->_product = $product;
+        return $this;
+    }
+
+    /**
+     * Product Instance getter
+     *
+     * @throws \Magento\Framework\Exception\LocalizedException
+     * @return \Magento\Catalog\Model\Product
+     */
+    public function getProduct()
+    {
+        if ($this->_product instanceof \Magento\Catalog\Model\Product) {
+            return $this->_product;
+        }
+        throw new LocalizedException(__('The product instance type in options group is incorrect.'));
+    }
+
+    /**
+     * Getter for Configuration Item Option
+     *
+     * @return \Magento\Catalog\Model\Product\Configuration\Item\Option\OptionInterface
+     * @throws LocalizedException
+     */
+    public function getConfigurationItemOption()
+    {
+        if ($this->_getData(
+            'configuration_item_option'
+        ) instanceof \Magento\Catalog\Model\Product\Configuration\Item\Option\OptionInterface
+        ) {
+            return $this->_getData('configuration_item_option');
+        }
+
+        // Back compatibility with quote specific keys to set configuration item options
+        if ($this->_getData('quote_item_option') instanceof \Magento\Quote\Model\Quote\Item\Option) {
+            return $this->_getData('quote_item_option');
+        }
+
+        throw new LocalizedException(__('The configuration item option instance in options group is incorrect.'));
+    }
+
+    /**
+     * Getter for Configuration Item
+     *
+     * @return \Magento\Catalog\Model\Product\Configuration\Item\ItemInterface
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getConfigurationItem()
+    {
+        if ($this->_getData(
+            'configuration_item'
+        ) instanceof \Magento\Catalog\Model\Product\Configuration\Item\ItemInterface
+        ) {
+            return $this->_getData('configuration_item');
+        }
+
+        // Back compatibility with quote specific keys to set configuration item
+        if ($this->_getData('quote_item') instanceof \Magento\Quote\Model\Quote\Item) {
+            return $this->_getData('quote_item');
+        }
+
+        throw new LocalizedException(__('The configuration item instance in options group is incorrect.'));
+    }
+
+    /**
+     * Getter for Buy Request
+     *
+     * @return \Magento\Framework\DataObject
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function getRequest()
+    {
+        if ($this->_getData('request') instanceof \Magento\Framework\DataObject) {
+            return $this->_getData('request');
+        }
+        throw new LocalizedException(__('The BuyRequest instance in options group is incorrect.'));
+    }
+
+    /**
+     * Store Config value
+     *
+     * @param string $key Config value key
+     * @return string
+     */
+    public function getConfigData($key)
+    {
+        return $this->_scopeConfig->getValue('catalog/custom_options/' . $key, \Magento\Store\Model\ScopeInterface::SCOPE_STORE);
+    }
+
+    /**
+     * Validate user input for option
+     *
+     * @param array $values All product option values, i.e. array (option_id => mixed, option_id => mixed...)
+     * @return $this
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function validateUserValue($values)
+    {
+        $this->_checkoutSession->setUseNotice(false);
+
+        $this->setIsValid(false);
+
+        $option = $this->getOption();
+        if (!isset($values[$option->getId()]) && $option->getIsRequire() && !$this->getSkipCheckRequiredOption()) {
+            throw new LocalizedException(__('Please specify product\'s required option(s).'));
+        } elseif (isset($values[$option->getId()])) {
+            $this->setUserValue($values[$option->getId()]);
+            $this->setIsValid(true);
+        }
+        return $this;
+    }
+
+    /**
+     * Check skip required option validation
+     *
+     * @return bool
+     * @SuppressWarnings(PHPMD.BooleanGetMethodName)
+     */
+    public function getSkipCheckRequiredOption()
+    {
+        return $this->getProduct()->getSkipCheckRequiredOption() ||
+            $this->getProcessMode() == \Magento\Catalog\Model\Product\Type\AbstractType::PROCESS_MODE_LITE;
+    }
+
+    /**
+     * Prepare option value for cart
+     *
+     * @return string|null Prepared option value
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function prepareForCart()
+    {
+        if ($this->getIsValid()) {
+            return $this->getUserValue();
+        }
+        throw new LocalizedException(
+            __('We can\'t add the product to the cart because of an option validation issue.')
+        );
+    }
+
+    /**
+     * Flag to indicate that custom option has own customized output (blocks, native html etc.)
+     *
+     * @return boolean
+     */
+    public function isCustomizedView()
+    {
+        return false;
+    }
+
+    /**
+     * Return formatted option value for quote option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getFormattedOptionValue($optionValue)
+    {
+        return $optionValue;
+    }
+
+    /**
+     * Return option html
+     *
+     * @param array $optionInfo
+     * @return string
+     */
+    public function getCustomizedView($optionInfo)
+    {
+        return isset($optionInfo['value']) ? $optionInfo['value'] : $optionInfo;
+    }
+
+    /**
+     * Return printable option value
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getPrintableOptionValue($optionValue)
+    {
+        return $optionValue;
+    }
+
+    /**
+     * Return formatted option value ready to edit, ready to parse
+     * (ex: Admin re-order, see \Magento\Sales\Model\AdminOrder\Create)
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getEditableOptionValue($optionValue)
+    {
+        return $optionValue;
+    }
+
+    /**
+     * Parse user input value and return cart prepared value, i.e. "one, two" => "1,2"
+     *
+     * @param string $optionValue
+     * @param array $productOptionValues Values for product option
+     * @return string|null
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function parseOptionValue($optionValue, $productOptionValues)
+    {
+        return $optionValue;
+    }
+
+    /**
+     * Prepare option value for info buy request
+     *
+     * @param string $optionValue
+     * @return string|null
+     */
+    public function prepareOptionValueForRequest($optionValue)
+    {
+        return $optionValue;
+    }
+
+    /**
+     * Return Price for selected option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @param float $basePrice For percent price type
+     * @return float
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function getOptionPrice($optionValue, $basePrice)
+    {
+        $option = $this->getOption();
+
+        return $this->_getChargableOptionPrice($option->getPrice(), $option->getPriceType() == 'percent', $basePrice);
+    }
+
+    /**
+     * Return SKU for selected option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @param string $skuDelimiter Delimiter for Sku parts
+     * @return string
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function getOptionSku($optionValue, $skuDelimiter)
+    {
+        return $this->getOption()->getSku();
+    }
+
+    /**
+     * Return value => key all product options (using for parsing)
+     *
+     * @return array Array of Product custom options, reversing option values and option ids
+     */
+    public function getProductOptions()
+    {
+        if (!isset($this->_productOptions[$this->getProduct()->getId()])) {
+            $options = $this->getProduct()->getOptions();
+            if ($options != null) {
+                foreach ($options as $_option) {
+                    /* @var $option \Magento\Catalog\Model\Product\Option */
+                    $this->_productOptions[$this->getProduct()->getId()][$_option->getTitle()] = [
+                        'option_id' => $_option->getId(),
+                    ];
+                    if ($_option->getGroupByType() == ProductCustomOptionInterface::OPTION_GROUP_SELECT) {
+                        $optionValues = [];
+                        foreach ($_option->getValues() as $_value) {
+                            /* @var $value \Magento\Catalog\Model\Product\Option\Value */
+                            $optionValues[$_value->getTitle()] = $_value->getId();
+                        }
+                        $this->_productOptions[$this
+                            ->getProduct()
+                            ->getId()][$_option
+                            ->getTitle()]['values'] = $optionValues;
+                    } else {
+                        $this->_productOptions[$this->getProduct()->getId()][$_option->getTitle()]['values'] = [];
+                    }
+                }
+            }
+        }
+        if (isset($this->_productOptions[$this->getProduct()->getId()])) {
+            return $this->_productOptions[$this->getProduct()->getId()];
+        }
+        return [];
+    }
+
+    /**
+     * Return final chargable price for option
+     *
+     * @param float $price Price of option
+     * @param boolean $isPercent Price type - percent or fixed
+     * @param float $basePrice For percent price type
+     * @return float
+     */
+    protected function _getChargableOptionPrice($price, $isPercent, $basePrice)
+    {
+        if ($isPercent) {
+            return $basePrice * $price / 100;
+        } else {
+            return $price;
+        }
+    }
+}
diff --git a/Model/Usage/Option/Type/Factory.php b/Model/Usage/Option/Type/Factory.php
new file mode 100644
index 0000000..d37554b
--- /dev/null
+++ b/Model/Usage/Option/Type/Factory.php
@@ -0,0 +1,50 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+/**
+ * Catalog product option factory
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+class Factory
+{
+    /**
+     * Object Manager
+     *
+     * @var \Magento\Framework\ObjectManagerInterface
+     */
+    protected $_objectManager;
+
+    /**
+     * Construct
+     *
+     * @param \Magento\Framework\ObjectManagerInterface $objectManager
+     */
+    public function __construct(\Magento\Framework\ObjectManagerInterface $objectManager)
+    {
+        $this->_objectManager = $objectManager;
+    }
+
+    /**
+     * Create product option
+     *
+     * @param string $className
+     * @param array $data
+     * @return \Magento\Catalog\Model\Product\Option\Type\DefaultType
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function create($className, array $data = [])
+    {
+        $option = $this->_objectManager->create($className, $data);
+
+        if (!$option instanceof \Magento\Catalog\Model\Product\Option\Type\DefaultType) {
+            throw new \Magento\Framework\Exception\LocalizedException(
+                __('%1 doesn\'t extends \Magento\Catalog\Model\Product\Option\Type\DefaultType', $className)
+            );
+        }
+        return $option;
+    }
+}
diff --git a/Model/Usage/Option/Type/File.php b/Model/Usage/Option/Type/File.php
new file mode 100644
index 0000000..52ad9b4
--- /dev/null
+++ b/Model/Usage/Option/Type/File.php
@@ -0,0 +1,532 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Framework\Filesystem;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Catalog\Model\Product\Exception as ProductException;
+use Magento\Framework\Serialize\Serializer\Json;
+use Magento\Framework\App\ObjectManager;
+
+/**
+ * Catalog product option file type
+ *
+ * @author     Magento Core Team <core@magentocommerce.com>
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class File extends \Magento\Catalog\Model\Product\Option\Type\DefaultType
+{
+    /**
+     * Url for custom option download controller
+     * @var string
+     */
+    protected $_customOptionDownloadUrl = 'sales/download/downloadCustomOption';
+
+    /**
+     * @var string|null
+     */
+    protected $_formattedOptionValue = null;
+
+    /**
+     * @var \Magento\Framework\Filesystem\Directory\ReadInterface
+     * @deprecated 101.1.0
+     * @see $mediaDirectory
+     */
+    protected $_rootDirectory;
+
+    /**
+     * @var \Magento\Framework\Filesystem\Directory\WriteInterface
+     */
+    private $mediaDirectory;
+
+    /**
+     * Core file storage database
+     *
+     * @var \Magento\MediaStorage\Helper\File\Storage\Database
+     */
+    protected $_coreFileStorageDatabase = null;
+
+    /**
+     * @var \Magento\Framework\Escaper
+     */
+    protected $_escaper;
+
+    /**
+     * Url
+     *
+     * @var \Magento\Catalog\Model\Product\Option\UrlBuilder
+     */
+    protected $_urlBuilder;
+
+    /**
+     * Item option factory
+     *
+     * @var \Magento\Quote\Model\Quote\Item\OptionFactory
+     */
+    protected $_itemOptionFactory;
+
+    /**
+     * @var File\ValidatorInfo
+     */
+    protected $validatorInfo;
+
+    /**
+     * @var File\ValidatorFile
+     */
+    protected $validatorFile;
+
+    /**
+     * @var Json
+     */
+    private $serializer;
+
+    /**
+     * @var Filesystem
+     */
+    private $filesystem;
+
+    /**
+     * @param \Magento\Checkout\Model\Session $checkoutSession
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Quote\Model\Quote\Item\OptionFactory $itemOptionFactory
+     * @param \Magento\MediaStorage\Helper\File\Storage\Database $coreFileStorageDatabase
+     * @param File\ValidatorInfo $validatorInfo
+     * @param File\ValidatorFile $validatorFile
+     * @param \Magento\Catalog\Model\Product\Option\UrlBuilder $urlBuilder
+     * @param \Magento\Framework\Escaper $escaper
+     * @param array $data
+     * @param Filesystem $filesystem
+     * @param Json|null $serializer
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        \Magento\Checkout\Model\Session $checkoutSession,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Quote\Model\Quote\Item\OptionFactory $itemOptionFactory,
+        \Magento\MediaStorage\Helper\File\Storage\Database $coreFileStorageDatabase,
+        \Magento\Catalog\Model\Product\Option\Type\File\ValidatorInfo $validatorInfo,
+        \Magento\Catalog\Model\Product\Option\Type\File\ValidatorFile $validatorFile,
+        \Magento\Catalog\Model\Product\Option\UrlBuilder $urlBuilder,
+        \Magento\Framework\Escaper $escaper,
+        array $data = [],
+        Filesystem $filesystem = null,
+        Json $serializer = null
+    ) {
+        $this->_itemOptionFactory = $itemOptionFactory;
+        $this->_urlBuilder = $urlBuilder;
+        $this->_escaper = $escaper;
+        $this->_coreFileStorageDatabase = $coreFileStorageDatabase;
+        $this->filesystem = $filesystem ?: \Magento\Framework\App\ObjectManager::getInstance()->get(Filesystem::class);
+        /** The _rootDirectory is deprecated. The field is initialized for backward compatibility */
+        $this->_rootDirectory = $this->filesystem->getDirectoryRead(DirectoryList::MEDIA);
+        $this->mediaDirectory = $this->filesystem->getDirectoryWrite(DirectoryList::MEDIA);
+        $this->validatorInfo = $validatorInfo;
+        $this->validatorFile = $validatorFile;
+        $this->serializer = $serializer ? $serializer : ObjectManager::getInstance()->get(Json::class);
+        parent::__construct($checkoutSession, $scopeConfig, $data);
+    }
+
+    /**
+     * Flag to indicate that custom option has own customized output (blocks, native html etc.)
+     *
+     * @return boolean
+     */
+    public function isCustomizedView()
+    {
+        return true;
+    }
+
+    /**
+     * Return option html
+     *
+     * @param array $optionInfo
+     * @return string|void
+     */
+    public function getCustomizedView($optionInfo)
+    {
+        try {
+            if (isset($optionInfo['option_value'])) {
+                return $this->_getOptionHtml($optionInfo['option_value']);
+            } elseif (isset($optionInfo['value'])) {
+                return $optionInfo['value'];
+            }
+        } catch (\Exception $e) {
+            return $optionInfo['value'];
+        }
+    }
+
+    /**
+     * Returns additional params for processing options
+     *
+     * @return \Magento\Framework\DataObject
+     */
+    protected function _getProcessingParams()
+    {
+        $buyRequest = $this->getRequest();
+        $params = $buyRequest->getData('_processing_params');
+        /*
+         * Notice check for params to be \Magento\Framework\DataObject - by using object we protect from
+         * params being forged and contain data from user frontend input
+         */
+        if ($params instanceof \Magento\Framework\DataObject) {
+            return $params;
+        }
+        return new \Magento\Framework\DataObject();
+    }
+
+    /**
+     * Returns file info array if we need to get file from already existing file.
+     * Or returns null, if we need to get file from uploaded array.
+     *
+     * @return null|array
+     */
+    protected function _getCurrentConfigFileInfo()
+    {
+        $option = $this->getOption();
+        $optionId = $option->getId();
+        $processingParams = $this->_getProcessingParams();
+        $buyRequest = $this->getRequest();
+
+        // Check maybe restore file from config requested
+        $optionActionKey = 'options_' . $optionId . '_file_action';
+        if ($buyRequest->getData($optionActionKey) == 'save_old') {
+            $fileInfo = [];
+            $currentConfig = $processingParams->getCurrentConfig();
+            if ($currentConfig) {
+                $fileInfo = $currentConfig->getData('options/' . $optionId);
+            }
+            return $fileInfo;
+        }
+        return null;
+    }
+
+    /**
+     * Validate user input for option
+     *
+     * @param array $values All product option values, i.e. array (option_id => mixed, option_id => mixed...)
+     * @return $this
+     * @throws LocalizedException
+     * @throws \Exception
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     */
+    public function validateUserValue($values)
+    {
+        $this->_checkoutSession->setUseNotice(false);
+
+        $this->setIsValid(true);
+        $option = $this->getOption();
+
+        /*
+         * Check whether we receive uploaded file or restore file by: reorder/edit configuration or
+         * previous configuration with no newly uploaded file
+         */
+        $fileInfo = null;
+        if (isset($values[$option->getId()]) && is_array($values[$option->getId()])) {
+            // Legacy style, file info comes in array with option id index
+            $fileInfo = $values[$option->getId()];
+        } else {
+            /*
+             * New recommended style - file info comes in request processing parameters and we
+             * sure that this file info originates from Magento, not from manually formed POST request
+             */
+            $fileInfo = $this->_getCurrentConfigFileInfo();
+        }
+        if ($fileInfo !== null) {
+            try {
+                $value = $this->validatorInfo->setUseQuotePath($this->getUseQuotePath())
+                    ->validate($fileInfo, $option) ? $fileInfo : null;
+                $this->setUserValue($value);
+                return $this;
+            } catch (LocalizedException $exception) {
+                $this->setIsValid(false);
+                throw $exception;
+            }
+        }
+
+        // Process new uploaded file
+        try {
+            $value = $this->validatorFile->setProduct($this->getProduct())
+                ->validate($this->_getProcessingParams(), $option);
+            $this->setUserValue($value);
+        } catch (ProductException $e) {
+            switch ($this->getProcessMode()) {
+                case \Magento\Catalog\Model\Product\Type\AbstractType::PROCESS_MODE_FULL:
+                    throw new LocalizedException(__('Please specify product\'s required option(s).'));
+                    break;
+                default:
+                    $this->setUserValue(null);
+                    break;
+            }
+        } catch (\Magento\Framework\Validator\Exception $e) {
+            $this->setUserValue(null);
+        } catch (LocalizedException $e) {
+            $this->setIsValid(false);
+            throw new LocalizedException(__($e->getMessage()));
+        } catch (\Exception $e) {
+            if ($this->getSkipCheckRequiredOption()) {
+                $this->setUserValue(null);
+            } else {
+                throw new LocalizedException(__($e->getMessage()));
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * Prepare option value for cart
+     *
+     * @return string|null Prepared option value
+     */
+    public function prepareForCart()
+    {
+        $option = $this->getOption();
+        $optionId = $option->getId();
+        $buyRequest = $this->getRequest();
+
+        // Prepare value and fill buyRequest with option
+        $requestOptions = $buyRequest->getOptions();
+        if ($this->getIsValid() && $this->getUserValue() !== null) {
+            $value = $this->getUserValue();
+
+            // Save option in request, because we have no $_FILES['options']
+            $requestOptions[$this->getOption()->getId()] = $value;
+            $result = $this->serializer->serialize($value);
+        } else {
+            /*
+             * Clear option info from request, so it won't be stored in our db upon
+             * unsuccessful validation. Otherwise some bad file data can happen in buyRequest
+             * and be used later in reorders and reconfigurations.
+             */
+            if (is_array($requestOptions)) {
+                unset($requestOptions[$this->getOption()->getId()]);
+            }
+            $result = null;
+        }
+        $buyRequest->setOptions($requestOptions);
+
+        // Clear action key from buy request - we won't need it anymore
+        $optionActionKey = 'options_' . $optionId . '_file_action';
+        $buyRequest->unsetData($optionActionKey);
+
+        return $result;
+    }
+
+    /**
+     * Return formatted option value for quote option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getFormattedOptionValue($optionValue)
+    {
+        if ($this->_formattedOptionValue === null) {
+            $value = $this->serializer->unserialize($optionValue);
+            if ($value === null) {
+                return $optionValue;
+            }
+            $customOptionUrlParams = $this->getCustomOptionUrlParams()
+                ? $this->getCustomOptionUrlParams()
+                : [
+                    'id' => $this->getConfigurationItemOption()->getId(),
+                    'key' => $value['secret_key']
+                ];
+
+            $value['url'] = ['route' => $this->_customOptionDownloadUrl, 'params' => $customOptionUrlParams];
+
+            $this->_formattedOptionValue = $this->_getOptionHtml($value);
+            $this->getConfigurationItemOption()->setValue($this->serializer->serialize($value));
+        }
+        return $this->_formattedOptionValue;
+    }
+
+    /**
+     * Format File option html
+     *
+     * @param string|array $optionValue Serialized string of option data or its data array
+     * @return string
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    protected function _getOptionHtml($optionValue)
+    {
+        $value = $this->_unserializeValue($optionValue);
+        try {
+            $sizes = $this->prepareSize($value);
+
+            $urlRoute = !empty($value['url']['route']) ? $value['url']['route'] : '';
+            $urlParams = !empty($value['url']['params']) ? $value['url']['params'] : '';
+            $title = !empty($value['title']) ? $value['title'] : '';
+
+            return sprintf(
+                '<a href="%s" target="_blank">%s</a> %s',
+                $this->_getOptionDownloadUrl($urlRoute, $urlParams),
+                $this->_escaper->escapeHtml($title),
+                $sizes
+            );
+        } catch (\Exception $e) {
+            throw new LocalizedException(__('The file options format is not valid.'));
+        }
+    }
+
+    /**
+     * Create a value from a storable representation
+     *
+     * @param string|array $value
+     * @return array
+     */
+    protected function _unserializeValue($value)
+    {
+        if (is_array($value)) {
+            return $value;
+        } elseif (is_string($value) && !empty($value)) {
+            return $this->serializer->unserialize($value);
+        } else {
+            return [];
+        }
+    }
+
+    /**
+     * Return printable option value
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getPrintableOptionValue($optionValue)
+    {
+        return strip_tags($this->getFormattedOptionValue($optionValue));
+    }
+
+    /**
+     * Return formatted option value ready to edit, ready to parse
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     *
+     * @deprecated 101.1.0
+     */
+    public function getEditableOptionValue($optionValue)
+    {
+        $unserializedValue = $this->serializer->unserialize($optionValue);
+        if ($unserializedValue !== null) {
+            return sprintf(
+                '%s [%d]',
+                $this->_escaper->escapeHtml($unserializedValue['title']),
+                $this->getConfigurationItemOption()->getId()
+            );
+        }
+        return $optionValue;
+    }
+
+    /**
+     * Parse user input value and return cart prepared value
+     *
+     * @param string $optionValue
+     * @param array $productOptionValues Values for product option
+     * @return string|null
+     *
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     *
+     * @deprecated 101.1.0
+     */
+    public function parseOptionValue($optionValue, $productOptionValues)
+    {
+        // search quote item option Id in option value
+        if (preg_match('/\[([0-9]+)\]/', $optionValue, $matches)) {
+            $confItemOptionId = $matches[1];
+            $option = $this->_itemOptionFactory->create()->load($confItemOptionId);
+            if ($this->serializer->unserialize($option->getValue()) !== null) {
+                return $option->getValue();
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Prepare option value for info buy request
+     *
+     * @param string $optionValue
+     * @return string|null
+     */
+    public function prepareOptionValueForRequest($optionValue)
+    {
+        $unserializedValue = $this->serializer->unserialize($optionValue);
+        if ($unserializedValue !== null) {
+            return $unserializedValue;
+        }
+        return null;
+    }
+
+    /**
+     * Quote item to order item copy process
+     *
+     * @return $this
+     */
+    public function copyQuoteToOrder()
+    {
+        $quoteOption = $this->getConfigurationItemOption();
+        try {
+            $value = $this->serializer->unserialize($quoteOption->getValue());
+            if (!isset($value['quote_path'])) {
+                throw new \Exception();
+            }
+            $quotePath = $value['quote_path'];
+            $orderPath = $value['order_path'];
+
+            if (!$this->mediaDirectory->isFile($quotePath) || !$this->mediaDirectory->isReadable($quotePath)) {
+                throw new \Exception();
+            }
+
+            if ($this->_coreFileStorageDatabase->checkDbUsage()) {
+                $this->_coreFileStorageDatabase->copyFile(
+                    $this->mediaDirectory->getAbsolutePath($quotePath),
+                    $this->mediaDirectory->getAbsolutePath($orderPath)
+                );
+            } else {
+                $this->mediaDirectory->copyFile($quotePath, $orderPath);
+            }
+        } catch (\Exception $e) {
+            return $this;
+        }
+        return $this;
+    }
+
+    /**
+     * Set url to custom option download controller
+     *
+     * @param string $url
+     * @return $this
+     */
+    public function setCustomOptionDownloadUrl($url)
+    {
+        $this->_customOptionDownloadUrl = $url;
+        return $this;
+    }
+
+    /**
+     * Return URL for option file download
+     *
+     * @param string|null $route
+     * @param array|null $params
+     * @return string
+     */
+    protected function _getOptionDownloadUrl($route, $params)
+    {
+        return $this->_urlBuilder->getUrl($route, $params);
+    }
+
+    /**
+     * @param array $value
+     * @return string
+     */
+    protected function prepareSize($value)
+    {
+        $sizes = '';
+        if (!empty($value['width']) && !empty($value['height']) && $value['width'] > 0 && $value['height'] > 0) {
+            $sizes = $value['width'] . ' x ' . $value['height'] . ' ' . __('px.');
+        }
+        return $sizes;
+    }
+}
diff --git a/Model/Usage/Option/Type/File/ValidateFactory.php b/Model/Usage/Option/Type/File/ValidateFactory.php
new file mode 100644
index 0000000..6bac550
--- /dev/null
+++ b/Model/Usage/Option/Type/File/ValidateFactory.php
@@ -0,0 +1,18 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type\File;
+
+class ValidateFactory
+{
+    /**
+     * @return \Zend_Validate
+     */
+    public function create()
+    {
+        return new \Zend_Validate();
+    }
+}
diff --git a/Model/Usage/Option/Type/File/Validator.php b/Model/Usage/Option/Type/File/Validator.php
new file mode 100644
index 0000000..438c5a0
--- /dev/null
+++ b/Model/Usage/Option/Type/File/Validator.php
@@ -0,0 +1,201 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type\File;
+
+use Magento\Framework\App\Filesystem\DirectoryList;
+
+/**
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+abstract class Validator
+{
+    /**
+     * @var \Magento\Framework\App\Config\ScopeConfigInterface
+     */
+    protected $scopeConfig;
+
+    /**
+     * @var \Magento\Framework\File\Size
+     */
+    protected $fileSize;
+
+    /**
+     * @var \Magento\Framework\Filesystem\Directory\ReadInterface
+     */
+    protected $rootDirectory;
+
+    /**
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Filesystem $filesystem
+     * @param \Magento\Framework\File\Size $fileSize
+     */
+    public function __construct(
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Filesystem $filesystem,
+        \Magento\Framework\File\Size $fileSize
+    ) {
+        $this->scopeConfig = $scopeConfig;
+        $this->rootDirectory = $filesystem->getDirectoryRead(DirectoryList::MEDIA);
+        $this->fileSize = $fileSize;
+    }
+
+    /**
+     * Store Config value
+     *
+     * @param string $key Config value key
+     * @return string
+     */
+    protected function getConfigData($key)
+    {
+        return $this->scopeConfig->getValue(
+            'catalog/custom_options/' . $key,
+            \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+        );
+    }
+
+    /**
+     * Get Error messages for validator Errors
+     *
+     * @param string[] $errors Array of validation failure message codes @see \Zend_Validate::getErrors()
+     * @param array $fileInfo File info
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @return string[] Array of error messages
+     * @see \Magento\Catalog\Model\Product\Option\Type\File::_getValidatorErrors
+     */
+    protected function getValidatorErrors($errors, $fileInfo, $option)
+    {
+        $result = [];
+        foreach ($errors as $errorCode) {
+            switch ($errorCode) {
+                case \Zend_Validate_File_ExcludeExtension::FALSE_EXTENSION:
+                    $result[] = __(
+                        "The file '%1' for '%2' has an invalid extension.",
+                        $fileInfo['title'],
+                        $option->getTitle()
+                    );
+                    break;
+                case \Zend_Validate_File_Extension::FALSE_EXTENSION:
+                    $result[] = __(
+                        "The file '%1' for '%2' has an invalid extension.",
+                        $fileInfo['title'],
+                        $option->getTitle()
+                    );
+                    break;
+                case \Zend_Validate_File_ImageSize::WIDTH_TOO_BIG:
+                case \Zend_Validate_File_ImageSize::HEIGHT_TOO_BIG:
+                    $result[] = __(
+                        "The maximum allowed image size for '%1' is %2x%3 px.",
+                        $option->getTitle(),
+                        $option->getImageSizeX(),
+                        $option->getImageSizeY()
+                    );
+                    break;
+                case \Zend_Validate_File_FilesSize::TOO_BIG:
+                    $result[] = __(
+                        "The file '%1' you uploaded is larger than the %2 megabytes allowed by our server.",
+                        $fileInfo['title'],
+                        $this->fileSize->getMaxFileSizeInMb()
+                    );
+                    break;
+                case \Zend_Validate_File_ImageSize::NOT_DETECTED:
+                    $result[] = __(
+                        "The file '%1' is empty. Please choose another one",
+                        $fileInfo['title']
+                    );
+                    break;
+                default:
+                    $result[] = __(
+                        "The file '%1' is invalid. Please choose another one",
+                        $fileInfo['title']
+                    );
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * Parse file extensions string with various separators
+     *
+     * @param string $extensions String to parse
+     * @return array|null
+     * @see \Magento\Catalog\Model\Product\Option\Type\File::_parseExtensionsString
+     */
+    protected function parseExtensionsString($extensions)
+    {
+        if (preg_match_all('/(?<extension>[a-z0-9]+)/si', strtolower($extensions), $matches)) {
+            return $matches['extension'] ?: null;
+        }
+        return null;
+    }
+
+    /**
+     * @param \Zend_File_Transfer_Adapter_Http|\Zend_Validate $object
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @param array $fileFullPath
+     * @return \Zend_File_Transfer_Adapter_Http|\Zend_Validate $object
+     * @throws \Magento\Framework\Exception\InputException
+     */
+    protected function buildImageValidator($object, $option, $fileFullPath = null)
+    {
+        $dimensions = [];
+
+        if ($option->getImageSizeX() > 0) {
+            $dimensions['maxwidth'] = $option->getImageSizeX();
+        }
+        if ($option->getImageSizeY() > 0) {
+            $dimensions['maxheight'] = $option->getImageSizeY();
+        }
+        if (count($dimensions) > 0) {
+            if ($fileFullPath !== null && !$this->isImage($fileFullPath)) {
+                throw new \Magento\Framework\Exception\InputException(
+                    __('File \'%1\' is not an image.', $option->getTitle())
+                );
+            }
+            $object->addValidator(new \Zend_Validate_File_ImageSize($dimensions));
+        }
+
+        // File extension
+        $allowed = $this->parseExtensionsString($option->getFileExtension());
+        if ($allowed !== null) {
+            $object->addValidator(new \Zend_Validate_File_Extension($allowed));
+        } else {
+            $forbidden = $this->parseExtensionsString($this->getConfigData('forbidden_extensions'));
+            if ($forbidden !== null) {
+                $object->addValidator(new \Zend_Validate_File_ExcludeExtension($forbidden));
+            }
+        }
+
+        $object->addValidator(
+            new \Zend_Validate_File_FilesSize(['max' => $this->fileSize->getMaxFileSize()])
+        );
+        return $object;
+    }
+
+    /**
+     * Simple check if file is image
+     *
+     * @param array|string $fileInfo - either file data from \Zend_File_Transfer or file path
+     * @return boolean
+     * @see \Magento\Catalog\Model\Product\Option\Type\File::_isImage
+     */
+    protected function isImage($fileInfo)
+    {
+        // Maybe array with file info came in
+        if (is_array($fileInfo)) {
+            return strstr($fileInfo['type'], 'image/');
+        }
+
+        // File path came in - check the physical file
+        if (!$this->rootDirectory->isReadable($this->rootDirectory->getRelativePath($fileInfo))) {
+            return false;
+        }
+        $imageInfo = getimagesize($fileInfo);
+        if (!$imageInfo) {
+            return false;
+        }
+        return true;
+    }
+}
diff --git a/Model/Usage/Option/Type/File/ValidatorFile.php b/Model/Usage/Option/Type/File/ValidatorFile.php
new file mode 100644
index 0000000..0ef3a67
--- /dev/null
+++ b/Model/Usage/Option/Type/File/ValidatorFile.php
@@ -0,0 +1,244 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type\File;
+
+use Magento\Catalog\Model\Product;
+use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Catalog\Model\Product\Exception as ProductException;
+use Magento\Framework\Exception\LocalizedException;
+
+/**
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class ValidatorFile extends Validator
+{
+    /**
+     * Relative path for main destination folder
+     *
+     * @var string
+     */
+    protected $path = 'custom_options';
+
+    /**
+     * Relative path for quote folder
+     *
+     * @var string
+     */
+    protected $quotePath = 'custom_options/quote';
+
+    /**
+     * Relative path for order folder
+     *
+     * @var string
+     */
+    protected $orderPath = 'custom_options/order';
+
+    /**
+     * @var \Magento\Framework\Filesystem\Directory\WriteInterface
+     */
+    protected $mediaDirectory;
+
+    /**
+     * @var \Magento\Framework\Filesystem
+     */
+    protected $filesystem;
+
+    /**
+     * @var \Magento\Framework\HTTP\Adapter\FileTransferFactory
+     */
+    protected $httpFactory;
+
+    /**
+     * @var Product
+     */
+    protected $product;
+
+    /**
+     * @var \Magento\Framework\Validator\File\IsImage
+     */
+    protected $isImageValidator;
+
+    /**
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Filesystem $filesystem
+     * @param \Magento\Framework\File\Size $fileSize
+     * @param \Magento\Framework\HTTP\Adapter\FileTransferFactory $httpFactory
+     * @param \Magento\Framework\Validator\File\IsImage $isImageValidator
+     * @throws \Magento\Framework\Exception\FileSystemException
+     */
+    public function __construct(
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Filesystem $filesystem,
+        \Magento\Framework\File\Size $fileSize,
+        \Magento\Framework\HTTP\Adapter\FileTransferFactory $httpFactory,
+        \Magento\Framework\Validator\File\IsImage $isImageValidator
+    ) {
+        $this->mediaDirectory = $filesystem->getDirectoryWrite(DirectoryList::MEDIA);
+        $this->filesystem = $filesystem;
+        $this->httpFactory = $httpFactory;
+        $this->isImageValidator = $isImageValidator;
+        parent::__construct($scopeConfig, $filesystem, $fileSize);
+    }
+
+    /**
+     * @param Product $product
+     * @return $this
+     */
+    public function setProduct(Product $product)
+    {
+        $this->product = $product;
+        return $this;
+    }
+
+    /**
+     * @param \Magento\Framework\DataObject $processingParams
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @return array
+     * @throws LocalizedException
+     * @throws ProductException
+     * @throws \Exception
+     * @throws \Magento\Framework\Exception\InputException
+     * @throws \Magento\Framework\Validator\Exception
+     * @throws \Zend_File_Transfer_Exception
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    public function validate($processingParams, $option)
+    {
+        $upload = $this->httpFactory->create();
+        $file = $processingParams->getFilesPrefix() . 'options_' . $option->getId() . '_file';
+        try {
+            $runValidation = $option->getIsRequire() || $upload->isUploaded($file);
+            if (!$runValidation) {
+                throw new \Magento\Framework\Validator\Exception(
+                    __('Validation failed. Required options were not filled or the file was not uploaded.')
