FightSystem/FightSystem_Main/src/de/steamwar/fightsystem/utils/TechHider.java

package de.steamwar.fightsystem.utils;

import com.comphenix.protocol.PacketType;
import com.comphenix.protocol.ProtocolLibrary;
import com.comphenix.protocol.events.PacketAdapter;
import com.comphenix.protocol.events.PacketContainer;
import com.comphenix.protocol.events.PacketEvent;
import com.comphenix.protocol.reflect.StructureModifier;
import com.comphenix.protocol.wrappers.BlockPosition;
import com.comphenix.protocol.wrappers.ChunkCoordIntPair;
import com.comphenix.protocol.wrappers.MultiBlockChangeInfo;
import com.comphenix.protocol.wrappers.WrappedBlockData;
import com.comphenix.protocol.wrappers.nbt.NbtCompound;
import com.comphenix.protocol.wrappers.nbt.NbtFactory;
import de.steamwar.core.Core;
import de.steamwar.fightsystem.Config;
import de.steamwar.fightsystem.FightSystem;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.UnpooledByteBufAllocator;
import javafx.util.Pair;
import org.bukkit.Bukkit;
import org.bukkit.GameMode;
import org.bukkit.Material;
import org.bukkit.entity.Player;

import java.util.*;

import static de.steamwar.fightsystem.utils.ITechHider.bypass;

public class TechHider {
    private TechHider(){}

    private static Map<PacketContainer, PacketContainer> packetCache = new HashMap<>();

    private static int arenaMinX;
    private static int arenaMaxX;
    private static int arenaMinZ;
    private static int arenaMaxZ;
    private static short obfuscateShift4;
    private static Material obfuscateMaterial;
    private static boolean running = false;
    private static int threadMultiplier = 1;

    public static void init(){
        if(disabled())
            return;

        arenaMinX = ITechHider.posToChunk(Config.ArenaMinX);
        arenaMinZ = ITechHider.posToChunk(Config.ArenaMinZ);
        arenaMaxX = ITechHider.posToChunk(Config.ArenaMaxX) + 1;
        arenaMaxZ = ITechHider.posToChunk(Config.ArenaMaxZ) + 1;

        obfuscateShift4 = (short)(Config.ObfuscateWith << 4);
        //noinspection deprecation
        obfuscateMaterial = Material.getMaterial(Config.ObfuscateWith);

        if(Config.event())
            threadMultiplier = 4;

        if(Core.getVersion() > 8){
            ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Client.USE_ITEM) {
                @Override
                public void onPacketReceiving(PacketEvent e) {
                    Player p = e.getPlayer();

                    if(p.getGameMode() == GameMode.SPECTATOR){
                        e.setCancelled(true);
                    }
                }
            });
        }
        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Client.USE_ENTITY) {
            @Override
            public void onPacketReceiving(PacketEvent e) {
                Player p = e.getPlayer();

                if(p.getGameMode() == GameMode.SPECTATOR){
                    e.setCancelled(true);
                }
            }
        });
    }

    public static void start(){
        if(running)
            return;
        running = true;

        if(disabled())
            return;

        Bukkit.getScheduler().runTaskTimer(FightSystem.getPlugin(), packetCache::clear, 1, 1);

        switch(Core.getVersion()){
            case 8:
                break;
            default:
                chunkHider();
                multiBlockHider();
                blockHider();
                blockActionHider();
        }
    }

    private static void chunkHider(){
        ProtocolLibrary.getProtocolManager().getAsynchronousManager().registerAsyncHandler(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Server.MAP_CHUNK) {
            @Override
            public void onPacketSending(PacketEvent e) {
                PacketContainer packet = e.getPacket();
                StructureModifier<Integer> ints = packet.getIntegers();

                int chunkX = ints.read(0);
                int chunkZ = ints.read(1);
                Player p = e.getPlayer();
                if(bypass(p, chunkX, chunkZ))
                    return;

                PacketContainer cached = packetCache.get(packet);
                if(cached != null){
                    e.setPacket(cached);
                    return;
                }

                cached = packet.deepClone();
                packetCache.put(packet, cached);
                e.setPacket(cached);
                StructureModifier<List> list = cached.getSpecificModifier(List.class);
                List nmsTags = list.read(0);
                boolean changed = false;
                for(int i = nmsTags.size() - 1; i >= 0; i--){
                    NbtCompound nbt = NbtFactory.fromNMSCompound(nmsTags.get(i));
                    if(Config.HiddenBlockEntities.contains(nbt.getString("id"))){
                        nmsTags.remove(i);
                        changed = true;
                    }
                }
                if(changed){
                    list.write(0, nmsTags);
                }

                changed = false;
                StructureModifier<byte[]> byteArray = cached.getByteArrays();
                byte [] data = byteArray.read(0);
                ByteBuf buffer = UnpooledByteBufAllocator.DEFAULT.directBuffer(data.length + 100);
                int i = 0;

                while(i < data.length){
                    byte bitsPerBlock = data[i++];
                    buffer.writeByte(bitsPerBlock);
                    if(bitsPerBlock < 4)
                        bitsPerBlock = 4;
                    else if(bitsPerBlock > 8){
                        bitsPerBlock = 13;
                        buffer.writeByte(data[++i]);
                    }

                    if(bitsPerBlock != 13){
                        int paletteLength = ITechHider.readVarInt(data, i);
                        int paletteLengthLength = ITechHider.readVarIntLength(data, i);
                        buffer.writeBytes(data, i, paletteLengthLength);
                        i += paletteLengthLength;
                        for(int actPaletteId = 0; actPaletteId < paletteLength; actPaletteId++){
                            int actPalette = ITechHider.readVarInt(data, i);
                            int actPaletteLength = ITechHider.readVarIntLength(data, i);

