Improve the default world keys.

The API made an assumption these keys would always be the same key id.
While I highly doubt Mojang would change, there is no reason to make it
contract.

Also deprecate defaultWorld in WorldManager and OVERWORLD to better
match what we are doing.

Signed-off-by: Chris Sanders <[email protected]>

Author: Zidane

src/main/java/org/spongepowered/api/world/DefaultWorldKeys.java

@@ -25,19 +25,46 @@
 package org.spongepowered.api.world;
 
 import org.spongepowered.api.ResourceKey;
+import org.spongepowered.api.Sponge;
 import org.spongepowered.api.world.server.ServerWorld;
 
 /**
  * A listing of the {@link ResourceKey keys} of the default {@link ServerWorld worlds} in Minecraft.
  */
 public final class DefaultWorldKeys {
 
+    /**
+     * @deprecated Use {@link #DEFAULT} instead
+     */
+    @Deprecated
     public static final ResourceKey OVERWORLD = ResourceKey.minecraft("overworld");
 
-    public static final ResourceKey THE_NETHER = ResourceKey.minecraft("the_nether");
+    /**
+     * The default "world" of a running game session. Typically, the Overworld.
+     * <p>
+     * Refer to: <a href="https://minecraft.fandom.com/wiki/Overworld">Overworld</a>
+     */
+    public static final ResourceKey DEFAULT = Sponge.game().factoryProvider().provide(DefaultWorldKeys.Factory.class).defaultWorld();
 
-    public static final ResourceKey THE_END = ResourceKey.minecraft("the_end");
+    /**
+     * Refer to: <a href="https://minecraft.fandom.com/wiki/The_Nether">The Nether</a>
+     */
+    public static final ResourceKey THE_NETHER = Sponge.game().factoryProvider().provide(DefaultWorldKeys.Factory.class).theNether();
+
+    /**
+     * Refer to: <a href="https://minecraft.fandom.com/wiki/The_End">The End</a>
+     */
+    public static final ResourceKey THE_END = Sponge.game().factoryProvider().provide(DefaultWorldKeys.Factory.class).theEnd();
 
     private DefaultWorldKeys() {
     }
+
+    public interface Factory {
+
+        ResourceKey defaultWorld();
+
+        ResourceKey theNether();
+
+        ResourceKey theEnd();
+    }
 }

src/main/java/org/spongepowered/api/world/server/WorldManager.java

@@ -74,7 +74,10 @@ public interface WorldManager {
      * <p>It is up to the implementation to define what the default world actually is.</p>
      *
      * @return The default world
+     *
+     * @deprecated Use {@link #world(ResourceKey)} with {@link org.spongepowered.api.world.DefaultWorldKeys#DEFAULT} instead
      */
+    @Deprecated
     ServerWorld defaultWorld();
 
     /**