// ========================================================================
   // Copyright (c) 2008-2009 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.client.webdav;
  
  import java.io.IOException;
  
  import org.eclipse.jetty.client.HttpDestination;
  import org.eclipse.jetty.client.HttpEventListenerWrapper;
  import org.eclipse.jetty.client.HttpExchange;
  import org.eclipse.jetty.client.security.SecurityListener;
  import org.eclipse.jetty.http.HttpMethods;
  import org.eclipse.jetty.http.HttpStatus;
  import org.eclipse.jetty.io.Buffer;
  import org.eclipse.jetty.util.URIUtil;
  import org.eclipse.jetty.util.log.Log;
  
  /**
   * WebdavListener
   * 
   * 
   * 
   * 
   */
  public class WebdavListener extends HttpEventListenerWrapper
  {
      private HttpDestination _destination;
      private HttpExchange _exchange;
      private boolean _requestComplete;
      private boolean _responseComplete; 
      private boolean _webdavEnabled;
      private boolean _needIntercept;
  
      public WebdavListener(HttpDestination destination, HttpExchange ex)
      {
          // Start of sending events through to the wrapped listener
          // Next decision point is the onResponseStatus
          super(ex.getEventListener(),true);
          _destination=destination;
          _exchange=ex;
  
          // We'll only enable webdav if this is a PUT request
          if ( HttpMethods.PUT.equalsIgnoreCase( _exchange.getMethod() ) )
          {
              _webdavEnabled = true;
          }
      }
  
      public void onResponseStatus(Buffer version, int status, Buffer reason) throws IOException
      {
          if ( !_webdavEnabled )
          {
              _needIntercept = false;
              super.onResponseStatus(version, status, reason);
              return;
          }
          
          if (Log.isDebugEnabled())
              Log.debug("WebdavListener:Response Status: " + status );
  
          // The dav spec says that CONFLICT should be returned when the parent collection doesn't exist but I am seeing
          // FORBIDDEN returned instead so running with that.
          if ( status == HttpStatus.FORBIDDEN_403 || status == HttpStatus.CONFLICT_409 )
          {
              if ( _webdavEnabled )
              {
                  if (Log.isDebugEnabled())
                      Log.debug("WebdavListener:Response Status: dav enabled, taking a stab at resolving put issue" );
                  setDelegatingResponses( false ); // stop delegating, we can try and fix this request
                  _needIntercept = true;
              }
              else
              {
                  if (Log.isDebugEnabled())
                      Log.debug("WebdavListener:Response Status: Webdav Disabled" );
                  setDelegatingResponses( true ); // just make sure we delegate
                  setDelegatingRequests( true );
                  _needIntercept = false;
              }
          }
          else
          {
              _needIntercept = false;
              setDelegatingResponses( true );
              setDelegatingRequests( true );
          }
  
          super.onResponseStatus(version, status, reason);
     }
 
     public void onResponseComplete() throws IOException
     {
         _responseComplete = true;
         if (_needIntercept)
         {
             if ( _requestComplete && _responseComplete)
             {
                 try
                 {
                     // we have some work to do before retrying this
                     if ( resolveCollectionIssues() )
                     {
                         setDelegatingRequests( true );
                         setDelegatingResponses(true);
                         _requestComplete = false;
                         _responseComplete = false;
                         _destination.resend(_exchange);
                     }
                     else
                     {
                         // admit defeat but retry because someone else might have 
                         setDelegatingRequests( true );
                         setDelegatingResponses(true);
                         super.onResponseComplete();
                     }
                 }
                 catch ( IOException ioe )
                 {
                     Log.debug("WebdavListener:Complete:IOException: might not be dealing with dav server, delegate");
                     super.onResponseComplete();
                 }
             }
             else
             {
                 if (Log.isDebugEnabled())
                     Log.debug("WebdavListener:Not ready, calling super");
                 super.onResponseComplete();
             }
         }
         else
         {
             super.onResponseComplete();
         }
     }
 
