package com.company;

import java.io.IOException;
import java.net.*;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.SocketTimeoutException;
import java.nio.ByteBuffer;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        String message = "pugs_do_drug_uuu_vatrushki";
        byte[] sendPacket = new byte[32];
        byte[] rcvPacket = new byte[32];

        UUID uuid = UUID.nameUUIDFromBytes(message.getBytes());
        UUID uuidUnique = UUID.randomUUID();

        ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
        bb.putLong(uuid.getMostSignificantBits());
        bb.putLong(uuid.getLeastSignificantBits());
        byte[] sendFirstPart = bb.array();

        bb = ByteBuffer.wrap(new byte[16]);
        bb.putLong(uuidUnique.getMostSignificantBits());
        bb.putLong(uuidUnique.getLeastSignificantBits());
        byte[] sendSecondPart = bb.array();

        for ( int i =0; i < sendPacket.length; i++){
            sendPacket[i] = i < sendFirstPart.length ? sendFirstPart[i] : sendSecondPart[i - sendFirstPart.length];
        }


        MulticastSocket multicastSocket = new MulticastSocket(8000);
        InetAddress inetGroupAddress = InetAddress.getByName("224.1.1.1");
        multicastSocket.joinGroup(inetGroupAddress);

        DatagramPacket datagramSendPacket = new DatagramPacket(sendPacket, sendPacket.length, inetGroupAddress, 8000 );
        DatagramPacket datagramRcvPacket = new DatagramPacket(rcvPacket, rcvPacket.length);

        long timeout = 2000;
        while (true) {
            multicastSocket.send(datagramSendPacket);
            long sendTime = System.currentTimeMillis();

            while (timeout - (System.currentTimeMillis() - sendTime) > 0) {
                multicastSocket.setSoTimeout((Long.valueOf(timeout - (System.currentTimeMillis() - sendTime))).intValue() + 1);

                try {
                    multicastSocket.receive(datagramRcvPacket);
                } catch (SocketTimeoutException exception) {
                    continue;
                }

                //String inetRcvAddress = datagramRcvPacket.getAddress().getHostAddress();

                rcvPacket = datagramRcvPacket.getData();
                byte[] firstPartRcv = new byte[16];
                byte[] secondPartRcv = new byte[16];
                for ( int i = 0; i < rcvPacket.length/2; i++){
                    firstPartRcv[i] = rcvPacket[i];
                    secondPartRcv[i] = rcvPacket[i+rcvPacket.length/2];
                }

                ByteBuffer byteBuffer = ByteBuffer.wrap(firstPartRcv);
                Long high = byteBuffer.getLong();
                Long low = byteBuffer.getLong();
                UUID uuidFirst = new UUID(high, low);

                byteBuffer = ByteBuffer.wrap(secondPartRcv);
                high = byteBuffer.getLong();
                low = byteBuffer.getLong();
                UUID uuidSecond = new UUID(high, low);

                if (!uuidSecond.equals(uuidUnique) && uuidFirst.equals(uuid)) {
                    System.out.println("Clone appeared!!!");
                } else System.out.println("No clone appeared!!!");
            }
        }
    }
}