+                );
+            }
+
+            $fileInfo = $upload->getFileInfo($file)[$file];
+            $fileInfo['title'] = $fileInfo['name'];
+        } catch (\Magento\Framework\Validator\Exception $e) {
+            throw $e;
+        } catch (\Exception $e) {
+            // when file exceeds the upload_max_filesize, $_FILES is empty
+            if ($this->validateContentLength()) {
+                $value = $this->fileSize->getMaxFileSizeInMb();
+                throw new LocalizedException(
+                    __('The file you uploaded is larger than %1 Megabytes allowed by server', $value)
+                );
+            } else {
+                throw new ProductException(__('Option required.'));
+            }
+        }
+
+        /**
+         * Option Validations
+         */
+        $upload = $this->buildImageValidator($upload, $option);
+
+        /**
+         * Upload process
+         */
+        $this->initFilesystem();
+        $userValue = [];
+
+        if ($upload->isUploaded($file) && $upload->isValid($file)) {
+            $extension = pathinfo(strtolower($fileInfo['name']), PATHINFO_EXTENSION);
+
+            $fileName = \Magento\MediaStorage\Model\File\Uploader::getCorrectFileName($fileInfo['name']);
+            $dispersion = \Magento\MediaStorage\Model\File\Uploader::getDispretionPath($fileName);
+
+            $filePath = $dispersion;
+
+            $tmpDirectory = $this->filesystem->getDirectoryRead(DirectoryList::SYS_TMP);
+            $fileHash = md5($tmpDirectory->readFile($tmpDirectory->getRelativePath($fileInfo['tmp_name'])));
+            $filePath .= '/' . $fileHash . '.' . $extension;
+            $fileFullPath = $this->mediaDirectory->getAbsolutePath($this->quotePath . $filePath);
+
+            $upload->addFilter(new \Zend_Filter_File_Rename(['target' => $fileFullPath, 'overwrite' => true]));
+
+            if ($this->product !== null) {
+                $this->product->getTypeInstance()->addFileQueue(
+                    [
+                        'operation' => 'receive_uploaded_file',
+                        'src_name' => $file,
+                        'dst_name' => $fileFullPath,
+                        'uploader' => $upload,
+                        'option' => $this,
+                    ]
+                );
+            }
+
+            $_width = 0;
+            $_height = 0;
+
+            if ($tmpDirectory->isReadable($tmpDirectory->getRelativePath($fileInfo['tmp_name']))) {
+                if (filesize($fileInfo['tmp_name'])) {
+                    if ($this->isImageValidator->isValid($fileInfo['tmp_name'])) {
+                        $imageSize = getimagesize($fileInfo['tmp_name']);
+                    }
+                } else {
+                    throw new LocalizedException(__('The file is empty. Please choose another one'));
+                }
+
+                if (!empty($imageSize)) {
+                    $_width = $imageSize[0];
+                    $_height = $imageSize[1];
+                }
+            }
+
+            $userValue = [
+                'type' => $fileInfo['type'],
+                'title' => $fileInfo['name'],
+                'quote_path' => $this->quotePath . $filePath,
+                'order_path' => $this->orderPath . $filePath,
+                'fullpath' => $fileFullPath,
+                'size' => $fileInfo['size'],
+                'width' => $_width,
+                'height' => $_height,
+                'secret_key' => substr($fileHash, 0, 20),
+            ];
+        } elseif ($upload->getErrors()) {
+            $errors = $this->getValidatorErrors($upload->getErrors(), $fileInfo, $option);
+
+            if (count($errors) > 0) {
+                throw new LocalizedException(__(implode("\n", $errors)));
+            }
+        } else {
+            throw new LocalizedException(__('Please specify product\'s required option(s).'));
+        }
+        return $userValue;
+    }
+
+    /**
+     * Directory structure initializing
+     *
+     * @return void
+     * @see \Magento\Catalog\Model\Product\Option\Type\File::_initFilesystem
+     */
+    protected function initFilesystem()
+    {
+        $this->mediaDirectory->create($this->path);
+        $this->mediaDirectory->create($this->quotePath);
+        $this->mediaDirectory->create($this->orderPath);
+
+        // Directory listing and hotlink secure
+        $path = $this->path . '/.htaccess';
+        if (!$this->mediaDirectory->isFile($path)) {
+            $this->mediaDirectory->writeFile($path, "Order deny,allow\nDeny from all");
+        }
+    }
+
+    /**
+     * @return bool
+     * @todo need correctly name
+     */
+    protected function validateContentLength()
+    {
+        return isset($_SERVER['CONTENT_LENGTH']) && $_SERVER['CONTENT_LENGTH'] > $this->fileSize->getMaxFileSize();
+    }
+}
diff --git a/Model/Usage/Option/Type/File/ValidatorInfo.php b/Model/Usage/Option/Type/File/ValidatorInfo.php
new file mode 100644
index 0000000..7e94064
--- /dev/null
+++ b/Model/Usage/Option/Type/File/ValidatorInfo.php
@@ -0,0 +1,151 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type\File;
+
+class ValidatorInfo extends Validator
+{
+    /**
+     * @var \Magento\MediaStorage\Helper\File\Storage\Database
+     */
+    protected $coreFileStorageDatabase;
+
+    /**
+     * @var ValidateFactory
+     */
+    protected $validateFactory;
+
+    /**
+     * @var mixed
+     */
+    protected $useQuotePath;
+
+    /**
+     * @var string
+     */
+    protected $fileFullPath;
+
+    /**
+     * @var string
+     */
+    protected $fileRelativePath;
+
+    /**
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Filesystem $filesystem
+     * @param \Magento\Framework\File\Size $fileSize
+     * @param \Magento\MediaStorage\Helper\File\Storage\Database $coreFileStorageDatabase
+     * @param ValidateFactory $validateFactory
+     */
+    public function __construct(
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Filesystem $filesystem,
+        \Magento\Framework\File\Size $fileSize,
+        \Magento\MediaStorage\Helper\File\Storage\Database $coreFileStorageDatabase,
+        \Magento\Catalog\Model\Product\Option\Type\File\ValidateFactory $validateFactory
+    ) {
+        $this->coreFileStorageDatabase = $coreFileStorageDatabase;
+        $this->validateFactory = $validateFactory;
+        parent::__construct($scopeConfig, $filesystem, $fileSize);
+    }
+
+    /**
+     * @param mixed $useQuotePath
+     * @return $this
+     */
+    public function setUseQuotePath($useQuotePath)
+    {
+        $this->useQuotePath = $useQuotePath;
+        return $this;
+    }
+
+    /**
+     * @param array $optionValue
+     * @param \Magento\Catalog\Model\Product\Option $option
+     * @return bool
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function validate($optionValue, $option)
+    {
+        if (!is_array($optionValue)) {
+            return false;
+        }
+
+        $this->fileFullPath = null;
+        $this->fileRelativePath = null;
+        $this->initFilePath($optionValue);
+
+        if ($this->fileFullPath === null) {
+            return false;
+        }
+
+        $validatorChain = $this->validateFactory->create();
+        try {
+            $validatorChain = $this->buildImageValidator($validatorChain, $option, $this->fileFullPath);
+        } catch (\Magento\Framework\Exception\InputException $notImage) {
+            return false;
+        }
+
+        $result = false;
+        if ($validatorChain->isValid($this->fileFullPath)) {
+            $result = $this->rootDirectory->isReadable($this->fileRelativePath)
+                && isset($optionValue['secret_key'])
+                && $this->buildSecretKey($this->fileRelativePath) == $optionValue['secret_key'];
+        } elseif ($validatorChain->getErrors()) {
+            $errors = $this->getValidatorErrors($validatorChain->getErrors(), $optionValue, $option);
+
+            if (count($errors) > 0) {
+                throw new \Magento\Framework\Exception\LocalizedException(__(implode("\n", $errors)));
+            }
+        } else {
+            throw new \Magento\Framework\Exception\LocalizedException(
+                __('Please specify product\'s required option(s).')
+            );
+        }
+        return $result;
+    }
+
+    /**
+     * @param string $fileRelativePath
+     * @return string
+     */
+    protected function buildSecretKey($fileRelativePath)
+    {
+        return substr(md5($this->rootDirectory->readFile($fileRelativePath)), 0, 20);
+    }
+
+    /**
+     * @param array $optionValue
+     * @return void
+     */
+    protected function initFilePath($optionValue)
+    {
+        /**
+         * @see \Magento\Catalog\Model\Product\Option\Type\File\ValidatorFile::validate
+         *              There setUserValue() sets correct fileFullPath only for
+         *              quote_path. So we must form both full paths manually and
+         *              check them.
+         */
+        $checkPaths = [];
+        if (isset($optionValue['quote_path'])) {
+            $checkPaths[] = $optionValue['quote_path'];
+        }
+        if (isset($optionValue['order_path']) && !$this->useQuotePath) {
+            $checkPaths[] = $optionValue['order_path'];
+        }
+
+        foreach ($checkPaths as $path) {
+            if (!$this->rootDirectory->isFile($path)) {
+                if (!$this->coreFileStorageDatabase->saveFileToFilesystem($path)) {
+                    continue;
+                }
+            }
+            $this->fileFullPath = $this->rootDirectory->getAbsolutePath($path);
+            $this->fileRelativePath = $path;
+            break;
+        }
+    }
+}
diff --git a/Model/Usage/Option/Type/Select.php b/Model/Usage/Option/Type/Select.php
new file mode 100644
index 0000000..85d4631
--- /dev/null
+++ b/Model/Usage/Option/Type/Select.php
@@ -0,0 +1,310 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+use Magento\Framework\Exception\LocalizedException;
+
+/**
+ * Catalog product option select type
+ */
+class Select extends \Magento\Catalog\Model\Product\Option\Type\DefaultType
+{
+    /**
+     * @var string|array
+     */
+    protected $_formattedOptionValue;
+
+    /**
+     * @var \Magento\Framework\Escaper
+     */
+    protected $_escaper;
+
+    /**
+     * Magento string lib
+     *
+     * @var \Magento\Framework\Stdlib\StringUtils
+     */
+    protected $string;
+
+    /**
+     * @param \Magento\Checkout\Model\Session $checkoutSession
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Stdlib\StringUtils $string
+     * @param \Magento\Framework\Escaper $escaper
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Checkout\Model\Session $checkoutSession,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Stdlib\StringUtils $string,
+        \Magento\Framework\Escaper $escaper,
+        array $data = []
+    ) {
+        $this->string = $string;
+        $this->_escaper = $escaper;
+        parent::__construct($checkoutSession, $scopeConfig, $data);
+    }
+
+    /**
+     * Validate user input for option
+     *
+     * @param array $values All product option values, i.e. array (option_id => mixed, option_id => mixed...)
+     * @return $this
+     * @throws LocalizedException
+     */
+    public function validateUserValue($values)
+    {
+        parent::validateUserValue($values);
+
+        $option = $this->getOption();
+        $value = $this->getUserValue();
+
+        if (empty($value) && $option->getIsRequire() && !$this->getSkipCheckRequiredOption()) {
+            $this->setIsValid(false);
+            throw new LocalizedException(__('Please specify product\'s required option(s).'));
+        }
+        if (!$this->_isSingleSelection()) {
+            $valuesCollection = $option->getOptionValuesByOptionId($value, $this->getProduct()->getStoreId())->load();
+            if ($valuesCollection->count() != count($value)) {
+                $this->setIsValid(false);
+                throw new LocalizedException(__('Please specify product\'s required option(s).'));
+            }
+        }
+        return $this;
+    }
+
+    /**
+     * Prepare option value for cart
+     *
+     * @return string|null Prepared option value
+     */
+    public function prepareForCart()
+    {
+        if ($this->getIsValid() && $this->getUserValue()) {
+            return is_array($this->getUserValue()) ? implode(',', $this->getUserValue()) : $this->getUserValue();
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Return formatted option value for quote option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getFormattedOptionValue($optionValue)
+    {
+        if ($this->_formattedOptionValue === null) {
+            $this->_formattedOptionValue = $this->_escaper->escapeHtml($this->getEditableOptionValue($optionValue));
+        }
+        return $this->_formattedOptionValue;
+    }
+
+    /**
+     * Return printable option value
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getPrintableOptionValue($optionValue)
+    {
+        return $this->getFormattedOptionValue($optionValue);
+    }
+
+    /**
+     * Return currently unavailable product configuration message
+     *
+     * @return \Magento\Framework\Phrase
+     */
+    protected function _getWrongConfigurationMessage()
+    {
+        return __('Some of the selected item options are not currently available.');
+    }
+
+    /**
+     * Return formatted option value ready to edit, ready to parse
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @return string
+     */
+    public function getEditableOptionValue($optionValue)
+    {
+        $option = $this->getOption();
+        $result = '';
+        if (!$this->_isSingleSelection()) {
+            foreach (explode(',', $optionValue) as $_value) {
+                $_result = $option->getValueById($_value);
+                if ($_result) {
+                    $result .= $_result->getTitle() . ', ';
+                } else {
+                    if ($this->getListener()) {
+                        $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                        $result = '';
+                        break;
+                    }
+                }
+            }
+            $result = $this->string->substr($result, 0, -2);
+        } elseif ($this->_isSingleSelection()) {
+            $_result = $option->getValueById($optionValue);
+            if ($_result) {
+                $result = $_result->getTitle();
+            } else {
+                if ($this->getListener()) {
+                    $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                }
+                $result = '';
+            }
+        } else {
+            $result = $optionValue;
+        }
+        return $result;
+    }
+
+    /**
+     * Parse user input value and return cart prepared value, i.e. "one, two" => "1,2"
+     *
+     * @param string $optionValue
+     * @param array $productOptionValues Values for product option
+     * @return string|null
+     */
+    public function parseOptionValue($optionValue, $productOptionValues)
+    {
+        $values = [];
+        if (!$this->_isSingleSelection()) {
+            foreach (explode(',', $optionValue) as $value) {
+                $value = trim($value);
+                if (array_key_exists($value, $productOptionValues)) {
+                    $values[] = $productOptionValues[$value];
+                }
+            }
+        } elseif ($this->_isSingleSelection() && array_key_exists($optionValue, $productOptionValues)) {
+            $values[] = $productOptionValues[$optionValue];
+        }
+        if (count($values)) {
+            return implode(',', $values);
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Prepare option value for info buy request
+     *
+     * @param string $optionValue
+     * @return string
+     */
+    public function prepareOptionValueForRequest($optionValue)
+    {
+        if (!$this->_isSingleSelection()) {
+            return explode(',', $optionValue);
+        }
+        return $optionValue;
+    }
+
+    /**
+     * Return Price for selected option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @param float $basePrice
+     * @return float
+     */
+    public function getOptionPrice($optionValue, $basePrice)
+    {
+        $option = $this->getOption();
+        $result = 0;
+
+        if (!$this->_isSingleSelection()) {
+            foreach (explode(',', $optionValue) as $value) {
+                $_result = $option->getValueById($value);
+                if ($_result) {
+                    $result += $this->_getChargableOptionPrice(
+                        $_result->getPrice(),
+                        $_result->getPriceType() == 'percent',
+                        $basePrice
+                    );
+                } else {
+                    if ($this->getListener()) {
+                        $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                        break;
+                    }
+                }
+            }
+        } elseif ($this->_isSingleSelection()) {
+            $_result = $option->getValueById($optionValue);
+            if ($_result) {
+                $result = $this->_getChargableOptionPrice(
+                    $_result->getPrice(),
+                    $_result->getPriceType() == 'percent',
+                    $basePrice
+                );
+            } else {
+                if ($this->getListener()) {
+                    $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Return SKU for selected option
+     *
+     * @param string $optionValue Prepared for cart option value
+     * @param string $skuDelimiter Delimiter for Sku parts
+     * @return string
+     */
+    public function getOptionSku($optionValue, $skuDelimiter)
+    {
+        $option = $this->getOption();
+
+        if (!$this->_isSingleSelection()) {
+            $skus = [];
+            foreach (explode(',', $optionValue) as $value) {
+                $optionSku = $option->getValueById($value);
+                if ($optionSku) {
+                    $skus[] = $optionSku->getSku();
+                } else {
+                    if ($this->getListener()) {
+                        $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                        break;
+                    }
+                }
+            }
+            $result = implode($skuDelimiter, $skus);
+        } elseif ($this->_isSingleSelection()) {
+            $result = $option->getValueById($optionValue);
+            if ($result) {
+                return $result->getSku();
+            } else {
+                if ($this->getListener()) {
+                    $this->getListener()->setHasError(true)->setMessage($this->_getWrongConfigurationMessage());
+                }
+                return '';
+            }
+        } else {
+            $result = parent::getOptionSku($optionValue, $skuDelimiter);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Check if option has single or multiple values selection
+     *
+     * @return boolean
+     */
+    protected function _isSingleSelection()
+    {
+        $single = [
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DROP_DOWN,
+            \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_RADIO,
+        ];
+        return in_array($this->getOption()->getType(), $single);
+    }
+}
diff --git a/Model/Usage/Option/Type/Text.php b/Model/Usage/Option/Type/Text.php
new file mode 100644
index 0000000..a4b0ce0
--- /dev/null
+++ b/Model/Usage/Option/Type/Text.php
@@ -0,0 +1,94 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option\Type;
+
+use Magento\Framework\Exception\LocalizedException;
+
+/**
+ * Catalog product option text type
+ */
+class Text extends \Magento\Catalog\Model\Product\Option\Type\DefaultType
+{
+    /**
+     * Magento string lib
+     *
+     * @var \Magento\Framework\Stdlib\StringUtils
+     */
+    protected $string;
+
+    /**
+     * @var \Magento\Framework\Escaper
+     */
+    protected $_escaper = null;
+
+    /**
+     * @param \Magento\Checkout\Model\Session $checkoutSession
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+     * @param \Magento\Framework\Escaper $escaper
+     * @param \Magento\Framework\Stdlib\StringUtils $string
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Checkout\Model\Session $checkoutSession,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
+        \Magento\Framework\Escaper $escaper,
+        \Magento\Framework\Stdlib\StringUtils $string,
+        array $data = []
+    ) {
+        $this->_escaper = $escaper;
+        $this->string = $string;
+        parent::__construct($checkoutSession, $scopeConfig, $data);
+    }
+
+    /**
+     * Validate user input for option
+     *
+     * @param array $values All product option values, i.e. array (option_id => mixed, option_id => mixed...)
+     * @return $this
+     * @throws \Magento\Framework\Exception\LocalizedException
+     */
+    public function validateUserValue($values)
+    {
+        parent::validateUserValue($values);
+
+        $option = $this->getOption();
+        $value = trim($this->getUserValue());
+
+        // Check requires option to have some value
+        if (strlen($value) == 0 && $option->getIsRequire() && !$this->getSkipCheckRequiredOption()) {
+            $this->setIsValid(false);
+            throw new LocalizedException(__('Please specify product\'s required option(s).'));
+        }
+
+        $this->setUserValue($value);
+        return $this;
+    }
+
+    /**
+     * Prepare option value for cart
+     *
+     * @return string|null Prepared option value
+     */
+    public function prepareForCart()
+    {
+        if ($this->getIsValid() && strlen($this->getUserValue()) > 0) {
+            return $this->getUserValue();
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Return formatted option value for quote option
+     *
+     * @param string $value Prepared for cart option value
+     * @return string
+     */
+    public function getFormattedOptionValue($value)
+    {
+        return $this->_escaper->escapeHtml($value);
+    }
+}
diff --git a/Model/Usage/Option/UrlBuilder.php b/Model/Usage/Option/UrlBuilder.php
new file mode 100644
index 0000000..6fcbdb7
--- /dev/null
+++ b/Model/Usage/Option/UrlBuilder.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+class UrlBuilder
+{
+    /**
+     * @var \Magento\Framework\UrlInterface
+     */
+    protected $_frontendUrlBuilder;
+
+    /**
+     * @param \Magento\Framework\UrlInterface $frontendUrlBuilder
+     */
+    public function __construct(\Magento\Framework\UrlInterface $frontendUrlBuilder)
+    {
+        $this->_frontendUrlBuilder = $frontendUrlBuilder;
+    }
+
+    /**
+     * @param string|null $route
+     * @param array|null $params
+     * @return string
+     */
+    public function getUrl($route, $params)
+    {
+        return $this->_frontendUrlBuilder->getUrl($route, $params);
+    }
+}
diff --git a/Model/Usage/Option/Validator/DefaultValidator.php b/Model/Usage/Option/Validator/DefaultValidator.php
new file mode 100644
index 0000000..33d0b5a
--- /dev/null
+++ b/Model/Usage/Option/Validator/DefaultValidator.php
@@ -0,0 +1,167 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Validator;
+
+use DevStone\UsageCalculator\Model\Usage\Option;
+use Zend_Validate_Exception;
+
+class DefaultValidator extends \Magento\Framework\Validator\AbstractValidator
+{
+    /**
+     * Product option types
+     *
+     * @var string[]
+     */
+    protected $productOptionTypes;
+
+    /**
+     * Price types
+     *
+     * @var string[]
+     */
+    protected $priceTypes;
+
+    /**
+     * @param \Magento\Catalog\Model\ProductOptions\ConfigInterface $productOptionConfig
+     * @param \Magento\Catalog\Model\Config\Source\Product\Options\Price $priceConfig
+     */
+    public function __construct(
+        \Magento\Catalog\Model\ProductOptions\ConfigInterface $productOptionConfig,
+        \Magento\Catalog\Model\Config\Source\Product\Options\Price $priceConfig
+    ) {
+        foreach ($productOptionConfig->getAll() as $option) {
+            foreach ($option['types'] as $type) {
+                $this->productOptionTypes[] = $type['name'];
+            }
+        }
+
+        foreach ($priceConfig->toOptionArray() as $item) {
+            $this->priceTypes[] = $item['value'];
+        }
+    }
+
+    /**
+     * Returns true if and only if $value meets the validation requirements
+     *
+     * If $value fails validation, then this method returns false, and
+     * getMessages() will return an array of messages that explain why the
+     * validation failed.