                            int blockId = actPalette >> 4;
                            if(Config.HiddenBlocks.contains(blockId)){
                                byte[] a = ITechHider.writeVarInt(obfuscateShift4);
                                buffer.writeBytes(a);
                                changed = true;
                            }else{
                                buffer.writeBytes(data, i, actPaletteLength);
                            }
                            i += actPaletteLength;
                        }
                        int dataArrayLength = ITechHider.readVarInt(data, i);
                        int dataArrayLengthLength = ITechHider.readVarIntLength(data, i);
                        buffer.writeBytes(data, i, dataArrayLength * 8 + dataArrayLengthLength);
                        i += dataArrayLengthLength;
                        i += dataArrayLength * 8;
                    }else{
                        int dataArrayLength = ITechHider.readVarInt(data, i);
                        int dataArrayLengthLength = ITechHider.readVarIntLength(data, i);
                        buffer.writeBytes(data, i, dataArrayLength*8 + dataArrayLengthLength);
                        i += dataArrayLengthLength;
                        i += dataArrayLength * 8;
                    }

                    buffer.writeBytes(data, i, 4096);
                    i += 4096; //Skylight (Not in Nether/End!!!) 2048 + Blocklight 2048
                }

                if(changed){
                    data = new byte[buffer.readableBytes()];
                    buffer.readBytes(data);
                    byteArray.write(0, data);
                }
            }
        }).start(threadMultiplier * 4);
    }

    private static void multiBlockHider(){
        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Server.MULTI_BLOCK_CHANGE) {
            @Override
            public void onPacketSending(PacketEvent e) {
                PacketContainer packet = e.getPacket();

                Player p = e.getPlayer();
                ChunkCoordIntPair pos = packet.getChunkCoordIntPairs().read(0);
                if(bypass(p, pos.getChunkX(), pos.getChunkZ()))
                    return;

                PacketContainer cached = packetCache.get(packet);
                if(cached != null){
                    e.setPacket(cached);
                    return;
                }

                cached = packet.shallowClone();
                packetCache.put(packet, cached);
                e.setPacket(cached);
                StructureModifier<MultiBlockChangeInfo[]> blockStructure = cached.getMultiBlockChangeInfoArrays();
                MultiBlockChangeInfo[] changes = blockStructure.read(0).clone();
                boolean changed = false;
                for(MultiBlockChangeInfo mbci : changes){
                    WrappedBlockData block = mbci.getData();
                    //noinspection deprecation
                    if(Config.HiddenBlocks.contains(block.getType().getId())){
                        changed = true;
                        block.setType(obfuscateMaterial);
                        mbci.setData(block);
                    }
                }

                if(changed){
                    blockStructure.write(0, changes);
                }
            }
        });
    }

    private static void blockHider(){
        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Server.BLOCK_CHANGE) {
            @Override
            public void onPacketSending(PacketEvent e) {
                PacketContainer packet = e.getPacket();
                BlockPosition pos = packet.getBlockPositionModifier().read(0);

                Player p = e.getPlayer();
                if(bypass(p, ITechHider.posToChunk(pos.getX()), ITechHider.posToChunk(pos.getZ())))
                    return;

                PacketContainer cached = packetCache.get(packet);
                if(cached != null){
                    e.setPacket(cached);
                    return;
                }

                cached = packet.deepClone();
                packetCache.put(packet, cached);
                e.setPacket(cached);
                StructureModifier<WrappedBlockData> blockStructure = cached.getBlockData();
                WrappedBlockData block = blockStructure.read(0);
                //noinspection deprecation
                if(Config.HiddenBlocks.contains(block.getType().getId())){
                    block.setType(obfuscateMaterial);
                    blockStructure.write(0, block);
                }
            }
        });
    }

    private static void blockActionHider(){
        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(FightSystem.getPlugin(), PacketType.Play.Server.BLOCK_ACTION) {
            @Override
            public void onPacketSending(PacketEvent e) {
                PacketContainer packet = e.getPacket();
                BlockPosition pos = packet.getBlockPositionModifier().read(0);

                Player p = e.getPlayer();
                if(bypass(p, ITechHider.posToChunk(pos.getX()), ITechHider.posToChunk(pos.getZ())))
                    return;

                e.setCancelled(true);
            }
        });
    }

    public static List<Pair<Integer, Integer>> prepareChunkReload(Player p){
        if(disabled())
            return Collections.emptyList();
        List<Pair<Integer, Integer>> chunksToReload = new ArrayList<>();
        for(int x = arenaMinX; x <= arenaMaxX; x++)
            for(int z = arenaMinZ; z <= arenaMaxZ; z++)
                if(!bypass(p, x, z))
                    chunksToReload.add(new Pair<>(x, z));
        return chunksToReload;
    }

    public static void reloadChunks(Player p, List<Pair<Integer, Integer>> chunksToReload){
        if(disabled())
            return;
        Bukkit.getScheduler().runTaskLater(FightSystem.getPlugin(), () -> {
            for(Pair<Integer, Integer> chunk : chunksToReload){
                if(bypass(p, chunk.getKey(), chunk.getValue()))
                    reloadChunk(p, chunk);
            }
        }, 40);
    }

    private static void reloadChunk(Player p, Pair<Integer, Integer> chunk){
        switch(Core.getVersion()){
            case 8:
                TechHider_8.reloadChunk(p, chunk);
                break;
            default:
                TechHider_12.reloadChunk(p, chunk);
        }
    }

    private static boolean disabled(){
        return Config.OnlyPublicSchematics;
    }
}