From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Wed, 6 Jan 2021 00:34:04 -0800
Subject: [PATCH] Expand world key API


diff --git a/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java b/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
index be0ca9e82b88518109eec88735e628b8de9ebe72..2667822413c329fc004aad826e5890ab4dc5bfeb 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftRegionAccessor.java
@@ -505,5 +505,10 @@ public abstract class CraftRegionAccessor implements RegionAccessor {
     public io.papermc.paper.world.MoonPhase getMoonPhase() {
         return io.papermc.paper.world.MoonPhase.getPhase(this.getHandle().dayTime() / 24000L);
     }
+
+    @Override
+    public org.bukkit.NamespacedKey getKey() {
+        return org.bukkit.craftbukkit.util.CraftNamespacedKey.fromMinecraft(this.getHandle().getLevel().dimension().location());
+    }
     // Paper end
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 508ccf9685058674020c04914d8107e7fb1912ce..0d0f575c07fc1cc31a3b648720558c6f8d639eb5 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -1137,9 +1137,15 @@ public final class CraftServer implements Server {
         File folder = new File(this.getWorldContainer(), name);
         World world = this.getWorld(name);
 
-        if (world != null) {
-            return world;
+        // Paper start
+        World worldByKey = this.getWorld(creator.key());
+        if (world != null || worldByKey != null) {
+            if (world == worldByKey) {
+                return world;
+            }
+            throw new IllegalArgumentException("Cannot create a world with key " + creator.key() + " and name " + name + " one (or both) already match a world that exists");
         }
+        // Paper end
 
         if (folder.exists()) {
             Preconditions.checkArgument(folder.isDirectory(), "File (%s) exists and isn't a folder", name);
@@ -1263,7 +1269,7 @@ public final class CraftServer implements Server {
         } else if (name.equals(levelName + "_the_end")) {
             worldKey = net.minecraft.world.level.Level.END;
         } else {
-            worldKey = ResourceKey.create(Registries.DIMENSION, new ResourceLocation(name.toLowerCase(java.util.Locale.ENGLISH)));
+            worldKey = ResourceKey.create(Registries.DIMENSION, new net.minecraft.resources.ResourceLocation(creator.key().getNamespace().toLowerCase(java.util.Locale.ENGLISH), creator.key().getKey().toLowerCase(java.util.Locale.ENGLISH))); // Paper
         }
 
         ServerLevel internal = (ServerLevel) new ServerLevel(this.console, this.console.executor, worldSession, worlddata, worldKey, worlddimension, this.getServer().progressListenerFactory.create(11),
@@ -1356,6 +1362,15 @@ public final class CraftServer implements Server {
         return null;
     }
 
+    // Paper start
+    @Override
+    public World getWorld(NamespacedKey worldKey) {
+        ServerLevel worldServer = console.getLevel(ResourceKey.create(net.minecraft.core.registries.Registries.DIMENSION, CraftNamespacedKey.toMinecraft(worldKey)));
+        if (worldServer == null) return null;
+        return worldServer.getWorld();
+    }
+    // Paper end
+
     public void addWorld(World world) {
         // Check if a World already exists with the UID.
         if (this.getWorld(world.getUID()) != null) {
diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index bcf88a137616b83f3400afd18c6fe9f3b2b2db34..01b71837d1c1836b72216f97a09d43b13a875186 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -515,6 +515,11 @@ public final class CraftMagicNumbers implements UnsafeValues {
     public int nextEntityId() {
         return net.minecraft.world.entity.Entity.nextEntityId();
     }
+
+    @Override
+    public String getMainLevelName() {
+        return ((net.minecraft.server.dedicated.DedicatedServer) net.minecraft.server.MinecraftServer.getServer()).getProperties().levelName;
+    }
     // Paper end
 
     /**