+     *
+     * @param  \Magento\Catalog\Model\Product\Option $value
+     * @return boolean
+     * @throws Zend_Validate_Exception If validation of $value is impossible
+     */
+    public function isValid($value)
+    {
+        $messages = [];
+
+        if (!$this->validateOptionRequiredFields($value)) {
+            $messages['option required fields'] = 'Missed values for option required fields';
+        }
+
+        if (!$this->validateOptionType($value)) {
+            $messages['option type'] = 'Invalid option type';
+        }
+
+        if (!$this->validateOptionValue($value)) {
+            $messages['option values'] = 'Invalid option value';
+        }
+
+        $this->_addMessages($messages);
+
+        return empty($messages);
+    }
+
+    /**
+     * Validate option required fields
+     *
+     * @param Option $option
+     * @return bool
+     */
+    protected function validateOptionRequiredFields(Option $option)
+    {
+        $storeId = \Magento\Store\Model\Store::DEFAULT_STORE_ID;
+        $product = $option->getProduct();
+        if ($product) {
+            $storeId = $product->getStoreId();
+        }
+        $title = $option->getTitle();
+        return $this->isValidOptionTitle($title, $storeId) && !$this->isEmpty($option->getType());
+    }
+
+    /**
+     * Validate option title
+     *
+     * @param string $title
+     * @param int $storeId
+     * @return bool
+     */
+    protected function isValidOptionTitle($title, $storeId)
+    {
+        // we should be able to set null title for not default store (used for deletion from store view)
+        if ($storeId > \Magento\Store\Model\Store::DEFAULT_STORE_ID && $title === null) {
+            return true;
+        }
+        if ($this->isEmpty($title)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Validate option type fields
+     *
+     * @param Option $option
+     * @return bool
+     */
+    protected function validateOptionType(Option $option)
+    {
+        return $this->isInRange($option->getType(), $this->productOptionTypes);
+    }
+
+    /**
+     * Validate option type fields
+     *
+     * @param Option $option
+     * @return bool
+     */
+    protected function validateOptionValue(Option $option)
+    {
+        return $this->isInRange($option->getPriceType(), $this->priceTypes) && !$this->isNegative($option->getPrice());
+    }
+
+    /**
+     * Check whether value is empty
+     *
+     * @param mixed $value
+     * @return bool
+     */
+    protected function isEmpty($value)
+    {
+        return empty($value);
+    }
+
+    /**
+     * Check whether value is in range
+     *
+     * @param string $value
+     * @param array $range
+     * @return bool
+     */
+    protected function isInRange($value, array $range)
+    {
+        return in_array($value, $range);
+    }
+
+    /**
+     * Check whether value is not negative
+     *
+     * @param string $value
+     * @return bool
+     */
+    protected function isNegative($value)
+    {
+        return intval($value) < 0;
+    }
+}
diff --git a/Model/Usage/Option/Validator/File.php b/Model/Usage/Option/Validator/File.php
new file mode 100644
index 0000000..5440d1d
--- /dev/null
+++ b/Model/Usage/Option/Validator/File.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Validator;
+
+use DevStone\UsageCalculator\Model\Usage\Option;
+
+class File extends DefaultValidator
+{
+    /**
+     * Validate option type fields
+     *
+     * @param Option $option
+     * @return bool
+     */
+    protected function validateOptionValue(Option $option)
+    {
+        $result = parent::validateOptionValue($option);
+        return $result && !$this->isNegative($option->getImageSizeX()) && !$this->isNegative($option->getImageSizeY());
+    }
+}
diff --git a/Model/Usage/Option/Validator/Pool.php b/Model/Usage/Option/Validator/Pool.php
new file mode 100644
index 0000000..27cd876
--- /dev/null
+++ b/Model/Usage/Option/Validator/Pool.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Validator;
+
+class Pool
+{
+    /**
+     * @var \Zend_Validate_Interface
+     */
+    protected $validators;
+
+    /**
+     * @param \Zend_Validate_Interface[] $validators
+     */
+    public function __construct(array $validators)
+    {
+        $this->validators = $validators;
+    }
+
+    /**
+     * Get validator
+     *
+     * @param string $type
+     * @return \Zend_Validate_Interface
+     */
+    public function get($type)
+    {
+        return isset($this->validators[$type]) ? $this->validators[$type] : $this->validators['default'];
+    }
+}
diff --git a/Model/Usage/Option/Validator/Select.php b/Model/Usage/Option/Validator/Select.php
new file mode 100644
index 0000000..c2a90a0
--- /dev/null
+++ b/Model/Usage/Option/Validator/Select.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Validator;
+
+use DevStone\UsageCalculator\Model\Usage\Option;
+
+class Select extends DefaultValidator
+{
+    /**
+     * Check if all values are marked for removal
+     *
+     * @param array $values
+     * @return bool
+     */
+    protected function checkAllValuesRemoved($values)
+    {
+        foreach ($values as $value) {
+            if (!array_key_exists('is_delete', $value) || $value['is_delete'] != 1) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Validate option type fields
+     *
+     * @param Option $option
+     * @return bool
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
+     * @SuppressWarnings(PHPMD.NPathComplexity)
+     */
+    protected function validateOptionValue(Option $option)
+    {
+        $values = $option->getValues() ?: $option->getData('values');
+
+        if (!is_array($values) || $this->isEmpty($values)) {
+            return false;
+        }
+
+        //forbid removal of last value for option
+        if ($this->checkAllValuesRemoved($values)) {
+            return false;
+        }
+
+        $storeId = \Magento\Store\Model\Store::DEFAULT_STORE_ID;
+        if ($option->getProduct()) {
+            $storeId = $option->getProduct()->getStoreId();
+        }
+        foreach ($values as $value) {
+            if (isset($value['is_delete']) && (bool)$value['is_delete']) {
+                continue;
+            }
+            $type = isset($value['price_type']) ? $value['price_type'] : null;
+            $price = isset($value['price']) ? $value['price'] : null;
+            $title = isset($value['title']) ? $value['title'] : null;
+            if (!$this->isValidOptionPrice($type, $price, $storeId)
+                || !$this->isValidOptionTitle($title, $storeId)
+            ) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Validate option price
+     *
+     * @param string $priceType
+     * @param int $price
+     * @param int $storeId
+     * @return bool
+     */
+    protected function isValidOptionPrice($priceType, $price, $storeId)
+    {
+        // we should be able to remove website values for default store fallback
+        if ($storeId > \Magento\Store\Model\Store::DEFAULT_STORE_ID && $priceType === null && $price === null) {
+            return true;
+        }
+        if (!$priceType && !$price) {
+            return true;
+        }
+        if (!$this->isInRange($priceType, $this->priceTypes) || $this->isNegative($price)) {
+            return false;
+        }
+
+        return true;
+    }
+}
diff --git a/Model/Usage/Option/Validator/Text.php b/Model/Usage/Option/Validator/Text.php
new file mode 100644
index 0000000..d86971d
--- /dev/null
+++ b/Model/Usage/Option/Validator/Text.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option\Validator;
+
+use DevStone\UsageCalculator\Model\Usage\Option;
+
+class Text extends DefaultValidator
+{
+    /**
+     * Validate option type fields
+     *
+     * @param Option $option
+     * @return bool
+     */
+    protected function validateOptionValue(Option $option)
+    {
+        return parent::validateOptionValue($option);
+    }
+}
diff --git a/Model/Usage/Option/Value.php b/Model/Usage/Option/Value.php
new file mode 100644
index 0000000..90146ac
--- /dev/null
+++ b/Model/Usage/Option/Value.php
@@ -0,0 +1,411 @@
+<?php
+
+namespace DevStone\UsageCalculator\Model\Usage\Option;
+
+use DevStone\UsageCalculator\Model\Usage;
+use DevStone\UsageCalculator\Model\Usage\Option;
+use Magento\Framework\Model\AbstractModel;
+
+/**
+ * Usage option select type model
+ *
+ * @api
+ * @method int getOptionId()
+ * @method \DevStone\UsageCalculator\Model\Usage\Option\Value setOptionId(int $value)
+ *
+ * @SuppressWarnings(PHPMD.LongVariable)
+ */
+class Value extends AbstractModel implements \DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface
+{
+    /**
+     * Option type percent
+     */
+    const TYPE_PERCENT = 'percent';
+
+    /**#@+
+     * Constants
+     */
+    const KEY_TITLE = 'title';
+    const KEY_SORT_ORDER = 'sort_order';
+    const KEY_PRICE = 'price';
+    const KEY_PRICE_TYPE = 'price_type';
+    const KEY_OPTION_TYPE_ID = 'option_type_id';
+    /**#@-*/
+
+    /**#@-*/
+    protected $_values = [];
+
+    /**
+     * @var Product
+     */
+    protected $_product;
+
+    /**
+     * @var Option
+     */
+    protected $_option;
+
+    /**
+     * Value collection factory
+     *
+     * @var \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\CollectionFactory
+     */
+    protected $_valueCollectionFactory;
+
+    /**
+     * @param \Magento\Framework\Model\Context $context
+     * @param \Magento\Framework\Registry $registry
+     * @param \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\CollectionFactory $valueCollectionFactory
+     * @param \Magento\Framework\Model\ResourceModel\AbstractResource $resource
+     * @param \Magento\Framework\Data\Collection\AbstractDb $resourceCollection
+     * @param array $data
+     */
+    public function __construct(
+        \Magento\Framework\Model\Context $context,
+        \Magento\Framework\Registry $registry,
+        \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\CollectionFactory $valueCollectionFactory,
+        \Magento\Framework\Model\ResourceModel\AbstractResource $resource = null,
+        \Magento\Framework\Data\Collection\AbstractDb $resourceCollection = null,
+        array $data = []
+    ) {
+        $this->_valueCollectionFactory = $valueCollectionFactory;
+        parent::__construct(
+            $context,
+            $registry,
+            $resource,
+            $resourceCollection,
+            $data
+        );
+    }
+
+    /**
+     * @return void
+     */
+    protected function _construct()
+    {
+        $this->_init(\DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value::class);
+    }
+
+    /**
+     * @codeCoverageIgnoreStart
+     * @param mixed $value
+     * @return $this
+     */
+    public function addValue($value)
+    {
+        $this->_values[] = $value;
+        return $this;
+    }
+
+    /**
+     * @return array
+     */
+    public function getValues()
+    {
+        return $this->_values;
+    }
+
+    /**
+     * @param array $values
+     * @return $this
+     */
+    public function setValues($values)
+    {
+        $this->_values = $values;
+        return $this;
+    }
+
+    /**
+     * @return $this
+     */
+    public function unsetValues()
+    {
+        $this->_values = [];
+        return $this;
+    }
+
+    /**
+     * @param Option $option
+     * @return $this
+     */
+    public function setOption(Option $option)
+    {
+        $this->_option = $option;
+        return $this;
+    }
+
+    /**
+     * @return $this
+     */
+    public function unsetOption()
+    {
+        $this->_option = null;
+        return $this;
+    }
+
+    /**
+     * Enter description here...
+     *
+     * @return Option
+     */
+    public function getOption()
+    {
+        return $this->_option;
+    }
+
+    /**
+     * @param Usage $usage
+     * @return $this
+     */
+    public function setProduct(Usage $usage)
+    {
+        $this->_usage = $usage;
+        return $this;
+    }
+
+    //@codeCoverageIgnoreEnd
+
+    /**
+     * @return Usage
+     */
+    public function getUsage()
+    {
+        if (is_null($this->_usage)) {
+            $this->_usage = $this->getOption()->getUsage();
+        }
+        return $this->_usage;
+    }
+
+    /**
+     * @return $this
+     */
+    public function saveValues()
+    {
+        foreach ($this->getValues() as $value) {
+            $this->setData(
+                $value
+            )->setData(
+                'option_id',
+                $this->getOption()->getId()
+            )->setData(
+                'store_id',
+                $this->getOption()->getStoreId()
+            );
+
+            if ($this->getData('is_delete') == '1') {
+                if ($this->getId()) {
+                    $this->deleteValues($this->getId());
+                    $this->delete();
+                }
+            } else {
+                $this->save();
+            }
+        }
+        //eof foreach()
+        return $this;
+    }
+
+    /**
+     * Return price. If $flag is true and price is percent
+     *  return converted percent to price
+     *
+     * @param bool $flag
+     * @return float|int
+     */
+    public function getPrice($flag = false)
+    {
+        if ($flag && $this->getPriceType() == self::TYPE_PERCENT) {
+            $basePrice = $this->getOption()->getUsage()->getPrice();
+            $price = $basePrice * ($this->_getData(self::KEY_PRICE) / 100);
+            return $price;
+        }
+        return $this->_getData(self::KEY_PRICE);
+    }
+
+    /**
+     * Return regular price.
+     *
+     * @return float|int
+     */
+    public function getRegularPrice()
+    {
+        if ($this->getPriceType() == self::TYPE_PERCENT) {
+            $basePrice = $this->getOption()->getUsage()->getPrice();
+            $price = $basePrice * ($this->_getData(self::KEY_PRICE) / 100);
+            return $price;
+        }
+        return $this->_getData(self::KEY_PRICE);
+    }
+
+    /**
+     * Enter description here...
+     *
+     * @param Option $option
+     * @return \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\Collection
+     */
+    public function getValuesCollection(Option $option)
+    {
+        $collection = $this->_valueCollectionFactory->create()->addFieldToFilter(
+            'option_id',
+            $option->getId()
+        )->getValues(
+            $option->getStoreId()
+        );
+
+        return $collection;
+    }
+
+    /**
+     * @param array $optionIds
+     * @param int $option_id
+     * @param int $store_id
+     * @return \DevStone\UsageCalculator\Model\ResourceModel\Usage\Option\Value\Collection
+     */
+    public function getValuesByOption($optionIds, $option_id, $store_id)
+    {
+        $collection = $this->_valueCollectionFactory->create()->addFieldToFilter(
+            'option_id',
+            $option_id
+        )->getValuesByOption(
+            $optionIds,
+            $store_id
+        );
+
+        return $collection;
+    }
+
+    /**
+     * @param int $option_id
+     * @return $this
+     */
+    public function deleteValue($option_id)
+    {
+        $this->getResource()->deleteValue($option_id);
+        return $this;
+    }
+
+    /**
+     * @param int $option_type_id
+     * @return $this
+     */
+    public function deleteValues($option_type_id)
+    {
+        $this->getResource()->deleteValues($option_type_id);
+        return $this;
+    }
+
+    /**
+     * Duplicate usage options value
+     *
+     * @param int $oldOptionId
+     * @param int $newOptionId
+     * @return $this
+     */
+    public function duplicate($oldOptionId, $newOptionId)
+    {
+        $this->getResource()->duplicate($this, $oldOptionId, $newOptionId);
+        return $this;
+    }
+
+    /**
+     * Get option title
+     *
+     * @return string
+     * @codeCoverageIgnoreStart
+     */
+    public function getTitle()
+    {
+        return $this->_getData(self::KEY_TITLE);
+    }
+
+    /**
+     * Get sort order
+     *
+     * @return int
+     */
+    public function getSortOrder()
+    {
+        return $this->_getData(self::KEY_SORT_ORDER);
+    }
+
+    /**
+     * Get price type
+     *
+     * @return string
+     */
+    public function getPriceType()
+    {
+        return $this->_getData(self::KEY_PRICE_TYPE);
+    }
+
+
+
+    /**
+     * Get Sku
+     *
+     * @return string|null
+     */
+    public function getOptionTypeId()
+    {
+        return $this->_getData(self::KEY_OPTION_TYPE_ID);
+    }
+
+    /**
+     * Set option title
+     *
+     * @param string $title
+     * @return $this
+     */
+    public function setTitle($title)
+    {
+        return $this->setData(self::KEY_TITLE, $title);
+    }
+
+    /**
+     * Set sort order
+     *
+     * @param int $sortOrder
+     * @return $this
+     */
+    public function setSortOrder($sortOrder)
+    {
+        return $this->setData(self::KEY_SORT_ORDER, $sortOrder);
+    }
+
+    /**
+     * Set price
+     *
+     * @param float $price
+     * @return $this
+     */
+    public function setPrice($price)
+    {
+        return $this->setData(self::KEY_PRICE, $price);
+    }
+
+    /**
+     * Set price type
+     *
+     * @param string $priceType
+     * @return $this
+     */
+    public function setPriceType($priceType)
+    {
+        return $this->setData(self::KEY_PRICE_TYPE, $priceType);
+    }
+
+
+
+    /**
+     * Set Option type id
+     *
+     * @param int $optionTypeId
+     * @return int|null
+     */
+    public function setOptionTypeId($optionTypeId)
+    {
+        return $this->setData(self::KEY_OPTION_TYPE_ID, $optionTypeId);
+    }
+
+    //@codeCoverageIgnoreEnd
+}
diff --git a/Model/Usage/SizesOptionsProvider.php b/Model/Usage/SizesOptionsProvider.php
new file mode 100644
index 0000000..05b0551
--- /dev/null
+++ b/Model/Usage/SizesOptionsProvider.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace DevStone\UsageCalculator\Model\Usage;
+
+class SizesOptionsProvider implements \Magento\Framework\Data\OptionSourceInterface
+{
+    /**
+     * @var \DevStone\UsageCalculator\Api\SizeRepositoryInterface
+     */
+    private $sizeRepository;
+
+    /**
+     * @var \Magento\Framework\Api\SearchCriteriaBuilder
+     */
+    private $searchCriteriaBuilder;
+
+    /**
+     * @var \Magento\Framework\Convert\DataObject
+     */
+    private $objectConverter;
+
+    /**
+     * @param \DevStone\UsageCalculator\Api\SizeRepositoryInterface $groupRepository
+     * @param \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder
+     * @param \Magento\Framework\Convert\DataObject $objectConverter
+     */
+    public function __construct(
+        \DevStone\UsageCalculator\Api\SizeRepositoryInterface $sizeRepository,
+        \Magento\Framework\Api\SearchCriteriaBuilder $searchCriteriaBuilder,
+        \Magento\Framework\Convert\DataObject $objectConverter
+    ) {
+        $this->sizeRepository = $sizeRepository;
+        $this->searchCriteriaBuilder = $searchCriteriaBuilder;
+        $this->objectConverter = $objectConverter;
+    }
+
+    /**
+     * @return array
+     */
+    public function toOptionArray($placeholder = false)
+    {
+        $sizes = $this->sizeRepository->getList(
+            $this->searchCriteriaBuilder->create()
+        )->getItems();
+        
+        $optionArray = $this->objectConverter->toOptionArray($sizes, 'entity_id', 'code');
+		
+		if ($placeholder) {
+			array_unshift($optionArray, ['value' => '', 'label' => $placeholder]);
+		}
+
+		return $optionArray;
+    }
+}
diff --git a/Model/UsageRepository.php b/Model/UsageRepository.php
new file mode 100644
index 0000000..a5e334e
--- /dev/null
+++ b/Model/UsageRepository.php
@@ -0,0 +1,184 @@
+<?php
+
+
+namespace DevStone\UsageCalculator\Model;
+
+use Magento\Framework\Exception\CouldNotDeleteException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\Exception\CouldNotSaveException;
+use DevStone\UsageCalculator\Api\Data\UsageSearchResultsInterfaceFactory;
+use Magento\Framework\Reflection\DataObjectProcessor;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage as ResourceUsage;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\CollectionFactory as UsageCollectionFactory;
+use Magento\Framework\Api\SortOrder;
+use DevStone\UsageCalculator\Api\UsageRepositoryInterface;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Framework\Api\DataObjectHelper;
+
+class UsageRepository implements UsageRepositoryInterface
+{
+
+    protected $dataObjectProcessor;
+
+    protected $usageFactory;
+
+    protected $dataObjectHelper;
+
+    protected $usageCollectionFactory;
+
+    protected $searchResultsFactory;
+
+    protected $resource;
+
+    private $storeManager;
+    
+    /**
+     * @var \Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface
+     */
+    protected $extensionAttributesJoinProcessor;
+
+
+
+    /**
+     * @param ResourceUsage $resource
+     * @param UsageFactory $usageFactory
+     * @param UsageCollectionFactory $usageCollectionFactory
+     * @param UsageSearchResultsInterfaceFactory $searchResultsFactory
+     * @param DataObjectHelper $dataObjectHelper
+     * @param DataObjectProcessor $dataObjectProcessor
+     * @param StoreManagerInterface $storeManager
+     */
+    public function __construct(
+        ResourceUsage $resource,
+        UsageFactory $usageFactory,
+        UsageCollectionFactory $usageCollectionFactory,
+        UsageSearchResultsInterfaceFactory $searchResultsFactory,
+        DataObjectHelper $dataObjectHelper,
+        DataObjectProcessor $dataObjectProcessor,
+        StoreManagerInterface $storeManager,
+        \Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface $extensionAttributesJoinProcessor
+    ) {
+        $this->resource = $resource;
+        $this->usageFactory = $usageFactory;
+        $this->usageCollectionFactory = $usageCollectionFactory;
+        $this->searchResultsFactory = $searchResultsFactory;
+        $this->dataObjectHelper = $dataObjectHelper;
+        $this->dataObjectProcessor = $dataObjectProcessor;
+        $this->storeManager = $storeManager;
+        $this->extensionAttributesJoinProcessor = $extensionAttributesJoinProcessor;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function save(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+    ) {
+        /* if (empty($usage->getStoreId())) {
+            $storeId = $this->storeManager->getStore()->getId();
+            $usage->setStoreId($storeId);
+        } */
+        try {
+            $usage->getResource()->save($usage);
+        } catch (\Exception $exception) {
+            throw new CouldNotSaveException(__(
+                'Could not save the usage: %1',
+                $exception->getMessage()
+            ));
+        }
+        return $usage;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getById($usageId)
+    {
+//        $usage = $this->usageFactory->create();
+//        $usage->setData('store_id', 5);
+//
+//        $usage->getResource()->load($usage, $usageId);
+
+        $collection = $this->usageCollectionFactory->create();
+
+        $collection->addAttributeToSelect('*');
+
+//        $collection->addStoreFilter($this->storeManager->getStore()->getId(), false);
+
+        $collection->addFieldToFilter('entity_id', $usageId);
+
+        $items = $collection->getItems();
+        $usage = current($items);
+        $usage->afterLoad();
+        if (!$usage->getId()) {
+            throw new NoSuchEntityException(__('Usage with id "%1" does not exist.', $usageId));
+        }
+        return $usage;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getList(
+        \Magento\Framework\Api\SearchCriteriaInterface $criteria
+    ) {
+        $collection = $this->usageCollectionFactory->create();
+
+        $collection->addAttributeToSelect('*');
+        
+        foreach ($criteria->getFilterGroups() as $filterGroup) {
+            foreach ($filterGroup->getFilters() as $filter) {
+                if ($filter->getField() === 'store_id') {
+                    $collection->addStoreFilter($filter->getValue(), false);
+                    continue;
+                }
+                $condition = $filter->getConditionType() ?: 'eq';
+                $collection->addFieldToFilter($filter->getField(), [$condition => $filter->getValue()]);
+            }
+        }
+        
+        $sortOrders = $criteria->getSortOrders();
+        if ($sortOrders) {
+            /** @var SortOrder $sortOrder */
+            foreach ($sortOrders as $sortOrder) {
+                $collection->addOrder(
+                    $sortOrder->getField(),
+                    ($sortOrder->getDirection() == SortOrder::SORT_ASC) ? 'ASC' : 'DESC'
+                );
+            }
+        }
+        $collection->setCurPage($criteria->getCurrentPage());
+        $collection->setPageSize($criteria->getPageSize());
+        
+        $searchResults = $this->searchResultsFactory->create();
+        $searchResults->setSearchCriteria($criteria);
+        $searchResults->setTotalCount($collection->getSize());
+        $searchResults->setItems($collection->getItems());
+        return $searchResults;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function delete(
+        \DevStone\UsageCalculator\Api\Data\UsageInterface $usage
+    ) {
+        try {
+            $usage->getResource()->delete($usage);
+        } catch (\Exception $exception) {
+            throw new CouldNotDeleteException(__(
+                'Could not delete the Usage: %1',
+                $exception->getMessage()
+            ));
+        }
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function deleteById($usageId)
+    {
+        return $this->delete($this->getById($usageId));
+    }
+}
diff --git a/Plugin/Block/Product/ListProduct.php b/Plugin/Block/Product/ListProduct.php
new file mode 100644
index 0000000..6016f40
--- /dev/null
+++ b/Plugin/Block/Product/ListProduct.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace DevStone\UsageCalculator\Plugin\Block\Product;
+
+class ListProduct
+{
+
+    /**
+     * @param \Magento\Catalog\Block\Product\ListProduct $subject
+     * @param \Closure $proceed
+     * @param \Magento\Catalog\Model\Product $product
+     * @return string
+     */
+    public function aroundGetProductPrice(
+        \Magento\Catalog\Block\Product\ListProduct $subject,
+        \Closure $proceed,
+        \Magento\Catalog\Model\Product $product
+    ) {
+
+        if (\DevStone\ImageProducts\Model\Product\Type::TYPE_ID !== $product->getTypeId()) {
+            return $proceed($product);
+        }
+
+        $priceText = 'Calculate Price';
+
+        return $priceText;
+    }
+}
diff --git a/Setup/EavTablesSetup.php b/Setup/EavTablesSetup.php
new file mode 100644
index 0000000..dc6f843
--- /dev/null
+++ b/Setup/EavTablesSetup.php
@@ -0,0 +1,203 @@
+<?php
+/**
+ * EavTablesSetup
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Setup;
+
+use Magento\Framework\DB\Adapter\AdapterInterface;
+use Magento\Framework\DB\Ddl\Table;
+use Magento\Framework\Setup\SchemaSetupInterface;
+
+class EavTablesSetup
+{
+    /**
+     * @var SchemaSetupInterface
+     */
+    protected $setup;
+
+    /**
+     * EavTablesSetup constructor.
