/***********************************************************************
 *
 * 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.*;

/*******************************************************************************
*
* 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();

   /**
    * creates socket, logs on
    *
    * @param host
    *      hostname of telnetserver
    * @param port
    *       destination port
    * @param pass
    *       password
    *
    */

    public TelnetInterface(String host, int port, String pass){
    		try{
        		this.tc.connect(host,port);
        		this.out = new PrintStream(this.tc.getOutputStream());
        		this.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 ) {
    	   try {
    		 out.println( value );
    		 out.flush();
    		 System.out.println( value );
    	   }
    	   catch( Exception e ) {
    		 e.printStackTrace();
    	   }
    }    
    
    /**
     * reads output of telnet client
     * @param pattern 
     * 		for stop reading
     * @return String
     */
    public String readUntil( String 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){
        
    		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(){
        try {
            this.tc.disconnect();
        } catch(IOException e){
            return false;
        }
        return true;
    }
}