Rewrote the spellbook pages system

src/main/java/com/minelittlepony/unicopia/Unicopia.java

@@ -47,6 +47,7 @@
 import com.minelittlepony.unicopia.advancements.UAdvancements;
 import com.minelittlepony.unicopia.block.ITillable;
 import com.minelittlepony.unicopia.command.Commands;
+import com.minelittlepony.unicopia.enchanting.Pages;
 import com.minelittlepony.unicopia.enchanting.SpellRecipe;
 import com.minelittlepony.unicopia.forgebullshit.FBS;
 import com.minelittlepony.unicopia.inventory.gui.ContainerSpellBook;
@@ -112,6 +113,8 @@ protected void registerRecipeTypes(Map<String, Function<JsonObject, IRecipe>> ty
             }
         };
 
+        Pages.instance().load();
+
         Biome.REGISTRY.forEach(UEntities::registerSpawnEntries);
         UClient.instance().posInit(event);
 

src/main/java/com/minelittlepony/unicopia/enchanting/CompoundCondition.java

@@ -0,0 +1,56 @@
+package com.minelittlepony.unicopia.enchanting;
+
+import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+
+import com.google.common.collect.Lists;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+
+public class CompoundCondition implements IUnlockCondition<IUnlockEvent> {
+
+    final Op operation;
+
+    final List<IUnlockCondition<IUnlockEvent>> conditions = Lists.newArrayList();
+
+    CompoundCondition(JsonObject json) {
+        require(json, "operation");
+        require(json, "conditions");
+
+        operation = Op.valueOf(json.get("operation").getAsString().toUpperCase());
+
+        json.get("conditions").getAsJsonArray().forEach(this::addElement);
+    }
+
+    void addElement(JsonElement element) {
+        JsonObject obj = element.getAsJsonObject();
+
+        conditions.add(Pages.instance().createCondition(obj));
+    }
+
+    @Override
+    public boolean accepts(IUnlockEvent event) {
+        return true;
+    }
+
+    @Override
+    public boolean matches(IPageOwner owner, IUnlockEvent event) {
+        return operation.test.apply(conditions.stream(), condition -> condition.accepts(event) && condition.matches(owner, event));
+    }
+
+    enum Op {
+        AND(Stream::allMatch),
+        OR(Stream::anyMatch);
+
+        final Test test;
+
+        Op(Test test) {
+            this.test = test;
+        }
+
+        interface Test {
+            boolean apply(Stream<IUnlockCondition<IUnlockEvent>> stream, Predicate<IUnlockCondition<IUnlockEvent>> predicate);
+        }
+    }
+}

src/main/java/com/minelittlepony/unicopia/enchanting/IConditionFactory.java

@@ -0,0 +1,8 @@
+package com.minelittlepony.unicopia.enchanting;
+
+import com.google.gson.JsonObject;
+
+@FunctionalInterface
+public interface IConditionFactory {
+    IUnlockCondition<?> create(JsonObject json);
+}

src/main/java/com/minelittlepony/unicopia/enchanting/IPage.java

@@ -0,0 +1,40 @@
+package com.minelittlepony.unicopia.enchanting;
+
+import net.minecraft.util.ResourceLocation;
+
+/**
+ * A spellbook page
+ */
+public interface IPage extends Comparable<IPage> {
+    /**
+     * Gets the index.
+     * This is the position the page appears in the book gui.
+     */
+    int getIndex();
+
+    /**
+     * The unique name of this page.
+     */
+    ResourceLocation getName();
+
+    /**
+     * Tests unlock conditions for this page.
+     * Returns true if the owner is permitted to read this page.
+     */
+    boolean canUnlock(IPageOwner owner, IUnlockEvent event);
+
+    /**
+     * Gets the texture.
+     * This is what's shown when this page is opened in the book gui.
+     */
+    ResourceLocation getTexture();
+
+    /**
+     * The default state.
+     */
+    PageState getDefaultState();
+
+    IPage next();
+
+    IPage prev();
+}

src/main/java/com/minelittlepony/unicopia/enchanting/IPageOwner.java

@@ -1,32 +1,32 @@
 package com.minelittlepony.unicopia.enchanting;
 
-import java.util.List;
+import java.util.Map;
 
 import javax.annotation.Nonnull;
 
 import com.minelittlepony.unicopia.network.ITransmittable;
 
+import net.minecraft.util.ResourceLocation;
+
+/**
+ * Interface for things that own and can unlock pages.
+ *
+ */
 public interface IPageOwner extends ITransmittable {
 
     @Nonnull
-    List<Integer> getUnlockedPages();
-
-    default boolean hasPageUnlock(int pageIndex) {
-        return getUnlockedPages().contains(pageIndex);
-    }
-
-    default boolean unlockPage(int pageIndex) {
-        if (!hasPageUnlock(pageIndex)) {
-            if (getUnlockedPages().add(pageIndex)) {
-                sendCapabilities(true);
+    Map<ResourceLocation, PageState> getPageStates();
 
-                return true;
-            }
+    default void setPageState(IPage page, PageState state) {
+        if (state == PageState.LOCKED) {
+            getPageStates().remove(page.getName());
+        } else {
+            getPageStates().put(page.getName(), state);
         }
-        return false;
+        sendCapabilities(true);
     }
 
-    default boolean hasUnlockedPages() {
-        return getUnlockedPages().size() > 0;
+    default PageState getPageState(IPage page) {
+        return getPageStates().getOrDefault(page.getName(), page.getDefaultState());
     }
 }

src/main/java/com/minelittlepony/unicopia/enchanting/IPageUnlockListener.java

@@ -1,5 +1,12 @@
 package com.minelittlepony.unicopia.enchanting;
 
+@FunctionalInterface
 public interface IPageUnlockListener {
-	public void onPageUnlocked();
+    /**
+     * Called when a page is unlocked.
+     *
+     * @param page The page that has been unlocked
+     * @return True to allow, false to block.
+     */
+	boolean onPageUnlocked(IPage page);
 }

src/main/java/com/minelittlepony/unicopia/enchanting/IUnlockCondition.java

@@ -0,0 +1,30 @@
+package com.minelittlepony.unicopia.enchanting;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+
+/**
+ * A PageEvent for determining when certain pages must be unlocked.
+ */
+public interface IUnlockCondition<T extends IUnlockEvent> {
+
+    /**
+     * Returns true if event instanceof T
+     */
+    default boolean accepts(IUnlockEvent event) {
+        return true;
+    }
+
+    /**
+     * Checks if this event's conditions are met.
+     * @param prop      PlayerExtension for the player doing the crafting
+     * @param stack     ItemStack crafted
+     */
+    boolean matches(IPageOwner owner, T event);
+
+    default void require(JsonObject json, String memberName) {
+        if (!json.has(memberName)) {
+            throw new JsonParseException(String.format("%s condition must have a %s", getClass().getSimpleName(), memberName));
+        }
+    }
+}

src/main/java/com/minelittlepony/unicopia/enchanting/IUnlockEvent.java

@@ -0,0 +1,5 @@
+package com.minelittlepony.unicopia.enchanting;
+
+public interface IUnlockEvent {
+
+}