     
     
     public void onRequestComplete () throws IOException
     {
         _requestComplete = true;
         if (_needIntercept)
         {
             if ( _requestComplete && _responseComplete)
             {
                 try
                 {
                     // we have some work to do before retrying this
                     if ( resolveCollectionIssues() )
                     {
                         setDelegatingRequests( true );
                         setDelegatingResponses(true);
                         _requestComplete = false;
                         _responseComplete = false;
                         _destination.resend(_exchange);
                     }
                     else
                     {
                         // admit defeat but retry because someone else might have 
                         setDelegatingRequests( true );
                         setDelegatingResponses(true);
                         super.onRequestComplete();
                     }
                 }
                 catch ( IOException ioe )
                 {
                     Log.debug("WebdavListener:Complete:IOException: might not be dealing with dav server, delegate");
                     super.onRequestComplete();
                 }
             }
             else
             {
                 if (Log.isDebugEnabled())
                     Log.debug("WebdavListener:Not ready, calling super");
                 super.onRequestComplete();
             }
         }
         else
         {
             super.onRequestComplete();
         } 
     }
 
    
     
     
     /**
      * walk through the steps to try and resolve missing parent collection issues via webdav
      *
      * @return
      * @throws IOException
      */
     private boolean resolveCollectionIssues() throws IOException
     {
 
         String uri = _exchange.getURI();
         String[] uriCollection = _exchange.getURI().split("/");
         int checkNum = uriCollection.length;
         int rewind = 0;
 
         String parentUri = URIUtil.parentPath( uri );
         while ( !checkExists( parentUri ) )
         {
             ++rewind;
             parentUri = URIUtil.parentPath( parentUri );
         }
 
         // confirm webdav is supported for this collection
         if ( checkWebdavSupported() )
         {
             for (int i = 0; i < rewind;)
             {
                 makeCollection(parentUri + "/" + uriCollection[checkNum - rewind - 1]);
                 parentUri = parentUri + "/" + uriCollection[checkNum - rewind - 1];
                 --rewind;
             }
         }
         else
         {
             return false;
         }
 
         return true;
     }
 
     private boolean checkExists( String uri ) throws IOException
     {
         PropfindExchange propfindExchange = new PropfindExchange();
         propfindExchange.setAddress( _exchange.getAddress() );
         propfindExchange.setMethod( HttpMethods.GET ); // PROPFIND acts wonky, just use get
         propfindExchange.setScheme( _exchange.getScheme() );
         propfindExchange.setEventListener( new SecurityListener( _destination, propfindExchange ) );
         propfindExchange.setConfigureListeners( false );
         propfindExchange.setURI( uri );
 
         _destination.send( propfindExchange );
 
         try
         {
             propfindExchange.waitForDone();
 
             return propfindExchange.exists();
         }
         catch ( InterruptedException ie )
         {
             Log.ignore( ie );                  
             return false;
         }
     }
 
     private boolean makeCollection( String uri ) throws IOException
     {
         MkcolExchange mkcolExchange = new MkcolExchange();
         mkcolExchange.setAddress( _exchange.getAddress() );
         mkcolExchange.setMethod( "MKCOL " + uri + " HTTP/1.1" );
         mkcolExchange.setScheme( _exchange.getScheme() );
         mkcolExchange.setEventListener( new SecurityListener( _destination, mkcolExchange ) );
         mkcolExchange.setConfigureListeners( false );
         mkcolExchange.setURI( uri );
 
         _destination.send( mkcolExchange );
 
         try
         {
             mkcolExchange.waitForDone();
 
             return mkcolExchange.exists();
         }
         catch ( InterruptedException ie )
         {
             Log.ignore( ie );
             return false;
         }
     }
 
     
     private boolean checkWebdavSupported() throws IOException
     {
         WebdavSupportedExchange supportedExchange = new WebdavSupportedExchange();
         supportedExchange.setAddress( _exchange.getAddress() );
         supportedExchange.setMethod( HttpMethods.OPTIONS );
         supportedExchange.setScheme( _exchange.getScheme() );
         supportedExchange.setEventListener( new SecurityListener( _destination, supportedExchange ) );
         supportedExchange.setConfigureListeners( false );
         supportedExchange.setURI( _exchange.getURI() );
 
         _destination.send( supportedExchange );
 
         try
         {
             supportedExchange.waitTilCompletion();
             return supportedExchange.isWebdavSupported();
         }
         catch (InterruptedException ie )
         {            
             Log.ignore( ie );
             return false;
         }
 
     }
 
 }