+     * @param SchemaSetupInterface $setup
+     */
+    public function __construct(SchemaSetupInterface $setup)
+    {
+        $this->setup = $setup;
+    }
+
+    public function createEavTables($entityCode)
+    {
+        $this->createEAVMainTable($entityCode);
+        $this->createEntityTable($entityCode, 'datetime', Table::TYPE_DATETIME);
+        $this->createEntityTable($entityCode, 'decimal', Table::TYPE_DECIMAL, '12,4');
+        $this->createEntityTable($entityCode, 'int', Table::TYPE_INTEGER);
+        $this->createEntityTable($entityCode, 'text', Table::TYPE_TEXT, '64k');
+        $this->createEntityTable($entityCode, 'varchar', Table::TYPE_TEXT, 255);
+    }
+
+    protected function createEAVMainTable($entityCode)
+    {
+        $tableName = $entityCode . '_eav_attribute';
+
+        $table = $this->setup->getConnection()->newTable(
+            $this->setup->getTable($tableName)
+        )->addColumn(
+            'attribute_id',
+            Table::TYPE_SMALLINT,
+            null,
+            ['identity' => false, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+            'Attribute Id'
+        )->addColumn(
+            'is_global',
+            Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '1'],
+            'Is Global'
+        )->addColumn(
+            'is_filterable',
+            Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'Is Filterable'
+        )->addColumn(
+            'is_visible',
+            Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '1'],
+            'Is Visible'
+        )->addColumn(
+            'validate_rules',
+            Table::TYPE_TEXT,
+            '64k',
+            [],
+            'Validate Rules'
+        )->addColumn(
+            'is_system',
+            Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'Is System'
+        )->addColumn(
+            'sort_order',
+            Table::TYPE_INTEGER,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'Sort Order'
+        )->addColumn(
+            'data_model',
+            Table::TYPE_TEXT,
+            255,
+            [],
+            'Data Model'
+        )->addForeignKey(
+            $this->setup->getFkName($tableName, 'attribute_id', 'eav_attribute', 'attribute_id'),
+            'attribute_id',
+            $this->setup->getTable('eav_attribute'),
+            'attribute_id',
+            Table::ACTION_CASCADE
+        )->setComment(
+            $entityCode . 'Eav Attribute'
+        );
+        $this->setup->getConnection()->createTable($table);
+    }
+
+    protected function createEntityTable($entityCode, $type, $valueType, $valueLength = null)
+    {
+        $tableName = $entityCode . '_entity_' . $type;
+
+        $table = $this->setup->getConnection()
+            ->newTable($this->setup->getTable($tableName))
+            ->addColumn(
+                'value_id',
+                Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'nullable' => false, 'primary' => true],
+                'Value ID'
+            )
+            ->addColumn(
+                'attribute_id',
+                Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Attribute ID'
+            )
+            ->addColumn(
+                'store_id',
+                Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'entity_id',
+                Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Entity ID'
+            )
+            ->addColumn(
+                'value',
+                $valueType,
+                $valueLength,
+                [],
+                'Value'
+            )
+            ->addIndex(
+                $this->setup->getIdxName(
+                    $tableName,
+                    ['entity_id', 'attribute_id', 'store_id'],
+                    AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['entity_id', 'attribute_id', 'store_id'],
+                ['type' => AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $this->setup->getIdxName($tableName, ['entity_id']),
+                ['entity_id']
+            )
+            ->addIndex(
+                $this->setup->getIdxName($tableName, ['attribute_id']),
+                ['attribute_id']
+            )
+            ->addIndex(
+                $this->setup->getIdxName($tableName, ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $this->setup->getFkName(
+                    $tableName,
+                    'attribute_id',
+                    'eav_attribute',
+                    'attribute_id'
+                ),
+                'attribute_id',
+                $this->setup->getTable('eav_attribute'),
+                'attribute_id',
+                Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $this->setup->getFkName(
+                    $tableName,
+                    'entity_id',
+                    $entityCode,
+                    'entity_id'
+                ),
+                'entity_id',
+                $this->setup->getTable($entityCode . '_entity'),
+                'entity_id',
+                Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $this->setup->getFkName($tableName, 'store_id', 'store', 'store_id'),
+                'store_id',
+                $this->setup->getTable('store'),
+                'store_id',
+                Table::ACTION_CASCADE
+            )
+            ->setComment($entityCode . ' ' . $type . 'Attribute Backend Table');
+        $this->setup->getConnection()->createTable($table);
+    }
+}
diff --git a/Setup/InstallData.php b/Setup/InstallData.php
new file mode 100644
index 0000000..515cdac
--- /dev/null
+++ b/Setup/InstallData.php
@@ -0,0 +1,58 @@
+<?php
+/**
+ * InstallData
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Setup;
+
+use Magento\Framework\Setup\InstallDataInterface;
+use Magento\Framework\Setup\ModuleContextInterface;
+use Magento\Framework\Setup\ModuleDataSetupInterface;
+
+/**
+ * @codeCoverageIgnore
+ */
+class InstallData implements InstallDataInterface
+{
+    /**
+     * Usage setup factory
+     *
+     * @var UsageSetupFactory
+     */
+    protected $usageSetupFactory;
+    
+
+    /**
+     * Init
+     *
+     * @param UsageSetupFactory $usageSetupFactory
+     */
+    public function __construct(
+        UsageSetupFactory $usageSetupFactory
+    ) {
+        $this->usageSetupFactory = $usageSetupFactory;
+    }
+
+    /**
+     * {@inheritdoc}
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context) //@codingStandardsIgnoreLine
+    {
+        /** @var UsageSetup $usageSetup */
+        $usageSetup = $this->usageSetupFactory->create(['setup' => $setup]);
+        
+        $setup->startSetup();
+
+        $usageSetup->installEntities();
+        $entities = $usageSetup->getDefaultEntities();
+        foreach ($entities as $entityName => $entity) {
+            $usageSetup->addEntityType($entityName, $entity);
+        }
+       
+        $setup->endSetup();
+    }
+}
diff --git a/Setup/InstallSchema.php b/Setup/InstallSchema.php
new file mode 100644
index 0000000..9274d59
--- /dev/null
+++ b/Setup/InstallSchema.php
@@ -0,0 +1,716 @@
+<?php
+/**
+ * installSchema.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Setup;
+
+use Magento\Framework\DB\Ddl\Table;
+use Magento\Framework\Setup\InstallSchemaInterface;
+use Magento\Framework\Setup\ModuleContextInterface;
+use Magento\Framework\Setup\SchemaSetupInterface;
+use DevStone\UsageCalculator\Setup\EavTablesSetupFactory;
+
+/**
+ * @codeCoverageIgnore
+ */
+class InstallSchema implements InstallSchemaInterface
+{
+    /**
+     * @var EavTablesSetupFactory
+     */
+    protected $eavTablesSetupFactory;
+
+    /**
+     * Init
+     *
+     * @internal param EavTablesSetupFactory $EavTablesSetupFactory
+     */
+    public function __construct(EavTablesSetupFactory $eavTablesSetupFactory)
+    {
+        $this->eavTablesSetupFactory = $eavTablesSetupFactory;
+    }
+
+    /**
+     * {@inheritdoc}
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function install(SchemaSetupInterface $setup, ModuleContextInterface $context) //@codingStandardsIgnoreLine
+    {
+        $setup->startSetup();
+        
+        /** @var \DevStone\UsageCalculator\Setup\EavTablesSetup $eavTablesSetup */
+        $eavTablesSetup = $this->eavTablesSetupFactory->create(['setup' => $setup]);
+        
+        $categoryTableName = 'devstone_usage_category';
+
+        $categoryTable = $setup->getConnection()
+            ->newTable($setup->getTable($categoryTableName))
+            ->addColumn(
+                'entity_id',
+                Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Entity ID'
+        )->addColumn(
+            'name',
+            \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+            100,
+            ['nullable' => false, 'default' => ''],
+            'Category Name'
+        )->addColumn(
+            'terms',
+            \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+            10000,
+            ['nullable' => false, 'default' => ''],
+            'Category Terms'
+        )->addColumn(
+            'created_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT],
+            'Creation Time'
+        )->addColumn(
+            'updated_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT_UPDATE],
+            'Update Time'
+        )->setComment('Usage Category Entity Table');
+        
+        $setup->getConnection()->createTable($categoryTable);
+                
+        $sizeTableName = 'devstone_downloadable_image_size';
+
+        $sizeTable = $setup->getConnection()
+            ->newTable($setup->getTable($sizeTableName))
+            ->addColumn(
+                'entity_id',
+                Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Entity ID'
+        )->addColumn(
+            'is_active',
+            \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '1'],
+            'Is Active'
+        )->addColumn(
+            'max_width',
+            \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'maximum width in pixels (0 unlimited)'
+        )->addColumn(
+            'max_height',
+            \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'maximum width in pixels (0 unlimited)'
+        )->addColumn(
+            'code',
+            \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+            100,
+            ['nullable' => false, 'default' => ''],
+            'code to identify size'
+        )->addColumn(
+            'created_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT],
+            'Creation Time'
+        )->addColumn(
+            'updated_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT_UPDATE],
+            'Update Time'
+        )->setComment('Downloadable image sizes');
+        
+        $setup->getConnection()->createTable($sizeTable);
+
+        $tableName = UsageSetup::ENTITY_TYPE_CODE . '_entity';
+        
+        $table = $setup->getConnection()
+            ->newTable($setup->getTable($tableName))
+            ->addColumn(
+                'entity_id',
+                Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Entity ID'
+            )->setComment('Usage Entity Table');
+        $table->addColumn(
+            'category_id',
+            \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'Usage Category Id'
+        )->addIndex(
+            $setup->getIdxName($tableName, ['category_id']),
+            ['category_id']
+        )->addForeignKey(
+            $setup->getFkName($tableName, 'category_id', $categoryTableName, 'entity_id'),
+            'category_id',
+            $setup->getTable($categoryTableName),
+            'entity_id'
+        )->addColumn(
+            'is_active',
+            \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '1'],
+            'Is Active'
+        )->addColumn(
+            'price',
+            \Magento\Framework\DB\Ddl\Table::TYPE_DECIMAL,
+            '12,4',
+            ['nullable' => false, 'default' => '0.0000'],
+            'Price'
+        );
+        
+        $table->addColumn(
+            'size_id',
+            \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+            null,
+            ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+            'Usage Size Id'
+        )->addIndex(
+            $setup->getIdxName($tableName, ['size_id']),
+            ['size_id']
+        )->addForeignKey(
+            $setup->getFkName($tableName, 'size_id', $sizeTableName, 'entity_id'),
+            'size_id',
+            $setup->getTable($sizeTableName),
+            'entity_id'
+        );
+
+        $table->addColumn(
+            'created_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT],
+            'Creation Time'
+        )->addColumn(
+            'updated_at',
+            Table::TYPE_TIMESTAMP,
+            null,
+            ['nullable' => false, 'default' => Table::TIMESTAMP_INIT_UPDATE],
+            'Update Time'
+        );
+
+        $setup->getConnection()->createTable($table);
+
+        $eavTablesSetup->createEavTables(UsageSetup::ENTITY_TYPE_CODE);
+        
+
+        /**
+         * Create table 'devstone_usage_option'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option')
+            )
+            ->addColumn(
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option ID'
+            )
+            ->addColumn(
+                'usage_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Usage ID'
+            )
+            ->addColumn(
+                'type',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                50,
+                ['nullable' => true, 'default' => null],
+                'Type'
+            )
+            ->addColumn(
+                'is_require',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['nullable' => false, 'default' => '1'],
+                'Is Required'
+            )
+            ->addColumn(
+                'sort_order',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Sort Order'
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option', ['usage_id']),
+                ['usage_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option', 'usage_id', UsageSetup::ENTITY_TYPE_CODE.'_entity', 'entity_id'),
+                'usage_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_entity'),
+                'entity_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+
+        /**
+         * Create table 'devstone_usage_option_price'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_price')
+            )
+            ->addColumn(
+                'option_price_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Price ID'
+            )
+            ->addColumn(
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option ID'
+            )
+            ->addColumn(
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'price',
+                \Magento\Framework\DB\Ddl\Table::TYPE_DECIMAL,
+                '12,4',
+                ['nullable' => false, 'default' => '0.0000'],
+                'Price'
+            )
+            ->addColumn(
+                'price_type',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                7,
+                ['nullable' => false, 'default' => 'fixed'],
+                'Price Type'
+            )
+            ->addIndex(
+                $setup->getIdxName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_price',
+                    ['option_id', 'store_id'],
+                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['option_id', 'store_id'],
+                ['type' => \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_price', ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_price',
+                    'option_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option',
+                    'option_id'
+                ),
+                'option_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option'),
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_price', 'store_id', 'store', 'store_id'),
+                'store_id',
+                $setup->getTable('store'),
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Price Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+
+        /**
+         * Create table 'devstone_usage_option_title'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_title')
+            )
+            ->addColumn(
+                'option_title_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Title ID'
+            )
+            ->addColumn(
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option ID'
+            )
+            ->addColumn(
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'title',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                255,
+                ['nullable' => true, 'default' => null],
+                'Title'
+            )
+            ->addIndex(
+                $setup->getIdxName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_title',
+                    ['option_id', 'store_id'],
+                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['option_id', 'store_id'],
+                ['type' => \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_title', ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_title',
+                    'option_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option',
+                    'option_id'
+                ),
+                'option_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option'),
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_title', 'store_id', 'store', 'store_id'),
+                'store_id',
+                $setup->getTable('store'),
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Title Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+		
+		/**
+         * Create table 'devstone_usage_option_help'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_help')
+            )
+            ->addColumn(
+                'option_help_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Title ID'
+            )
+            ->addColumn(
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option ID'
+            )
+            ->addColumn(
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'help',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                1024,
+                ['nullable' => true, 'default' => null],
+                'Help Text'
+            )
+            ->addIndex(
+                $setup->getIdxName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_help',
+                    ['option_id', 'store_id'],
+                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['option_id', 'store_id'],
+                ['type' => \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_title', ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_help',
+                    'option_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option',
+                    'option_id'
+                ),
+                'option_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option'),
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_help', 'store_id', 'store', 'store_id'),
+                'store_id',
+                $setup->getTable('store'),
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Help Text Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+		
+
+        /**
+         * Create table 'devstone_usage_option_type_value'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value')
+            )
+            ->addColumn(
+                'option_type_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Type ID'
+            )
+            ->addColumn(
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option ID'
+            )
+            ->addColumn(
+				'size_id',
+				\Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+				null,
+				['unsigned' => true, 'nullable' => true, 'default' => 'NULL'],
+				'Usage Option Size Id'
+			)->addIndex(
+				$setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value', ['size_id']),
+				['size_id']
+			)->addForeignKey(
+				$setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value', 'size_id', $sizeTableName, 'entity_id'),
+				'size_id',
+				$setup->getTable($sizeTableName),
+				'entity_id'
+			)
+            ->addColumn(
+                'sort_order',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Sort Order'
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value', ['option_id']),
+                ['option_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_value',
+                    'option_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option',
+                    'option_id'
+                ),
+                'option_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option'),
+                'option_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Type Value Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+
+        /**
+         * Create table 'devstone_usage_option_type_price'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_type_price')
+            )
+            ->addColumn(
+                'option_type_price_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Type Price ID'
+            )
+            ->addColumn(
+                'option_type_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option Type ID'
+            )
+            ->addColumn(
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'price',
+                \Magento\Framework\DB\Ddl\Table::TYPE_DECIMAL,
+                '12,4',
+                ['nullable' => false, 'default' => '0.0000'],
+                'Price'
+            )
+            ->addColumn(
+                'price_type',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                7,
+                ['nullable' => false, 'default' => 'fixed'],
+                'Price Type'
+            )
+            ->addIndex(
+                $setup->getIdxName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_price',
+                    ['option_type_id', 'store_id'],
+                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['option_type_id', 'store_id'],
+                ['type' => \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_price', ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_price',
+                    'option_type_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_value',
+                    'option_type_id'
+                ),
+                'option_type_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value'),
+                'option_type_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_price', 'store_id', 'store', 'store_id'),
+                'store_id',
+                $setup->getTable('store'),
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Type Price Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+
+        /**
+         * Create table 'devstone_usage_option_type_title'
+         */
+        $table = $setup->getConnection()
+            ->newTable(
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_type_title')
+            )
+            ->addColumn(
+                'option_type_title_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
+                'Option Type Title ID'
+            )
+            ->addColumn(
+                'option_type_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Option Type ID'
+            )
+            ->addColumn(
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT,
+                null,
+                ['unsigned' => true, 'nullable' => false, 'default' => '0'],
+                'Store ID'
+            )
+            ->addColumn(
+                'title',
+                \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
+                255,
+                ['nullable' => true, 'default' => null],
+                'Title'
+            )
+            ->addIndex(
+                $setup->getIdxName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_title',
+                    ['option_type_id', 'store_id'],
+                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE
+                ),
+                ['option_type_id', 'store_id'],
+                ['type' => \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_UNIQUE]
+            )
+            ->addIndex(
+                $setup->getIdxName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_title', ['store_id']),
+                ['store_id']
+            )
+            ->addForeignKey(
+                $setup->getFkName(
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_title',
+                    'option_type_id',
+                    UsageSetup::ENTITY_TYPE_CODE.'_option_type_value',
+                    'option_type_id'
+                ),
+                'option_type_id',
+                $setup->getTable(UsageSetup::ENTITY_TYPE_CODE.'_option_type_value'),
+                'option_type_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->addForeignKey(
+                $setup->getFkName(UsageSetup::ENTITY_TYPE_CODE.'_option_type_title', 'store_id', 'store', 'store_id'),
+                'store_id',
+                $setup->getTable('store'),
+                'store_id',
+                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
+            )
+            ->setComment(
+                'Usage Option Type Title Table'
+            );
+        $setup->getConnection()
+            ->createTable($table);
+        
+        $setup->endSetup();
+    }
+}
diff --git a/Setup/Uninstall.php b/Setup/Uninstall.php
new file mode 100644
index 0000000..8a8b384
--- /dev/null
+++ b/Setup/Uninstall.php
@@ -0,0 +1,55 @@
+<?php
+
+/**
+ * Uninstall.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Setup;
+
+use Magento\Framework\Setup\UninstallInterface;
+use Magento\Framework\Setup\SchemaSetupInterface;
+use Magento\Framework\Setup\ModuleContextInterface;
+
+class Uninstall implements UninstallInterface
+{
+    /**
+     * @var array
+     */
+    protected $tablesToUninstall = [
+        UsageSetup::ENTITY_TYPE_CODE . '_entity',
+        UsageSetup::ENTITY_TYPE_CODE . '_eav_attribute',
+        UsageSetup::ENTITY_TYPE_CODE . '_entity_datetime',
+        UsageSetup::ENTITY_TYPE_CODE . '_entity_decimal',
+        UsageSetup::ENTITY_TYPE_CODE . '_entity_int',
+        UsageSetup::ENTITY_TYPE_CODE . '_entity_text',
+        UsageSetup::ENTITY_TYPE_CODE . '_entity_varchar',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_eav_attribute',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity_datetime',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity_decimal',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity_int',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity_text',
+        UsageCategorySetup::ENTITY_TYPE_CODE . '_entity_varchar',
+        'devstone_downloadable_image_size',
+    ];
+
+    /**
+     * {@inheritdoc}
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function uninstall(SchemaSetupInterface $setup, ModuleContextInterface $context) //@codingStandardsIgnoreLine
+    {
+        $setup->startSetup();
+
+        foreach ($this->tablesToUninstall as $table) {
+            if ($setup->tableExists($table)) {
+                $setup->getConnection()->dropTable($setup->getTable($table));
+            }
+        }
+
+        $setup->endSetup();
+    }
+}
diff --git a/Setup/UsageSetup.php b/Setup/UsageSetup.php
new file mode 100644
index 0000000..8a9ee6e
--- /dev/null
+++ b/Setup/UsageSetup.php
@@ -0,0 +1,95 @@
+<?php
+/**
+ * UsageSetup
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Setup;
+
+use Magento\Eav\Setup\EavSetup;
+
+/**
+ * @codeCoverageIgnore
+ */
+class UsageSetup extends EavSetup
+{
+    /**
+     * Entity type for Usage EAV attributes
+     */
+    const ENTITY_TYPE_CODE = 'devstone_usage';
+
+    /**
+     * Retrieve Entity Attributes
+     *
+     * @return array
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
+     */
+    protected function getAttributes()
+    {
+        return [
+            'name' => [
+                'type' => 'varchar',
+                'label' => 'Name',
+                'input' => 'text',
+                'sort_order' => 1,
+                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
+                'group' => 'General Information',
+            ],
+            'is_active' => [
+                'type' => 'int',
+                'label' => 'Is Active',
+                'input' => 'select',
+                'source' => \Magento\Eav\Model\Entity\Attribute\Source\Boolean::class,
+                'sort_order' => 10,
+                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
+                'group' => 'General Information',
+            ],
+            'terms' => [
+                'type' => 'text',
+                'label' => 'Description',
+                'input' => 'textarea',
+                'required' => false,
+                'sort_order' => 4,
+                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
+                'wysiwyg_enabled' => true,
+                'is_html_allowed_on_front' => true,
+                'group' => 'General Information',
+            ],
+            'price' => [
+                'type' => 'decimal',
+                'label' => 'Price',
+                'input' => 'price',
+                'backend' => \Magento\Catalog\Model\Product\Attribute\Backend\Price::class,
+                'sort_order' => 1,
+                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
+                'group' => 'General',
+            ],
+        ];
+    }
+
+    /**
+     * Retrieve default entities: usage
+     *
+     * @return array
+     */
+    public function getDefaultEntities()
+    {
+        $categoryAttributes = $this->getAttributes();
+        unset($categoryAttributes['price']);
+        
+        $entities = [
+            self::ENTITY_TYPE_CODE => [
+                'entity_model' => \DevStone\UsageCalculator\Model\ResourceModel\Usage::class,
+                'attribute_model' => \DevStone\UsageCalculator\Model\ResourceModel\Eav\Attribute::class,
+                'table' => self::ENTITY_TYPE_CODE . '_entity',
+                'increment_model' => null,
+                'additional_attribute_table' => self::ENTITY_TYPE_CODE . '_eav_attribute',
+                'entity_attribute_collection' => \DevStone\UsageCalculator\Model\ResourceModel\Attribute\Collection::class,
+                'attributes' => $this->getAttributes(),
+            ],
+        ];
+        return $entities;
+    }
+}
diff --git a/Ui/Component/Form/Category/DataProvider.php b/Ui/Component/Form/Category/DataProvider.php
new file mode 100644
index 0000000..e813ebf
--- /dev/null
+++ b/Ui/Component/Form/Category/DataProvider.php
@@ -0,0 +1,71 @@
+<?php
+/**
+ * DataProvider
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Form\Category;
+
+use Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool;
+use Magento\Ui\DataProvider\AbstractDataProvider;
+use DevStone\UsageCalculator\Model\ResourceModel\Category\Collection;
+
+class DataProvider extends AbstractDataProvider
+{
+    /**
+     * @var Collection
+     */
+    protected $collection;
+    
+    /**
+     * @var FilterPool
+     */
+    protected $filterPool;
+
+    /**
+     * @var array
+     */
+    protected $loadedData;
+
+    /**
+     * Construct
+     *
+     * @param string $name
+     * @param string $primaryFieldName
+     * @param string $requestFieldName
+     * @param Collection $collection
+     * @param FilterPool $filterPool
+     * @param array $meta
+     * @param array $data
+     */
+    public function __construct(
+        $name,
+        $primaryFieldName,
+        $requestFieldName,
+        Collection $collection,
+        FilterPool $filterPool,
+        array $meta = [],
+        array $data = []
+    ) {
+        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
+        $this->collection = $collection;
+        $this->filterPool = $filterPool;
+    }
+
+    /**
+     * Get data
+     *
+     * @return array
+     */
+    public function getData()
+    {
+        if (!$this->loadedData) {
+            $items = $this->collection->getItems();       
+            foreach ($items as $item) {
+                $this->loadedData[$item->getId()] = $item->getData();
+            }
+        }
+        return $this->loadedData;
+    }
+}
diff --git a/Ui/Component/Form/Size/DataProvider.php b/Ui/Component/Form/Size/DataProvider.php
new file mode 100644
index 0000000..3029577
--- /dev/null
+++ b/Ui/Component/Form/Size/DataProvider.php
@@ -0,0 +1,87 @@
+<?php
+/**
+ * DataProvider
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Form\Size;
+
+use Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool;
+use Magento\Ui\DataProvider\AbstractDataProvider;
+use DevStone\UsageCalculator\Model\ResourceModel\Size\Collection;
+
+class DataProvider extends AbstractDataProvider
+{
+    /**
+     * @var Collection
+     */
+    protected $collection;
+    
+    /**
+     * @var FilterPool
+     */
+    protected $filterPool;
+
+    /**
+     * @var array
+     */
+    protected $loadedData;
+
+    /**
+     * Construct
+     *
+     * @param string $name
+     * @param string $primaryFieldName
+     * @param string $requestFieldName
+     * @param Collection $collection
+     * @param FilterPool $filterPool
+     * @param array $meta
+     * @param array $data
+     */
+    public function __construct(
+        $name,
+        $primaryFieldName,
+        $requestFieldName,
+        Collection $collection,
+        FilterPool $filterPool,
+        array $meta = [],
+        array $data = []
+    ) {
+        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
+        $this->collection = $collection;
+        $this->filterPool = $filterPool;
+    }
+
+    /**
+     * Get data
+     *
+     * @return array
+     */
+    public function getData()
+    {
+        if (!$this->loadedData) {
+            $items = $this->collection->getItems();
+            foreach ($items as $item) {
+                
+                $this->loadedData[$item->getId()] = $item->getData();
+                break;
+            }
+        }
+        return $this->loadedData;
+        
+        
+        $data = $this->dataPersistor->get('devstone_pricecalculator_usage');
+        
+        if (!empty($data)) {
+            $model = $this->collection->getNewEmptyItem();
+            $model->setData($data);
+            $this->loadedData[$model->getId()] = $model->getData();
+            $this->dataPersistor->clear('devstone_pricecalculator_usage');
+        }
+        
+        return $this->loadedData;
+    }
+    
+    
+}
diff --git a/Ui/Component/Form/Usage/DataProvider.php b/Ui/Component/Form/Usage/DataProvider.php
new file mode 100644
index 0000000..6c6d9cc
--- /dev/null
+++ b/Ui/Component/Form/Usage/DataProvider.php
@@ -0,0 +1,106 @@
+<?php
+/**
+ * DataProvider
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Form\Usage;
+
+use Magento\Framework\App\RequestInterface;
+use Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool;
+use Magento\Ui\DataProvider\AbstractDataProvider;
+use DevStone\UsageCalculator\Model\ResourceModel\Usage\Collection;
+
+class DataProvider extends AbstractDataProvider
+{
+    /**
+     * @var Collection
+     */
+    protected $collection;
+    
+    /**
+     * @var FilterPool
+     */
+    protected $filterPool;
+
+    /**
+     * @var array
+     */
+    protected $loadedData;
+
+    /**
+     * @var RequestInterface
+     */
+    protected $request;
+
+    /**
+     * @var UsageOptions
+     */
+    protected $usageOptions;
+    
+    /**
+     * Construct
+     *
+     * @param string $name
+     * @param string $primaryFieldName
+     * @param string $requestFieldName
+     * @param Collection $collection
+     * @param FilterPool $filterPool
+     * @param RequestInterface $request
+     * @param UsageOptions $usageOptions
+     * @param array $meta
+     * @param array $data
+     */
+    public function __construct(
+        $name,
+        $primaryFieldName,
+        $requestFieldName,
+        Collection $collection,
+        FilterPool $filterPool,
+        RequestInterface $request,
+        UsageOptions $usageOptions,
+        array $meta = [],
+        array $data = []
+    ) {
+        parent::__construct($name, $primaryFieldName, $requestFieldName, $meta, $data);
+        $this->collection = $collection;
+        $this->filterPool = $filterPool;
+        
+        $this->request = $request;
+        $this->usageOptions = $usageOptions;
+    }
+
+    /**
+     * Get data
+     *
+     * @return array
+     */
+    public function getData()
+    {
+        if (!$this->loadedData) {
+            $this->loadedData = [];
+            $storeId = (int)$this->request->getParam('store');
+            $this->collection
+                ->setStoreId($storeId)
+                ->addAttributeToSelect('*');
+            $items = $this->collection->getItems();
+            foreach ($items as $item) {
+                $item->setStoreId($storeId);
+                $this->loadedData[$item->getId()] = $item->getData();
+                break;
+            }
+            
+            $this->loadedData = $this->usageOptions->modifydata($this->loadedData);
+        }
+        return $this->loadedData;
+    }
+
+    public function getMeta() 
+    {
+        $meta = parent::getMeta();
+        
+        return $this->usageOptions->modifyMeta($meta);
+    }
+
+}
diff --git a/Ui/Component/Form/Usage/UsageOptions.php b/Ui/Component/Form/Usage/UsageOptions.php
new file mode 100644
index 0000000..78be963
--- /dev/null
+++ b/Ui/Component/Form/Usage/UsageOptions.php
@@ -0,0 +1,966 @@
+<?php
+
+namespace DevStone\UsageCalculator\Ui\Component\Form\Usage;
+
+use Magento\Catalog\Model\Locator\LocatorInterface;
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\Catalog\Model\Config\Source\Product\Options\Price as ProductOptionsPrice;
+use Magento\Framework\UrlInterface;
+use Magento\Framework\Stdlib\ArrayManager;
+use Magento\Ui\Component\Modal;
+use Magento\Ui\Component\Container;
+use Magento\Ui\Component\DynamicRows;
+use Magento\Ui\Component\Form\Fieldset;
+use Magento\Ui\Component\Form\Field;
+use Magento\Ui\Component\Form\Element\Input;
+use Magento\Ui\Component\Form\Element\Select;
+use Magento\Ui\Component\Form\Element\Checkbox;
+use Magento\Ui\Component\Form\Element\ActionDelete;
+use Magento\Ui\Component\Form\Element\DataType\Text;
+use Magento\Ui\Component\Form\Element\DataType\Number;
+use Magento\Framework\Locale\CurrencyInterface;
+
+/**
+ * Data provider for "Usage Options" panel
+ *
+ * @api
+ *
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ */
+class UsageOptions extends \Magento\Catalog\Ui\DataProvider\Product\Form\Modifier\AbstractModifier
+{    
+    const DATA_SOURCE_DEFAULT = 'usage';
+
+    /**#@+
+     * Group values
+     */
+    const GROUP_CUSTOM_OPTIONS_NAME = 'custom_options';
+    const GROUP_CUSTOM_OPTIONS_SCOPE = 'usage';
+    const GROUP_CUSTOM_OPTIONS_PREVIOUS_NAME = 'search-engine-optimization';
+    const GROUP_CUSTOM_OPTIONS_DEFAULT_SORT_ORDER = 31;
+    /**#@-*/
+
+    /**#@+
+     * Button values
+     */
+    const BUTTON_ADD = 'button_add';
+    const BUTTON_IMPORT = 'button_import';
+    /**#@-*/
+
+    /**#@+
+     * Container values
+     */
+    const CONTAINER_HEADER_NAME = 'container_header';
+    const CONTAINER_OPTION = 'container_option';
+    const CONTAINER_COMMON_NAME = 'container_common';
+    const CONTAINER_TYPE_STATIC_NAME = 'container_type_static';
+    /**#@-*/
+
+    /**#@+
+     * Grid values
+     */
+    const GRID_OPTIONS_NAME = 'options';
+    const GRID_TYPE_SELECT_NAME = 'values';
+    /**#@-*/
+
+    /**#@+
+     * Field values
+     */
+    const FIELD_ENABLE = 'affect_usage_custom_options';
+    const FIELD_OPTION_ID = 'option_id';
+    const FIELD_TITLE_NAME = 'title';
+	const FIELD_HELP_NAME = 'help';
+    const FIELD_STORE_TITLE_NAME = 'store_title';
+    const FIELD_TYPE_NAME = 'type';
+    const FIELD_IS_REQUIRE_NAME = 'is_require';
+    const FIELD_SORT_ORDER_NAME = 'sort_order';
+    const FIELD_PRICE_NAME = 'price';
+    const FIELD_PRICE_TYPE_NAME = 'price_type';
+    const FIELD_IMAGE_SIZE = 'size_id';
+    const FIELD_IS_DELETE = 'is_delete';
+    const FIELD_IS_USE_DEFAULT = 'is_use_default';
+    /**#@-*/
+
+    /**#@+
+     * Import options values
+     */
+    const IMPORT_OPTIONS_MODAL = 'import_options_modal';
+    const CUSTOM_OPTIONS_LISTING = 'product_custom_options_listing';
+    /**#@-*/
+
+    /**
+     * @var LocatorInterface
+     */
+    protected $locator;
+
+    /**
+     * @var \Magento\Store\Model\StoreManagerInterface
+     */
+    protected $storeManager;
+
+    /**
+     * @var \Magento\Catalog\Model\Config\Source\Product\Options\Price
+     */
+    protected $productOptionsPrice;
+
+    /**
+     * @var UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * @var ArrayManager
+     */
+    protected $arrayManager;
+
+    /**
+     * @var array
+     */
+    protected $meta = [];
+
+    /**
+     * @var CurrencyInterface
+     */
+    private $localeCurrency;
+    
+    
+    /**
+     * @var \DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface 
+     */
+    protected $optionRepository;
+	
+	/**
+	 * @var \DevStone\UsageCalculator\Model\Usage\SizesOptionsProvider
+	 */
+	protected $sizesOptionsProvider;
+
+	/**
+     * @param LocatorInterface $locator
+     * @param StoreManagerInterface $storeManager
+     * @param ProductOptionsPrice $productOptionsPrice
+     * @param UrlInterface $urlBuilder
+     * @param ArrayManager $arrayManager
+     */
+    public function __construct(
+        LocatorInterface $locator,
+        StoreManagerInterface $storeManager,
+        ProductOptionsPrice $productOptionsPrice,
+        UrlInterface $urlBuilder,
+        ArrayManager $arrayManager,
+        \DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface $optionRepo,
+		\DevStone\UsageCalculator\Model\Usage\SizesOptionsProvider $sizesOptionsProvider
+    ) {
+        $this->locator = $locator;
+        $this->storeManager = $storeManager;
+        $this->productOptionsPrice = $productOptionsPrice;
+        $this->urlBuilder = $urlBuilder;
+        $this->arrayManager = $arrayManager;
+        $this->optionRepository = $optionRepo;
+		$this->sizesOptionsProvider = $sizesOptionsProvider;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function modifyData(array $data)
+    {
+        foreach($data as $id => &$usage) {
+            $options = [];
+            $productOptions = $this->optionRepository->getList($id);
+            /** @var \DevStone\UsageCalculator\Model\Usage\Option $option */
+            foreach ($productOptions as $index => $option) {
+                $optionData = $option->getData();
+                $optionData[static::FIELD_IS_USE_DEFAULT] = !$option->getData(static::FIELD_STORE_TITLE_NAME);
+                $options[$index] = $this->formatPriceByPath(static::FIELD_PRICE_NAME, $optionData);
+                $values = $option->getValues() ?: [];
+
+                foreach ($values as $value) {
+                    $value->setData(static::FIELD_IS_USE_DEFAULT, !$value->getData(static::FIELD_STORE_TITLE_NAME));
+                }
+                /** @var \Magento\Catalog\Model\Product\Option $value */
+                foreach ($values as $value) {
+                    $options[$index][static::GRID_TYPE_SELECT_NAME][] = $this->formatPriceByPath(
+                        static::FIELD_PRICE_NAME,
+                        $value->getData()
+                    );
+                }
+            }
+            
+            $usage[static::DATA_SOURCE_DEFAULT] = [
+                static::FIELD_ENABLE => 1,
+                static::GRID_OPTIONS_NAME => $options,
+            ];
+        }
+        
+        return $data;
+    }
+
+    /**
+     * Format float number to have two digits after delimiter
+     *
+     * @param string $path
+     * @param array $data
+     * @return array
+     */
+    protected function formatPriceByPath($path, array $data)
+    {
+        $value = $this->arrayManager->get($path, $data);
+
+        if (is_numeric($value)) {
+            $data = $this->arrayManager->replace($path, $data, $this->formatPrice($value));
+        }
+
+        return $data;
+    }
+
+    /**
+     * {@inheritdoc}
+     * @since 101.0.0
+     */
+    public function modifyMeta(array $meta)
+    {
+        $this->meta = $meta;
+
+        $this->createCustomOptionsPanel();
+
+        return $this->meta;
+    }
+
+    /**
+     * Create "Customizable Options" panel
+     *
+     * @return $this
+     * @since 101.0.0
+     */
+    protected function createCustomOptionsPanel()
+    {
+        $this->meta = array_replace_recursive(
+            $this->meta,
+            [
+                static::GROUP_CUSTOM_OPTIONS_NAME => [
+                    'arguments' => [
+                        'data' => [
+                            'config' => [
+                                'label' => __('Usage Options'),
+                                'componentType' => Fieldset::NAME,
+                                'dataScope' => static::GROUP_CUSTOM_OPTIONS_SCOPE,
+                                'collapsible' => false,
+                                'sortOrder' => $this->getNextGroupSortOrder(
+                                    $this->meta,
+                                    static::GROUP_CUSTOM_OPTIONS_PREVIOUS_NAME,
+                                    static::GROUP_CUSTOM_OPTIONS_DEFAULT_SORT_ORDER
+                                ),
+                            ],
