diff --git a/.gitignore b/.gitignore
deleted file mode 100644
index 485dee6..0000000
--- a/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-.idea
diff --git a/README.md b/README.md
index 23f8cd5..2e658be 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,10 @@
 # Diffy Acquia cloud hooks integration
 
-Automates triggering "compare" job for your Acquia project whenever you do deployment.
+Automates triggering "compare" job for your Acquia project whenever you do a
+deployment.
 
-If you do deployment to "dev" or "test" environments this script triggers job to compare dev/test with prod.
+If you do a deployment to "dev" or "test" environments this script triggers a 
+job to compare "dev"/"test" with "prod".
 
 More on Acquia cloud hooks: https://docs.acquia.com/acquia-cloud/develop/api/cloud-hooks/
 
@@ -12,6 +14,8 @@ Video tutorial: https://youtu.be/wOuB8tRNNYw
 
 ## Installation notes
 
-You would need to have a project created in Diffy (need its ID). Also you need to provide API key so script can authenticate. 
+You would need to have a project created in Diffy (need its ID). Also you need 
+to provide API key so the script can authenticate.
 
-Please provide these details https://github.com/DiffyWebsite/diffy-acquia/blob/master/hooks/diffy/diffy_trigger_compare_job.php.
+Provide these details either as `DIFFY_API_KEY` and `DIFFY_PROJECT_ID` 
+environment variables or update [diffy_trigger_compare_job.php](hooks/diffy/diffy_trigger_compare_job.php) file.
diff --git a/hooks/diffy/diffy_trigger_compare_job.php b/hooks/diffy/diffy_trigger_compare_job.php
index a6297c1..814b9ac 100644
--- a/hooks/diffy/diffy_trigger_compare_job.php
+++ b/hooks/diffy/diffy_trigger_compare_job.php
@@ -1,65 +1,115 @@
 <?php
+
 /**
- * Script to trigger compare jobs on Diffy API.
- * @see https://diffy.website for more details.
- **/
-list($script, $site, $target_env, $source_branch, $deployed_tag, ) = $argv;
+ * @file
+ * Trigger compare jobs using Diffy API.
+ *
+ * @see https://diffy.website
+ */
+
+list($script, $site, $target_env, $source_branch, $deployed_tag,) = $argv;
+
+// Provide Diffy API key and project id as environment variables or
+// override here.
+define('DIFFY_API_KEY', getenv('DIFFY_API_KEY') ? getenv('DIFFY_API_KEY') : 'DIFFY_API_KEY_PLACEHOLDER');
+define('DIFFY_PROJECT_ID', getenv('DIFFY_PROJECT_ID') ? getenv('DIFFY_PROJECT_ID') : 'DIFFY_PROJECT_ID_PLACEHOLDER');
 
-// Settings. Please provide your own here.
-$api_key = 'AAA';
-$project_id = 111;
+// Default base environment to compare to. Defaults to 'prod'.
+define('DIFFY_BASE_ENVIRONMENT', getenv('DIFFY_BASE_ENVIRONMENT') ? getenv('DIFFY_BASE_ENVIRONMENT') : 'prod');
+
+if (empty(DIFFY_API_KEY)) {
+  print 'Please provide DIFFY_API_KEY';
+  exit(1);
+}
+
+if (empty(DIFFY_PROJECT_ID)) {
+  print 'Please provide DIFFY_PROJECT_ID';
+  exit(1);
+}
+
+if (empty(DIFFY_BASE_ENVIRONMENT)) {
+  print 'Please provide DIFFY_BASE_ENVIRONMENT';
+  exit(1);
+}
 
 // Choose what environments to compare.
 switch ($target_env) {
   case 'dev':
-    $operation = 'prod-dev';
+    $environments = DIFFY_BASE_ENVIRONMENT . '-dev';
     break;
+
   case 'test':
-    $operation = 'prod-stage';
+    $environments = DIFFY_BASE_ENVIRONMENT . '-stage';
     break;
+
   default:
-    echo 'Neither Dev nor Test environment. Do not trigger any job.';
-    exit;
+    exit('Neither Dev nor Test environment. Do not trigger any jobs.');
 }
 
-// Get access token from key.
+print "Getting access token from the key.";
 $ch = curl_init();
-$curl_options = array(
+curl_setopt_array($ch, [
   CURLOPT_URL => 'https://diffy.website/api/auth/key',
-  CURLOPT_HTTPHEADER => array(
+  CURLOPT_HTTPHEADER => [
     'Accept: application/json',
-    'Content-Type: application/json'
-  ),
+    'Content-Type: application/json',
+  ],
   CURLOPT_CUSTOMREQUEST => 'POST',
-  CURLOPT_POSTFIELDS => json_encode(array(
-    'key' => $api_key
-  )),
+  CURLOPT_POSTFIELDS => json_encode([
+    'key' => DIFFY_API_KEY,
+  ]),
   CURLOPT_RETURNTRANSFER => TRUE,
-);
-curl_setopt_array($ch, $curl_options);
-$curl_response = json_decode(curl_exec($ch));
+]);
+
+$curl_response = curl_exec($ch);
+// Check if the curl request succeeded.
+if ($curl_response === FALSE) {
+  $info = var_export(curl_getinfo($ch), TRUE);
+  $error = curl_error($ch);
+  curl_close($ch);
+
+  print_r($info);
+  print_r($error);
+
+  exit(1);
+}
+
+print "Successfully retrieved access token from the key.";
+$curl_response = json_decode($curl_response);
 curl_close($ch);
 
 $token = $curl_response->token;
 
-// Run Compare job.
+print "Starting compare job.";
 $ch = curl_init();
-$curl_options = array(
-  CURLOPT_URL => 'https://diffy.website/api/projects/' . $project_id . '/compare',
-  CURLOPT_HTTPHEADER => array(
+curl_setopt_array($ch, [
+  CURLOPT_URL => 'https://diffy.website/api/projects/' . DIFFY_PROJECT_ID . '/compare',
+  CURLOPT_HTTPHEADER => [
     'Accept: application/json',
     'Content-Type: application/json',
     'Authorization: Bearer ' . $token,
-  ),
+  ],
   CURLOPT_CUSTOMREQUEST => 'POST',
-  CURLOPT_POSTFIELDS => json_encode(array(
-    'environments' => $operation,
-  )),
+  CURLOPT_POSTFIELDS => json_encode([
+    'environments' => $environments,
+  ]),
   CURLOPT_RETURNTRANSFER => TRUE,
-);
-curl_setopt_array($ch, $curl_options);
-$curl_response = json_decode(curl_exec($ch));
+]);
+$curl_response = curl_exec($ch);
+
+if ($curl_response === FALSE) {
+  $info = var_export(curl_getinfo($ch), TRUE);
+  $error = curl_error($ch);
+  curl_close($ch);
+
+  print_r($info);
+  print_r($error);
+
+  exit(1);
+}
+
+$curl_response = json_decode($curl_response);
 curl_close($ch);
 
-echo "Compare job has started.\n";
-echo 'Check out the result here: https://diffy.website/ui#/diffs/' . str_replace('diff: ', '', $curl_response) . "\n";
+print "Compare job has started.";
+print 'Check out the result here: https://diffy.website/ui#/diffs/' . str_replace('diff: ', '', $curl_response);