// ========================================================================
   // 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.security;
  
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.StringTokenizer;
  
  import org.eclipse.jetty.client.HttpDestination;
  import org.eclipse.jetty.client.HttpEventListenerWrapper;
  import org.eclipse.jetty.client.HttpExchange;
  import org.eclipse.jetty.http.HttpHeaders;
  import org.eclipse.jetty.http.HttpStatus;
  import org.eclipse.jetty.io.Buffer;
  import org.eclipse.jetty.util.StringUtil;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  
  /**
   * SecurityListener
   * 
   * Allow for insertion of security dialog when performing an
   * HttpExchange.
   */
  public class SecurityListener extends HttpEventListenerWrapper
  {
      private static final Logger LOG = Log.getLogger(SecurityListener.class);
  	
      private HttpDestination _destination;
      private HttpExchange _exchange;
      private boolean _requestComplete;
      private boolean _responseComplete;  
      private boolean _needIntercept;
      
      private int _attempts = 0; // TODO remember to settle on winning solution
  
      public SecurityListener(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;
      }
      
      
      /**
       * scrapes an authentication type from the authString
       * 
       * @param authString
       * @return the authentication type
       */
      protected String scrapeAuthenticationType( String authString )
      {
          String authType;
  
          if ( authString.indexOf( " " ) == -1 )
          {
              authType = authString.toString().trim();
          }
          else
          {
              String authResponse = authString.toString();
              authType = authResponse.substring( 0, authResponse.indexOf( " " ) ).trim();
          }
          return authType;
      }
      
      /**
       * scrapes a set of authentication details from the authString
       * 
       * @param authString
       * @return the authentication details
       */
      protected Map<String, String> scrapeAuthenticationDetails( String authString )
      {
          Map<String, String> authenticationDetails = new HashMap<String, String>();
          authString = authString.substring( authString.indexOf( " " ) + 1, authString.length() );
          StringTokenizer strtok = new StringTokenizer( authString, ",");
          
          while ( strtok.hasMoreTokens() )
          {
              String token = strtok.nextToken();
              String[] pair = token.split( "=" );
              
              // authentication details ought to come in two parts, if not then just skip
             if ( pair.length == 2 )
             {
                 String itemName = pair[0].trim();
                 String itemValue = pair[1].trim();
                 
                 itemValue = StringUtil.unquote( itemValue );
                 
                 authenticationDetails.put( itemName, itemValue );
             }    
             else
             {
                 LOG.debug("SecurityListener: missed scraping authentication details - " + token );
             }
         }
         return authenticationDetails;
     }
 
   
     @Override
     public void onResponseStatus( Buffer version, int status, Buffer reason )
         throws IOException
     {
         if (LOG.isDebugEnabled())
             LOG.debug("SecurityListener:Response Status: " + status );
 
         if ( status == HttpStatus.UNAUTHORIZED_401 && _attempts<_destination.getHttpClient().maxRetries()) 
         {
             // Let's absorb events until we have done some retries
             setDelegatingResponses(false);
             _needIntercept = true;
         }
         else 
         {
             setDelegatingResponses(true);
             setDelegatingRequests(true);
             _needIntercept = false;
         }
         super.onResponseStatus(version,status,reason);
     }
 
 
     @Override
     public void onResponseHeader( Buffer name, Buffer value )
         throws IOException
     {
         if (LOG.isDebugEnabled())
             LOG.debug( "SecurityListener:Header: " + name.toString() + " / " + value.toString() );
         
         
         if (!isDelegatingResponses())
         {
             int header = HttpHeaders.CACHE.getOrdinal(name);
             switch (header)
             {
                 case HttpHeaders.WWW_AUTHENTICATE_ORDINAL:
 
                     // TODO don't hard code this bit.
                     String authString = value.toString();
                     String type = scrapeAuthenticationType( authString );                  
 
                     // TODO maybe avoid this map creation
                     Map<String,String> details = scrapeAuthenticationDetails( authString );
                     String pathSpec="/"; // TODO work out the real path spec
                     RealmResolver realmResolver = _destination.getHttpClient().getRealmResolver();
                     
                     if ( realmResolver == null )
                     {
                         break;
                     }
                     
                     Realm realm = realmResolver.getRealm( details.get("realm"), _destination, pathSpec ); // TODO work our realm correctly 
                     
                     if ( realm == null )
                     {
                         LOG.warn( "Unknown Security Realm: " + details.get("realm") );
                     }
                     else if ("digest".equalsIgnoreCase(type))
                     {
                         _destination.addAuthorization("/",new DigestAuthentication(realm,details));
                         
                     }
                     else if ("basic".equalsIgnoreCase(type))
                     {
                         _destination.addAuthorization(pathSpec,new BasicAuthentication(realm));
                     }
                     
                     break;
             }
         }
         super.onResponseHeader(name,value);
     }
     
 
     @Override
     public void onRequestComplete() throws IOException
     {
         _requestComplete = true;
 
         if (_needIntercept)
         {
             if (_requestComplete && _responseComplete)
             {
                if (LOG.isDebugEnabled())
                    LOG.debug("onRequestComplete, Both complete: Resending from onResponseComplete "+_exchange); 
                 _responseComplete = false;
                 _requestComplete = false;
                 setDelegatingRequests(true);
                 setDelegatingResponses(true);
                 _destination.resend(_exchange);  
             } 
             else
             {
                 if (LOG.isDebugEnabled())
                     LOG.debug("onRequestComplete, Response not yet complete onRequestComplete, calling super for "+_exchange);
                 super.onRequestComplete(); 
             }
         }
         else
         {
             if (LOG.isDebugEnabled())
                 LOG.debug("onRequestComplete, delegating to super with Request complete="+_requestComplete+", response complete="+_responseComplete+" "+_exchange);
             super.onRequestComplete();
         }
     }
 
 
     @Override
     public void onResponseComplete() throws IOException
     {   
         _responseComplete = true;
         if (_needIntercept)
         {  
             if (_requestComplete && _responseComplete)
             {              
                 if (LOG.isDebugEnabled())
                     LOG.debug("onResponseComplete, Both complete: Resending from onResponseComplete"+_exchange);
                 _responseComplete = false;
                 _requestComplete = false;
                 setDelegatingResponses(true);
                 setDelegatingRequests(true);
                 _destination.resend(_exchange); 
 
             }
             else
             {
                if (LOG.isDebugEnabled())
                    LOG.debug("onResponseComplete, Request not yet complete from onResponseComplete,  calling super "+_exchange);
                 super.onResponseComplete(); 
             }
         }
         else
         {
             if (LOG.isDebugEnabled())
                 LOG.debug("OnResponseComplete, delegating to super with Request complete="+_requestComplete+", response complete="+_responseComplete+" "+_exchange);
             super.onResponseComplete();  
         }
     }
 
     @Override
     public void onRetry()
     {
         _attempts++;
         setDelegatingRequests(true);
         setDelegatingResponses(true);
         _requestComplete=false;
         _responseComplete=false;
         _needIntercept=false;
         super.onRetry();
     }  
     
     
 }