Make fake players compatible with adventure platform lib and minor refactor around them (#1235)

* Make fake players compatible with adventure platform and minor refactor around them

Cleaner approach

* Remove no longer needed enderpearl mixin for fake players

Their ClientConnection now has an open channel so isOpen returns true

src/main/java/carpet/fakes/ClientConnectionInterface.java

@@ -0,0 +1,7 @@
+package carpet.fakes;
+
+import io.netty.channel.Channel;
+
+public interface ClientConnectionInterface {
+    void setChannel(Channel channel);
+}

src/main/java/carpet/mixins/ClientConnectionMixin.java

@@ -1,18 +1,21 @@
 package carpet.mixins;
 
+import carpet.fakes.ClientConnectionInterface;
 import carpet.logging.logHelpers.PacketCounter;
+import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.GenericFutureListener;
 import net.minecraft.network.ClientConnection;
 import net.minecraft.network.Packet;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 @Mixin(ClientConnection.class)
-public abstract class ClientConnectionMixin
+public abstract class ClientConnectionMixin implements ClientConnectionInterface
 {
     // Add to the packet counter whenever a packet is received.
     @Inject(method = "channelRead0", at = @At("HEAD"))
@@ -28,4 +31,8 @@ public abstract class ClientConnectionMixin
     {
         PacketCounter.totalOut++;
     }
+
+    @Override
+    @Accessor //Compat with adventure-platform-fabric
+    public abstract void setChannel(Channel channel);
 }

src/main/java/carpet/mixins/PlayerManager_fakePlayersMixin.java

@@ -1,9 +1,7 @@
 package carpet.mixins;
 
-import com.mojang.authlib.GameProfile;
 import net.minecraft.nbt.NbtCompound;
 import net.minecraft.network.ClientConnection;
-import net.minecraft.text.TranslatableText;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.PlayerManager;
 import net.minecraft.server.network.ServerPlayNetworkHandler;
@@ -15,14 +13,9 @@ import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.Redirect;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
-import org.spongepowered.asm.mixin.injection.callback.LocalCapture;
 import carpet.patches.NetHandlerPlayServerFake;
 import carpet.patches.EntityPlayerMPFake;
 
-import java.util.Iterator;
-import java.util.List;
-import java.util.UUID;
-
 @Mixin(PlayerManager.class)
 public abstract class PlayerManager_fakePlayersMixin
 {
@@ -42,38 +35,13 @@ public abstract class PlayerManager_fakePlayersMixin
     @Redirect(method = "onPlayerConnect", at = @At(value = "NEW", target = "net/minecraft/server/network/ServerPlayNetworkHandler"))
     private ServerPlayNetworkHandler replaceNetworkHandler(MinecraftServer server, ClientConnection clientConnection, ServerPlayerEntity playerIn)
     {
-        boolean isServerPlayerEntity = playerIn instanceof EntityPlayerMPFake;
-        if (isServerPlayerEntity)
+        if (playerIn instanceof EntityPlayerMPFake fake)
         {
-            return new NetHandlerPlayServerFake(this.server, clientConnection, playerIn);
+            return new NetHandlerPlayServerFake(this.server, clientConnection, fake);
         }
         else
         {
             return new ServerPlayNetworkHandler(this.server, clientConnection, playerIn);
         }
     }
-
-    @Redirect(method = "createPlayer", at = @At(value = "INVOKE", target = "Ljava/util/Iterator;hasNext()Z"))
-    private boolean cancelWhileLoop(Iterator iterator)
-    {
-        return false;
-    }
-
-    @Inject(method = "createPlayer", at = @At(value = "INVOKE", shift = At.Shift.BEFORE,
-            target = "Ljava/util/Iterator;hasNext()Z"), locals = LocalCapture.CAPTURE_FAILHARD)
-    private void newWhileLoop(GameProfile gameProfile_1, CallbackInfoReturnable<ServerPlayerEntity> cir, UUID uUID_1,
-                              List list_1, ServerPlayerEntity serverPlayerEntity, Iterator var5)
-    {
-        while (var5.hasNext())
-        {
-            ServerPlayerEntity serverPlayerEntity_3 = (ServerPlayerEntity) var5.next();
-            if(serverPlayerEntity_3 instanceof EntityPlayerMPFake)
-            {
-                ((EntityPlayerMPFake)serverPlayerEntity_3).kill(new TranslatableText("multiplayer.disconnect.duplicate_login"));
-                continue;
-            }
-            serverPlayerEntity_3.networkHandler.disconnect(new TranslatableText("multiplayer.disconnect.duplicate_login"));
-        }
-    }
-
 }

src/main/java/carpet/mixins/ThrownEnderpearlEntity_fakePlayersMixin.java

@@ -1,29 +0,0 @@
-package carpet.mixins;
-
-import carpet.patches.EntityPlayerMPFake;
-import net.minecraft.entity.EntityType;
-import net.minecraft.entity.projectile.thrown.EnderPearlEntity;
-import net.minecraft.entity.projectile.thrown.ThrownItemEntity;
-import net.minecraft.network.ClientConnection;
-import net.minecraft.world.World;
-import org.spongepowered.asm.mixin.Mixin;
-import org.spongepowered.asm.mixin.injection.At;
-import org.spongepowered.asm.mixin.injection.Redirect;
-
-@Mixin(EnderPearlEntity.class)
-public abstract class ThrownEnderpearlEntity_fakePlayersMixin extends ThrownItemEntity
-{
-    public ThrownEnderpearlEntity_fakePlayersMixin(EntityType<? extends ThrownItemEntity> entityType_1, World world_1)
-    {
-        super(entityType_1, world_1);
-    }
-
-    @Redirect(method =  "onCollision", at = @At(
-            value = "INVOKE",
-            target = "Lnet/minecraft/network/ClientConnection;isOpen()Z"
-    ))
-    private boolean isConnectionGood(ClientConnection clientConnection)
-    {
-        return clientConnection.isOpen() || getOwner() instanceof EntityPlayerMPFake;
-    }
-}

