src_io_minelights_lights_ColorMode.java

package io.minelights.lights;

public enum ColorMode {
    MIX((byte)0),OVERRIDE((byte)1);

    public final byte value;

    ColorMode(byte b){
        this.value = b;
    }
}

src_io_minelights_lights_LightEvent.java

package io.minelights.lights;

public enum LightEvent {


    RELEASE((byte)-128),
    LIGHTNING((byte)-127),
    EXPLOSION((byte)-126);

    public final byte point;

    LightEvent(byte b){
        this.point = b;
    }
}

src_io_minelights_Main.java

package io.minelights;

import io.minelights.lights.ColorMode;
import io.minelights.lights.LightEvent;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import net.minecraft.server.v1_12_R1.NBTCompressedStreamTools;
import net.minecraft.server.v1_12_R1.NBTTagCompound;
import net.minecraft.server.v1_12_R1.PacketDataSerializer;
import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.AsyncPlayerChatEvent;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.plugin.messaging.PluginMessageListener;

import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.Executors;

public class Main extends JavaPlugin implements PluginMessageListener,Listener {

    private NBTTagCompound currentAmbientLighting = null;
    public void onEnable(){
        getServer().getMessenger().registerIncomingPluginChannel(this, "MINELIGHTS", this);
        getServer().getMessenger().registerOutgoingPluginChannel(this, "MINELIGHTS");
        getServer().getPluginManager().registerEvents(this,this);

        Bukkit.getScheduler().scheduleSyncRepeatingTask(this,()->{
            if(currentAmbientLighting != null){
                for(Player player : Bukkit.getOnlinePlayers()){
                    player.sendPluginMessage(this,"MINELIGHTS",convertNBTToBytes(currentAmbientLighting));
                }
            }
        },100,100);

    }

    public NBTTagCompound createLightEvent(LightEvent event){
        NBTTagCompound compound = new NBTTagCompound();
        compound.setByte("event",event.point);
        return compound;
    }

    public byte[] convertNBTToBytes(NBTTagCompound tag){
        ByteArrayOutputStream data = new ByteArrayOutputStream();
        byte[] b = {0};
        data.write(b,0,1);
        try {
            NBTCompressedStreamTools.a(tag,data);
        } catch (IOException e) {
            e.printStackTrace();
        }
        byte[] result = data.toByteArray();
        return result;
    }

    public NBTTagCompound setAmbient(byte r, byte g, byte b, ColorMode colorMode){
        NBTTagCompound external = new NBTTagCompound();
        NBTTagCompound ambient = new NBTTagCompound();
        byte[] byteArray = {r,g,b};
        ambient.setByteArray("color",byteArray);
        ambient.setByte("color", colorMode.value);
        external.setByteArray("message",convertNBTToBytes(ambient));

        this.currentAmbientLighting = external;

        return external;
    }

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if(command.getName().equalsIgnoreCase("light")){
            if(args.length == 4){
                int r = Integer.parseInt(args[0]);
                int g = Integer.parseInt(args[1]);
                int b = Integer.parseInt(args[2]);
                ColorMode colorMode = ColorMode.valueOf(args[3]);
                setAmbient((byte)r,(byte)g,(byte)b,colorMode);
                sender.sendMessage("Setting ambient lighting to: {" + r + ", "+ g + ", " + b + "} with color mode: " + colorMode.toString());
                return true;
            }
            else if(args.length == 1 && args[0].equalsIgnoreCase("release")){
                for(Player player : Bukkit.getOnlinePlayers()){
                    player.sendPluginMessage(this,"MINELIGHTS",convertNBTToBytes(createLightEvent(LightEvent.RELEASE)));
                }
                sender.sendMessage("Releasing client lights.");
            }
            else{
                sender.sendMessage("Incorrect usage.");
                return true;
            }
        }
        return true;
    }

    @Override
    public void onPluginMessageReceived(String s, Player player, byte[] bytes) {
        if(!s.equalsIgnoreCase("MINELIGHTS")) return;
        InputStream inputStream = new ByteArrayInputStream(bytes);
        try {
            NBTTagCompound tag = NBTCompressedStreamTools.a(inputStream);
            Bukkit.broadcastMessage("[" + player.getName() + "] Has sent the following message: " + tag.getString("message"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @EventHandler
    public void asyncPlayerChat(AsyncPlayerChatEvent event){
        if(event.getPlayer().getName().equalsIgnoreCase("Andrewcpu")){
            try {
                NBTTagCompound tag = new NBTTagCompound();
                tag.setString("message", event.getMessage());
                ByteArrayOutputStream data = new ByteArrayOutputStream();
                NBTCompressedStreamTools.a(tag,data);
                byte[] result = data.toByteArray();
                onPluginMessageReceived("MINELIGHTS",event.getPlayer(),result);
              //  player.sendPluginMessage(this,"MINELIGHTS",result);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @EventHandler
    public void onJoin(PlayerJoinEvent event){
        try {
            Player player = event.getPlayer();
            NBTTagCompound tag = new NBTTagCompound();
            tag.setString("message", "Greetings, " + event.getPlayer().getName() + ". This probably works...");
            byte[] result = convertNBTToBytes(tag);
            player.sendPluginMessage(this,"MINELIGHTS",result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

src_plugin.yml

name: MineLights
main: io.minelights.Main
version: 1.0
commands:
    light: