import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
 
public class mchat extends Frame
{
 String instring, outstring, laststring;
 static final int gport = 1918;
 Socket csocket;  // connection socket to server (other guy)
 ServerSocket ssocket;  // listening, passive socket
 InetAddress me, you;

    InputStreamReader isr;  OutputStreamWriter osw;
    BufferedReader br;  PrintWriter pw;
    DataOutputStream dos;  DataInputStream dis;

Button sbutton = new Button(" Connect");
Button cbutton = new Button("clear");
TextField mytext, yourtext, iptext;
Label prompt;
boolean beserver = false;

receiver rthread;
sender sthread;
int lastindex = 0;  // index of last new char read

public void init() 
{ int i;

  sbutton.addActionListener( new ActionListener()
 		{
		  public void actionPerformed( ActionEvent e )
		   { try {
		     you = InetAddress.getByName(iptext.getText());
		     me = InetAddress.getLocalHost();
                     connect();
		        } catch (Exception E) 
			    { System.out.println(E.toString()); iptext.setText(""); }
		   }   
                }   );

  cbutton.addActionListener( new ActionListener()
 		{
		  public void actionPerformed( ActionEvent e )
		   { mytext.setText("");
		   }   
                }   );

  mytext = new TextField(60);
  yourtext = new TextField(60);
  iptext = new TextField(30);
  add(new Label("Peer Address: "));
  add(iptext);
  add(sbutton);   // "connect" button
  add(mytext);  add(cbutton);
  add(yourtext);
  rthread = new receiver(this);
  sthread = new sender(this);
} // inita

public void connect()
{ try {  

    ssocket = new ServerSocket(gport);  // uses same port
    ssocket.setSoTimeout(300000);          // 5 minute timeout on blocks

    try { csocket = new Socket(you,gport); }   // try to be client first
    catch (Exception E) { beserver = true; }
    if (beserver)
     { System.out.println("waiting for connection ...");
       csocket = ssocket.accept();  // wait for client
     }

    System.out.println("Connected to " + csocket.getInetAddress());
    //    System.out.println("");

    dos = new DataOutputStream(csocket.getOutputStream());
    dis = new DataInputStream(csocket.getInputStream());

    // set up IO objects br and pw
    isr = new InputStreamReader(csocket.getInputStream());
    br = new BufferedReader(isr);
    osw = new OutputStreamWriter(csocket.getOutputStream());
    pw = new PrintWriter(osw,true);  // true for autoflush
    outstring = "";  instring = ""; laststring = "";

    rthread.start();	// start threads
    sthread.start();

     } catch (Exception E) { System.err.println(E.toString()); }
} // connect

public static void main(String[] args) // needed for application
{
mchat session  = new mchat();
session.setLayout(new FlowLayout(FlowLayout.CENTER));
session.resize(500,350);

session.init();  
session.show();

//session.start();  
} // end main

} // end mchat class

class receiver extends Thread
{  mchat chat;
   receiver(mchat j) 
        {  super();
           chat = j;
        }

  public void run()
    {  int i = 0;
       try {
       while (!(chat.outstring.equals("sign off")))
	   {  
                 chat.instring = chat.br.readLine();  // update?
                 chat.yourtext.setText(chat.instring);
//     	         Thread.sleep(10);  // slight delay
           }
       chat.hide();
       chat.dispose();
    } catch (Exception E) {System.out.println(E);}
    } // run

} // end receiver

class sender extends Thread
{  mchat chat;
   sender(mchat j)  // constructor
        {  super();
           chat = j;
        }

  public void run()
    {  int i = 0;
       try {
       while (!(chat.outstring.equals("sign off")))
	   {   chat.outstring = chat.mytext.getText();
                 if (!(chat.outstring.equals(chat.laststring)))
                  { chat.laststring = new String(chat.outstring); // copy
	            chat.pw.println(chat.outstring);  // send
 		  } // if
 	         Thread.sleep(20);  // slight delay
           }
       chat.hide();
       chat.dispose();
    } catch (Exception E) {System.out.println(E);}
    } // run

} // end sender