/**
 * VECR IO Applet
 *
 * R. Perry, Oct. 2004
 */

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

public class IOapplet extends Applet
implements Runnable, ActionListener
{
 // IO protocol
 //
  static final byte DATA   = 0;
  static final byte EOF    = 1;
  static final byte STOP   = 2;
  static final byte SAVE   = 3;

 // GUI
 //
  Button bEOF, bSAVE, bSTOP, bRESTART, bPFONT, bMFONT;
  TextArea diag, output;
  TextField input;
  Thread listener;
  Font font;
  String font_name;
  int font_style;
  int font_size;

 // network
 //
  String host;
  Socket s;
  BufferedInputStream in;
  DataOutputStream out;

  String newline;	// "\n" ?

  public void init()
  {
    newline = System.getProperty("line.separator");

    host = getCodeBase().getHost();

    diag = new TextArea( "", 13, 60);
    diag.setEditable( false);
    diag.setBackground( Color.white);

    output = new TextArea( "");
    output.setEditable( false);
    output.setBackground( Color.white);

    input = new TextField();

    bEOF = new Button( "EOF");
    bSAVE = new Button( "Save");
    bSTOP = new Button( "Stop");
    bRESTART = new Button( "Restart");
    bPFONT = new Button( "++Font");
    bMFONT = new Button( "--Font");

    GridBagLayout gridBag = new GridBagLayout();
    setLayout( gridBag);
    GridBagConstraints c = new GridBagConstraints();

    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridwidth = GridBagConstraints.REMAINDER;
    c.weightx = 1.0;
    c.weighty = 0.0;
    gridBag.setConstraints( diag, c);
    add( diag);

    c.fill = GridBagConstraints.BOTH;
    c.gridwidth = GridBagConstraints.REMAINDER;
    c.weightx = 1.0;
    c.weighty = 1.0;
    gridBag.setConstraints( output, c);
    add( output);

    c.fill = GridBagConstraints.HORIZONTAL;
    c.weighty = 0.0;
    gridBag.setConstraints( input, c);
    add( input);

    c.gridwidth = 1;
    gridBag.setConstraints( bEOF, c);
    add( bEOF);
    gridBag.setConstraints( bSTOP, c);
    add( bSTOP);
    gridBag.setConstraints( bRESTART, c);
    add( bRESTART);
    gridBag.setConstraints( bPFONT, c);
    add( bPFONT);
    gridBag.setConstraints( bMFONT, c);
    add( bMFONT);
    gridBag.setConstraints( bSAVE, c);
    add( bSAVE);

    validate();

    font = output.getFont();
    // font_name = font.getName();
    font_name = "Monospaced";
    font_style = font.getStyle();
    font_size = font.getSize();

    font = new Font( font_name, font_style, font_size);
    diag.setFont( font);
    output.setFont( font);

    // repaint();

    input.addActionListener( this);

    bSAVE.addActionListener(this);
    bEOF.addActionListener(this);
    bSTOP.addActionListener(this);
    bRESTART.addActionListener(this);
    bPFONT.addActionListener(this);
    bMFONT.addActionListener(this);

    input.requestFocus();
  }

  public void start()
  {
    bEOF.setEnabled( true);
    bSTOP.setEnabled( true);
    bSAVE.setEnabled( true);
    bRESTART.setEnabled( true);
    bPFONT.setEnabled( true);
    bMFONT.setEnabled( true);
    input.setEnabled( true);

    input.requestFocus();

    try
    {
      int port = 80;
      //
      // int port = getCodeBase().getPort(); -- only if a port was specified in the URL
      // int defaultport = getCodeBase().getDefaultPort(); -- only in newer JREs

      diag.append( "* Connecting to " + host + ":" + port + newline);
      diag.setCaretPosition(diag.getText().length());

      s = new Socket( host, port);

      s.setSoTimeout( 1800000); // 30 minutes

      in = new BufferedInputStream( s.getInputStream());
      out = new DataOutputStream( new BufferedOutputStream( s.getOutputStream()));

      // initialize the proxy connection
      //
      String connect = "CONNECT localhost:7\n";

      diag.append( "* Sending proxy request: ");
      diag.append( connect);
      diag.setCaretPosition(diag.getText().length());
      out.writeBytes( connect);
      out.flush();

      read_diag();

      // send authentication data
      //
      String user = getParameter( "user");
      diag.append( "* Sending authentication data for ");
      diag.append( user);
      diag.append( newline);
      diag.setCaretPosition(diag.getText().length());

      out.writeUTF( user);
      out.writeUTF( getParameter( "uid"));
      out.writeUTF( getParameter( "time"));
      out.writeUTF( getParameter( "ticket"));
      out.writeUTF( getParameter( "dir"));
      out.writeUTF( getParameter( "prog"));
      out.writeUTF( getParameter( "args"));
      out.flush();

