Add click callback for REntityServer

SpigotCore_Main/src/de/steamwar/entity/REntityServer.java

@@ -19,8 +19,10 @@
 
 package de.steamwar.entity;
 
+import com.comphenix.tinyprotocol.Reflection;
 import com.comphenix.tinyprotocol.TinyProtocol;
 import de.steamwar.core.Core;
+import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -33,7 +35,9 @@ import org.bukkit.event.player.PlayerQuitEvent;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 
 
@@ -42,13 +46,41 @@ public class REntityServer implements Listener {
     private static final HashSet<REntity> emptyEntities = new HashSet<>(0);
     private static final HashSet<Player> emptyPlayers = new HashSet<>(0);
 
+    private static final Class<?> useEntity = Reflection.getClass("{nms.network.protocol.game}.PacketPlayInUseEntity");
+    private static final Reflection.FieldAccessor<Integer> useEntityTarget = Reflection.getField(useEntity, int.class, 0);
+    private static final Reflection.FieldAccessor<Integer> useEntityAction = Reflection.getField(useEntity, int.class, 1);
+
+    private final HashMap<Integer, REntity> entityMap = new HashMap<>();
     private final HashMap<Long, HashSet<REntity>> entities = new HashMap<>();
     private final HashMap<Long, Set<Player>> players = new HashMap<>();
     private final HashMap<Player, Location> lastLocation = new HashMap<>();
     private final HashMap<Player, Integer> viewDistance = new HashMap<>();
 
+    private EntityActionListener callback = null;
+
+    private BiFunction<Player, Object, Object> filter = (player, packet) -> {
+        if (callback == null) return packet;
+        int target = useEntityTarget.get(packet);
+        if (!entityMap.containsKey(target)) return packet;
+
+        REntity entity = entityMap.get(target);
+        int action = useEntityAction.get(packet);
+        if (action == 2) action = 0;
+        int finalAction = action;
+
+        Bukkit.getScheduler().runTaskLater(Core.getInstance(), () -> {
+            callback.onAction(player, entity, finalAction == 0 ? EntityAction.INTERACT : EntityAction.ATTACK);
+        }, 0);
+        return null;
+    };
+
     public REntityServer() {
         Core.getInstance().getServer().getPluginManager().registerEvents(this, Core.getInstance());
+        TinyProtocol.instance.addFilter(useEntity, filter);
+    }
+
+    public void setCallback(EntityActionListener callback) {
+        this.callback = callback;
     }
 
     public void addPlayer(Player player) {
@@ -64,6 +96,7 @@ public class REntityServer implements Listener {
     }
 
     public void close() {
+        TinyProtocol.instance.removeFilter(useEntity, filter);
         for(Player player : lastLocation.keySet().toArray(new Player[0])) {
             removePlayer(player);
         }
@@ -71,6 +104,7 @@ public class REntityServer implements Listener {
     }
 
     void addEntity(REntity entity) {
+        entityMap.put(entity.entityId, entity);
         addEntityToChunk(entity);
         entity.spawn(packet -> updateEntity(entity, packet));
     }
@@ -104,6 +138,7 @@ public class REntityServer implements Listener {
     void removeEntity(REntity entity) {
         entity.despawn(packet -> updateEntity(entity, packet));
         removeEntityFromChunk(entity);
+        entityMap.put(entity.entityId, entity);
     }
 
     private void addEntityToChunk(REntity entity) {
@@ -226,4 +261,13 @@ public class REntityServer implements Listener {
     private long chunkToId(int x, int z) {
         return ((long) x << 32) + z;
     }
+
+    public enum EntityAction {
+        INTERACT,
+        ATTACK,
+    }
+
+    public interface EntityActionListener {
+        void onAction(Player player, REntity entity, EntityAction action);
+    }
 }