//
// WaveTest.java	Steve Lang & Jim Phillips
//
// This example creates a simple interface in which you can type
// Wave commands and see the text and graphic output produced by
// Wave.  This is accomplished by communicating with a Wave server
// running on the machine which is also serving the Java applet
// (e.g. the web server machine).  A CGI script is used as the
// method of communication between the applet and the Wave server
// because this will work reliably across firewalls, where a 
// direct socket connection between the applet and Wave might not.
//

import java.io.*;
import java.awt.*;
import java.applet.*;
import java.awt.image.*;
import java.net.*;
import sun.awt.image.URLImageSource;

//
// The WaveTest Applet
//
public class WaveTest extends Applet {

    WaveControls controls;

    public void init() {

	//
	// Create a canvas for Wave graphics and center 
	// it by placing an empty label on the left
	// (inelegant but does the trick).
	//
	setLayout(new BorderLayout());
	WaveCanvas c = new WaveCanvas(this);
	add("West",new Label("              "));
	add("Center", c);

	//
	// Add the text input and output areas
	//
	add("South", controls = new WaveControls(c,this));
    }

    public void start() {
	controls.enable();
    }

    public void stop() {
	controls.disable();
    }

    public boolean handleEvent(Event e) {
	if (e.id == Event.WINDOW_DESTROY) {
	    System.exit(0);
	}
	return false;
    }

    public static void main(String args[]) {
	Frame f = new Frame("WaveTest");
	WaveTest	waveTest = new WaveTest();

	f.add("Center", waveTest);
	f.resize(400, 350);
	f.show();
    }

}
    

//
// Create a graphics area and set the paint method to 
// retrieve a gif file from the web server.
//
class WaveCanvas extends Canvas {

	WaveTest par;
	Image img;

	public WaveCanvas (WaveTest parent) {
	par=parent;
	}

    public void paint(Graphics g) {
	img = par.getImage(par.getDocumentBase(),"java.gif");
	g.drawImage(img,0,0,400,350,this);
    }

    public void flush() {
        img.flush();
    }

    public void update(Graphics g) {
	paint(g);
    }

    public void redraw() {
	repaint();
    }
}

//
// Create a text area for input of Wave commands and a text 
// region to display the output of Wave. Also include a button
// to refresh the graphic area (although this should be unnecessary
// because it will be done automatically when you issue a command
// that changes the graphic area.)
//
class WaveControls extends Panel {
   TextField cmd;
   TextArea res;
   WaveCanvas canvas;
   WaveTest par;
   String msg;
		
    public WaveControls(WaveCanvas canvas, WaveTest parent) {
	this.canvas = canvas;
	par = parent;
        boolean autoflush = true;

	//
	// Create the Wave command input field and the Redraw button
	//
	Panel towave = new Panel();
	towave.setLayout(new BorderLayout());
	towave.add ("West",new Label("WAVE> "));
	towave.add ("Center",cmd = new TextField("",40));
	towave.add ("East",new Button("Redraw"));

	//
	// Create the text area to show Wave's stdout
	//
	Panel frmwave = new Panel();
	frmwave.setLayout(new BorderLayout());
	frmwave.add ("West",new Label("           "));
	frmwave.add ("Center",res = new TextArea(10,40));

	setLayout(new BorderLayout());
	add("North",towave);
	add("South",frmwave);

    }

    //
    // Handle the events from the applet
    //
    public boolean action(Event ev, Object arg) {

	//
	// If Redraw is pressed, send Wave the Redraw command
	// (which is part of the java_server.pro) which causes
	// Wave to copy it's internal Z buffer window to a 
	// GIF file.  Finally flush the canvas in the applet
	// which causes it to get a fresh copy of the graphic
	// from the server.
	// 
	if (ev.target instanceof Button) {
		//System.out.println("Sending Redraw request");
		//par.showStatus("Requesting Graphics Update...");
		//par.show();
		send_msg("REDRAW");
		canvas.flush(); 
		canvas.repaint(); 
                //par.showStatus("");
	    return true;
	}

	//
	// Get the text from the command area, erase the command 
	// area, and send the command to Wave to be executed.
	//
	if (ev.target instanceof TextField) {
		//System.out.println("Sending Command");
                //par.showStatus("Sending Command to Wave...");
                //par.show();
		String s = cmd.getText();
		cmd.setText("");
		send_msg(s);
                //par.showStatus("");
	   return true;
	}

	return false;
    }

	//
	// This method actually makes the connection with Wave.
	// It does this by executing a CGI script that communicates
	// with Wave via an RPC client.  Wave is assumed to be running
	// as an RPC server, but the client knows to restart the server
	// if it is not running for any reason.
	//
	public void send_msg(String s) {

	try {
		//
		// Open a URL connection to the CGI script
		//
                
		// We could get the URL of the server something like this:
		//res.appendText("codebase: " + par.getCodeBase() + "\n" );
		//URL url = new URL(par.getCodeBase(), "../cgi-test/call_wave");

		// Here the URL is absolute:
		URL url = new URL("http://www.jwave.vt.edu/cgi-bin/call_wave");
		URLConnection connection = url.openConnection();
                connection.setDoOutput(true);
		connection.setDoInput(true);

		//
		// Send the command to Wave
		//
		PrintStream outStream = new PrintStream(connection.getOutputStream(),true);
		outStream.println(s);
                outStream.close();

		//
		// Wait for response
		//
		DataInputStream inStream = new DataInputStream(connection.getInputStream());
		while (null != (msg = inStream.readLine())) {

			//
			// If Wave sends back REDRAW get a new copy
			// of the GIF file for the graphic display.
			//
			if (msg.equals("REDRAW")) {
				canvas.flush(); 
				canvas.repaint(); 
			}
			else {

			//
			// Add the text from Wave to the text area
			//
				res.appendText(msg + "\n" );
			}
		}
		inStream.close();

	//
	// Handle exceptions
	//
	} catch (MalformedURLException e) {
			res.appendText("Malformed send_msg: " + e + "\n" );
			return;
	} catch (IOException e) {
			res.appendText("IOException in send_msg: " + e + "\n" );
			return;
	} 


	}
}