      // start listening
      //
      listener = new Thread( this);
      listener.start(); // invokes run()
    }
    catch (Exception ex)
    {
      ByteArrayOutputStream error = new ByteArrayOutputStream();
      ex.printStackTrace( new PrintStream( error));
      diag.append( error.toString());
      diag.setCaretPosition(diag.getText().length());
    }
  }

  public void close_all()
  {
    if( listener != null)
      try { listener.interrupt(); listener = null; } catch (Exception ex) { }

    if( in != null)
      try { in.close(); in = null; } catch (Exception ex) { }

    if( out != null)
      try { out.close(); out = null; } catch (Exception ex) { }

    if( s != null)
      try { s.close(); s = null; } catch (Exception ex) { }
  }

  public void stop()
  {
    if( s != null)
    {
      diag.append( "* Disconnecting");
      diag.append( newline);
      diag.setCaretPosition(diag.getText().length());
    }

    bEOF.setEnabled( false);
    bSTOP.setEnabled( false);
    bSAVE.setEnabled( false);
    input.setEnabled( false);

    close_all();
  }

 // read initial connection diagnostics
 //
  public void read_diag() throws Exception
  {
    int n;
    int count = 0;
    byte buf[] = new byte[2048];

    while( in.available() == 0)
    {
      if( ++count > 50 )
	throw new Exception( "No response from server");

      Thread.sleep(100);
    }

    do
    {
      n = in.read( buf);

      if( n <= 0) break;

      diag.append( new String( buf, 0, n) );
      diag.setCaretPosition(diag.getText().length());

      // Thread.yield();
    }
    while( in.available() > 0);
  }

  public void run()
  {
    int n;
    byte buf[] = new byte[2048];

    try
    {
      while( true)
      {
	n = in.read( buf);

	if( n <= 0) break;

        output.append( new String( buf, 0, n) );
	output.setCaretPosition(output.getText().length());

        input.requestFocus();
      }
    }
    catch (Exception ex)
    {
    }
  }

 // handle action events
 //
  public void actionPerformed( ActionEvent e)
  {
    Object source = e.getSource();

    try
    {
      if( source == bRESTART)
      {
	stop();
	diag.append( "* Restarting");
        diag.append( newline);
	diag.setCaretPosition(diag.getText().length());
	start();
      }
      else if( source == bPFONT)
      {
	int new_font_size = font_size + 4;
	diag.append( "* Changing font size from " + font_size + " to " + new_font_size);
        diag.append( newline);
	font = new Font( font_name, font_style, new_font_size);
	font_size = new_font_size;
	diag.setFont( font);
	diag.setCaretPosition(diag.getText().length());
	output.setFont( font);
	output.setCaretPosition(output.getText().length());
      }
      else if( source == bMFONT)
      {
	int new_font_size = font_size - 4;
	if( new_font_size < 4)
	{
	  diag.append( "* Sorry, new font size would be too small");
          diag.append( newline);
	  diag.setCaretPosition(diag.getText().length());
	}
	else
	{
	  diag.append( "* Changing font size from " + font_size + " to " + new_font_size);
          diag.append( newline);
	  font = new Font( font_name, font_style, new_font_size);
	  font_size = new_font_size;
	  diag.setFont( font);
	  diag.setCaretPosition(diag.getText().length());
	  output.setFont( font);
	  output.setCaretPosition(output.getText().length());
	}
      }
      else if( listener != null)
      {
	if (source == input) // for input TextField action events
	{
	  String line = input.getText();
	  input.setText("");
	  output.append( line);
	  output.append( newline);
	  output.setCaretPosition(output.getText().length());
	  out.writeByte( DATA);
	  out.writeUTF( line);
	  out.flush();
	}
	else if( source == bEOF)
	{
	  diag.append( "* Sending EOF");
	  diag.append( newline);
	  diag.setCaretPosition(diag.getText().length());
	  out.writeByte( EOF);
	  out.flush();
	}
	else if( source == bSTOP)
	{
	  out.writeByte( STOP);
	  out.flush();
	  Thread.sleep(100); // wait for server response
	  stop();
	}
	else if (source == bSAVE)
	{
	  diag.append( "* Saving output.txt on server");
          diag.append( newline);
	  diag.setCaretPosition(diag.getText().length());
	  out.writeByte( SAVE);
	  out.writeUTF( output.getText());
	  out.flush();
	}

      } // if( listener != null)

      input.requestFocus();
    }
    catch (Exception ex)
    {
      ByteArrayOutputStream error = new ByteArrayOutputStream();
      ex.printStackTrace( new PrintStream( error));
      diag.append( error.toString());
      diag.setCaretPosition(diag.getText().length());
    }
  } 

}