Add chunk reset logic for Minecraft 1.21 in CraftbukkitWrapper21 to support advanced chunk management.

FightSystem/FightSystem_21/src/de/steamwar/fightsystem/utils/CraftbukkitWrapper21.java

@@ -20,9 +20,17 @@
 package de.steamwar.fightsystem.utils;
 
 import de.steamwar.fightsystem.Config;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.LevelChunkSection;
 import org.bukkit.GameRule;
+import org.bukkit.World;
+import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.entity.Entity;
 
+import java.util.HashSet;
+import java.util.Set;
+
 public class CraftbukkitWrapper21 extends CraftbukkitWrapper18 {
 
     @Override
@@ -34,4 +42,20 @@ public class CraftbukkitWrapper21 extends CraftbukkitWrapper18 {
     public void setupGamerule() {
         Config.world.setGameRule(GameRule.LOCATOR_BAR, false);
     }
+
+    private LevelChunk getChunk(World world, int x, int z) {
+        return ((CraftWorld) world).getHandle().getChunk(x, z);
+    }
+
+    @Override
+    public void resetChunk(World world, World backup, int x, int z) {
+        LevelChunk worldChunk = getChunk(world, x, z);
+        LevelChunk backupChunk = getChunk(backup, x, z);
+        LevelChunkSection[] sections = worldChunk.getSections();
+        System.arraycopy(backupChunk.getSections(), 0, sections, 0, sections.length);
+        Set<BlockPos> blocks = new HashSet<>(worldChunk.blockEntities.keySet());
+        blocks.stream().filter(key -> !backupChunk.blockEntities.containsKey(key)).forEach(worldChunk::removeBlockEntity);
+        worldChunk.heightmaps.clear();
+        worldChunk.heightmaps.putAll(backupChunk.heightmaps);
+    }
 }