/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
import java.net.*;
import java.io.*;

class KnockKnockServer {
    public static void main(String args[]) {
	ServerSocket serverSocket = null;

        try {
            serverSocket = new ServerSocket(4444);
        } catch (IOException e) {
            System.out.println("Could not listen on port: " + 4444 + ", " + e);
            System.exit(1);
        }

	Socket clientSocket = null;
	try {
	    clientSocket = serverSocket.accept();
	} catch (IOException e) {
            System.out.println("Accept failed: " + 4444 + ", " + e);
            System.exit(1);
	}

	try {
	    DataInputStream is = new DataInputStream(
				 new BufferedInputStream(clientSocket.getInputStream()));
            PrintStream os = new PrintStream(
			     new BufferedOutputStream(clientSocket.getOutputStream(), 1024), false);
	    KKProtocol kkp = new KKProtocol();
	    String inputLine, outputLine;

	    outputLine = kkp.processInput(null);
	    os.println(outputLine);
	    os.flush();

	    while ((inputLine = is.readLine()) != null) {
	 	outputLine = kkp.processInput(inputLine);
	 	os.println(outputLine);
	        os.flush();
	 	if (outputLine.equals("Bye"))
		    break;
	    }
	    os.close();
	    is.close();
	    clientSocket.close();
	    serverSocket.close();

	} catch (IOException e) {
            e.printStackTrace();
	}
    }
}