/*
 * Copyright (c) 2006 Manuel Traut and Volker Dahnke
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors: Manuel Traut and Volker Dahnke
 */

package YalpOutputs.YalpVlcTelnetOutput;

import java.net.Socket;
import java.io.*;

import org.apache.commons.net.telnet.*;

import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;

/*
 * Class TelnetInterface
 *
 * <em>handels telnet connection</em>
 *
 * @author Volker Dahnke / Manuel Traut
 *
 * @version 0.1 20-11-2005<br>
 *
 * @see VlcStreamer
 */

public class TelnetInterface {

	private PrintStream out;
	private InputStream in;
	private TelnetClient tc = new TelnetClient();

	private String log4jFile = "log4j_output_plugin.conf";

	private static Logger logger =
		Logger.getLogger("Yalp.OutputPlugins.VlcTelnetOutput.TelnetInterface");

	public TelnetInterface(String host, int port, String pass) {

		PropertyConfigurator.configureAndWatch(log4jFile);
		logger.debug("TelnetInterface("+host+" "+port+" "+pass+")");

		try {
			tc.connect(host, port);
			out = new PrintStream(this.tc.getOutputStream());
			in = this.tc.getInputStream();
		} catch(IOException e) {
			System.out.println("server.TelnetInterface.java: Telnet connection "+host+":"+port+" failed");
			return;
		}

		readUntil( "Password:" );
		write(pass);
		// Advance to a prompt
		readUntil("> ");
	}

/*
 * write to TelnetInterface
 * @param value
 * 		 String to write to Interface
 */
	public void write( String value ) {
		logger.debug("write("+value+")");
		try {
			out.println( value );
			out.flush();
		} catch( Exception e ) {
			e.printStackTrace();
		}
	}

/*
 * reads output of telnet client
 * @param pattern
 * 		for stop reading
 * @return String
 */
	public String readUntil( String pattern ) {
		logger.debug("readUntil("+pattern+")");
		try {
			char lastChar = pattern.charAt( pattern.length() - 1 );
			StringBuffer sb = new StringBuffer();
			char ch = ( char )in.read();
			while( true ) {
				System.out.print( ch );
				sb.append( ch );
				if( ch == lastChar ) {
					if( sb.toString().endsWith( pattern ) ) {
						return sb.toString();
					}
				}
				ch = ( char )in.read();
			}
		} catch( Exception e ) {
			e.printStackTrace();
		}
		return null;
	}

/*
 * executes command
 * @param cmd
 *  any telnet command
 * @return String
 * 	telnet output caused by the command
 * 		null if failed
 */
	public String exec(String cmd){
		logger.debug("exec("+cmd+")");
		try {
			write(cmd);
			return readUntil( "> " );
		} catch( Exception e ) {
			e.printStackTrace();
		}
		return null;
	}

/*
 * close telnet connection
 *
 * @return boolean
 *       true:  connection closed
 *       false: connection close failed
 */
	public boolean close(){
		logger.debug("close()");
		try {
			tc.disconnect();
		} catch(IOException e) {
			return false;
		}
		return true;
	}

}