//
   //  ========================================================================
   //  Copyright (c) 1995-2013 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;
  
  import java.util.List;
  
  import org.eclipse.jetty.client.api.Request;
  import org.eclipse.jetty.client.api.Response;
  import org.eclipse.jetty.client.api.Result;
  import org.eclipse.jetty.client.util.BufferingResponseListener;
  import org.eclipse.jetty.http.HttpHeader;
  import org.eclipse.jetty.http.HttpHeaderValue;
  
  public class ContinueProtocolHandler implements ProtocolHandler
  {
      private static final String ATTRIBUTE = ContinueProtocolHandler.class.getName() + ".100continue";
  
      private final HttpClient client;
      private final ResponseNotifier notifier;
  
      public ContinueProtocolHandler(HttpClient client)
      {
          this.client = client;
          this.notifier = new ResponseNotifier(client);
      }
  
      @Override
      public boolean accept(Request request, Response response)
      {
          boolean expect100 = request.getHeaders().contains(HttpHeader.EXPECT, HttpHeaderValue.CONTINUE.asString());
          HttpConversation conversation = client.getConversation(request.getConversationID(), false);
          boolean handled100 = conversation != null && conversation.getAttribute(ATTRIBUTE) != null;
          return expect100 && !handled100;
      }
  
      @Override
      public Response.Listener getResponseListener()
      {
          // Return new instances every time to keep track of the response content
          return new ContinueListener();
      }
  
      protected class ContinueListener extends BufferingResponseListener
      {
          @Override
          public void onSuccess(Response response)
          {
              // Handling of success must be done here and not from onComplete(),
              // since the onComplete() is not invoked because the request is not completed yet.
  
              HttpConversation conversation = client.getConversation(response.getConversationID(), false);
              // Mark the 100 Continue response as handled
              conversation.setAttribute(ATTRIBUTE, Boolean.TRUE);
  
              // Reset the conversation listeners, since we are going to receive another response code
              conversation.updateResponseListeners(null);
  
              HttpExchange exchange = conversation.getExchanges().peekLast();
              assert exchange.getResponse() == response;
              switch (response.getStatus())
              {
                  case 100:
                  {
                      // All good, continue
                      exchange.resetResponse(true);
                      exchange.proceed(true);
                      break;
                  }
                  default:
                  {
                      // Server either does not support 100 Continue,
                      // or it does and wants to refuse the request content,
                      // or we got some other HTTP status code like a redirect.
                      List<Response.ResponseListener> listeners = exchange.getResponseListeners();
                      HttpContentResponse contentResponse = new HttpContentResponse(response, getContent(), getEncoding());
                      notifier.forwardSuccess(listeners, contentResponse);
                      exchange.proceed(false);
                      break;
                  }
              }
          }
  
          @Override
         public void onFailure(Response response, Throwable failure)
         {
             HttpConversation conversation = client.getConversation(response.getConversationID(), false);
             // Mark the 100 Continue response as handled
             conversation.setAttribute(ATTRIBUTE, Boolean.TRUE);
             // Reset the conversation listeners to allow the conversation to be completed
             conversation.updateResponseListeners(null);
 
             HttpExchange exchange = conversation.getExchanges().peekLast();
             assert exchange.getResponse() == response;
             List<Response.ResponseListener> listeners = exchange.getResponseListeners();
             HttpContentResponse contentResponse = new HttpContentResponse(response, getContent(), getEncoding());
             notifier.forwardFailureComplete(listeners, exchange.getRequest(), exchange.getRequestFailure(), contentResponse, failure);
         }
 
         @Override
         public void onComplete(Result result)
         {
         }
     }
 }