src/main/java/carpet/patches/EntityPlayerMPFake.java

@@ -62,7 +62,7 @@ public class EntityPlayerMPFake extends ServerPlayerEntity
         }
         EntityPlayerMPFake instance = new EntityPlayerMPFake(server, worldIn, gameprofile, false);
         instance.fixStartingPosition = () -> instance.refreshPositionAndAngles(d0, d1, d2, (float) yaw, (float) pitch);
-        server.getPlayerManager().onPlayerConnect(new NetworkManagerFake(NetworkSide.SERVERBOUND), instance);
+        server.getPlayerManager().onPlayerConnect(new FakeClientConnection(NetworkSide.SERVERBOUND), instance);
         instance.teleport(worldIn, d0, d1, d2, (float)yaw, (float)pitch);
         instance.setHealth(20.0F);
         instance.unsetRemoved();
@@ -83,7 +83,7 @@ public class EntityPlayerMPFake extends ServerPlayerEntity
         ServerWorld worldIn = player.getServerWorld();//.getWorld(player.dimension);
         GameProfile gameprofile = player.getGameProfile();
         EntityPlayerMPFake playerShadow = new EntityPlayerMPFake(server, worldIn, gameprofile, true);
-        server.getPlayerManager().onPlayerConnect(new NetworkManagerFake(NetworkSide.SERVERBOUND), playerShadow);
+        server.getPlayerManager().onPlayerConnect(new FakeClientConnection(NetworkSide.SERVERBOUND), playerShadow);
 
         playerShadow.setHealth(player.getHealth());
         playerShadow.networkHandler.requestTeleport(player.getX(), player.getY(), player.getZ(), player.getYaw(), player.getPitch());

src/main/java/carpet/patches/FakeClientConnection.java

@@ -0,0 +1,27 @@
+package carpet.patches;
+
+import carpet.fakes.ClientConnectionInterface;
+import io.netty.channel.embedded.EmbeddedChannel;
+import net.minecraft.network.ClientConnection;
+import net.minecraft.network.NetworkSide;
+
+public class FakeClientConnection extends ClientConnection
+{
+    public FakeClientConnection(NetworkSide p)
+    {
+        super(p);
+        // compat with adventure-platform-fabric. This does NOT trigger other vanilla handlers for establishing a channel
+        // also makes #isOpen return true, allowing enderpearls to teleport fake players
+        ((ClientConnectionInterface)this).setChannel(new EmbeddedChannel());
+    }
+
+    @Override
+    public void disableAutoRead()
+    {
+    }
+
+    @Override
+    public void handleDisconnection()
+    {
+    }
+}

src/main/java/carpet/patches/NetHandlerPlayServerFake.java

@@ -4,13 +4,12 @@ import net.minecraft.network.ClientConnection;
 import net.minecraft.network.Packet;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.network.ServerPlayNetworkHandler;
-import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.text.Text;
 import net.minecraft.text.TranslatableText;
 
 public class NetHandlerPlayServerFake extends ServerPlayNetworkHandler
 {
-    public NetHandlerPlayServerFake(MinecraftServer server, ClientConnection cc, ServerPlayerEntity playerIn)
+    public NetHandlerPlayServerFake(MinecraftServer server, ClientConnection cc, EntityPlayerMPFake playerIn)
     {
         super(server, cc, playerIn);
     }
@@ -23,9 +22,9 @@ public class NetHandlerPlayServerFake extends ServerPlayNetworkHandler
     @Override
     public void disconnect(Text message)
     {
-        if (player instanceof EntityPlayerMPFake && message instanceof TranslatableText && ((TranslatableText) message).getKey().equals("multiplayer.disconnect.idling"))
+        if (message instanceof TranslatableText text && (text.getKey().equals("multiplayer.disconnect.idling") || text.getKey().equals("multiplayer.disconnect.duplicate_login")))
         {
-            ((EntityPlayerMPFake) player).kill(new TranslatableText(((TranslatableText) message).getKey()));
+            ((EntityPlayerMPFake) player).kill(message);
         }
     }
 }

src/main/java/carpet/patches/NetworkManagerFake.java

@@ -1,22 +0,0 @@
-package carpet.patches;
-
-import net.minecraft.network.ClientConnection;
-import net.minecraft.network.NetworkSide;
-
-public class NetworkManagerFake extends ClientConnection
-{
-    public NetworkManagerFake(NetworkSide p)
-    {
-        super(p);
-    }
-
-    @Override
-    public void disableAutoRead()
-    {
-    }
-
-    @Override
-    public void handleDisconnection()
-    {
-    }
-}

src/main/resources/carpet.mixins.json

@@ -68,7 +68,6 @@
     "VillagerEntity_aiMixin",
 
     "PlayerEntity_fakePlayersMixin",
-    "ThrownEnderpearlEntity_fakePlayersMixin",
 
     "ServerPlayNetworkHandler_coreMixin",