From 6fdf0f82553eab17c755869080aa9dc4404de521 Mon Sep 17 00:00:00 2001
From: Dan Mulloy <dmulloy2@live.com>
Date: Tue, 18 Sep 2018 17:01:55 -0400
Subject: [PATCH] Add modifier for dimensions

---
 .../protocol/events/PacketContainer.java      | 19 ++++++--
 .../protocol/wrappers/BukkitConverters.java   | 47 +++++++++++++++++++
 .../protocol/events/PacketContainerTest.java  |  7 +++
 3 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/modules/API/src/main/java/com/comphenix/protocol/events/PacketContainer.java b/modules/API/src/main/java/com/comphenix/protocol/events/PacketContainer.java
index b7be62e0..e7edf8a5 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/events/PacketContainer.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/events/PacketContainer.java
@@ -42,8 +42,6 @@ import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.StreamSerializer;
 import com.comphenix.protocol.wrappers.*;
 import com.comphenix.protocol.wrappers.EnumWrappers.*;
-import com.comphenix.protocol.wrappers.EnumWrappers.Difficulty;
-import com.comphenix.protocol.wrappers.EnumWrappers.SoundCategory;
 import com.comphenix.protocol.wrappers.nbt.NbtBase;
 import com.comphenix.protocol.wrappers.nbt.NbtCompound;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
@@ -55,8 +53,10 @@ import com.google.common.collect.Sets;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.UnpooledByteBufAllocator;
 
-import org.bukkit.*;
-import org.bukkit.Particle;
+import org.bukkit.Material;
+import org.bukkit.Sound;
+import org.bukkit.World;
+import org.bukkit.WorldType;
 import org.bukkit.entity.Entity;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.potion.PotionEffectType;
@@ -936,6 +936,17 @@ public class PacketContainer implements Serializable {
 			    MinecraftKey.getConverter());
     }
 
+	/**
+	 * Retrive a read/write structure for dimension IDs in 1.13.1+
+	 * @return A modifier for dimension IDs
+	 */
+	public StructureModifier<Integer> getDimensions() {
+		return structureModifier.withType(
+				MinecraftReflection.getMinecraftClass("DimensionManager"),
+				BukkitConverters.getDimensionIDConverter()
+		);
+    }
+
 	/**
 	 * Retrieve a read/write structure for the Map class.
 	 * @param keyConverter Converter for map keys
diff --git a/modules/API/src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java b/modules/API/src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java
index 7b341c27..55fe0046 100644
--- a/modules/API/src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java
+++ b/modules/API/src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java
@@ -1070,4 +1070,51 @@ public class BukkitConverters {
 			}
 		});
 	}
+
+	private static MethodAccessor dimensionFromId = null;
+	private static MethodAccessor idFromDimension = null;
+
+	public static EquivalentConverter<Integer> getDimensionIDConverter() {
+		return new EquivalentConverter<Integer>() {
+
+			@Override
+			public Object getGeneric(Integer specific) {
+				if (dimensionFromId == null) {
+					Class<?> clazz = MinecraftReflection.getMinecraftClass("DimensionManager");
+					FuzzyReflection reflection = FuzzyReflection.fromClass(clazz, false);
+					FuzzyMethodContract contract = FuzzyMethodContract
+							.newBuilder()
+							.requireModifier(Modifier.STATIC)
+							.parameterExactType(int.class)
+							.returnTypeExact(clazz)
+							.build();
+					dimensionFromId = Accessors.getMethodAccessor(reflection.getMethod(contract));
+				}
+
+				return dimensionFromId.invoke(null, (int) specific);
+			}
+
+			@Override
+			public Integer getSpecific(Object generic) {
+				if (idFromDimension == null) {
+					Class<?> clazz = MinecraftReflection.getMinecraftClass("DimensionManager");
+					FuzzyReflection reflection = FuzzyReflection.fromClass(clazz, false);
+					FuzzyMethodContract contract = FuzzyMethodContract
+							.newBuilder()
+							.banModifier(Modifier.STATIC)
+							.returnTypeExact(int.class)
+							.parameterCount(0)
+							.build();
+					idFromDimension = Accessors.getMethodAccessor(reflection.getMethod(contract));
+				}
+
+				return (Integer) idFromDimension.invoke(generic);
+			}
+
+			@Override
+			public Class<Integer> getSpecificType() {
+				return Integer.class;
+			}
+		};
+	}
 }
diff --git a/modules/ProtocolLib/src/test/java/com/comphenix/protocol/events/PacketContainerTest.java b/modules/ProtocolLib/src/test/java/com/comphenix/protocol/events/PacketContainerTest.java
index c1047439..00bd2db9 100644
--- a/modules/ProtocolLib/src/test/java/com/comphenix/protocol/events/PacketContainerTest.java
+++ b/modules/ProtocolLib/src/test/java/com/comphenix/protocol/events/PacketContainerTest.java
@@ -467,6 +467,13 @@ public class PacketContainerTest {
 		assertEquals(container.getEnumModifier(Action.class, PacketPlayOutBoss.Action.class).read(0), Action.UPDATE_PCT);
 	}
 
+	@Test
+	public void testDimensionManager() {
+		PacketContainer container = new PacketContainer(PacketType.Play.Server.RESPAWN);
+		container.getDimensions().write(0, 1);
+		assertEquals((Object) 1, container.getDimensions().read(0));
+	}
+
 	/**
 	 * Actions from the outbound Boss packet. Used for testing generic enums.
 	 * @author dmulloy2