import java.net.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;

public class ChatClient implements Runnable, WindowListener, ActionListener {
	protected String host;
	protected int port;
	protected Frame frame;
	protected TextArea output;
	protected TextField input;

	public ChatClient (String host, int port) {
		this.host=host;
		this.port=port;
		frame=new Frame("ChatClient [ "+host+" : "+port+" ]");
		frame.addWindowListener(this);
		output=new TextArea();
		output.setEditable(false);
		input=new TextField();
		input.addActionListener(this);
		frame.add("Center", output);
		frame.add("South",input);
		frame.pack();
	}
	
	protected DataInputStream dataIn;
	protected DataOutputStream dataOut;
	protected Thread listener;

	public synchronized void start() throws IOException {
		if(listener==null) {
			Socket socket=new Socket(host, port);
			try{ dataIn=new DataInputStream
				(new BufferedInputStream(
				socket.getInputStream()));
			     dataOut=new DataOutputStream
				(new BufferedOutputStream(
				socket.getOutputStream()));
			} catch (IOException ex) {
			  socket.close();
			  throw ex;
			}
			listener=new Thread(this);
			listener.start();
			frame.setVisible(true);
		}
	}

	public synchronized void stop() throws IOException {
		frame.setVisible (false);
		if (listener !=null) {
			listener.interrupt();
			listener = null;
			dataOut.close();
		}
	}

	public void run() {
		try{ while(!Thread.interrupted()){
			String line=dataIn.readUTF();
			output.append(line+"\n");
		     }
		} catch (IOException ex) {
		  handleIOException (ex);
		}
	}

	protected synchronized void handleIOException (IOException ex) {
		if (listener !=null) {
			output.append(ex+"\n");
			input.setVisible(false);
			frame.validate();
			if (listener !=Thread.currentThread())
				listener.interrupt();
			listener=null;
			try { dataOut.close();
			} catch (IOException ignored) {
			}
		}
	}
	
	public void windowOpened (WindowEvent event) {
		output.requestFocus();
	}

	public void windowClosing (WindowEvent event) {
		try { stop();
		} catch (IOException ex) {
		  ex.printStackTrace();
   		}
	}

	public void windowClosed (WindowEvent event) {}
	public void windowIconified (WindowEvent event) {}
	public void windowDeiconified (WindowEvent event) {}
	public void windowActivated (WindowEvent event) {}
	public void windowDeactivated (WindowEvent event) {}
		
        public void actionPerformed (ActionEvent event) {
		try { input.selectAll();
		      dataOut.writeUTF (event.getActionCommand());
		      dataOut.flush();
     		} catch (IOException ex) {
		  handleIOException (ex);
		}
	}
	
	public static void main (String[] args) throws IOException {
		if ((args.length!=1)||(args[0].indexOf(":")<0))
                	throw new IllegalArgumentException("Syntax: ChatClient <host>:<port>");
		int idx=args[0].indexOf(":");
		String host=args[0].substring(0,idx);
		int port=Integer.parseInt(args[0].substring(idx+1));
		
		ChatClient client=new ChatClient(host, port);
		client.start();
	}
}