+                        ],
+                    ],
+                    'children' => [
+                        static::CONTAINER_HEADER_NAME => $this->getHeaderContainerConfig(10),
+                        static::FIELD_ENABLE => $this->getEnableFieldConfig(20),
+                        static::GRID_OPTIONS_NAME => $this->getOptionsGridConfig(30)
+                    ]
+                ]
+            ]
+        );
+
+
+        return $this;
+    }
+
+    /**
+     * Get config for header container
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getHeaderContainerConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'label' => null,
+                        'formElement' => Container::NAME,
+                        'componentType' => Container::NAME,
+                        'template' => 'ui/form/components/complex',
+                        'sortOrder' => $sortOrder,
+                        'content' => __('Usage options provide more details about how an image will be used.'),
+                    ],
+                ],
+            ],
+            'children' => [
+                static::BUTTON_ADD => [
+                    'arguments' => [
+                        'data' => [
+                            'config' => [
+                                'title' => __('Add Option'),
+                                'formElement' => Container::NAME,
+                                'componentType' => Container::NAME,
+                                'component' => 'Magento_Ui/js/form/components/button',
+                                'sortOrder' => 20,
+                                'actions' => [
+                                    [
+                                        'targetName' => 'ns = ${ $.ns }, index = ' . static::GRID_OPTIONS_NAME,
+                                        'actionName' => 'processingAddChild',
+                                    ]
+                                ]
+                            ]
+                        ],
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for the whole grid
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getOptionsGridConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'addButtonLabel' => __('Add Option'),
+                        'componentType' => DynamicRows::NAME,
+                        'component' => 'Magento_Catalog/js/components/dynamic-rows-import-custom-options',
+                        'template' => 'ui/dynamic-rows/templates/collapsible',
+                        'additionalClasses' => 'admin__field-wide',
+                        'deleteProperty' => static::FIELD_IS_DELETE,
+                        'deleteValue' => '1',
+                        'addButton' => false,
+                        'renderDefaultRecord' => false,
+                        'columnsHeader' => false,
+                        'collapsibleHeader' => true,
+                        'sortOrder' => $sortOrder,
+                        'dataProvider' => static::CUSTOM_OPTIONS_LISTING,
+                        'imports' => ['insertData' => '${ $.provider }:${ $.dataProvider }'],
+                    ],
+                ],
+            ],
+            'children' => [
+                'record' => [
+                    'arguments' => [
+                        'data' => [
+                            'config' => [
+                                'headerLabel' => __('New Option'),
+                                'componentType' => Container::NAME,
+                                'component' => 'Magento_Ui/js/dynamic-rows/record',
+                                'positionProvider' => static::CONTAINER_OPTION . '.' . static::FIELD_SORT_ORDER_NAME,
+                                'isTemplate' => true,
+                                'is_collection' => true,
+                            ],
+                        ],
+                    ],
+                    'children' => [
+                        static::CONTAINER_OPTION => [
+                            'arguments' => [
+                                'data' => [
+                                    'config' => [
+                                        'componentType' => Fieldset::NAME,
+                                        'collapsible' => true,
+                                        'label' => null,
+                                        'sortOrder' => 10,
+                                        'opened' => true,
+                                    ],
+                                ],
+                            ],
+                            'children' => [
+                                static::FIELD_SORT_ORDER_NAME => $this->getPositionFieldConfig(40),
+                                static::CONTAINER_COMMON_NAME => $this->getCommonContainerConfig(10),
+                                static::CONTAINER_TYPE_STATIC_NAME => $this->getStaticTypeContainerConfig(20),
+                                static::GRID_TYPE_SELECT_NAME => $this->getSelectTypeGridConfig(30)
+                            ]
+                        ],
+                    ]
+                ]
+            ]
+        ];
+    }
+
+    /**
+     * Get config for hidden field responsible for enabling custom options processing
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getEnableFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'formElement' => Field::NAME,
+                        'componentType' => Input::NAME,
+                        'dataScope' => static::FIELD_ENABLE,
+                        'dataType' => Number::NAME,
+                        'visible' => false,
+                        'sortOrder' => $sortOrder,
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for container with common fields for any type
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getCommonContainerConfig($sortOrder)
+    {
+        $commonContainer = [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'componentType' => Container::NAME,
+                        'formElement' => Container::NAME,
+                        'component' => 'Magento_Ui/js/form/components/group',
+                        'breakLine' => false,
+                        'showLabel' => false,
+                        'additionalClasses' => 'admin__field-group-columns admin__control-group-equal',
+                        'sortOrder' => $sortOrder,
+                    ],
+                ],
+            ],
+            'children' => [
+                static::FIELD_OPTION_ID => $this->getOptionIdFieldConfig(10),
+                static::FIELD_TITLE_NAME => $this->getTitleFieldConfig(
+                    20,
+                    [
+                        'arguments' => [
+                            'data' => [
+                                'config' => [
+                                    'label' => __('Option Title'),
+                                    'component' => 'Magento_Catalog/component/static-type-input',
+                                    'valueUpdate' => 'input',
+                                    'imports' => [
+                                        'optionId' => '${ $.provider }:${ $.parentScope }.option_id',
+                                        'isUseDefault' => '${ $.provider }:${ $.parentScope }.is_use_default'
+                                    ]
+                                ],
+                            ],
+                        ],
+                    ]
+                ),
+				static::FIELD_HELP_NAME => [
+					'arguments' => [
+						'data' => [
+							'config' => [
+								'label' => __('Help Text'),
+								'component' => 'Magento_Catalog/component/static-type-input',
+								'componentType' => Field::NAME,
+								'formElement' => Input::NAME,
+								'dataScope' => static::FIELD_HELP_NAME,
+								'dataType' => Text::NAME,
+								'sortOrder' => 21,
+								'validation' => [
+									'required-entry' => true
+								],
+								'imports' => [
+									'optionId' => '${ $.provider }:${ $.parentScope }.option_id',
+									'isUseDefault' => '${ $.provider }:${ $.parentScope }.is_use_default'
+								]
+							],
+						],
+					],
+				],
+                static::FIELD_TYPE_NAME => $this->getTypeFieldConfig(30),
+                static::FIELD_IS_REQUIRE_NAME => $this->getIsRequireFieldConfig(40)
+            ]
+        ];
+
+        return $commonContainer;
+    }
+
+    /**
+     * Get config for container with fields for all types except "select"
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getStaticTypeContainerConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'componentType' => Container::NAME,
+                        'formElement' => Container::NAME,
+                        'component' => 'Magento_Ui/js/form/components/group',
+                        'breakLine' => false,
+                        'showLabel' => false,
+                        'additionalClasses' => 'admin__field-group-columns admin__control-group-equal',
+                        'sortOrder' => $sortOrder,
+                        'fieldTemplate' => 'Magento_Catalog/form/field',
+                        'visible' => false,
+                    ],
+                ],
+            ],
+            'children' => [
+                static::FIELD_PRICE_NAME => $this->getPriceFieldConfig(10),
+                static::FIELD_PRICE_TYPE_NAME => $this->getPriceTypeFieldConfig(20),
+            ]
+        ];
+    }
+
+    /**
+     * Get config for grid for "select" types
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getSelectTypeGridConfig($sortOrder)
+    {
+        $options = [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'imports' => [
+                            'optionId' => '${ $.provider }:${ $.parentScope }.option_id',
+                            'optionTypeId' => '${ $.provider }:${ $.parentScope }.option_type_id',
+                            'isUseDefault' => '${ $.provider }:${ $.parentScope }.is_use_default'
+                        ],
+                        'service' => [
+                            'template' => 'Magento_Catalog/form/element/helper/custom-option-type-service',
+                        ],
+                    ],
+                ],
+            ],
+        ];
+
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'addButtonLabel' => __('Add Value'),
+                        'componentType' => DynamicRows::NAME,
+                        'component' => 'Magento_Ui/js/dynamic-rows/dynamic-rows',
+                        'additionalClasses' => 'admin__field-wide',
+                        'deleteProperty' => static::FIELD_IS_DELETE,
+                        'deleteValue' => '1',
+                        'renderDefaultRecord' => false,
+                        'sortOrder' => $sortOrder,
+                    ],
+                ],
+            ],
+            'children' => [
+                'record' => [
+                    'arguments' => [
+                        'data' => [
+                            'config' => [
+                                'componentType' => Container::NAME,
+                                'component' => 'Magento_Ui/js/dynamic-rows/record',
+                                'positionProvider' => static::FIELD_SORT_ORDER_NAME,
+                                'isTemplate' => true,
+                                'is_collection' => true,
+                            ],
+                        ],
+                    ],
+                    'children' => [
+                        static::FIELD_TITLE_NAME => $this->getTitleFieldConfig(
+                            10,
+                            [] 
+                        ),
+                        static::FIELD_PRICE_NAME => $this->getPriceFieldConfigForSelectType(20),
+                        static::FIELD_PRICE_TYPE_NAME => $this->getPriceTypeFieldConfig(30, ['fit' => true]),
+						static::FIELD_IMAGE_SIZE => $this->getImageSizeFieldConfig(40),
+                        static::FIELD_SORT_ORDER_NAME => $this->getPositionFieldConfig(50),
+                        static::FIELD_IS_DELETE => $this->getIsDeleteFieldConfig(60)
+                    ]
+                ]
+            ]
+        ];
+    }
+
+    /**
+     * Get config for hidden id field
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getOptionIdFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'formElement' => Input::NAME,
+                        'componentType' => Field::NAME,
+                        'dataScope' => static::FIELD_OPTION_ID,
+                        'sortOrder' => $sortOrder,
+                        'visible' => false,
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for "Title" fields
+     *
+     * @param int $sortOrder
+     * @param array $options
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getTitleFieldConfig($sortOrder, array $options = [])
+    {
+        return array_replace_recursive(
+            [
+                'arguments' => [
+                    'data' => [
+                        'config' => [
+                            'label' => __('Title'),
+                            'componentType' => Field::NAME,
+                            'formElement' => Input::NAME,
+                            'dataScope' => static::FIELD_TITLE_NAME,
+                            'dataType' => Text::NAME,
+                            'sortOrder' => $sortOrder,
+                            'validation' => [
+                                'required-entry' => true
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+            $options
+        );
+    }
+
+    /**
+     * Get config for "Option Type" field
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getTypeFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'label' => __('Option Type'),
+                        'componentType' => Field::NAME,
+                        'formElement' => Select::NAME,
+                        'component' => 'Magento_Catalog/js/custom-options-type',
+                        'elementTmpl' => 'ui/grid/filters/elements/ui-select',
+                        'selectType' => 'optgroup',
+                        'dataScope' => static::FIELD_TYPE_NAME,
+                        'dataType' => Text::NAME,
+                        'sortOrder' => $sortOrder,
+                        'options' => $this->getProductOptionTypes(),
+                        'disableLabel' => true,
+                        'multiple' => false,
+                        'selectedPlaceholders' => [
+                            'defaultPlaceholder' => __('-- Please select --'),
+                        ],
+                        'validation' => [
+                            'required-entry' => true
+                        ],
+                        'groupsConfig' => [
+                            'text' => [
+                                'values' => ['field', 'area'],
+                                'indexes' => [
+                                    static::CONTAINER_TYPE_STATIC_NAME,
+                                    static::FIELD_PRICE_NAME,
+                                    static::FIELD_PRICE_TYPE_NAME
+                                ]
+                            ],
+                            'select' => [
+                                'values' => ['drop_down', 'radio', 'checkbox', 'multiple'],
+                                'indexes' => [
+                                    static::GRID_TYPE_SELECT_NAME
+                                ]
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for "Required" field
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getIsRequireFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'label' => __('Required'),
+                        'componentType' => Field::NAME,
+                        'formElement' => Checkbox::NAME,
+                        'dataScope' => static::FIELD_IS_REQUIRE_NAME,
+                        'dataType' => Text::NAME,
+                        'sortOrder' => $sortOrder,
+                        'value' => '1',
+                        'valueMap' => [
+                            'true' => '1',
+                            'false' => '0'
+                        ],
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for hidden field used for sorting
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getPositionFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'componentType' => Field::NAME,
+                        'formElement' => Input::NAME,
+                        'dataScope' => static::FIELD_SORT_ORDER_NAME,
+                        'dataType' => Number::NAME,
+                        'visible' => false,
+                        'sortOrder' => $sortOrder,
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for hidden field used for removing rows
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getIsDeleteFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'componentType' => ActionDelete::NAME,
+                        'fit' => true,
+                        'sortOrder' => $sortOrder
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for "Price" field
+     *
+     * @param int $sortOrder
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getPriceFieldConfig($sortOrder)
+    {
+        return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'label' => __('Price'),
+                        'componentType' => Field::NAME,
+                        'component' => 'Magento_Catalog/js/components/custom-options-component',
+                        'formElement' => Input::NAME,
+                        'dataScope' => static::FIELD_PRICE_NAME,
+                        'dataType' => Number::NAME,
+                        'addbefore' => $this->getCurrencySymbol(),
+                        'addbeforePool' => $this->productOptionsPrice->prefixesToOptionArray(),
+                        'sortOrder' => $sortOrder,
+                        'validation' => [
+                            'validate-zero-or-greater' => true
+                        ],
+                    ],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Get config for "Price" field for select type.
+     *
+     * @param int $sortOrder
+     * @return array
+     */
+    private function getPriceFieldConfigForSelectType($sortOrder)
+    {
+        $priceFieldConfig = $this->getPriceFieldConfig($sortOrder);
+        $priceFieldConfig['arguments']['data']['config']['template'] = 'Magento_Catalog/form/field';
+
+        return $priceFieldConfig;
+    }
+
+    /**
+     * Get config for "Price Type" field
+     *
+     * @param int $sortOrder
+     * @param array $config
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getPriceTypeFieldConfig($sortOrder, array $config = [])
+    {
+        return array_replace_recursive(
+            [
+                'arguments' => [
+                    'data' => [
+                        'config' => [
+                            'label' => __('Price Type'),
+                            'component' => 'Magento_Catalog/js/components/custom-options-price-type',
+                            'componentType' => Field::NAME,
+                            'formElement' => Select::NAME,
+                            'dataScope' => static::FIELD_PRICE_TYPE_NAME,
+                            'dataType' => Text::NAME,
+                            'sortOrder' => $sortOrder,
+                            'options' => $this->productOptionsPrice->toOptionArray(),
+                            'imports' => [
+                                'priceIndex' => self::FIELD_PRICE_NAME,
+                            ],
+                        ],
+                    ],
+                ],
+            ],
+            $config
+        );
+    }
+	
+	protected function getImageSizeFieldConfig($sortOrder)
+	{
+		return [
+            'arguments' => [
+                'data' => [
+                    'config' => [
+                        'label' => __('Image Size'),
+                        'componentType' => Field::NAME,
+                        'formElement' => Select::NAME,
+                        'dataScope' => static::FIELD_IMAGE_SIZE,
+                        'dataType' => Text::NAME,
+                        'sortOrder' => $sortOrder,
+                        'options' => $this->sizesOptionsProvider->toOptionArray('---'),
+                    ],
+                ],
+            ],
+        ];
+	}
+
+    /**
+     * Get options for drop-down control with product option types
+     *
+     * @return array
+     * @since 101.0.0
+     */
+    protected function getProductOptionTypes()
+    {
+        
+        return  array(
+                    array(
+                        'value' => 0,
+                        'label' => 'Text',
+                        'optgroup' =>
+                        array(
+                            array(
+                                'label' => 'Field',
+                                'value' => 'field',
+                            ),
+                            array(
+                                'label' => 'Area',
+                                'value' => 'area',
+                            ),
+                        ),
+                    ),
+                    array(
+                        'value' => 2,
+                        'label' => 'Select',
+                        'optgroup' =>
+                        array(
+                            array(
+                                'label' => 'Drop-down',
+                                'value' => 'drop_down',
+                            ),
+                            array(
+                                'label' => 'Radio Buttons',
+                                'value' => 'radio',
+                            ),
+                            array(
+                                'label' => 'Checkbox',
+                                'value' => 'checkbox',
+                            ),
+                            array(
+                                'label' => 'Multiple Select',
+                                'value' => 'multiple',
+                            ),
+                        ),
+                    ),
+                    
+        );
+    }
+
+    /**
+     * Get currency symbol
+     *
+     * @return string
+     * @since 101.0.0
+     */
+    protected function getCurrencySymbol()
+    {
+        return $this->storeManager->getStore()->getBaseCurrency()->getCurrencySymbol();
+    }
+
+    /**
+     * The getter function to get the locale currency for real application code
+     *
+     * @return \Magento\Framework\Locale\CurrencyInterface
+     *
+     * @deprecated 101.0.0
+     */
+    private function getLocaleCurrency()
+    {
+        if ($this->localeCurrency === null) {
+            $this->localeCurrency = \Magento\Framework\App\ObjectManager::getInstance()->get(CurrencyInterface::class);
+        }
+        return $this->localeCurrency;
+    }
+
+    /**
+     * Format price according to the locale of the currency
+     *
+     * @param mixed $value
+     * @return string
+     * @since 101.0.0
+     */
+    protected function formatPrice($value)
+    {
+        if (!is_numeric($value)) {
+            return null;
+        }
+
+        $store = $this->storeManager->getStore();
+        $currency = $this->getLocaleCurrency()->getCurrency($store->getBaseCurrencyCode());
+        $value = $currency->toCurrency($value, ['display' => \Magento\Framework\Currency::NO_SYMBOL]);
+
+        return $value;
+    }
+}
diff --git a/Ui/Component/Listing/Column/CategoryActions.php b/Ui/Component/Listing/Column/CategoryActions.php
new file mode 100644
index 0000000..938248b
--- /dev/null
+++ b/Ui/Component/Listing/Column/CategoryActions.php
@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * CategoryActions.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Listing\Column;
+
+use Magento\Framework\UrlInterface;
+use Magento\Framework\View\Element\UiComponent\ContextInterface;
+use Magento\Framework\View\Element\UiComponentFactory;
+use Magento\Ui\Component\Listing\Columns\Column;
+
+class CategoryActions extends Column
+{
+    /**
+     * Url path
+     */
+    const URL_PATH_EDIT = 'devstone_usagecalculator/category/edit';
+
+    /**
+     * @var UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param ContextInterface $context
+     * @param UiComponentFactory $uiComponentFactory
+     * @param UrlInterface $urlBuilder
+     * @param array $components
+     * @param array $data
+     */
+    public function __construct(
+        ContextInterface $context,
+        UiComponentFactory $uiComponentFactory,
+        UrlInterface $urlBuilder,
+        array $components = [],
+        array $data = []
+    ) {
+        $this->urlBuilder = $urlBuilder;
+        parent::__construct($context, $uiComponentFactory, $components, $data);
+    }
+
+    /**
+     * Prepare Data Source
+     *
+     * @param array $dataSource
+     * @return array
+     */
+    public function prepareDataSource(array $dataSource)
+    {
+        if (isset($dataSource['data']['items'])) {
+            $storeId = $this->context->getFilterParam('store_id');
+
+            foreach ($dataSource['data']['items'] as &$item) {
+                if (isset($item['entity_id'])) {
+                    $item[$this->getData('name')]['edit'] = [
+                        'href' => $this->urlBuilder->getUrl(
+                            self::URL_PATH_EDIT,
+                            ['entity_id' => $item['entity_id'], 'store' => $storeId]
+                        ),
+                        'label' => __('Edit'),
+                        'hidden' => false,
+                    ];
+                }
+            }
+        }
+
+        return $dataSource;
+    }
+}
diff --git a/Ui/Component/Listing/Column/SizeActions.php b/Ui/Component/Listing/Column/SizeActions.php
new file mode 100644
index 0000000..12fb1fc
--- /dev/null
+++ b/Ui/Component/Listing/Column/SizeActions.php
@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * SizeActions.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Listing\Column;
+
+use Magento\Framework\UrlInterface;
+use Magento\Framework\View\Element\UiComponent\ContextInterface;
+use Magento\Framework\View\Element\UiComponentFactory;
+use Magento\Ui\Component\Listing\Columns\Column;
+
+class SizeActions extends Column
+{
+    /**
+     * Url path
+     */
+    const URL_PATH_EDIT = 'devstone_usagecalculator/size/edit';
+
+    /**
+     * @var UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param ContextInterface $context
+     * @param UiComponentFactory $uiComponentFactory
+     * @param UrlInterface $urlBuilder
+     * @param array $components
+     * @param array $data
+     */
+    public function __construct(
+        ContextInterface $context,
+        UiComponentFactory $uiComponentFactory,
+        UrlInterface $urlBuilder,
+        array $components = [],
+        array $data = []
+    ) {
+        $this->urlBuilder = $urlBuilder;
+        parent::__construct($context, $uiComponentFactory, $components, $data);
+    }
+
+    /**
+     * Prepare Data Source
+     *
+     * @param array $dataSource
+     * @return array
+     */
+    public function prepareDataSource(array $dataSource)
+    {
+        if (isset($dataSource['data']['items'])) {
+            $storeId = $this->context->getFilterParam('store_id');
+
+            foreach ($dataSource['data']['items'] as &$item) {
+                if (isset($item['entity_id'])) {
+                    $item[$this->getData('name')]['edit'] = [
+                        'href' => $this->urlBuilder->getUrl(
+                            self::URL_PATH_EDIT,
+                            ['entity_id' => $item['entity_id'], 'store' => $storeId]
+                        ),
+                        'label' => __('Edit'),
+                        'hidden' => false,
+                    ];
+                }
+            }
+        }
+
+        return $dataSource;
+    }
+}
diff --git a/Ui/Component/Listing/Column/UsageActions.php b/Ui/Component/Listing/Column/UsageActions.php
new file mode 100644
index 0000000..5f179d6
--- /dev/null
+++ b/Ui/Component/Listing/Column/UsageActions.php
@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * UsageActions.php
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+namespace DevStone\UsageCalculator\Ui\Component\Listing\Column;
+
+use Magento\Framework\UrlInterface;
+use Magento\Framework\View\Element\UiComponent\ContextInterface;
+use Magento\Framework\View\Element\UiComponentFactory;
+use Magento\Ui\Component\Listing\Columns\Column;
+
+class UsageActions extends Column
+{
+    /**
+     * Url path
+     */
+    const URL_PATH_EDIT = 'devstone_usagecalculator/usage/edit';
+
+    /**
+     * @var UrlInterface
+     */
+    protected $urlBuilder;
+
+    /**
+     * Constructor
+     *
+     * @param ContextInterface $context
+     * @param UiComponentFactory $uiComponentFactory
+     * @param UrlInterface $urlBuilder
+     * @param array $components
+     * @param array $data
+     */
+    public function __construct(
+        ContextInterface $context,
+        UiComponentFactory $uiComponentFactory,
+        UrlInterface $urlBuilder,
+        array $components = [],
+        array $data = []
+    ) {
+        $this->urlBuilder = $urlBuilder;
+        parent::__construct($context, $uiComponentFactory, $components, $data);
+    }
+
+    /**
+     * Prepare Data Source
+     *
+     * @param array $dataSource
+     * @return array
+     */
+    public function prepareDataSource(array $dataSource)
+    {
+        if (isset($dataSource['data']['items'])) {
+            $storeId = $this->context->getFilterParam('store_id');
+
+            foreach ($dataSource['data']['items'] as &$item) {
+                if (isset($item['entity_id'])) {
+                    $item[$this->getData('name')]['edit'] = [
+                        'href' => $this->urlBuilder->getUrl(
+                            self::URL_PATH_EDIT,
+                            ['entity_id' => $item['entity_id'], 'store' => $storeId]
+                        ),
+                        'label' => __('Edit'),
+                        'hidden' => false,
+                    ];
+                }
+            }
+        }
+
+        return $dataSource;
+    }
+}
diff --git a/Ui/Component/Listing/DataProvider.php b/Ui/Component/Listing/DataProvider.php
new file mode 100644
index 0000000..eb0d0c2
--- /dev/null
+++ b/Ui/Component/Listing/DataProvider.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ * DataProvider
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Ui\Component\Listing;
+
+use Magento\Framework\Api\Search\SearchResultInterface;
+use Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider as UiDataProvider;
+
+class DataProvider extends UiDataProvider
+{
+    /**
+     * @param SearchResultInterface $searchResult
+     * @return array
+     */
+    protected function searchResultToOutput(SearchResultInterface $searchResult)
+    {
+        $searchResult->setStoreId($this->request->getParam('store', 0))
+            ->addAttributeToSelect(['price', 'name', 'terms']); 
+
+        return parent::searchResultToOutput($searchResult);
+    }
+
+    /**
+     * @return void
+     */
+    protected function prepareUpdateUrl()
+    {
+        $storeId = $this->request->getParam('store', 0);
+        if ($storeId) {
+            $this->data['config']['update_url'] = sprintf(
+                '%s%s/%s',
+                $this->data['config']['update_url'],
+                'store',
+                $storeId
+            );
+        }
+        return parent::prepareUpdateUrl();
+    }
+}
diff --git a/Ui/Component/Listing/DataProvider/Document.php b/Ui/Component/Listing/DataProvider/Document.php
new file mode 100644
index 0000000..fcafb96
--- /dev/null
+++ b/Ui/Component/Listing/DataProvider/Document.php
@@ -0,0 +1,19 @@
+<?php
+/**
+ * Document
+ *
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+
+namespace DevStone\UsageCalculator\Ui\Component\Listing\DataProvider;
+
+class Document extends \Magento\Framework\View\Element\UiComponent\DataProvider\Document
+{
+    protected $_idFieldName = 'entity_id';
+
+    public function getIdFieldName()
+    {
+        return $this->_idFieldName;
+    }
+}
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..e9e5c8a
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,19 @@
+{
+  "name": "devstone/magento2-module-usagecalculator",
+  "description": "Usage calculator for purchasing images or artwork at various resolutions.",
+  "type": "magento2-module",
+  "license": [
+    "GPL-3.0"
+  ],
+  "require": {
+    "devstone/module-imageproducts": "*"
+  },
+  "autoload": {
+    "files": [
+      "registration.php"
+    ],
+    "psr-4": {
+      "DevStone\\UsageCalculator\\": ""
+    }
+  }
+}
diff --git a/etc/acl.xml b/etc/acl.xml
new file mode 100644
index 0000000..209d6e4
--- /dev/null
+++ b/etc/acl.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * acl
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
+    <acl>
+        <resources>
+            <resource id="Magento_Backend::admin">
+                <resource id="DevStone_UsageCalculator::usage" title="Usage" sortOrder="10" />
+                <resource id="DevStone_UsageCalculator::size" title="Size" sortOrder="11" />
+                <resource id="DevStone_UsageCalculator::category" title="Category" sortOrder="12" />
+            </resource>
+        </resources>
+    </acl>
+</config>
diff --git a/etc/adminhtml/menu.xml b/etc/adminhtml/menu.xml
new file mode 100644
index 0000000..f2bcc00
--- /dev/null
+++ b/etc/adminhtml/menu.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * menu
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Backend:etc/menu.xsd">
+    <menu>
+        <add id="DevStone_UsageCalculator::usaget_elements" title="Calculator" translate="title" module="DevStone_UsageCalculator" sortOrder="20" parent="Magento_Catalog::catalog" resource="DevStone_UsageCalculator::usaget_elements"/>
+        
+        <add id="DevStone_UsageCalculator::category" title="Categories" module="DevStone_UsageCalculator" sortOrder="20" parent="DevStone_UsageCalculator::usaget_elements" action="devstone_usagecalculator/category" resource="DevStone_UsageCalculator::category"/>
+        <add id="DevStone_UsageCalculator::usage" title="Usages" module="DevStone_UsageCalculator" sortOrder="25" parent="DevStone_UsageCalculator::usaget_elements" action="devstone_usagecalculator/usage" resource="DevStone_UsageCalculator::usage"/>
+        <add id="DevStone_UsageCalculator::size" title="Image Sizes" module="DevStone_UsageCalculator" sortOrder="30" parent="DevStone_UsageCalculator::usaget_elements" action="devstone_usagecalculator/size" resource="DevStone_UsageCalculator::size"/>
+    </menu>
+</config>
diff --git a/etc/adminhtml/routes.xml b/etc/adminhtml/routes.xml
new file mode 100644
index 0000000..71d1cc9
--- /dev/null
+++ b/etc/adminhtml/routes.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * routes
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
+    <router id="admin">
+        <route id="devstone_usagecalculator" frontName="devstone_usagecalculator">
+            <module name="DevStone_UsageCalculator" />
+        </route>
+    </router>
+</config>
diff --git a/etc/di.xml b/etc/di.xml
new file mode 100644
index 0000000..8ad6bb9
--- /dev/null
+++ b/etc/di.xml
@@ -0,0 +1,181 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * di
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
+    <!-- Temporal fix to 2.1 problem with eav attributes: https://github.com/magento/magento2/issues/5339 -->
+    <type name="Magento\Eav\Model\Entity\AttributeCache">
+        <arguments>
+            <argument name="unsupportedTypes" xsi:type="array">
+                <item name="devstone_usage" xsi:type="string">devstone_usage</item>
+            </argument>
+        </arguments>
+    </type>
+    <!-- end temporal fix -->
+    <type name="DevStone\UsageCalculator\UI\Component\Listing\DataProvider">
+        <arguments>
+            <argument name="collection" xsi:type="object" shared="false">DevStone\UsageCalculator\Model\ResourceModel\Usage\Collection</argument>
+            <argument name="filterPool" xsi:type="object" shared="false">RefGridFilterPool</argument>
+        </arguments>
+    </type>
+    <virtualType name="RefGridFilterPool" type="Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool">
+        <arguments>
+            <argument name="appliers" xsi:type="array">
+                <item name="regular" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\RegularFilter</item>
+                <item name="fulltext" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\FulltextFilter</item>
+            </argument>
+        </arguments>
+    </virtualType>
+    <type name="Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory">
+        <arguments>
+            <argument name="collections" xsi:type="array">
+                <item name="devstone_usagecalculator_usage_listing_data_source" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Usage\Grid\Collection</item>
+            </argument>
+        </arguments>
+    </type>
+    <type name="DevStone\UsageCalculator\Model\ResourceModel\Usage\Grid\Collection">
+        <arguments>
+            <argument name="eventPrefix" xsi:type="string">devstone_usagecalculator_usage_grid_collection</argument>
+            <argument name="eventObject" xsi:type="string">devstone_usagecalculator_usage_grid_collection</argument>
+            <argument name="resourceModel" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Usage</argument>
+        </arguments>
+    </type>
+    <virtualType name="DevStoneSizeGridDataProvider" type="Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider">
+        <arguments>
+            <argument name="collection" xsi:type="object" shared="false">DevStone\UsageCalculator\Model\ResourceModel\Size\Collection</argument>
+            <argument name="filterPool" xsi:type="object" shared="false">DevStoneSizeGridFilterPool</argument>
+        </arguments>
+    </virtualType>
+    <virtualType name="DevStoneSizeGridFilterPool" type="Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool">
+        <arguments>
+            <argument name="appliers" xsi:type="array">
+                <item name="regular" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\RegularFilter</item>
+                <item name="fulltext" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\FulltextFilter</item>
+            </argument>
+        </arguments>
+    </virtualType>
+    
+    <virtualType name="DevStoneCategoryGridDataProvider" type="Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider">
+        <arguments>
+            <argument name="collection" xsi:type="object" shared="false">DevStone\UsageCalculator\Model\ResourceModel\Category\Collection</argument>
+            <argument name="filterPool" xsi:type="object" shared="false">DevStoneCategoryGridFilterPool</argument>
+        </arguments>
+    </virtualType>
+    <virtualType name="DevStoneCategoryGridFilterPool" type="Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool">
+        <arguments>
+            <argument name="appliers" xsi:type="array">
+                <item name="regular" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\RegularFilter</item>
+                <item name="fulltext" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\FulltextFilter</item>
+            </argument>
+        </arguments>
+    </virtualType>
+    
+    <type name="Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory">
+        <arguments>
+            <argument name="collections" xsi:type="array">
+                <item name="devstone_usagecalculator_size_listing_data_source" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Size\Grid\Collection</item>
+                <item name="devstone_usagecalculator_category_listing_data_source" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Category\Grid\Collection</item>
+            </argument>
+        </arguments>
+    </type>
+    <type name="DevStone\UsageCalculator\Model\ResourceModel\Size\Grid\Collection">
+        <arguments>
+            <argument name="mainTable" xsi:type="string">devstone_downloadable_image_size</argument>
+            <argument name="eventPrefix" xsi:type="string">devstone_usagecalculator_size_grid_collection</argument>
+            <argument name="eventObject" xsi:type="string">devstone_usagecalculator_size_grid_collection</argument>
+            <argument name="resourceModel" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Size</argument>
+        </arguments>
+    </type>
+    
+    <type name="DevStone\UsageCalculator\Model\ResourceModel\Category\Grid\Collection">
+        <arguments>
+            <argument name="mainTable" xsi:type="string">devstone_usage_category</argument>
+            <argument name="eventPrefix" xsi:type="string">devstone_usagecalculator_category_grid_collection</argument>
+            <argument name="eventObject" xsi:type="string">devstone_usagecalculator_category_grid_collection</argument>
+            <argument name="resourceModel" xsi:type="string">DevStone\UsageCalculator\Model\ResourceModel\Category</argument>
+        </arguments>
+    </type>
+    
+    <preference for="DevStone\UsageCalculator\Api\UsageRepositoryInterface" type="DevStone\UsageCalculator\Model\UsageRepository"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\UsageInterface" type="DevStone\UsageCalculator\Model\Usage"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\UsageSearchResultsInterface" type="Magento\Framework\Api\SearchResults"/>
+    
+    <preference for="DevStone\UsageCalculator\Api\SizeRepositoryInterface" type="DevStone\UsageCalculator\Model\SizeRepository"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\SizeInterface" type="DevStone\UsageCalculator\Model\Size"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\SizeSearchResultsInterface" type="Magento\Framework\Api\SearchResults"/>
+    
+    <preference for="DevStone\UsageCalculator\Api\CategoryRepositoryInterface" type="DevStone\UsageCalculator\Model\CategoryRepository"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\CategoryInterface" type="DevStone\UsageCalculator\Model\Category"/>
+	<preference for="DevStone\UsageCalculator\Api\Data\CategorySearchResultsInterface" type="Magento\Framework\Api\SearchResults"/>
+    
+    <type name="DevStone\UsageCalculator\Model\Usage\Option\Validator\Pool">
+        <arguments>
+            <argument name="validators" xsi:type="array">
+                <item name="default" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\DefaultValidator</item>
+                <item name="drop_down" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Select</item>
+                <item name="radio" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Select</item>
+                <item name="checkbox" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Select</item>
+                <item name="multiple" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Select</item>
+                <item name="text" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Text</item>
+                <item name="area" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\Text</item>
+                <item name="file" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Validator\File</item>
+            </argument>
+        </arguments>
+    </type>
+    <type name="DevStone\UsageCalculator\Model\Usage\Option\Type\File">
+        <arguments>
+            <argument name="validatorInfo" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Type\File\ValidatorInfo\Proxy</argument>
+            <argument name="validatorFile" xsi:type="object">DevStone\UsageCalculator\Model\Usage\Option\Type\File\ValidatorFile\Proxy</argument>
+        </arguments>
+    </type>
+    <preference for="DevStone\UsageCalculator\Api\Data\UsageCustomOptionInterface" type="DevStone\UsageCalculator\Model\Usage\Option" />
+    <preference for="DevStone\UsageCalculator\Api\UsageCustomOptionRepositoryInterface" type="DevStone\UsageCalculator\Model\Usage\Option\Repository" />
+    <preference for="DevStone\UsageCalculator\Api\Data\UsageCustomOptionTypeInterface" type="DevStone\UsageCalculator\Model\Usage\Option\Type" />
+    
+    <preference for="DevStone\UsageCalculator\Api\UsageCustomOptionTypeListInterface" type="DevStone\UsageCalculator\Model\UsageOptions\TypeList" />
+    <preference for="DevStone\UsageCalculator\Api\Data\UsageCustomOptionValuesInterface" type="DevStone\UsageCalculator\Model\Usage\Option\Value" />
+    <preference for="DevStone\UsageCalculator\Api\Data\CustomOptionInterface" type="DevStone\UsageCalculator\Model\CustomOptions\CustomOption" />
+    <preference for="DevStone\UsageCalculator\Api\Data\UsageOptionInterface" type="DevStone\UsageCalculator\Model\UsageOption" />    
+    
+<!--    
+    <type name="Magento\Quote\Model\Quote\Item\Repository">
+        <arguments>
+            <argument name="cartItemProcessors" xsi:type="array">
+                <item name="custom_options" xsi:type="object">Magento\Catalog\Model\CustomOptions\CustomOptionProcessor\Proxy</item>
+            </argument>
+        </arguments>
+    </type>
+    <type name="Magento\Sales\Api\OrderItemRepositoryInterface">
+        <arguments>
+            <argument name="processorPool" xsi:type="array">
+                <item name="custom_options" xsi:type="object">Magento\Catalog\Model\UsageOptionProcessor</item>
+            </argument>
+        </arguments>
+    </type>-->
+<!--    This is the new hottness but only works if we are using entityManager which isn't in 2.
