Rewrite uuids in RemovePlayerInfoPacket tablist packet

plugin/src/main/java/net/elytrium/limboapi/LimboAPI.java

@@ -90,6 +90,7 @@
 import net.elytrium.limboapi.injection.packet.MinecraftDiscardCompressDecoder;
 import net.elytrium.limboapi.injection.packet.MinecraftLimitedCompressDecoder;
 import net.elytrium.limboapi.injection.packet.PreparedPacketImpl;
+import net.elytrium.limboapi.injection.packet.RemovePlayerInfoHook;
 import net.elytrium.limboapi.injection.packet.UpsertPlayerInfoHook;
 import net.elytrium.limboapi.material.Biome;
 import net.elytrium.limboapi.protocol.LimboProtocol;
@@ -189,6 +190,7 @@ public LimboAPI(Logger logger, ProxyServer server, Metrics.Factory metricsFactor
       EventManagerHook.init(this);
       LegacyPlayerListItemHook.init(this, LimboProtocol.PLAY_CLIENTBOUND_REGISTRY);
       UpsertPlayerInfoHook.init(this, LimboProtocol.PLAY_CLIENTBOUND_REGISTRY);
+      RemovePlayerInfoHook.init(this, LimboProtocol.PLAY_CLIENTBOUND_REGISTRY);
 
       LimboProtocol.init();
     } catch (Throwable e) {

plugin/src/main/java/net/elytrium/limboapi/injection/packet/RemovePlayerInfoHook.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2021 - 2024 Elytrium
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.elytrium.limboapi.injection.packet;
+
+import com.velocitypowered.api.network.ProtocolVersion;
+import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
+import com.velocitypowered.proxy.connection.backend.BackendPlaySessionHandler;
+import com.velocitypowered.proxy.connection.backend.VelocityServerConnection;
+import com.velocitypowered.proxy.connection.client.ConnectedPlayer;
+import com.velocitypowered.proxy.protocol.MinecraftPacket;
+import com.velocitypowered.proxy.protocol.StateRegistry;
+import com.velocitypowered.proxy.protocol.packet.RemovePlayerInfoPacket;
+import io.netty.util.collection.IntObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.function.Supplier;
+import net.elytrium.commons.utils.reflection.ReflectionException;
+import net.elytrium.limboapi.LimboAPI;
+import net.elytrium.limboapi.protocol.LimboProtocol;
+
+@SuppressWarnings("unchecked")
+public class RemovePlayerInfoHook extends RemovePlayerInfoPacket {
+
+  private static final MethodHandle SERVER_CONN_FIELD;
+
+  private final LimboAPI plugin;
+
+  private RemovePlayerInfoHook(LimboAPI plugin) {
+    this.plugin = plugin;
+  }
+
+  @Override
+  public boolean handle(MinecraftSessionHandler handler) {
+    if (handler instanceof BackendPlaySessionHandler) {
+      try {
+        ConnectedPlayer player = ((VelocityServerConnection) SERVER_CONN_FIELD.invokeExact((BackendPlaySessionHandler) handler)).getPlayer();
+        UUID initialID = this.plugin.getInitialID(player);
+        if (this.getProfilesToRemove() instanceof List<UUID> uuids) {
+          for (int i = 0; i < uuids.size(); i++) {
+            if (player.getUniqueId().equals(uuids.get(i))) {
+              uuids.set(i, initialID);
+            }
+          }
+        }
+      } catch (Throwable e) {
+        throw new ReflectionException(e);
+      }
+    }
+
+    return super.handle(handler);
+  }
+
+  static {
+    try {
+      SERVER_CONN_FIELD = MethodHandles.privateLookupIn(BackendPlaySessionHandler.class, MethodHandles.lookup())
+          .findGetter(BackendPlaySessionHandler.class, "serverConn", VelocityServerConnection.class);
+    } catch (NoSuchFieldException | IllegalAccessException e) {
+      throw new ReflectionException(e);
+    }
+  }
+
+  public static void init(LimboAPI plugin, StateRegistry.PacketRegistry registry) throws ReflectiveOperationException {
+    // See LimboProtocol#overlayRegistry about var.
+    var playProtocolRegistryVersions = (Map<ProtocolVersion, StateRegistry.PacketRegistry.ProtocolRegistry>) LimboProtocol.VERSIONS_FIELD.get(registry);
+    playProtocolRegistryVersions.forEach((protocolVersion, protocolRegistry) -> {
+      try {
+        var packetIDToSupplier = (IntObjectMap<Supplier<? extends MinecraftPacket>>) LimboProtocol.PACKET_ID_TO_SUPPLIER_FIELD.get(protocolRegistry);
+        var packetClassToID = (Object2IntMap<Class<? extends MinecraftPacket>>) LimboProtocol.PACKET_CLASS_TO_ID_FIELD.get(protocolRegistry);
+
+        int id = packetClassToID.getInt(RemovePlayerInfoPacket.class);
+        packetClassToID.put(RemovePlayerInfoHook.class, id);
+        packetIDToSupplier.put(id, () -> new RemovePlayerInfoHook(plugin));
+      } catch (ReflectiveOperationException e) {
+        throw new ReflectionException(e);
+      }
+    });
+  }
+}