// ========================================================================
   // Copyright (c) 2006-2011 Mort Bay Consulting Pty. Ltd.
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
   // The Apache License v2.0 is available at
  // http://www.opensource.org/licenses/apache2.0.php
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.osgi.equinoxtools.console;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.PipedInputStream;
  import java.io.PipedOutputStream;
  import java.io.PrintStream;
  import java.io.StringWriter;
  import java.util.List;
  
  import org.eclipse.jetty.osgi.equinoxtools.console.WebConsoleWriterOutputStream.OnFlushListener;
  import org.eclipse.osgi.framework.console.ConsoleSession;
  
  /**
   * A simple console session for equinox.
   * 
   * @author hmalphettes
   */
  public class WebConsoleSession extends ConsoleSession
  {
  
      private OutputStream _out;
      private StringWriter _outWriter;
      private PrintStream _source;
      private InputStream _in;
  
      public WebConsoleSession()
      {
          _outWriter = new StringWriter();
          _out = new WebConsoleWriterOutputStream(_outWriter,"UTF-8");
          try
          {
              PipedOutputStream source = new PipedOutputStream();
              PipedInputStream sink = new PipedInputStream(source);
              _in = sink;
              _source = new PrintStream(source);
          }
          catch (IOException e)
          {
              //this never happens?
              e.printStackTrace();
          }
      }
      
      @Override
      protected void doClose()
      {
          if (_out != null) try { _out.close(); } catch (IOException e) {}
          if (_in != null) try { _in.close(); } catch (IOException ioe) {}
      }
  
      @Override
      public InputStream getInput()
      {
          return _in;
      }
  
      @Override
      public OutputStream getOutput()
      {
          return _out;
      }
  
      /**
       * For the output we are using a string writer in fact.
       * @return
       */
      public StringWriter getOutputAsWriter()
      {
          return _outWriter;
      }
      
      /**
       * @return The print stream where commands can be written.
       */
      public PrintStream getSource()
      {
          return _source;
      }
      
      /**
       * Issue a command on the console.
       * @param cmd
       */
      public void issueCommand(String cmd)
      {
         if (cmd != null)
         {
             getSource().println(cmd);
         }
     }
     
     /**
      * @param flushListener Object that is called back when the outputstream is flushed.
      */
     public void addOnFlushListener(OnFlushListener flushListener)
     {
         ((WebConsoleWriterOutputStream)_out).addOnFlushListener(flushListener);
     }
     /**
      * @param flushListener Object that is called back when the outputstream is flushed.
      */
     public boolean removeOnFlushListener(OnFlushListener flushListener)
     {
         return ((WebConsoleWriterOutputStream)_out).removeOnFlushListener(flushListener);
     }
     
     /**
      * Process command comming from a web UI
      * @param cmd
      */
     public void processCommand(String cmd, boolean wait)
     {
         cmd = cmd.trim();
         while (cmd.startsWith("osgi>"))
         {
             cmd = cmd.substring("osgi>".length()).trim();
         }
         if (cmd.equals("clear"))
         {
             clearOutput();
         }
         else
         {
             getOutputAsWriter().append(cmd + "\n");
             int originalOutputLength = getOutputAsWriter().getBuffer().length();
             issueCommand(cmd);
             
             if (wait)
             {
                 //it does not get uglier than this:
                 //give a little time to equinox to interpret the command so we see the response
                 //we could do a lot better, but we might as well use the async servlets anyways.
                 int waitLoopNumber = 0;
                 int lastWaitOutputLength = -1;
                 while (waitLoopNumber < 10)
                 {
                     waitLoopNumber++;
                     try
                     {
                         Thread.sleep(100);
                     }
                     catch (InterruptedException e)
                     {
                         break;
                     }
                     int newOutputLength = getOutputAsWriter().getBuffer().length();
                     if (newOutputLength > originalOutputLength && newOutputLength == lastWaitOutputLength)
                     {
                         break;
                     }
                     lastWaitOutputLength = newOutputLength;
                 }
             }
         }
 
     }
     
     public void clearOutput()
     {
         StringBuffer buf = getOutputAsWriter().getBuffer();
         if (buf.length() > 0) buf.delete(0,buf.length()-1);
     }
     
     public List<OnFlushListener> getOnFlushListeners()
     {
         return ((WebConsoleWriterOutputStream)_out).getOnFlushListeners();
     }
     
 }