import java.net.*;
import java.util.*;

public class OnLineTerm {
   private final int SENDER_SLEEP_TIME = 1000;
   private final int INTERFACE_HANDLER_SLEEP_TIME = 5000;

   private String name, comment, host;
   private HashSet set = new HashSet();

   private int port = 2000;
   private String address = "234.235.236.237";

   public static void main(String[] args) {
      new OnLineTerm(args[0], args[1]);
   }

   public OnLineTerm(String name, String comment) {
      this.name = name;
      this.comment = comment;

      new Receiver();
      new Sender();
      new InterfaceHandler();
   }

   // #################### Sender #################### 
   class Sender extends Thread {
      private MulticastSocket ms;

         
      public Sender() {
         try {
            ms = new MulticastSocket();
            //ms.setInterface(InetAddress.getByName("localhost"));
         } catch(Exception e) {}
            
         start();
      }

      public void run() {
         while(true) {
            try {
               sleep(SENDER_SLEEP_TIME);
               String message = "From: " + name + " Host: " + InetAddress.getLocalHost().toString() + " Comment: " + comment;
               byte[] data = message.getBytes();
               DatagramPacket packet = new DatagramPacket(data, data.length, InetAddress.getByName(address), port);
               ms.send(packet);
               //System.out.println("SENT MESSAGE: " + message);
            } catch(Exception e) {e.printStackTrace();}
         }
      }
   }

   // #################### Receiver #################### 
   class Receiver extends Thread {
      private MulticastSocket ms;

      public Receiver() {
         try {
            ms = new MulticastSocket(port);
            ms.joinGroup(InetAddress.getByName(address));
            System.out.println("GROUP: " + address + " JOINED AT PORT: " + port + "\n");
            ms.setTimeToLive(20);
         } catch(Exception e) {}

         start();
      }

      public void run() {
         while(true) {
            String message = null;
            try {
               byte[] data = new byte[8192];
               DatagramPacket packet = new DatagramPacket(data, data.length);
               ms.receive(packet);
               message = new String(data, 0, packet.getLength());
               set.add(message);
               //System.out.println("RECEIVED MESSAGE: " + message);
            } catch(Exception e) {}
         }
      }
   }

   // #################### InterfaceHandler ####################
   class InterfaceHandler extends Thread {
      public InterfaceHandler() {
         start();
      }

      public void run() {
         while(true) {
            Iterator iter = set.iterator();
            while(iter.hasNext()) {
               String message = (String)iter.next();
               System.out.println(getItem("From:", message) + " --- " + getItem("Host:", message) + " --- " + getItem("Comment:", message));
            }
            set.clear();
            System.out.println();

            try {
               sleep(INTERFACE_HANDLER_SLEEP_TIME);
            } catch(Exception e) {}
         }
      }

      private String getItem(String item, String message) {
         try {
            StringTokenizer st = new StringTokenizer(message);
            while(!st.nextToken().equals(item)) {}
            return st.nextToken();
         } catch(Exception e) {
            return "COULD NOT PARSE MESSAGE";
         }
      }
   }
}