+    <type name="Magento\Framework\EntityManager\Operation\ExtensionPool">
+        <arguments>
+            <argument name="extensionActions" xsi:type="array">
+                <item name="DevStone\UsageCalculator\Api\Data\UsageInterface" xsi:type="array">
+                    <item name="read" xsi:type="array">
+                        <item name="usageOptionReader" xsi:type="string">DevStone\UsageCalculator\Model\Usage\Option\ReadHandler</item>
+                    </item>
+                    <item name="create" xsi:type="array">
+                        <item name="usage_custom_options" xsi:type="string">DevStone\UsageCalculator\Model\Usage\Option\SaveHandler</item>
+                    </item>
+                    <item name="update" xsi:type="array">
+                        <item name="usageOptionUpdater" xsi:type="string">DevStone\UsageCalculator\Model\Usage\Option\SaveHandler</item>
+                    </item>
+                </item>
+            </argument>
+        </arguments>
+    </type>-->
+    
+    <type name="Magento\Catalog\Block\Product\ListProduct">
+        <plugin name="devstone_calculate_price" type="DevStone\UsageCalculator\Plugin\Block\Product\ListProduct" sortOrder="1"/>
+    </type>
+</config>
\ No newline at end of file
diff --git a/etc/extension_attributesb.xml b/etc/extension_attributesb.xml
new file mode 100644
index 0000000..c21a4ae
--- /dev/null
+++ b/etc/extension_attributesb.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd">
+<!--    <extension_attributes for="DevStone\UsageCalculator\Api\Data\UsageInterface">
+        <attribute code="terms" type="string" />
+        <attribute code="name" type="string" />
+    </extension_attributes>-->
+</config>
+
diff --git a/etc/module.xml b/etc/module.xml
new file mode 100644
index 0000000..083f03d
--- /dev/null
+++ b/etc/module.xml
@@ -0,0 +1,8 @@
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
+    <module name="DevStone_UsageCalculator" setup_version="1.0.0" >
+        <sequence>
+            <module name="Magento_Catalog"/>
+            <module name="Magento_Sales"/>
+        </sequence>
+    </module>
+</config>
\ No newline at end of file
diff --git a/registration.php b/registration.php
new file mode 100644
index 0000000..e432869
--- /dev/null
+++ b/registration.php
@@ -0,0 +1,6 @@
+<?php
+\Magento\Framework\Component\ComponentRegistrar::register(
+    \Magento\Framework\Component\ComponentRegistrar::MODULE,
+    'DevStone_UsageCalculator',
+    __DIR__
+);
diff --git a/view/adminhtml/layout/devstone_usagecalculator_category_edit.xml b/view/adminhtml/layout/devstone_usagecalculator_category_edit.xml
new file mode 100644
index 0000000..773b171
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_category_edit.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_category_edit
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="admin-1column"
+      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_category_form"/>
+        </referenceContainer>
+    </body>
+</page>
\ No newline at end of file
diff --git a/view/adminhtml/layout/devstone_usagecalculator_category_index.xml b/view/adminhtml/layout/devstone_usagecalculator_category_index.xml
new file mode 100644
index 0000000..c95e843
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_category_index.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_category_index
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_category_listing"/>
+        </referenceContainer>
+    </body>
+</page>
+
diff --git a/view/adminhtml/layout/devstone_usagecalculator_size_edit.xml b/view/adminhtml/layout/devstone_usagecalculator_size_edit.xml
new file mode 100644
index 0000000..58a39f5
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_size_edit.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_size_edit
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="admin-1column"
+      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_size_form"/>
+        </referenceContainer>
+    </body>
+</page>
\ No newline at end of file
diff --git a/view/adminhtml/layout/devstone_usagecalculator_size_index.xml b/view/adminhtml/layout/devstone_usagecalculator_size_index.xml
new file mode 100644
index 0000000..cea4ad9
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_size_index.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_size_index
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_size_listing"/>
+        </referenceContainer>
+    </body>
+</page>
+
diff --git a/view/adminhtml/layout/devstone_usagecalculator_usage_edit.xml b/view/adminhtml/layout/devstone_usagecalculator_usage_edit.xml
new file mode 100644
index 0000000..fffa9db
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_usage_edit.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_usage_edit
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="admin-1column"
+      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="page.main.actions">
+            <block class="Magento\Backend\Block\Store\Switcher" name="devstone_usagecalculator_usage.store.switcher" template="Magento_Backend::store/switcher.phtml" >
+                <action method="setUseConfirm">
+                    <argument name="params" xsi:type="string">1</argument>
+                </action>
+            </block>
+        </referenceContainer>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_usage_form"/>
+        </referenceContainer>
+    </body>
+</page>
\ No newline at end of file
diff --git a/view/adminhtml/layout/devstone_usagecalculator_usage_index.xml b/view/adminhtml/layout/devstone_usagecalculator_usage_index.xml
new file mode 100644
index 0000000..05919b4
--- /dev/null
+++ b/view/adminhtml/layout/devstone_usagecalculator_usage_index.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_usage_index
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="page.main.actions">
+            <block class="Magento\Backend\Block\Store\Switcher" name="devstone_usagecalculator_usage.store.switcher" template="Magento_Backend::store/switcher.phtml" >
+                <action method="setUseConfirm">
+                    <argument name="params" xsi:type="string">1</argument>
+                </action>
+            </block>
+        </referenceContainer>
+        <referenceContainer name="content">
+            <uiComponent name="devstone_usagecalculator_usage_listing"/>
+        </referenceContainer>
+    </body>
+</page>
+
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_category_form.xml b/view/adminhtml/ui_component/devstone_usagecalculator_category_form.xml
new file mode 100644
index 0000000..e869f30
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_category_form.xml
@@ -0,0 +1,93 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_category_form
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_category_form.devstone_usagecalculator_category_form_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_category_form.devstone_usagecalculator_category_form_data_source</item>
+        </item>
+        <item name="config" xsi:type="array">
+            <item name="dataScope" xsi:type="string">data</item>
+        </item>
+        <item name="template" xsi:type="string">templates/form/collapsible</item>
+        <item name="label" xsi:type="string" translate="true">Category Form</item>
+        <item name="buttons" xsi:type="array">
+            <item name="back" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Category\Edit\BackButton</item>
+            <item name="delete" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Category\Edit\DeleteButton</item>
+            <item name="save" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Category\Edit\SaveButton</item>
+            <item name="save_and_continue" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Category\Edit\SaveAndContinueButton</item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_category_form_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStone\UsageCalculator\Ui\Component\Form\Category\DataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_category_form_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">entity_id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="submit_url" xsi:type="url" path="*/*/save"/>
+                    <item name="validate_url" xsi:type="url" path="*/*/validate"/>
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <fieldset name="main_fieldset">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="label" xsi:type="string" translate="true">Main Information</item>
+            </item>
+        </argument>
+        <field name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">false</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+        </field>
+        <field name="name">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string">Name</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">1</item>
+                </item>
+            </argument>
+        </field>
+        <field name="terms">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string">Terms</item>
+                    <item name="formElement" xsi:type="string">textarea</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+    </fieldset>
+</form>
\ No newline at end of file
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_category_listing.xml b/view/adminhtml/ui_component/devstone_usagecalculator_category_listing.xml
new file mode 100644
index 0000000..050c7d1
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_category_listing.xml
@@ -0,0 +1,241 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+/**
+ * devstone_usagecalculator_category_list
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing_data_source</item>
+        </item>
+        <item name="spinner" xsi:type="string">devstone_usagecalculator_category_columns</item>
+        <item name="buttons" xsi:type="array">
+            <item name="add" xsi:type="array">
+                <item name="name" xsi:type="string">add</item>
+                <item name="label" xsi:type="string" translate="true">Add New Category</item>
+                <item name="class" xsi:type="string">primary</item>
+                <item name="url" xsi:type="string">*/*/edit</item>
+            </item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_category_listing_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStoneCategoryGridDataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_category_listing_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="update_url" xsi:type="url" path="mui/index/render"/>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="indexField" xsi:type="string">entity_id</item>
+                    </item>
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/grid/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <container name="listing_top">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="template" xsi:type="string">ui/grid/toolbar</item>
+            </item>
+        </argument>
+        <bookmark name="bookmarks">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="namespace" xsi:type="string">devstone_usagecalculator_category_listing</item>
+                    </item>
+                </item>
+            </argument>
+        </bookmark>
+        <component name="columns_controls">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsData" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns</item>
+                    </item>
+                    <item name="component" xsi:type="string">Magento_Ui/js/grid/controls/columns</item>
+                    <item name="displayArea" xsi:type="string">dataGridActions</item>
+                </item>
+            </argument>
+        </component>
+        <filterSearch name="fulltext">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing_data_source</item>
+                    <item name="chipsProvider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.listing_filters_chips</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.search</item>
+                    </item>
+                </item>
+            </argument>
+        </filterSearch>
+        <filters name="listing_filters">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsProvider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.filters</item>
+                    </item>
+                    <item name="templates" xsi:type="array">
+                        <item name="filters" xsi:type="array">
+                            <item name="select" xsi:type="array">
+                                <item name="component" xsi:type="string">Magento_Ui/js/form/element/ui-select</item>
+                                <item name="template" xsi:type="string">ui/grid/filters/elements/ui-select</item>
+                            </item>
+                        </item>
+                    </item>
+                    <item name="childDefaults" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.listing_filters</item>
+                        <item name="imports" xsi:type="array">
+                            <item name="visible" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns.${ $.index }:visible</item>
+                        </item>
+                    </item>
+                </item>
+            </argument>
+        </filters>
+        <massaction name="listing_massaction">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns.ids</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+            <action name="delete">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">delete</item>
+                        <item name="label" xsi:type="string" translate="true">Delete</item>
+                        <item name="url" xsi:type="url" path="*/*/massDelete"/>
+                        <item name="confirm" xsi:type="array">
+                            <item name="title" xsi:type="string" translate="true">Delete items</item>
+                            <item name="message" xsi:type="string" translate="true">Are you sure you wan't to delete selected items?</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+            <action name="edit">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">edit</item>
+                        <item name="label" xsi:type="string" translate="true">Edit</item>
+                        <item name="callback" xsi:type="array">
+                            <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns_editor</item>
+                            <item name="target" xsi:type="string">editSelected</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+        </massaction>
+        <paging name="listing_paging">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.paging</item>
+                    </item>
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns.ids</item>
+                </item>
+            </argument>
+        </paging>
+    </container>
+    <columns name="devstone_usagecalculator_category_columns">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="storageConfig" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.bookmarks</item>
+                    <item name="namespace" xsi:type="string">current</item>
+                </item>
+                <item name="editorConfig" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns.ids</item>
+                    <item name="enabled" xsi:type="boolean">true</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                    <item name="clientConfig" xsi:type="array">
+                        <item name="saveUrl" xsi:type="url" path="*/*/inlineEdit"/>
+                        <item name="validateBeforeSave" xsi:type="boolean">false</item>
+                    </item>
+                </item>
+                <item name="childDefaults" xsi:type="array">
+                    <item name="fieldAction" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.devstone_usagecalculator_category_columns_editor</item>
+                        <item name="target" xsi:type="string">startEdit</item>
+                        <item name="params" xsi:type="array">
+                            <item name="0" xsi:type="string">${ $.$data.rowIndex }</item>
+                            <item name="1" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_category_listing.devstone_usagecalculator_category_listing.listing_top.bookmarks</item>
+                        <item name="root" xsi:type="string">columns.${ $.index }</item>
+                        <item name="namespace" xsi:type="string">current.${ $.storageConfig.root }</item>
+                    </item>
+                </item>
+            </item>
+        </argument>
+        <selectionsColumn name="ids">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="resizeEnabled" xsi:type="boolean">false</item>
+                    <item name="resizeDefaultWidth" xsi:type="string">55</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </selectionsColumn>
+        <column name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="filter" xsi:type="string">textRange</item>
+                    <item name="sorting" xsi:type="string">asc</item>
+                    <item name="label" xsi:type="string" translate="true">ID</item>
+                </item>
+            </argument>
+        </column>
+        <column name="name">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Name</item>
+                </item>
+            </argument>
+        </column>
+        <column name="terms">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Terms</item>
+                </item>
+            </argument>
+        </column>
+        <actionsColumn name="actions" class="DevStone\UsageCalculator\Ui\Component\Listing\Column\CategoryActions">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </actionsColumn>
+    </columns>
+</listing>
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_size_form.xml b/view/adminhtml/ui_component/devstone_usagecalculator_size_form.xml
new file mode 100644
index 0000000..1cf677d
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_size_form.xml
@@ -0,0 +1,138 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_size_form
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_size_form.devstone_usagecalculator_size_form_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_size_form.devstone_usagecalculator_size_form_data_source</item>
+        </item>
+        <item name="config" xsi:type="array">
+            <item name="dataScope" xsi:type="string">data</item>
+        </item>
+        <item name="template" xsi:type="string">templates/form/collapsible</item>
+        <item name="label" xsi:type="string" translate="true">Size Form</item>
+        <item name="buttons" xsi:type="array">
+            <item name="back" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Size\Edit\BackButton</item>
+            <item name="delete" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Size\Edit\DeleteButton</item>
+            <item name="save" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Size\Edit\SaveButton</item>
+            <item name="save_and_continue" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Size\Edit\SaveAndContinueButton</item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_size_form_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStone\UsageCalculator\Ui\Component\Form\Size\DataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_size_form_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">entity_id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="submit_url" xsi:type="url" path="*/*/save"/>
+                    <item name="validate_url" xsi:type="url" path="*/*/validate"/>
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <fieldset name="main_fieldset">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="label" xsi:type="string" translate="true">Main Information</item>
+            </item>
+        </argument>
+        <field name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">false</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+        </field>
+        <field name="code">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string">Code</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+        <field name="max_width">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">integer</item>
+                    <item name="label" xsi:type="string">Max Width</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+        <field name="max_height">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">integer</item>
+                    <item name="label" xsi:type="string">Max Height</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+        <field name="is_active" formElement="select">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+            <settings>
+                <dataType>number</dataType>
+                <label translate="true">Status</label>
+                <visible>true</visible>
+                <dataScope>is_active</dataScope>
+            </settings>
+            <formElements>
+                <select>
+                    <settings>
+                        <options>
+                            <option name="0" xsi:type="array">
+                                <item name="value" xsi:type="number">1</item>
+                                <item name="label" xsi:type="string" translate="true">Active</item>
+                            </option>
+                            <option name="1" xsi:type="array">
+                                <item name="value" xsi:type="number">0</item>
+                                <item name="label" xsi:type="string" translate="true">Inactive</item>
+                            </option>
+                        </options>
+                    </settings>
+                </select>
+            </formElements>
+        </field>
+        
+    </fieldset>
+</form>
\ No newline at end of file
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_size_listing.xml b/view/adminhtml/ui_component/devstone_usagecalculator_size_listing.xml
new file mode 100644
index 0000000..1d25602
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_size_listing.xml
@@ -0,0 +1,255 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+/**
+ * devstone_usagecalculator_size_list
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing_data_source</item>
+        </item>
+        <item name="spinner" xsi:type="string">devstone_usagecalculator_size_columns</item>
+        <item name="buttons" xsi:type="array">
+            <item name="add" xsi:type="array">
+                <item name="name" xsi:type="string">add</item>
+                <item name="label" xsi:type="string" translate="true">Add New Size</item>
+                <item name="class" xsi:type="string">primary</item>
+                <item name="url" xsi:type="string">*/*/edit</item>
+            </item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_size_listing_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStoneSizeGridDataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_size_listing_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="update_url" xsi:type="url" path="mui/index/render"/>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="indexField" xsi:type="string">entity_id</item>
+                    </item>
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/grid/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <container name="listing_top">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="template" xsi:type="string">ui/grid/toolbar</item>
+            </item>
+        </argument>
+        <bookmark name="bookmarks">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="namespace" xsi:type="string">devstone_usagecalculator_size_listing</item>
+                    </item>
+                </item>
+            </argument>
+        </bookmark>
+        <component name="columns_controls">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsData" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns</item>
+                    </item>
+                    <item name="component" xsi:type="string">Magento_Ui/js/grid/controls/columns</item>
+                    <item name="displayArea" xsi:type="string">dataGridActions</item>
+                </item>
+            </argument>
+        </component>
+        <filterSearch name="fulltext">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing_data_source</item>
+                    <item name="chipsProvider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.listing_filters_chips</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.search</item>
+                    </item>
+                </item>
+            </argument>
+        </filterSearch>
+        <filters name="listing_filters">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsProvider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.filters</item>
+                    </item>
+                    <item name="templates" xsi:type="array">
+                        <item name="filters" xsi:type="array">
+                            <item name="select" xsi:type="array">
+                                <item name="component" xsi:type="string">Magento_Ui/js/form/element/ui-select</item>
+                                <item name="template" xsi:type="string">ui/grid/filters/elements/ui-select</item>
+                            </item>
+                        </item>
+                    </item>
+                    <item name="childDefaults" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.listing_filters</item>
+                        <item name="imports" xsi:type="array">
+                            <item name="visible" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns.${ $.index }:visible</item>
+                        </item>
+                    </item>
+                </item>
+            </argument>
+        </filters>
+        <massaction name="listing_massaction">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns.ids</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+            <action name="delete">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">delete</item>
+                        <item name="label" xsi:type="string" translate="true">Delete</item>
+                        <item name="url" xsi:type="url" path="*/*/massDelete"/>
+                        <item name="confirm" xsi:type="array">
+                            <item name="title" xsi:type="string" translate="true">Delete items</item>
+                            <item name="message" xsi:type="string" translate="true">Are you sure you wan't to delete selected items?</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+            <action name="edit">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">edit</item>
+                        <item name="label" xsi:type="string" translate="true">Edit</item>
+                        <item name="callback" xsi:type="array">
+                            <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns_editor</item>
+                            <item name="target" xsi:type="string">editSelected</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+        </massaction>
+        <paging name="listing_paging">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.paging</item>
+                    </item>
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns.ids</item>
+                </item>
+            </argument>
+        </paging>
+    </container>
+    <columns name="devstone_usagecalculator_size_columns">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="storageConfig" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.bookmarks</item>
+                    <item name="namespace" xsi:type="string">current</item>
+                </item>
+                <item name="editorConfig" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns.ids</item>
+                    <item name="enabled" xsi:type="boolean">true</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                    <item name="clientConfig" xsi:type="array">
+                        <item name="saveUrl" xsi:type="url" path="*/*/inlineEdit"/>
+                        <item name="validateBeforeSave" xsi:type="boolean">false</item>
+                    </item>
+                </item>
+                <item name="childDefaults" xsi:type="array">
+                    <item name="fieldAction" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.devstone_usagecalculator_size_columns_editor</item>
+                        <item name="target" xsi:type="string">startEdit</item>
+                        <item name="params" xsi:type="array">
+                            <item name="0" xsi:type="string">${ $.$data.rowIndex }</item>
+                            <item name="1" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_size_listing.devstone_usagecalculator_size_listing.listing_top.bookmarks</item>
+                        <item name="root" xsi:type="string">columns.${ $.index }</item>
+                        <item name="namespace" xsi:type="string">current.${ $.storageConfig.root }</item>
+                    </item>
+                </item>
+            </item>
+        </argument>
+        <selectionsColumn name="ids">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="resizeEnabled" xsi:type="boolean">false</item>
+                    <item name="resizeDefaultWidth" xsi:type="string">55</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </selectionsColumn>
+        <column name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="filter" xsi:type="string">textRange</item>
+                    <item name="sorting" xsi:type="string">asc</item>
+                    <item name="label" xsi:type="string" translate="true">ID</item>
+                </item>
+            </argument>
+        </column>
+        <column name="code">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Code</item>
+                </item>
+            </argument>
+        </column>
+        <column name="max_width">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Max Width</item>
+                </item>
+            </argument>
+        </column>
+        <column name="max_height">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Max Height</item>
+                </item>
+            </argument>
+        </column>
+        <actionsColumn name="actions" class="DevStone\UsageCalculator\Ui\Component\Listing\Column\SizeActions">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </actionsColumn>
+    </columns>
+</listing>
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_usage_form.xml b/view/adminhtml/ui_component/devstone_usagecalculator_usage_form.xml
new file mode 100644
index 0000000..4817937
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_usage_form.xml
@@ -0,0 +1,192 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * devstone_usagecalculator_usage_form
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_usage_form.devstone_usagecalculator_usage_form_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_usage_form.devstone_usagecalculator_usage_form_data_source</item>
+        </item>
+        <item name="config" xsi:type="array">
+            <item name="dataScope" xsi:type="string">data</item>
+        </item>
+        <item name="template" xsi:type="string">templates/form/collapsible</item>
+        <item name="label" xsi:type="string" translate="true">Usage Form</item>
+        <item name="buttons" xsi:type="array">
+            <item name="back" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit\BackButton</item>
+            <item name="delete" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit\DeleteButton</item>
+            <item name="save" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit\SaveButton</item>
+            <item name="save_and_continue" xsi:type="string">DevStone\UsageCalculator\Block\Adminhtml\Usage\Edit\SaveAndContinueButton</item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_usage_form_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStone\UsageCalculator\Ui\Component\Form\Usage\DataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_usage_form_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">entity_id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="submit_url" xsi:type="url" path="*/*/save"/>
+                    <item name="validate_url" xsi:type="url" path="*/*/validate"/>
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/form/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <fieldset name="main_fieldset">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="label" xsi:type="string" translate="true">Main Information</item>
+            </item>
+        </argument>
+        <field name="store_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">number</item>
+                    <item name="formElement" xsi:type="string">hidden</item>
+                    <!--<item name="default" xsi:type="number">0</item>-->
+                    <item name="sortOrder" xsi:type="string">10</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+        </field>
+        <field name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">false</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+        </field>
+        <field name="name">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string">Name</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">1</item>
+                </item>
+            </argument>
+        </field>
+        <field name="terms">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string">Terms</item>
+                    <item name="formElement" xsi:type="string">textarea</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+        
+        <field name="price">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="visible" xsi:type="boolean">true</item>
+                    <item name="dataType" xsi:type="string">price</item>
+                    <item name="label" xsi:type="string">Price</item>
+                    <item name="formElement" xsi:type="string">input</item>
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                    <item name="validation" xsi:type="array">
+                        <item name="required-entry" xsi:type="boolean">true</item>
+                    </item>
+                    <item name="sortOrder" xsi:type="number">10</item>
+                </item>
+            </argument>
+        </field>
+        <field name="is_active" formElement="select">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+            <settings>
+                <dataType>number</dataType>
+                <label translate="true">Status</label>
+                <visible>true</visible>
+                <dataScope>is_active</dataScope>
+            </settings>
+            <formElements>
+                <select>
+                    <settings>
+                        <options>
+                            <option name="0" xsi:type="array">
+                                <item name="value" xsi:type="number">1</item>
+                                <item name="label" xsi:type="string" translate="true">Active</item>
+                            </option>
+                            <option name="1" xsi:type="array">
+                                <item name="value" xsi:type="number">0</item>
+                                <item name="label" xsi:type="string" translate="true">Inactive</item>
+                            </option>
+                        </options>
+                    </settings>
+                </select>
+            </formElements>
+        </field>
+        <field name="size_id" formElement="select">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+            <settings>
+                <dataType>number</dataType>
+                <label translate="true">Image Size</label>
+                <imports>
+                    <link name="value">${ $.provider }:data.usage.size_id</link>
+                </imports>
+            </settings>
+            <formElements>
+                <select>
+                    <settings>
+                        <options class="DevStone\UsageCalculator\Model\Usage\SizesOptionsProvider"/>
+                    </settings>
+                </select>
+            </formElements>
+        </field>
+        <field name="category_id" formElement="select">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="source" xsi:type="string">main_fieldset</item>
+                </item>
+            </argument>
+            <settings>
+                <dataType>number</dataType>
+                <label translate="true">Category</label>
+                <imports>
+                    <link name="value">${ $.provider }:data.usage.category_id</link>
+                </imports>
+            </settings>
+            <formElements>
+                <select>
+                    <settings>
+                        <options class="DevStone\UsageCalculator\Model\Usage\CatagoriesOptionsProvider"/>
+                    </settings>
+                </select>
+            </formElements>
+        </field>
+    </fieldset>
+</form>
\ No newline at end of file
diff --git a/view/adminhtml/ui_component/devstone_usagecalculator_usage_listing.xml b/view/adminhtml/ui_component/devstone_usagecalculator_usage_listing.xml
new file mode 100644
index 0000000..c95c413
--- /dev/null
+++ b/view/adminhtml/ui_component/devstone_usagecalculator_usage_listing.xml
@@ -0,0 +1,256 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+/**
+ * devstone_usagecalculator_usage_list
+ * @copyright Copyright © 2018 DevStone. All rights reserved.
