// mchat.java : multicast chat
// Synopsis: java mchat mip port

import java.io.*;
import java.net.*;

class ChatThread extends Thread {
        
        private MulticastSocket msocket;
        private DatagramPacket recv;
        
        public ChatThread(MulticastSocket msock ,InetAddress group_no , int Port_no)
	  {
                msocket= msock;
                start();                // start calls run
        }
        
        public void run()
        {
                byte[] buf = new byte[1000];
                String tmp;
                try{
                        for(;;)
                        {
                           // Handle the incoming data and print it to stnd output.
                           recv = new DatagramPacket(buf, buf.length);
                           msocket.receive(recv);
                           tmp = new String(recv.getData(),0,recv.getLength());
                           System.out.println("\n\nRecived: \""+ tmp + "\"\nMessage Length is: " + tmp.length());
                        }

                } catch (IOException e) {
                        System.out.println("Exit...");
                        e.printStackTrace();
                } finally {
                        msocket.close();
                }
        }
        
}

public class mchat {
        
        public static void main(String[] args) throws IOException
        {
                String strin;
                int flag=1;
                int port;

                if (args.length != 2) {
                        System.out.println("Usage: java mchat  mip port");
                        System.exit(0);
                }

                port = Integer.parseInt(args[1]); // Convert the Port No. to an integer.

                InetAddress group = InetAddress.getByName(args[0]);
                if (!group.isMulticastAddress()) {
                         System.out.println( "The address: " + group + " is not multicast address");
                         System.exit(0);

                }

                try {
                         
                        MulticastSocket s = new MulticastSocket(port);
                         
                        s.setReuseAddress(true);
                        System.out.println("ReuseAddress is: " + s.getReuseAddress());
                        
                        s.setLoopbackMode(false);
                        System.out.println("LoopbackMode is: " + s.getLoopbackMode());

                        
                        s.setTimeToLive(2);
                        System.out.println("TimeToLive is: " + s.getTimeToLive());

                        s.joinGroup(group);
                       
                        System.out.println("Joined Group: " + args[0] + " Port:" + args[1]);

                        // ChatThread will handle the incoming Data and print it out to STDN output.
                        new ChatThread(s,group,port);

                        // Now read from STDN input and send the Data to the Group.
                       
                        BufferedReader myinput = new BufferedReader(
                                       new InputStreamReader(System.in));  


                        System.out.println("Type anything followed by RETURN, or Ctrl+D to  terminate the program.");
                        for(;;)
                        {

                                //Read from the STDN input
                                strin=myinput.readLine();

                                if ( strin==null) break; // User Hit Ctrl+D
                                DatagramPacket dp = new DatagramPacket(strin.getBytes(), strin.length(),group, port);
                                
                                s.send(dp);

                        }

                        System.out.println("Leaving the Group...");
                        s.leaveGroup(group);
                        s.close();
                } catch (Exception err){
                          System.err.println("ERR: Can not join the group " + err);
                          err.printStackTrace();
                          System.exit(1);
                }
        }
      
}