package net.minecraft.client.server;

import com.mojang.logging.LogUtils;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.atomic.AtomicInteger;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.DefaultUncaughtExceptionHandler;
import org.jspecify.annotations.Nullable;
import org.slf4j.Logger;

@Environment(EnvType.CLIENT)
public class LanServerPinger extends Thread {
	private static final AtomicInteger UNIQUE_THREAD_ID = new AtomicInteger(0);
	private static final Logger LOGGER = LogUtils.getLogger();
	public static final String MULTICAST_GROUP = "224.0.2.60";
	public static final int PING_PORT = 4445;
	private static final long PING_INTERVAL = 1500L;
	private final String motd;
	private final DatagramSocket socket;
	private boolean isRunning = true;
	private final String serverAddress;

	public LanServerPinger(final String motd, final String serverAddress) throws IOException {
		super("LanServerPinger #" + UNIQUE_THREAD_ID.incrementAndGet());
		this.motd = motd;
		this.serverAddress = serverAddress;
		this.setDaemon(true);
		this.setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler(LOGGER));
		this.socket = new DatagramSocket();
	}

	public void run() {
		String pingString = createPingString(this.motd, this.serverAddress);
		byte[] ping = pingString.getBytes(StandardCharsets.UTF_8);

		while (!this.isInterrupted() && this.isRunning) {
			try {
				InetAddress group = InetAddress.getByName("224.0.2.60");
				DatagramPacket packet = new DatagramPacket(ping, ping.length, group, 4445);
				this.socket.send(packet);
			} catch (IOException var6) {
				LOGGER.warn("LanServerPinger: {}", var6.getMessage());
				break;
			}

			try {
				sleep(1500L);
			} catch (InterruptedException var5) {
			}
		}
	}

	public void interrupt() {
		super.interrupt();
		this.isRunning = false;
	}

	public static String createPingString(final String motd, final String address) {
		return "[MOTD]" + motd + "[/MOTD][AD]" + address + "[/AD]";
	}

	public static String parseMotd(final String pingString) {
		int startIndex = pingString.indexOf("[MOTD]");
		if (startIndex < 0) {
			return "missing no";
		} else {
			int endIndex = pingString.indexOf("[/MOTD]", startIndex + "[MOTD]".length());
			return endIndex < startIndex ? "missing no" : pingString.substring(startIndex + "[MOTD]".length(), endIndex);
		}
	}

	@Nullable
	public static String parseAddress(final String pingString) {
		int endMotdIndex = pingString.indexOf("[/MOTD]");
		if (endMotdIndex < 0) {
			return null;
		} else {
			int secondEndMotdIndex = pingString.indexOf("[/MOTD]", endMotdIndex + "[/MOTD]".length());
			if (secondEndMotdIndex >= 0) {
				return null;
			} else {
				int startIndex = pingString.indexOf("[AD]", endMotdIndex + "[/MOTD]".length());
				if (startIndex < 0) {
					return null;
				} else {
					int endIndex = pingString.indexOf("[/AD]", startIndex + "[AD]".length());
					return endIndex < startIndex ? null : pingString.substring(startIndex + "[AD]".length(), endIndex);
				}
			}
		}
	}
}