+ * @author    david@nnucomputerwhiz.com
+ */
+-->
+<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
+    <argument name="data" xsi:type="array">
+        <item name="js_config" xsi:type="array">
+            <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing_data_source</item>
+            <item name="deps" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing_data_source</item>
+        </item>
+        <item name="spinner" xsi:type="string">devstone_usagecalculator_usage_columns</item>
+        <item name="buttons" xsi:type="array">
+            <item name="add" xsi:type="array">
+                <item name="name" xsi:type="string">add</item>
+                <item name="label" xsi:type="string" translate="true">Add New Usage</item>
+                <item name="class" xsi:type="string">primary</item>
+                <item name="url" xsi:type="string">*/*/edit</item>
+            </item>
+        </item>
+    </argument>
+    <dataSource name="devstone_usagecalculator_usage_listing_data_source">
+        <argument name="dataProvider" xsi:type="configurableObject">
+            <argument name="class" xsi:type="string">DevStone\UsageCalculator\Ui\Component\Listing\DataProvider</argument>
+            <argument name="name" xsi:type="string">devstone_usagecalculator_usage_listing_data_source</argument>
+            <argument name="primaryFieldName" xsi:type="string">entity_id</argument>
+            <argument name="requestFieldName" xsi:type="string">id</argument>
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="update_url" xsi:type="url" path="mui/index/render"/>
+                    <!--<item name="filter_url_params" xsi:type="array">-->
+                        <!--<item name="store" xsi:type="string">*</item>-->
+                    <!--</item>-->
+                </item>
+            </argument>
+        </argument>
+        <argument name="data" xsi:type="array">
+            <item name="js_config" xsi:type="array">
+                <item name="component" xsi:type="string">Magento_Ui/js/grid/provider</item>
+            </item>
+        </argument>
+    </dataSource>
+    <container name="listing_top">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="template" xsi:type="string">ui/grid/toolbar</item>
+            </item>
+        </argument>
+        <bookmark name="bookmarks">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="namespace" xsi:type="string">devstone_usagecalculator_usage_listing</item>
+                    </item>
+                </item>
+            </argument>
+        </bookmark>
+        <component name="columns_controls">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsData" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns</item>
+                    </item>
+                    <item name="component" xsi:type="string">Magento_Ui/js/grid/controls/columns</item>
+                    <item name="displayArea" xsi:type="string">dataGridActions</item>
+                </item>
+            </argument>
+        </component>
+        <filterSearch name="fulltext">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing_data_source</item>
+                    <item name="chipsProvider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.listing_filters_chips</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.search</item>
+                    </item>
+                </item>
+            </argument>
+        </filterSearch>
+        <filters name="listing_filters">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="columnsProvider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns</item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.filters</item>
+                    </item>
+                    <item name="templates" xsi:type="array">
+                        <item name="filters" xsi:type="array">
+                            <item name="select" xsi:type="array">
+                                <item name="component" xsi:type="string">Magento_Ui/js/form/element/ui-select</item>
+                                <item name="template" xsi:type="string">ui/grid/filters/elements/ui-select</item>
+                            </item>
+                        </item>
+                    </item>
+                    <item name="childDefaults" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.listing_filters</item>
+                        <item name="imports" xsi:type="array">
+                            <item name="visible" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns.${ $.index }:visible</item>
+                        </item>
+                    </item>
+                </item>
+            </argument>
+        </filters>
+        <massaction name="listing_massaction">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns.ids</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+            <action name="delete">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">delete</item>
+                        <item name="label" xsi:type="string" translate="true">Delete</item>
+                        <item name="url" xsi:type="url" path="*/*/massDelete"/>
+                        <item name="confirm" xsi:type="array">
+                            <item name="title" xsi:type="string" translate="true">Delete items</item>
+                            <item name="message" xsi:type="string" translate="true">Are you sure you wan't to delete selected items?</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+            <action name="edit">
+                <argument name="data" xsi:type="array">
+                    <item name="config" xsi:type="array">
+                        <item name="type" xsi:type="string">edit</item>
+                        <item name="label" xsi:type="string" translate="true">Edit</item>
+                        <item name="callback" xsi:type="array">
+                            <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns_editor</item>
+                            <item name="target" xsi:type="string">editSelected</item>
+                        </item>
+                    </item>
+                </argument>
+            </action>
+        </massaction>
+        <paging name="listing_paging">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.bookmarks</item>
+                        <item name="namespace" xsi:type="string">current.paging</item>
+                    </item>
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns.ids</item>
+                </item>
+            </argument>
+        </paging>
+    </container>
+    <columns name="devstone_usagecalculator_usage_columns">
+        <argument name="data" xsi:type="array">
+            <item name="config" xsi:type="array">
+                <item name="storageConfig" xsi:type="array">
+                    <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.bookmarks</item>
+                    <item name="namespace" xsi:type="string">current</item>
+                </item>
+                <item name="editorConfig" xsi:type="array">
+                    <item name="selectProvider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns.ids</item>
+                    <item name="enabled" xsi:type="boolean">false</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                    <item name="clientConfig" xsi:type="array">
+                        <item name="saveUrl" xsi:type="url" path="*/*/inlineEdit"/>
+                        <item name="validateBeforeSave" xsi:type="boolean">false</item>
+                    </item>
+                </item>
+                <item name="childDefaults" xsi:type="array">
+                    <item name="fieldAction" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_columns_editor</item>
+                        <item name="target" xsi:type="string">startEdit</item>
+                        <item name="params" xsi:type="array">
+                            <item name="0" xsi:type="string">${ $.$data.rowIndex }</item>
+                            <item name="1" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="storageConfig" xsi:type="array">
+                        <item name="provider" xsi:type="string">devstone_usagecalculator_usage_listing.devstone_usagecalculator_usage_listing.listing_top.bookmarks</item>
+                        <item name="root" xsi:type="string">columns.${ $.index }</item>
+                        <item name="namespace" xsi:type="string">current.${ $.storageConfig.root }</item>
+                    </item>
+                </item>
+            </item>
+        </argument>
+        <selectionsColumn name="ids">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="resizeEnabled" xsi:type="boolean">false</item>
+                    <item name="resizeDefaultWidth" xsi:type="string">55</item>
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </selectionsColumn>
+        <column name="entity_id">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="filter" xsi:type="string">textRange</item>
+                    <item name="sorting" xsi:type="string">asc</item>
+                    <item name="label" xsi:type="string" translate="true">ID</item>
+                </item>
+            </argument>
+        </column>
+        <column name="name">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Name</item>
+                </item>
+            </argument>
+        </column>
+        <column name="price">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">price</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Price</item>
+                </item>
+            </argument>
+        </column>
+        <column name="terms">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="editor" xsi:type="array">
+                        <item name="editorType" xsi:type="string">text</item>
+                        <item name="validation" xsi:type="array">
+                            <item name="required-entry" xsi:type="boolean">true</item>
+                        </item>
+                    </item>
+                    <item name="filter" xsi:type="string">text</item>
+                    <item name="label" xsi:type="string" translate="true">Terms</item>
+                </item>
+            </argument>
+        </column>
+        <!-- Add your columns here -->
+        <actionsColumn name="actions" class="DevStone\UsageCalculator\Ui\Component\Listing\Column\UsageActions">
+            <argument name="data" xsi:type="array">
+                <item name="config" xsi:type="array">
+                    <item name="indexField" xsi:type="string">entity_id</item>
+                </item>
+            </argument>
+        </actionsColumn>
+    </columns>
+</listing>
diff --git a/view/frontend/layout/catalog_product_view_type_image.xml b/view/frontend/layout/catalog_product_view_type_image.xml
new file mode 100644
index 0000000..87c5449
--- /dev/null
+++ b/view/frontend/layout/catalog_product_view_type_image.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <head>
+        <css src="DevStone_UsageCalculator::css/styles-product-page.css" /> 
+    </head>
+    <body>
+        <attribute name="class" value="page-product-image"/>
+        <referenceBlock name="product.info.options.wrapper">
+            <block class="DevStone\UsageCalculator\Block\Catalog\Product\Usage" name="usage.info" as="type_image_usage" before="-" template="DevStone_UsageCalculator::catalog/product/usages.phtml">
+                <block class="DevStone\UsageCalculator\Block\Usage\View\Options\Type\DefaultType" name="usage.info.options.default" as="default" template="DevStone_UsageCalculator::catalog/product/type/default.phtml"/>
+                <block class="DevStone\UsageCalculator\Block\Usage\View\Options\Type\Text" name="usage.info.options.text" as="text" template="DevStone_UsageCalculator::catalog/product/type/text.phtml"/>
+                <block class="DevStone\UsageCalculator\Block\Usage\View\Options\Type\File" name="usage.info.options.file" as="file" template="DevStone_UsageCalculator::catalog/product/type/file.phtml"/>
+                <block class="DevStone\UsageCalculator\Block\Usage\View\Options\Type\Select" name="usage.info.options.select" as="select" template="DevStone_UsageCalculator::catalog/product/type/select.phtml"/>
+                <block class="DevStone\UsageCalculator\Block\Usage\View\Options\Type\Date" name="usage.info.options.date" as="date" template="DevStone_UsageCalculator::catalog/product/type/date.phtml"/>
+<!--                <block class="Magento\Catalog\Pricing\Render" name="product.price.link" after="product.info.usage.options">
+                    <arguments>
+                        <argument name="price_render" xsi:type="string">product.price.render.default</argument>
+                        <argument name="price_type_code" xsi:type="string">link_price</argument>
+                    </arguments>
+                </block>-->
+            </block>
+<!--            <block class="DevStone\UsageCalculator\Block\Usage\View\Options" name="usage.info.options" as="type_image_usage_options" after="usage.info" template="Magento_Catalog::product/view/options.phtml">-->
+                
+<!--            </block>-->
+        </referenceBlock>
+        <referenceBlock name="head.components">
+            <block class="Magento\Framework\View\Element\Js\Components" name="usage_page_head_components" template="DevStone_UsageCalculator::js/components.phtml"/>
+        </referenceBlock>
+<!--            <referenceContainer name="product.info.options.wrapper.bottom">
+            <block class="Magento\Catalog\Pricing\Render" name="product.price.final.copy" before="-">
+                <arguments>
+                    <argument name="price_render" xsi:type="string">product.price.render.default</argument>
+                    <argument name="price_type_code" xsi:type="string">final_price</argument>
+                    <argument name="display_msrp_help_message" xsi:type="string">1</argument>
+                    <argument name="zone" xsi:type="string">item_view</argument>
+                    <argument name="id_suffix" xsi:type="string">copy-</argument>
+                </arguments>
+            </block>
+        </referenceContainer>
+        
+        <move element="product.info" destination="content" after="product.info.media" />
+        <move element="product.info.social" destination="product.info.options.wrapper.bottom" after="-" />-->
+    </body>
+</page>
diff --git a/view/frontend/requirejs-config.js b/view/frontend/requirejs-config.js
new file mode 100644
index 0000000..7f04850
--- /dev/null
+++ b/view/frontend/requirejs-config.js
@@ -0,0 +1,8 @@
+
+var config = {
+    map: {
+        '*': {
+            usage: 'DevStone_UsageCalculator/usage'
+        }
+    }
+};
diff --git a/view/frontend/templates/catalog/product/type.phtml b/view/frontend/templates/catalog/product/type.phtml
new file mode 100644
index 0000000..d4afdf5
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type.phtml
@@ -0,0 +1,26 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+/**
+ * Downloadable product type
+ *
+ * @var $block \Magento\Downloadable\Block\Catalog\Product\View\Type
+ */
+?>
+<?php $_product = $block->getProduct() ?>
+
+<?php if ($_product->getIsSalable()): ?>
+    <div class="stock available" title="<?= /* @escapeNotVerified */ __('Availability') ?>">
+        <span><?= /* @escapeNotVerified */ __('In stock') ?></span>
+    </div>
+<?php else: ?>
+    <div class="stock unavailable" title="<?= /* @escapeNotVerified */ __('Availability') ?>">
+        <span><?= /* @escapeNotVerified */ __('Out of stock') ?></span>
+    </div>
+<?php endif; ?>
+<?= $block->getChildHtml() ?>
diff --git a/view/frontend/templates/catalog/product/type/date.phtml b/view/frontend/templates/catalog/product/type/date.phtml
new file mode 100644
index 0000000..3420512
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type/date.phtml
@@ -0,0 +1,58 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php $_option = $block->getOption() ?>
+<?php $_optionId = $_option->getId() ?>
+<?php $class = ($_option->getIsRequire()) ? ' required' : ''; ?>
+<div class="field date<?= /* @escapeNotVerified */ $class ?>"
+    data-mage-init='{"priceOptionDate":{"fromSelector":"#product_addtocart_form"}}'>
+    <fieldset class="fieldset fieldset-product-options-inner<?= /* @escapeNotVerified */ $class ?>">
+        <legend class="legend">
+            <span><?= $block->escapeHtml($_option->getTitle()) ?></span>
+            <?= /* @escapeNotVerified */ $block->getFormatedPrice() ?>
+        </legend>
+        <div class="control">
+            <?php if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME
+                || $_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DATE): ?>
+
+                <?= $block->getDateHtml() ?>
+
+            <?php endif; ?>
+
+            <?php if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_DATE_TIME
+                || $_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_TIME): ?>
+                <?= $block->getTimeHtml() ?>
+            <?php endif; ?>
+
+            <?php if ($_option->getIsRequire()): ?>
+                <input type="hidden"
+                       name="validate_datetime_<?= /* @escapeNotVerified */ $_optionId ?>"
+                       class="validate-datetime-<?= /* @escapeNotVerified */ $_optionId ?>"
+                       value=""
+                       data-validate="{'validate-required-datetime':<?= /* @escapeNotVerified */ $_optionId ?>}"/>
+            <?php else: ?>
+                <input type="hidden"
+                       name="validate_datetime_<?= /* @escapeNotVerified */ $_optionId ?>"
+                       class="validate-datetime-<?= /* @escapeNotVerified */ $_optionId ?>"
+                       value=""
+                       data-validate="{'validate-optional-datetime':<?= /* @escapeNotVerified */ $_optionId ?>}"/>
+            <?php endif; ?>
+            <script type="text/x-magento-init">
+            {
+                "#product_addtocart_form": {
+                    "validation": {
+                        "ignore": ":hidden:not(input[name^='validate_datetime_'])"
+                    }
+                }
+            }
+        </script>
+        </div>
+    </fieldset>
+
+</div>
diff --git a/view/frontend/templates/catalog/product/type/default.phtml b/view/frontend/templates/catalog/product/type/default.phtml
new file mode 100644
index 0000000..2006bf6
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type/default.phtml
@@ -0,0 +1,13 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php $_option = $block->getOption() ?>
+<div class="field">
+    <label class="label"><span><?= $block->escapeHtml($_option->getTitle()) ?></span></label>
+</div>
diff --git a/view/frontend/templates/catalog/product/type/file.phtml b/view/frontend/templates/catalog/product/type/file.phtml
new file mode 100644
index 0000000..3ceba2e
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type/file.phtml
@@ -0,0 +1,67 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php $_option = $block->getOption(); ?>
+<?php $_fileInfo = $block->getFileInfo(); ?>
+<?php $_fileExists = $_fileInfo->hasData(); ?>
+<?php $_fileName = 'options_' . $_option->getId() . '_file'; ?>
+<?php $_fieldNameAction = $_fileName . '_action'; ?>
+<?php $_fieldValueAction = $_fileExists ? 'save_old' : 'save_new'; ?>
+<?php $_fileNamed = $_fileName . '_name'; ?>
+<?php $class = ($_option->getIsRequire()) ? ' required' : ''; ?>
+
+<div class="field file<?= /* @escapeNotVerified */ $class ?>">
+    <label class="label" for="<?= /* @noEscape */ $_fileName ?>" id="<?= /* @noEscape */ $_fileName ?>-label">
+        <span><?= $block->escapeHtml($_option->getTitle()) ?></span>
+        <?= /* @escapeNotVerified */ $block->getFormatedPrice() ?>
+    </label>
+    <?php if ($_fileExists): ?>
+    <div class="control">
+        <span class="<?= /* @noEscape */ $_fileNamed ?>"><?= $block->escapeHtml($_fileInfo->getTitle()) ?></span>
+        <a href="javascript:void(0)" class="label" id="change-<?= /* @noEscape */ $_fileName ?>" >
+            <?= /* @escapeNotVerified */ __('Change') ?>
+        </a>
+        <?php if (!$_option->getIsRequire()): ?>
+            <input type="checkbox" id="delete-<?= /* @escapeNotVerified */ $_fileName ?>" />
+            <span class="label"><?= /* @escapeNotVerified */ __('Delete') ?></span>
+        <?php endif; ?>
+    </div>
+    <?php endif; ?>
+    <div class="control" id="input-box-<?= /* @escapeNotVerified */ $_fileName ?>"
+             data-mage-init='{"priceOptionFile":{
+                "fileName":"<?= /* @noEscape */ $_fileName ?>",
+                "fileNamed":"<?= /* @noEscape */ $_fileNamed ?>",
+                "fieldNameAction":"<?= /* @escapeNotVerified */ $_fieldNameAction ?>",
+                "changeFileSelector":"#change-<?= /* @escapeNotVerified */ $_fileName ?>",
+                "deleteFileSelector":"#delete-<?= /* @escapeNotVerified */ $_fileName ?>"}
+             }'
+            <?= $_fileExists ? 'style="display:none"' : '' ?>>
+        <input type="file"
+               name="<?= /* @escapeNotVerified */ $_fileName ?>"
+               id="<?= /* @escapeNotVerified */ $_fileName ?>"
+               class="product-custom-option<?= $_option->getIsRequire() ? ' required' : '' ?>"
+               <?= $_fileExists ? 'disabled="disabled"' : '' ?> />
+        <input type="hidden" name="<?= /* @escapeNotVerified */ $_fieldNameAction ?>" value="<?= /* @escapeNotVerified */ $_fieldValueAction ?>" />
+        <?php if ($_option->getFileExtension()): ?>
+            <p class="note">
+                <?= /* @escapeNotVerified */ __('Compatible file extensions to upload') ?>: <strong><?= /* @escapeNotVerified */ $_option->getFileExtension() ?></strong>
+            </p>
+        <?php endif; ?>
+        <?php if ($_option->getImageSizeX() > 0): ?>
+            <p class="note">
+                <?= /* @escapeNotVerified */ __('Maximum image width') ?>: <strong><?= /* @escapeNotVerified */ $_option->getImageSizeX() ?> <?= /* @escapeNotVerified */ __('px.') ?></strong>
+            </p>
+        <?php endif; ?>
+        <?php if ($_option->getImageSizeY() > 0): ?>
+            <p class="note">
+                <?= /* @escapeNotVerified */ __('Maximum image height') ?>: <strong><?= /* @escapeNotVerified */ $_option->getImageSizeY() ?> <?= /* @escapeNotVerified */ __('px.') ?></strong>
+            </p>
+        <?php endif; ?>
+    </div>
+</div>
diff --git a/view/frontend/templates/catalog/product/type/select.phtml b/view/frontend/templates/catalog/product/type/select.phtml
new file mode 100644
index 0000000..389f0ef
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type/select.phtml
@@ -0,0 +1,31 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+
+<?php /* @var $block \DevStone\UsageCalculator\Block\Usage\View\Options\Type\Select */ ?>
+<?php
+$_option = $block->getOption();
+$class = ($_option->getIsRequire()) ? ' required' : '';
+?>
+<div class="field<?= /* @escapeNotVerified */ $class ?>">
+    <label class="label" for="select_<?= /* @escapeNotVerified */ $_option->getId() ?>">
+        <span><?= $block->escapeHtml($_option->getTitle()) ?>:</span> <a href="#" data-less="<?= __('less info') ?>" tabindex="-1"><?= __('more info') ?></a>
+    </label>
+	<div class="help-text">
+		<?= $block->escapeHtml($_option->getHelp()); ?>
+	</div>
+    <div class="control">
+        <?= $block->getValuesHtml() ?>
+        <?php if ($_option->getIsRequire()): ?>
+            <?php if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_RADIO || $_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_CHECKBOX): ?>
+                <span id="options-<?= /* @escapeNotVerified */ $_option->getId() ?>-container"></span>
+            <?php endif; ?>
+        <?php endif;?>
+    </div>
+</div>
diff --git a/view/frontend/templates/catalog/product/type/text.phtml b/view/frontend/templates/catalog/product/type/text.phtml
new file mode 100644
index 0000000..6ab0370
--- /dev/null
+++ b/view/frontend/templates/catalog/product/type/text.phtml
@@ -0,0 +1,66 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php
+$_option = $block->getOption();
+$class = ($_option->getIsRequire()) ? ' required' : '';
+?>
+
+<div class="field<?php if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_AREA) {
+    echo ' textarea';
+} ?><?= /* @escapeNotVerified */ $class ?>">
+    <label class="label" for="options_<?= /* @escapeNotVerified */ $_option->getId() ?>_text">
+        <span><?= $block->escapeHtml($_option->getTitle()) ?>:</span> <a href="#" tabindex="-1" data-less="<?= __('less info') ?>">more info</a>
+    </label>
+	<div class="help-text">
+		<?= $block->escapeHtml($_option->getHelp()); ?>
+	</div>
+    <div class="control">
+        <?php if ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_FIELD): ?>
+            <?php $_textValidate = null;
+            if ($_option->getIsRequire()) {
+                $_textValidate['required'] = true;
+            }
+            if ($_option->getMaxCharacters()) {
+                $_textValidate['maxlength'] = $_option->getMaxCharacters();
+            }
+            $_textValidate['validate-no-utf8mb4-characters'] = true;
+            ?>
+            <input type="text"
+                   id="options_<?= /* @escapeNotVerified */ $_option->getId() ?>_text"
+                   class="input-text product-custom-option"
+                   <?php if (!empty($_textValidate)) {?>
+                   data-validate="<?= $block->escapeHtml(json_encode($_textValidate)) ?>"
+                   <?php } ?>
+				   data-title="<?= $block->escapeHtmlAttr($_option->getTitle()) ?>"
+                   name="options[<?= /* @escapeNotVerified */ $_option->getId() ?>]"
+                   data-selector="options[<?= /* @escapeNotVerified */ $_option->getId() ?>]"
+                   value="<?= $block->escapeHtml($block->getDefaultValue()) ?>"/>
+        <?php elseif ($_option->getType() == \Magento\Catalog\Api\Data\ProductCustomOptionInterface::OPTION_TYPE_AREA): ?>
+            <?php $_textAreaValidate = null;
+            if ($_option->getIsRequire()) {
+                $_textAreaValidate['required'] = true;
+            }
+            if ($_option->getMaxCharacters()) {
+                $_textAreaValidate['maxlength'] = $_option->getMaxCharacters();
+            }
+            $_textAreaValidate['validate-no-utf8mb4-characters'] = true;
+            ?>
+            <textarea id="options_<?= /* @escapeNotVerified */ $_option->getId() ?>_text"
+                      class="product-custom-option"
+                    <?php if (!empty($_textAreaValidate)) {?>
+                        data-validate="<?= $block->escapeHtml(json_encode($_textAreaValidate)) ?>"
+                    <?php } ?>
+                      name="options[<?= /* @escapeNotVerified */ $_option->getId() ?>]"
+                      data-selector="options[<?= /* @escapeNotVerified */ $_option->getId() ?>]"
+                      rows="5"
+                      cols="25"><?= $block->escapeHtml($block->getDefaultValue()) ?></textarea>
+        <?php endif; ?>
+    </div>
+</div>
diff --git a/view/frontend/templates/catalog/product/usages.phtml b/view/frontend/templates/catalog/product/usages.phtml
new file mode 100644
index 0000000..ca95adb
--- /dev/null
+++ b/view/frontend/templates/catalog/product/usages.phtml
@@ -0,0 +1,65 @@
+<?php /* @var $block \DevStone\UsageCalculator\Block\Catalog\Product\Usage */ ?>
+<?php if ($block->getProduct()->isSaleable() ):?>
+<div id="usages-container" class="usages-container field">
+    <button id="usage-button" class="cta-button" title="<?= __('License Image is a type of “renting” of an image for a specific use; examples include licensing an image for the cover of a book, an illustration for a magazine article, or use of an image in an evangelistic handbill.') ?>">
+        <span class="calc-icon">&nbsp;</span>
+        <span class="button-main">
+            <span><?= __('License Image') ?></span>
+            <span class="button-small"> <?= __('Download - price based on use.') ?></span>
+        </span>
+    </button>
+    <div class="usages-container-inner">
+    <button id="usage-button-close">
+        <?= __('Close') ?>
+    </button>
+    <legend class="legend usages-title"><?= __('License Pricing Calculator') ?></legend>
+    <p><?= __('Select options from the drop down menu to calculate a price to use this image.') ?></p>
+
+    <div class="control" id="downloadable-usages-list"
+         data-mage-init='{"usage":{
+             "categorySelectElement":"#usage_category",
+             "allElements":"#usages_all",
+             "config":<?= /* @escapeNotVerified */ $block->getJsonConfig() ?>}
+         }'
+         data-container-for="downloadable-usages">
+        <div class="field active">
+            <label class="label" for="usage_category">
+                <span><?= __('Choose Category') ?>:</span> <a href="#" data-less="<?= __('less info') ?>" tabindex="-1"><?= __('more info') ?></a>
+            </label>
+            <div class="help-text">
+                <?= __('Choose a category to see the specific usages available.') ?>
+            </div>
+            <div class="control">
+                <?= $block->getCategoriesSelectHtml() ?>
+            </div>
+        </div>
+        <?php foreach ($block->getCategories() as $category):  ?>
+            <?php $usages = $block->getUsages($category) ?>
+
+            <div class="category-container field" style="display:none;" id="category_container_<?= $category->getId() ?>">
+                <label class="label" for="usage_<?= $category->getId() ?>_usages">
+                    <span><?= __('Specific Usage') ?>:</span> <a href="#" data-less="<?= __('less info') ?>" tabindex="-1"><?= __('more info') ?></a>
+                </label>
+                <div class="help-text">
+                    <?= __('Choose the usage which best describes how you intend to use the image.') ?>
+                </div>
+                <div class="control">
+                    <?= $block->getUsagesSelectHtml($usages, $category); ?>
+                </div>
+            </div>
+
+            <?php foreach ($usages as $usage): ?>
+                <div class="usage-container" style="display:none;" id="usage_container_<?= $usage->getId() ?>">
+                <?php foreach ($usage->getOptions() as $_option): ?>
+
+                    <?= $block->getOptionHtml($_option) ?>
+
+                <?php endforeach; ?>
+                </div>
+            <?php endforeach; ?>
+        <?php endforeach; ?>
+    </div>
+    <span id="usages-advice-container"></span>
+    </div>
+</div>
+<?php endif; ?>
diff --git a/view/frontend/templates/checkout/success.phtml b/view/frontend/templates/checkout/success.phtml
new file mode 100644
index 0000000..a32d854
--- /dev/null
+++ b/view/frontend/templates/checkout/success.phtml
@@ -0,0 +1,12 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php if ($block->getOrderHasDownloadable()): ?>
+    <?= /* @escapeNotVerified */ __('Go to <a href="%1">My Downloadable Products</a>', $block->getDownloadableProductsUrl()) ?>
+<?php endif; ?>
diff --git a/view/frontend/templates/customer/products/list.phtml b/view/frontend/templates/customer/products/list.phtml
new file mode 100644
index 0000000..08cadb2
--- /dev/null
+++ b/view/frontend/templates/customer/products/list.phtml
