feat: implemented auto unloading chunks

api/src/main/java/ru/dragonestia/msb3/api/world/World.java

@@ -3,6 +3,8 @@ package ru.dragonestia.msb3.api.world;
 import lombok.Getter;
 import lombok.extern.log4j.Log4j2;
 import net.minestom.server.MinecraftServer;
+import net.minestom.server.event.EventListener;
+import net.minestom.server.event.player.PlayerChunkUnloadEvent;
 import net.minestom.server.instance.EntityTracker;
 import net.minestom.server.instance.InstanceContainer;
 
@@ -12,6 +14,8 @@ public class World {
 
     private final InstanceContainer instance;
 
+    private EventListener<PlayerChunkUnloadEvent> chunkUnloadListener;
+
     World(InstanceContainer instance) {
         this.instance = instance;
     }
@@ -28,4 +32,28 @@ public class World {
 
         MinecraftServer.getInstanceManager().unregisterInstance(instance);
     }
+
+    public synchronized void setChunkUnloading(boolean unload) {
+        if (chunkUnloadListener == null) {
+            if (!unload) return;
+
+            chunkUnloadListener = EventListener.of(PlayerChunkUnloadEvent.class, event -> {
+                var chunk = instance.getChunk(event.getChunkX(), event.getChunkZ());
+                if (chunk == null) return;
+
+                if (chunk.getViewers().isEmpty()) {
+                    try {
+                        instance.unloadChunk(event.getChunkX(), event.getChunkZ());
+                    } catch (NullPointerException ignored) {}
+                }
+            });
+            instance.eventNode().addListener(chunkUnloadListener);
+            return;
+        }
+
+        if (unload) return;
+
+        instance.eventNode().removeListener(chunkUnloadListener);
+        chunkUnloadListener = null;
+    }
 }