尝试添加DronesTool

src/main/java/com/atsuishio/superbwarfare/tools/DronesTool.java

@@ -0,0 +1,137 @@
+package com.atsuishio.superbwarfare.tools;
+
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.level.Level;
+
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Code based on @Mafuyu404's <a href="https://github.com/Mafuyu404/DiligentStalker">DiligentStalker</a>
+ */
+public class DronesTool {
+
+    private final UUID playerUUID;
+    private final int droneId;
+    public final Level level;
+    public static final ConcurrentHashMap<UUID, Integer> INSTANCE_MAP = new ConcurrentHashMap<>();
+
+    private static final ConcurrentHashMap<UUID, DronesTool> INSTANCE_CACHE = new ConcurrentHashMap<>();
+    private static final ConcurrentHashMap<Integer, DronesTool> DRONES_CACHE = new ConcurrentHashMap<>();
+    private static final ConcurrentHashMap<Integer, UUID> DRONE_TO_PLAYER = new ConcurrentHashMap<>();
+
+    // 缓存失效时间
+    private static final long CACHE_EXPIRE_TIME = 5000;
+    private long lastAccessTime;
+
+    public DronesTool(UUID playerUUID, int droneId, Level level) {
+        this.playerUUID = playerUUID;
+        this.droneId = droneId;
+        this.level = level;
+        this.lastAccessTime = System.currentTimeMillis();
+    }
+
+    public Player getPlayer() {
+        this.lastAccessTime = System.currentTimeMillis();
+        return this.level.getPlayerByUUID(this.playerUUID);
+    }
+
+    public Entity getDrone() {
+        this.lastAccessTime = System.currentTimeMillis();
+        return this.level.getEntity(this.droneId);
+    }
+
+    public static DronesTool connect(Player player, Entity stalker) {
+        if (player == null || stalker == null) return null;
+        if (hasInstanceOf(player) || hasInstanceOf(stalker)) return null;
+
+        if (player.level().isClientSide) {
+            // TODO 向客户端发送连接的网络包
+        }
+
+        INSTANCE_MAP.put(player.getUUID(), stalker.getId());
+        DRONE_TO_PLAYER.put(stalker.getId(), player.getUUID());
+
+        DronesTool instance = new DronesTool(player.getUUID(), stalker.getId(), player.level());
+        INSTANCE_CACHE.put(player.getUUID(), instance);
+        DRONES_CACHE.put(stalker.getId(), instance);
+
+        return instance;
+    }
+
+    public static DronesTool getInstanceOf(Entity entity) {
+        if (entity == null) return null;
+
+        UUID uuid = entity.getUUID();
+        int id = entity.getId();
+
+        DronesTool cache = INSTANCE_CACHE.get(uuid);
+        if (cache != null && !isCacheExpired(cache)) {
+            return cache;
+        }
+
+        cache = DRONES_CACHE.get(id);
+        if (cache != null && !isCacheExpired(cache)) {
+            return cache;
+        }
+
+        boolean isPlayer = INSTANCE_MAP.containsKey(uuid);
+        boolean isDrone = DRONE_TO_PLAYER.containsKey(id);
+
+        DronesTool instance = null;
+        if (isPlayer) {
+            var stalkerId = INSTANCE_MAP.get(uuid);
+            if (stalkerId != null) {
+                instance = new DronesTool(uuid, stalkerId, entity.level());
+                INSTANCE_CACHE.put(uuid, instance);
+            }
+        } else if (isDrone) {
+            UUID playerUUID = DRONE_TO_PLAYER.get(id);
+            if (playerUUID != null) {
+                instance = new DronesTool(playerUUID, id, entity.level());
+                DRONES_CACHE.put(id, instance);
+            }
+        }
+
+        return instance;
+    }
+
+    public void disconnect() {
+        if (level.isClientSide) {
+            // TODO 向客户端发送断开连接的网络包
+        }
+        INSTANCE_MAP.remove(this.playerUUID);
+        DRONE_TO_PLAYER.remove(this.droneId);
+        INSTANCE_CACHE.remove(this.playerUUID);
+        DRONES_CACHE.remove(this.droneId);
+    }
+
+    public static boolean hasInstanceOf(Entity entity) {
+        if (entity == null) return false;
+
+        UUID uuid = entity.getUUID();
+        if (INSTANCE_CACHE.containsKey(uuid) && !isCacheExpired(INSTANCE_CACHE.get(uuid))) {
+            return true;
+        }
+
+        int id = entity.getId();
+        if (DRONES_CACHE.containsKey(id) && !isCacheExpired(DRONES_CACHE.get(id))) {
+            return true;
+        }
+
+        return (INSTANCE_MAP.containsKey(uuid) || INSTANCE_MAP.containsValue(id));
+    }
+
+    private static boolean isCacheExpired(DronesTool instance) {
+        return System.currentTimeMillis() - instance.lastAccessTime > CACHE_EXPIRE_TIME;
+    }
+
+    public static void cleanupExpiredCache() {
+        long currentTime = System.currentTimeMillis();
+        INSTANCE_CACHE.entrySet().removeIf(entry ->
+                currentTime - entry.getValue().lastAccessTime > CACHE_EXPIRE_TIME);
+        DRONES_CACHE.entrySet().removeIf(entry ->
+                currentTime - entry.getValue().lastAccessTime > CACHE_EXPIRE_TIME);
+    }
+}