@@ -0,0 +1,67 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php
+/**
+ * @var $block \Magento\Downloadable\Block\Customer\Products\ListProducts
+ */
+?>
+<?php $_items = $block->getItems(); ?>
+<?php if (count($_items)): ?>
+    <div class="table-wrapper downloadable-products">
+        <table id="my-downloadable-products-table" class="data table table-downloadable-products">
+            <caption class="table-caption"><?= /* @escapeNotVerified */ __('Downloadable Products') ?></caption>
+            <thead>
+                <tr>
+                    <th scope="col" class="col id"><?= /* @escapeNotVerified */ __('Order #') ?></th>
+                    <th scope="col" class="col date"><?= /* @escapeNotVerified */ __('Date') ?></th>
+                    <th scope="col" class="col title"><?= /* @escapeNotVerified */ __('Title') ?></th>
+                    <th scope="col" class="col status"><?= /* @escapeNotVerified */ __('Status') ?></th>
+                    <th scope="col" class="col remaining"><?= /* @escapeNotVerified */ __('Remaining Downloads') ?></th>
+                </tr>
+            </thead>
+            <tbody>
+            <?php foreach ($_items as $_item): ?>
+                <tr>
+                    <td data-th="<?= $block->escapeHtml(__('Order #')) ?>" class="col id">
+                        <a href="<?= /* @escapeNotVerified */ $block->getOrderViewUrl($_item->getPurchased()->getOrderId()) ?>"
+                            title="<?= $block->escapeHtml(__('View Order')) ?>">
+                            <?= /* @escapeNotVerified */ $_item->getPurchased()->getOrderIncrementId() ?>
+                        </a>
+                    </td>
+                    <td data-th="<?= $block->escapeHtml(__('Date')) ?>" class="col date"><?= /* @escapeNotVerified */ $block->formatDate($_item->getPurchased()->getCreatedAt()) ?></td>
+                    <td data-th="<?= $block->escapeHtml(__('Title')) ?>" class="col title">
+                        <strong class="product-name"><?= $block->escapeHtml($_item->getPurchased()->getProductName()) ?></strong>
+                        <?php if ($_item->getStatus() == \Magento\Downloadable\Model\Link\Purchased\Item::LINK_STATUS_AVAILABLE): ?>
+                        <a href="<?= /* @escapeNotVerified */ $block->getDownloadUrl($_item) ?>" title="<?= $block->escapeHtml(__('Start Download')) ?>" class="action download" <?= $block->getIsOpenInNewWindow() ? 'onclick="this.target=\'_blank\'"' : '' ?>><?= $block->escapeHtml($_item->getLinkTitle()) ?></a>
+                        <?php endif; ?>
+                    </td>
+                    <td data-th="<?= $block->escapeHtml(__('Status')) ?>" class="col status"><?= /* @escapeNotVerified */ __(ucfirst($_item->getStatus())) ?></td>
+                    <td data-th="<?= $block->escapeHtml(__('Remaining Downloads')) ?>" class="col remaining"><?= /* @escapeNotVerified */ $block->getRemainingDownloads($_item) ?></td>
+                </tr>
+            <?php endforeach; ?>
+            </tbody>
+        </table>
+    </div>
+    <?php if ($block->getChildHtml('pager')): ?>
+        <div class="toolbar downloadable-products-toolbar bottom">
+            <?= $block->getChildHtml('pager') ?>
+        </div>
+    <?php endif; ?>
+<?php else: ?>
+    <div class="message info empty"><span><?= /* @escapeNotVerified */ __('You have not purchased any downloadable products yet.') ?></span></div>
+<?php endif; ?>
+
+<div class="actions-toolbar">
+    <div class="secondary">
+        <a href="<?= $block->escapeUrl($block->getBackUrl()) ?>" class="action back">
+            <span><?= /* @escapeNotVerified */ __('Back') ?></span>
+        </a>
+    </div>
+</div>
diff --git a/view/frontend/templates/email/order/items/creditmemo/downloadable.phtml b/view/frontend/templates/email/order/items/creditmemo/downloadable.phtml
new file mode 100644
index 0000000..0f5a065
--- /dev/null
+++ b/view/frontend/templates/email/order/items/creditmemo/downloadable.phtml
@@ -0,0 +1,41 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php /** @var $block \Magento\Downloadable\Block\Sales\Order\Email\Items\Image */ ?>
+<?php $_item = $block->getItem() ?>
+<?php $_order = $block->getItem()->getOrder(); ?>
+<tr>
+    <td class="item-info has-extra">
+        <p class="product-name"><?= $block->escapeHtml($_item->getName()) ?></p>
+        <p class="sku"><?= /* @escapeNotVerified */  __('SKU') ?>: <?= $block->escapeHtml($block->getSku($_item)) ?></p>
+        <?php if ($block->getItemOptions()): ?>
+        <dl>
+            <?php foreach ($block->getItemOptions() as $option): ?>
+            <dt><strong><em><?= /* @escapeNotVerified */  $option['label'] ?></em></strong></dt>
+            <dd><?= /* @escapeNotVerified */  $option['value'] ?></dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?php if ($links = $block->getLinks()->getPurchasedItems()): ?>
+        <dl>
+            <dt><strong><em><?= /* @escapeNotVerified */  $block->getLinksTitle() ?></em></strong></dt>
+            <?php foreach ($links as $link): ?>
+                <dd>
+                    <?= $block->escapeHtml($link->getLinkTitle()) ?>
+                </dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+    </td>
+    <td class="item-qty"><?= /* @escapeNotVerified */  $_item->getQty() * 1 ?></td>
+    <td class="item-price">
+        <?= /* @escapeNotVerified */  $block->getItemPrice($_item) ?>
+    </td>
+</tr>
diff --git a/view/frontend/templates/email/order/items/invoice/downloadable.phtml b/view/frontend/templates/email/order/items/invoice/downloadable.phtml
new file mode 100644
index 0000000..5cd9edd
--- /dev/null
+++ b/view/frontend/templates/email/order/items/invoice/downloadable.phtml
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php /** @var $block \Magento\Downloadable\Block\Sales\Order\Email\Items\Image */ ?>
+<?php $_item = $block->getItem() ?>
+<?php $_order = $block->getItem()->getOrder() ?>
+<tr>
+    <td class="item-info has-extra">
+        <p class="product-name"><?= $block->escapeHtml($_item->getName()) ?></p>
+        <p class="sku"><?= /* @escapeNotVerified */  __('SKU') ?>: <?= $block->escapeHtml($block->getSku($_item)) ?></p>
+        <?php if ($block->getItemOptions()): ?>
+        <dl>
+            <?php foreach ($block->getItemOptions() as $option): ?>
+            <dt><strong><em><?= /* @escapeNotVerified */  $option['label'] ?></em></strong></dt>
+            <dd><?= /* @escapeNotVerified */  $option['value'] ?></dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?php if ($links = $block->getLinks()->getPurchasedItems()): ?>
+        <dl>
+            <dt><strong><em><?= /* @escapeNotVerified */  $block->getLinksTitle() ?></em></strong></dt>
+            <?php foreach ($links as $link): ?>
+                <dd>
+                    <?= $block->escapeHtml($link->getLinkTitle()) ?>&nbsp;
+                    (<a href="<?= /* @escapeNotVerified */  $block->getPurchasedLinkUrl($link) ?>"><?= /* @escapeNotVerified */  __('download') ?></a>)
+                </dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+    </td>
+    <td class="item-qty"><?= /* @escapeNotVerified */  $_item->getQty() * 1 ?></td>
+    <td class="item-price">
+        <?= /* @escapeNotVerified */  $block->getItemPrice($_item) ?>
+    </td>
+</tr>
diff --git a/view/frontend/templates/email/order/items/order/downloadable.phtml b/view/frontend/templates/email/order/items/order/downloadable.phtml
new file mode 100644
index 0000000..338a7a4
--- /dev/null
+++ b/view/frontend/templates/email/order/items/order/downloadable.phtml
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?php /** @var $block \Magento\Downloadable\Block\Sales\Order\Email\Items\Order\Image */ ?>
+<?php $_item = $block->getItem() ?>
+<?php $_order = $block->getItem()->getOrder() ?>
+<tr>
+    <td class="item-info has-extra">
+        <p class="product-name"><?= $block->escapeHtml($_item->getName()) ?></p>
+        <p class="sku"><?= /* @escapeNotVerified */  __('SKU') ?>: <?= $block->escapeHtml($block->getSku($_item)) ?></p>
+        <?php if ($block->getItemOptions()): ?>
+        <dl>
+            <?php foreach ($block->getItemOptions() as $option): ?>
+            <dt><strong><em><?= /* @escapeNotVerified */  $option['label'] ?></em></strong></dt>
+            <dd><?= /* @escapeNotVerified */  $option['value'] ?></dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?php if ($links = $block->getLinks()->getPurchasedItems()): ?>
+        <dl>
+            <dt><strong><em><?= /* @escapeNotVerified */  $block->getLinksTitle() ?></em></strong></dt>
+            <?php foreach ($links as $link): ?>
+                <dd>
+                    <?= $block->escapeHtml($link->getLinkTitle()) ?>&nbsp;
+                    (<a href="<?= /* @escapeNotVerified */  $block->getPurchasedLinkUrl($link) ?>"><?= /* @escapeNotVerified */  __('download') ?></a>)
+                </dd>
+            <?php endforeach; ?>
+        </dl>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+        <?php if ($_item->getGiftMessageId() && $_giftMessage = $this->helper('Magento\GiftMessage\Helper\Message')->getGiftMessage($_item->getGiftMessageId())): ?>
+            <table class="message-gift">
+                <tr>
+                    <td>
+                        <h3><?= /* @escapeNotVerified */  __('Gift Message') ?></h3>
+                        <strong><?= /* @escapeNotVerified */  __('From:') ?></strong> <?= $block->escapeHtml($_giftMessage->getSender()) ?>
+                        <br /><strong><?= /* @escapeNotVerified */  __('To:') ?></strong> <?= $block->escapeHtml($_giftMessage->getRecipient()) ?>
+                        <br /><strong><?= /* @escapeNotVerified */  __('Message:') ?></strong>
+                        <br /><?= $block->escapeHtml($_giftMessage->getMessage()) ?>
+                    </td>
+                </tr>
+            </table>
+        <?php endif; ?>
+    </td>
+    <td class="item-qty"><?= /* @escapeNotVerified */  $_item->getQtyOrdered() * 1 ?></td>
+    <td class="item-price">
+        <?= /* @escapeNotVerified */  $block->getItemPrice($_item) ?>
+    </td>
+</tr>
diff --git a/view/frontend/templates/js/components.phtml b/view/frontend/templates/js/components.phtml
new file mode 100644
index 0000000..bad5acc
--- /dev/null
+++ b/view/frontend/templates/js/components.phtml
@@ -0,0 +1,10 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+?>
+<?= $block->getChildHtml() ?>
diff --git a/view/frontend/templates/sales/order/creditmemo/items/renderer/downloadable.phtml b/view/frontend/templates/sales/order/creditmemo/items/renderer/downloadable.phtml
new file mode 100644
index 0000000..2783749
--- /dev/null
+++ b/view/frontend/templates/sales/order/creditmemo/items/renderer/downloadable.phtml
@@ -0,0 +1,68 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+/** @var $block \Magento\Downloadable\Block\Sales\Order\Item\Renderer\Downloadable */
+?>
+<?php $_item = $block->getItem() ?>
+<?php $_order = $block->getItem()->getOrderItem()->getOrder() ?>
+<tr class="border" id="order-item-row-<?= /* @escapeNotVerified */ $_item->getId() ?>">
+    <td class="col name" data-th="<?= $block->escapeHtml(__('Product Name')) ?>">
+        <strong class="product name product-item-name"><?= $block->escapeHtml($_item->getName()) ?></strong>
+        <?php if ($_options = $block->getItemOptions()): ?>
+            <dl class="item-options links">
+                <?php foreach ($_options as $_option) : ?>
+                    <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                    <?php if (!$block->getPrintStatus()): ?>
+                        <?php $_formatedOptionValue = $block->getFormatedOptionValue($_option) ?>
+                        <dd<?php if (isset($_formatedOptionValue['full_view'])): ?> class="tooltip wrapper"<?php endif; ?>>
+                            <?= /* @escapeNotVerified */ $_formatedOptionValue['value'] ?>
+                            <?php if (isset($_formatedOptionValue['full_view'])): ?>
+                                <div class="tooltip content">
+                                    <dl class="item options">
+                                        <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                                        <dd><?= /* @escapeNotVerified */ $_formatedOptionValue['full_view'] ?></dd>
+                                    </dl>
+                                </div>
+                            <?php endif; ?>
+                        </dd>
+                    <?php else: ?>
+                        <dd><?= $block->escapeHtml((isset($_option['print_value']) ? $_option['print_value'] : $_option['value'])) ?></dd>
+                    <?php endif; ?>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* downloadable */?>
+        <?php if ($links = $block->getLinks()): ?>
+            <dl class="item-options links">
+                <dt><?= /* @escapeNotVerified */ $block->getLinksTitle() ?></dt>
+                <?php foreach ($links->getPurchasedItems() as $link): ?>
+                    <dd><?= $block->escapeHtml($link->getLinkTitle()) ?></dd>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* EOF downloadable */?>
+
+        <?php $addInfoBlock = $block->getProductAdditionalInformationBlock(); ?>
+        <?php if ($addInfoBlock) :?>
+            <?= $addInfoBlock->setItem($_item->getOrderItem())->toHtml() ?>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+    </td>
+    <td class="col sku" data-th="<?= $block->escapeHtml(__('SKU')) ?>"><?= /* @escapeNotVerified */ $block->prepareSku($block->getSku()) ?></td>
+    <td class="col price" data-th="<?= $block->escapeHtml(__('Price')) ?>">
+        <?= $block->getItemPriceHtml() ?>
+    </td>
+    <td class="col qty" data-th="<?= $block->escapeHtml(__('Qty')) ?>"><?= /* @escapeNotVerified */ $_item->getQty()*1 ?></td>
+    <td class="col subtotal" data-th="<?= $block->escapeHtml(__('Subtotal')) ?>">
+        <?= $block->getItemRowTotalHtml() ?>
+    </td>
+    <td class="col discount" data-th="<?= $block->escapeHtml(__('Discount Amount')) ?>"><?= /* @escapeNotVerified */ $_order->formatPrice(-$_item->getDiscountAmount()) ?></td>
+    <td class="col total" data-th="<?= $block->escapeHtml(__('Row Total')) ?>">
+        <?= $block->getItemRowTotalAfterDiscountHtml() ?>
+    </td>
+</tr>
diff --git a/view/frontend/templates/sales/order/invoice/items/renderer/downloadable.phtml b/view/frontend/templates/sales/order/invoice/items/renderer/downloadable.phtml
new file mode 100644
index 0000000..0cf1bf8
--- /dev/null
+++ b/view/frontend/templates/sales/order/invoice/items/renderer/downloadable.phtml
@@ -0,0 +1,65 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+/** @var $block \Magento\Downloadable\Block\Sales\Order\Item\Renderer\Downloadable */
+?>
+<?php $_item = $block->getItem() ?>
+<?php $_order = $block->getItem()->getOrderItem()->getOrder() ?>
+<tr id="order-item-row-<?= /* @escapeNotVerified */ $_item->getId() ?>">
+    <td class="col name" data-th="<?= $block->escapeHtml(__('Product Name')) ?>">
+        <strong class="product name product-item-name"><?= $block->escapeHtml($_item->getName()) ?></strong>
+        <?php if ($_options = $block->getItemOptions()): ?>
+            <dl class="item-options links">
+                <?php foreach ($_options as $_option) : ?>
+                    <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                    <?php if (!$block->getPrintStatus()): ?>
+                        <?php $_formatedOptionValue = $block->getFormatedOptionValue($_option) ?>
+                        <dd<?php if (isset($_formatedOptionValue['full_view'])): ?> class="tooltip wrapper"<?php endif; ?>>
+                            <?= /* @escapeNotVerified */ $_formatedOptionValue['value'] ?>
+                            <?php if (isset($_formatedOptionValue['full_view'])): ?>
+                                <div class="tooltip content">
+                                    <dl class="item options">
+                                        <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                                        <dd><?= /* @escapeNotVerified */ $_formatedOptionValue['full_view'] ?></dd>
+                                    </dl>
+                                </div>
+                            <?php endif; ?>
+                        </dd>
+                    <?php else: ?>
+                        <dd><?= $block->escapeHtml((isset($_option['print_value']) ? $_option['print_value'] : $_option['value'])) ?></dd>
+                    <?php endif; ?>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* downloadable */ ?>
+        <?php if ($links = $block->getLinks()): ?>
+            <dl class="item-options links">
+                <dt><?= /* @escapeNotVerified */ $block->getLinksTitle() ?></dt>
+                <?php foreach ($links->getPurchasedItems() as $link): ?>
+                    <dd><?= $block->escapeHtml($link->getLinkTitle()) ?></dd>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* EOF downloadable */ ?>
+        <?php $addInfoBlock = $block->getProductAdditionalInformationBlock(); ?>
+        <?php if ($addInfoBlock) :?>
+            <?= $addInfoBlock->setItem($_item->getOrderItem())->toHtml() ?>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+    </td>
+    <td class="col sku" data-th="<?= $block->escapeHtml(__('SKU')) ?>"><?= /* @escapeNotVerified */ $block->prepareSku($block->getSku()) ?></td>
+    <td class="col price" data-th="<?= $block->escapeHtml(__('Price')) ?>">
+        <?= $block->getItemPriceHtml() ?>
+    </td>
+    <td class="col qty" data-th="<?= $block->escapeHtml(__('Qty Invoiced')) ?>">
+        <span class="qty summary" data-label="<?= $block->escapeHtml(__('Qty Invoiced')) ?>"><?= /* @escapeNotVerified */ $_item->getQty()*1 ?></span>
+    </td>
+    <td class="col subtotal" data-th="<?= $block->escapeHtml(__('Subtotal')) ?>">
+        <?= $block->getItemRowTotalHtml() ?>
+    </td>
+</tr>
diff --git a/view/frontend/templates/sales/order/items/renderer/downloadable.phtml b/view/frontend/templates/sales/order/items/renderer/downloadable.phtml
new file mode 100644
index 0000000..40d965e
--- /dev/null
+++ b/view/frontend/templates/sales/order/items/renderer/downloadable.phtml
@@ -0,0 +1,91 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+// @codingStandardsIgnoreFile
+
+/** @var $block \Magento\Downloadable\Block\Sales\Order\Item\Renderer\Downloadable */
+?>
+<?php $_item = $block->getItem() ?>
+<tr id="order-item-row-<?= /* @escapeNotVerified */ $_item->getId() ?>">
+    <td class="col name" data-th="<?= $block->escapeHtml(__('Product Name')) ?>">
+        <strong class="product name product-item-name"><?= $block->escapeHtml($_item->getName()) ?></strong>
+        <?php if ($_options = $block->getItemOptions()): ?>
+            <dl class="item-options links">
+                <?php foreach ($_options as $_option) : ?>
+                    <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                    <?php if (!$block->getPrintStatus()): ?>
+                        <?php $_formatedOptionValue = $block->getFormatedOptionValue($_option) ?>
+                        <dd<?php if (isset($_formatedOptionValue['full_view'])): ?> class="tooltip wrapper"<?php endif; ?>>
+                            <?= /* @escapeNotVerified */ $_formatedOptionValue['value'] ?>
+                            <?php if (isset($_formatedOptionValue['full_view'])): ?>
+                                <div class="tooltip content">
+                                    <dl class="item options">
+                                        <dt><?= $block->escapeHtml($_option['label']) ?></dt>
+                                        <dd><?= /* @escapeNotVerified */ $_formatedOptionValue['full_view'] ?></dd>
+                                    </dl>
+                                </div>
+                            <?php endif; ?>
+                        </dd>
+                    <?php else: ?>
+                        <dd>
+                            <?= nl2br($block->escapeHtml((isset($_option['print_value']) ? $_option['print_value'] : $_option['value']))) ?>
+                        </dd>
+                    <?php endif; ?>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* downloadable */ ?>
+        <?php if ($links = $block->getLinks()): ?>
+            <dl class="item-options links">
+                <dt><?= /* @escapeNotVerified */ $block->getLinksTitle() ?></dt>
+                <?php foreach ($links->getPurchasedItems() as $link): ?>
+                    <dd><?= $block->escapeHtml($link->getLinkTitle()) ?></dd>
+                <?php endforeach; ?>
+            </dl>
+        <?php endif; ?>
+        <?php /* EOF downloadable */ ?>
+        <?php $addtInfoBlock = $block->getProductAdditionalInformationBlock(); ?>
+        <?php if ($addtInfoBlock) :?>
+            <?= $addtInfoBlock->setItem($_item)->toHtml() ?>
+        <?php endif; ?>
+        <?= $block->escapeHtml($_item->getDescription()) ?>
+    </td>
+    <td class="col sku" data-th="<?= $block->escapeHtml(__('SKU')) ?>"><?= /* @escapeNotVerified */ $block->prepareSku($block->getSku()) ?></td>
+    <td class="col price" data-th="<?= $block->escapeHtml(__('Price')) ?>">
+        <?= $block->getItemPriceHtml() ?>
+    </td>
+    <td class="col qty" data-th="<?= $block->escapeHtml(__('Qty')) ?>">
+        <ul class="items-qty">
+            <?php if ($block->getItem()->getQtyOrdered() > 0): ?>
+                <li class="item">
+                    <span class="title"><?= /* @escapeNotVerified */ __('Ordered') ?></span>
+                    <span class="content"><?= /* @escapeNotVerified */ $block->getItem()->getQtyOrdered()*1 ?></span>
+                </li>
+            <?php endif; ?>
+            <?php if ($block->getItem()->getQtyShipped() > 0): ?>
+                <li class="item">
+                    <span class="title"><?= /* @escapeNotVerified */ __('Shipped') ?></span>
+                    <span class="content"><?= /* @escapeNotVerified */ $block->getItem()->getQtyShipped() * 1 ?></span>
+                </li>
+            <?php endif; ?>
+            <?php if ($block->getItem()->getQtyCanceled() > 0): ?>
+                <li class="item">
+                    <span class="title"><?= /* @escapeNotVerified */ __('Canceled') ?></span>
+                    <span class="content"><?= /* @escapeNotVerified */ $block->getItem()->getQtyCanceled()*1 ?></span>
+                </li>
+            <?php endif; ?>
+            <?php if ($block->getItem()->getQtyRefunded() > 0): ?>
+                <li class="item">
+                    <span class="title"><?= /* @escapeNotVerified */ __('Refunded') ?></span>
+                    <span class="content"><?= /* @escapeNotVerified */ $block->getItem()->getQtyRefunded()*1 ?></span>
+                </li>
+            <?php endif; ?>
+        </ul>
+    </td>
+    <td class="col subtotal" data-th="<?= $block->escapeHtml(__('Subtotal')) ?>">
+        <?= $block->getItemRowTotalHtml() ?>
+    </td>
+</tr>
diff --git a/view/frontend/web/css/styles-product-page.less b/view/frontend/web/css/styles-product-page.less
new file mode 100644
index 0000000..7ca005a
--- /dev/null
+++ b/view/frontend/web/css/styles-product-page.less
@@ -0,0 +1,47 @@
+.fieldset .legend.usages-title {
+    margin: 0 0 11px;
+    font-weight: bold;
+    font-size: 1.5em;
+}
+#usages-container {
+    position: relative;
+    #usage-button-close {
+        position: absolute;
+        right: 0;
+        z-index: 10;
+    }
+    .field {
+        margin: 10px 0;
+        position: relative;
+        &:after {
+            content: ' ';
+            border-radius: 4px;
+            height: 100%;
+            position: absolute;
+            left: -10px;
+            width: 100%;
+            padding: 6px 10px;
+            top: -3px;
+            z-index: -1;
+            transition: background 0.5s ease;
+        }
+        &.active:after {
+            background: #f5f5f5;
+        }
+        .control {
+            margin-top: 1px;
+        }
+        .label {
+            font-weight: bold;
+            display: block;
+            a {
+                float: right;
+                font-weight: normal;
+            }
+        }
+    }
+}
+
+.product-info-main .product-info-price .price-box {
+    margin-top: 10px;
+}
\ No newline at end of file
diff --git a/view/frontend/web/usage.js b/view/frontend/web/usage.js
new file mode 100644
index 0000000..922478c
--- /dev/null
+++ b/view/frontend/web/usage.js
@@ -0,0 +1,172 @@
+/**
+ * @api
+ */
+define([
+    'jquery',
+    'priceBox',
+    'jquery/ui'
+], function ($, priceBox) {
+    'use strict';
+    var self;
+
+    $.widget('mage.usage', {
+        options: {
+            priceHolderSelector: '#product-options-wrapper .price-box'
+        },
+        hidden: true,
+
+        /** @inheritdoc */
+        _create: function () {
+            self = this;
+
+            this.element.find(this.options.categorySelectElement).on('change', function () {
+                self.element.find(".category-container").hide().find('select, input, textarea').prop('disabled', true);;
+                self.element.find(".usage-container").hide();
+                self.element.find("#category_container_"+$(this).val()).show()
+                    .find('.usage-select-box').val('').prop('disabled', false);
+            });
+
+            this.element.find('select, input, textarea').on('change', this._reloadPrice);
+
+            this.element.find('.help-text').hide();
+
+            this.element.find('label').on('click', function (e) {
+                e.preventDefault();
+                $(this).closest('.field').find('.help-text').toggle()
+                var $a = $(this).find('a');
+                var current = $a.html();
+                $a.html($a.data('less'));
+                $a.data('less', current);
+            });
+
+            this.element.find(".usage-select-box").on('change', function () {
+                self.element.find(".usage-container").hide().find('select, input, textarea').prop('disabled', true);
+                self.element.find("#usage_container_"+$(this).val()).show().find('select, input, textarea').prop('disabled', false);
+            });
+
+            $('.usages-container-inner').hide().find('select, input, textarea').prop('disabled', true);
+            $('#usage-button, #usage-button-close').on('click', function (e) {
+                e.preventDefault();
+                $('#maincontent .product.info.detailed').toggle();
+                $('#maincontent .product-info-main .product-info-main > div:not(.product-add-form)').toggle();
+                $('#product-options-wrapper > div > :not(.product-info-price):not(.usages-container)').toggle();
+                $('.usages-container-inner').toggle();
+                $('#usage-button').toggle();
+                if ( self.hidden ) {
+                    self.element.find(self.options.categorySelectElement).prop('disabled', false).val('').trigger('change');
+                } else {
+                    $('.usages-container-inner').find('select, input, textarea').prop('disabled', true);
+                }
+
+                self.hidden = ! self.hidden;
+            });
+
+            $(self.options.priceHolderSelector).priceBox('setDefault', {
+                'basePrice': {
+                    'amount': 0.0,
+                    'adjustments': []
+                },
+                'finalPrice': {
+                    'amount': 0.0,
+                    'adjustments': []
+                },
+                'oldPrice': {
+                    'amount': 0.0,
+                    'adjustments': []
+                }
+            });
+
+            $(self.options.priceHolderSelector + ', .product-options-bottom').hide();
+        },
+
+        /**
+         * Reload product price with selected link price included
+         * @private
+         */
+        _reloadPrice: function () {
+            var finalPrice = 0,
+                basePrice = 0,
+                $usage,
+                $selected,
+                terms,
+                categoryId,
+                haveActive = false;
+
+            self.element.find().show();
+
+            categoryId = self.element.find(self.options.categorySelectElement).val();
+
+            $usage = self.element.find("#category_container_"+categoryId+' .usage-select-box option:selected');
+
+            finalPrice = basePrice = parseFloat($usage.attr('price'));
+            terms = $usage.data('terms');
+
+            if (basePrice) {
+                self.element.find("#category_container_"+categoryId).removeClass('active');
+            } else if (categoryId) {
+                self.element.find('.field.active').removeClass('active');
+                self.element.find("#category_container_"+categoryId).addClass('active');
+            } else {
+                self.element.find('.usages-container-inner > .control > .field').addClass('active');
+            }
+
+            self.element.find("#usage_container_"+$usage.attr('value')+' select[name*=options]').each(function (index, select) {
+                $selected = $(select).find('option:selected');
+                if(!$selected.attr('price') && !haveActive) {
+                    $(select).closest('.field').addClass('active');
+                    haveActive = true;
+                } else {
+                    $(select).closest('.field.active').removeClass('active');
+                }
+
+                finalPrice *= parseFloat($selected.attr('price')) / 100;
+                terms = terms.replace(
+                    '('+select.title+')',
+                    '<strong>'+$selected.text()+'</strong>'
+                );
+            });
+
+            self.element.find("#usage_container_"+$usage.attr('value')+' input').each(function (index, input) {
+                if (!$(input).val() && !haveActive) {
+                    $(input).closest('.field').addClass('active');
+                    haveActive = true;
+                } else {
+                    $(input).closest('.field.active').removeClass('active');
+                }
+                terms = terms.replace(
+                    '('+$(input).data('title')+')',
+                    '<strong>'+$(input).val()+'</strong>'
+                );
+            });
+
+            if (isNaN(finalPrice)) {
+                finalPrice = 0;
+            }
+
+            if ( 95 !== ((finalPrice * 100) % 100)) {
+                finalPrice = Math.round(finalPrice);
+            }
+
+            $(self.options.priceHolderSelector).trigger('updatePrice', {
+                'prices': {
+                    'finalPrice': {
+                        'amount': finalPrice
+                    },
+                    'basePrice': {
+                        'amount': basePrice
+                    }
+                }
+            });
+
+            if (finalPrice <= 0) {
+                $(self.options.priceHolderSelector + ', .product-options-bottom').hide();
+                $('#usages-advice-container').html('');
+            } else {
+                $('#usages-advice-container').html(terms);
+                $(self.options.priceHolderSelector + ', .product-options-bottom').show();
+            }
+        }
+    });
+
+    return $.mage.usage;
+});