allow custom data provider registration

core/src/main/java/com/volmit/iris/core/link/ExternalDataProvider.java

@@ -2,22 +2,28 @@ package com.volmit.iris.core.link;
 
 import com.volmit.iris.engine.framework.Engine;
 import com.volmit.iris.util.collection.KMap;
+import com.volmit.iris.util.data.IrisBlockData;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 import org.bukkit.Bukkit;
 import org.bukkit.block.Block;
 import org.bukkit.block.data.BlockData;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.Plugin;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.MissingResourceException;
 
+@Getter
 @RequiredArgsConstructor
 public abstract class ExternalDataProvider {
 
-    @Getter
+    @NonNull
     private final String pluginId;
 
+    @Nullable
     public Plugin getPlugin() {
         return Bukkit.getPluginManager().getPlugin(pluginId);
     }
@@ -28,23 +34,60 @@ public abstract class ExternalDataProvider {
 
     public abstract void init();
 
-    public BlockData getBlockData(Identifier blockId) throws MissingResourceException {
+    /**
+     * @see ExternalDataProvider#getBlockData(Identifier, KMap)
+     */
+    @NotNull
+    public BlockData getBlockData(@NotNull Identifier blockId) throws MissingResourceException {
         return getBlockData(blockId, new KMap<>());
     }
 
-    public abstract BlockData getBlockData(Identifier blockId, KMap<String, String> state) throws MissingResourceException;
+    /**
+     * This method returns a {@link BlockData} corresponding to the blockID
+     * it is used in any place Iris accepts {@link BlockData}
+     *
+     * @param blockId The id of the block to get
+     * @param state The state of the block to get
+     * @return Corresponding {@link BlockData} to the blockId
+     *         may return {@link IrisBlockData} for blocks that need a world for placement
+     * @throws MissingResourceException when the blockId is invalid
+     */
+    @NotNull
+    public abstract BlockData getBlockData(@NotNull Identifier blockId, @NotNull KMap<String, String> state) throws MissingResourceException;
 
-    public ItemStack getItemStack(Identifier itemId) throws MissingResourceException {
+    /**
+     * @see ExternalDataProvider#getItemStack(Identifier)
+     */
+    @NotNull
+    public ItemStack getItemStack(@NotNull Identifier itemId) throws MissingResourceException {
         return getItemStack(itemId, new KMap<>());
     }
 
-    public abstract ItemStack getItemStack(Identifier itemId, KMap<String, Object> customNbt) throws MissingResourceException;
+    /**
+     * This method returns a {@link ItemStack} corresponding to the itemID
+     * it is used in loot tables
+     *
+     * @param itemId The id of the item to get
+     * @param customNbt Custom nbt to apply to the item
+     * @return Corresponding {@link ItemStack} to the itemId
+     * @throws MissingResourceException when the itemId is invalid
+     */
+    @NotNull
+    public abstract ItemStack getItemStack(@NotNull Identifier itemId, @NotNull KMap<String, Object> customNbt) throws MissingResourceException;
 
-    public void processUpdate(Engine engine, Block block, Identifier blockId) {}
+    /**
+     * This method is used for placing blocks that need to use the plugins api
+     * it will only be called when the {@link ExternalDataProvider#getBlockData(Identifier, KMap)} returned a {@link IrisBlockData}
+     *
+     * @param engine The engine of the world the block is being placed in
+     * @param block The block where the block should be placed
+     * @param blockId The blockId to place
+     */
+    public void processUpdate(@NotNull Engine engine, @NotNull Block block, @NotNull Identifier blockId) {}
 
-    public abstract Identifier[] getBlockTypes();
+    public abstract @NotNull Identifier @NotNull [] getBlockTypes();
 
-    public abstract Identifier[] getItemTypes();
+    public abstract @NotNull Identifier @NotNull [] getItemTypes();
 
-    public abstract boolean isValidProvider(Identifier id, boolean isItem);
+    public abstract boolean isValidProvider(@NotNull Identifier id, boolean isItem);
 }

core/src/main/java/com/volmit/iris/core/service/ExternalDataSVC.java

@@ -26,6 +26,7 @@ import com.volmit.iris.util.collection.KList;
 import com.volmit.iris.util.collection.KMap;
 import com.volmit.iris.util.plugin.IrisService;
 import lombok.Data;
+import lombok.NonNull;
 import org.bukkit.Bukkit;
 import org.bukkit.block.Block;
 import org.bukkit.block.data.BlockData;
@@ -99,6 +100,18 @@ public class ExternalDataSVC implements IrisService {
         }
     }
 
+    public void registerProvider(@NonNull ExternalDataProvider provider) {
+        String plugin = provider.getPluginId();
+        if (providers.stream().map(ExternalDataProvider::getPluginId).anyMatch(plugin::equals))
+            throw new IllegalArgumentException("A provider with the same plugin id already exists.");
+
+        providers.add(provider);
+        if (provider.isReady()) {
+            activeProviders.add(provider);
+            provider.init();
+        }
+    }
+
     public Optional<BlockData> getBlockData(final Identifier key) {
         var pair = parseState(key);
         Identifier mod = pair.getA();