//////////////////////////////////////////////////////////////////////////////
//                        DX SOURCEFILE					    //
//////////////////////////////////////////////////////////////////////////////

/*
 * $Header: /home/gda/dxcvs/dx/src/ui++/java/dx/client/DXClient.java,v 1.1.1.1 1999/03/24 15:17:30 gda Exp $
 */

/*
 *
 */

package dx.client;

import java.applet.*;
import java.awt.*;
import java.net.*;
import java.io.*;
import java.util.*;
import dx.protocol.server.*;

//
//
//
public abstract class DXClient extends Applet {

    private StopThread stoptr = null;
    private DXClientThread extr = null;
    protected abstract DXClientThread createCommandThread();

    private Socket dxSocket;
    protected PrintStream os;
    protected DataInputStream is;
    protected int getPort() { return 4655; }
    protected abstract dx.protocol.server.serverMsg getRequest();

    //
    // These are set later on.
    //
    private int ServerMajor = 0;
    private int ServerMinor = 0;
    private int ServerMicro = 0;

    protected final static int MajorVersion = 2;
    protected final static int MinorVersion = 0;
    protected final static int MicroVersion = 0;
    protected final static String version_string = 
	    MajorVersion + "." + MinorVersion + "." + MicroVersion;
    protected final static  String formal_version_string =
	"IBM Visualization Data Explorer / Java Explorer version " + version_string;


    public boolean isConnected() { 
	if (dxSocket != null) {
	    if (os.checkError() == true) {
		dxSocket = null;
		disconnect(null);
	    }
	}
	return (dxSocket != null); 
    }

    protected DXClient() {
	dxSocket = null;
	stoptr = null;
	extr = null;
    }

    public void init() {
	disconnect(null);
	try {
	    String bgcolor = this.getParameter("BACKGROUND");
	    if (bgcolor != null) {
		StringTokenizer stok = new StringTokenizer(bgcolor, "[, ]");
		String redstr = stok.nextToken();
		String greenstr = stok.nextToken();
		String bluestr = stok.nextToken();
		float red = Float.valueOf(redstr).floatValue();
		float green = Float.valueOf(greenstr).floatValue();
		float blue = Float.valueOf(bluestr).floatValue();
		Color c = new Color(red, green, blue);
		if (c != null) 
		    this.setBackground(c);
	    }
	} catch (Exception e) {
	}
    }

    public void destroy() {
	disconnect(null);
    }

    protected void disconnect(Thread t) {
	try {
	    if (dxSocket != null) dxSocket.close();
	    if (os != null) os.close();
	    if (is != null) is.close();
	} catch (Exception e) {
	}
	dxSocket = null;
	os = null;
	is = null;

	if ((extr != null) && (extr.isAlive())) {
	    if (extr != t)
		extr.stop();
	}
	//
	// Either of these 2 threads can call this routine.  By
	// stopping the thread, you're actually interrupting the call.
	// So we want the very last thing we do in this routine to be
	// the call the stop the StopThread.  We must make sure we
	// get it halted.
	//
	if ((stoptr != null) && (stoptr.isAlive())) {
	    if (stoptr != t)
		stoptr.stop();
	}
	stoptr = null;

	//
	// Don't add any code after the call to t.stop() because that
	// call will terminate execution of this routine in the case where
	// we were called from a thread.
	//
	if ((t != null) && (t.isAlive()))
	    t.stop();
    }

    public void stop() {
	if ((stoptr != null) && (stoptr.isAlive() == true))
	    stoptr.stop();
	stoptr = new StopThread(this);
	stoptr.start();
    }

    public void start() {
	if ((stoptr != null) && (stoptr.isAlive() == true))
	    stoptr.stop();
	stoptr = null;
	if (isConnected() == false) 
	    connect();
    }

    protected void connect() {
	String host = getDocumentBase().getHost();
	try {
	    dxSocket = new Socket(host, getPort()); 
	    os = new PrintStream(dxSocket.getOutputStream()); 
	    is = new DataInputStream(dxSocket.getInputStream()); 
	    serverMsg msg = getRequest();
	    send(msg.toString()+","+version_string); 
	    String servers_version = is.readLine(); 
	    if (versionMatch(servers_version) == false) {
		System.out.println ("ERROR: " + formal_version_string +
		    " is incompatible with server " + servers_version);
		disconnect(null);
	    }
	} catch (Exception e) {
	    System.err.println("DXClient: Couldn't get I/O for " + host);
	    dxSocket = null;
	    os = null;
	    is = null;
	}
	if (isConnected()) {
	    extr = this.createCommandThread();
	}
    }

    protected boolean send(String args) {

	boolean ok = isConnected();
	if (isConnected()) {
	    try {
		os.println(args);
		os.flush();
	    } catch (Exception e) {
		dxSocket = null;
		disconnect(null);
		ok = false;
	    }
	}
	return ok;
    }

    protected boolean versionMatch(String server_version) {
	boolean retval = false;

	serverVersionMsg svm = new serverVersionMsg(server_version);
	ServerMajor = svm.getMajor();
	ServerMinor = svm.getMinor();
	ServerMicro = svm.getMicro();

	//
	// We require a server whose Major,Minor are at least what ours are
	// If Micro is less than ours, we'll give a warning and proceed.
	//
	if ((ServerMajor >= DXClient.MajorVersion) && 
	    (ServerMinor >= DXClient.MinorVersion))
	    retval = true;
	if ((retval) && (ServerMicro < DXClient.MicroVersion))
	    System.out.println ("WARNING: Server is a earlier version.");


	return retval;
    }

} // end DXClient