/*
 * Copyright (C) 2024  Minecon724
 * Tweaks724 is licensed under the GNU General Public License. See the LICENSE.md file
 * in the project root for the full license text.
 */

package eu.m724.tweaks.ping;

import com.comphenix.protocol.PacketType;
import com.comphenix.protocol.ProtocolLibrary;
import com.comphenix.protocol.events.ListenerPriority;
import com.comphenix.protocol.events.PacketAdapter;
import com.comphenix.protocol.events.PacketContainer;
import com.comphenix.protocol.events.PacketEvent;
import org.bukkit.entity.Player;
import org.bukkit.plugin.Plugin;
import org.bukkit.scheduler.BukkitRunnable;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ThreadLocalRandom;

public class KeepAlivePingChecker extends BukkitRunnable {
    // ID, timestamp
    private final Map<Long, Long> keepAliveIDs = new HashMap<>();

    private final Plugin plugin;

    KeepAlivePingChecker(Plugin plugin) {
        this.plugin = plugin;
    }

    public void start() {
        ProtocolLibrary.getProtocolManager().addPacketListener(new PacketAdapter(
                plugin,
                ListenerPriority.NORMAL,
                PacketType.Play.Client.KEEP_ALIVE
        ) {
            @Override
            public void onPacketReceiving(PacketEvent event) {
                long id = event.getPacket().getLongs().read(0);
                Long start = keepAliveIDs.remove(id);

                if (start != null) {
                    Player player = event.getPlayer();

                    PlayerPingStorage.submitPing(player, System.nanoTime() - start);

                    // server will kick if we don't cancel
                    event.setCancelled(true);
                }
            }
        });

        this.runTaskTimerAsynchronously(plugin, 0, 40); // 2 secs
    }

    @Override
    public void run() {
        plugin.getServer().getOnlinePlayers().forEach(player -> {
            long id = ThreadLocalRandom.current().nextLong();
            keepAliveIDs.put(id, System.nanoTime());

            PacketContainer packet = new PacketContainer(PacketType.Play.Server.KEEP_ALIVE);
            packet.getLongs().write(0, id);
            ProtocolLibrary.getProtocolManager().sendServerPacket(player, packet);
        });
    }
}