/* 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
    * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  package org.esigate.http;
  
  import java.util.LinkedList;
  import java.util.Queue;
  
  import org.apache.http.HttpHost;
  import org.apache.http.HttpRequest;
  import org.apache.http.client.protocol.HttpClientContext;
  import org.apache.http.protocol.HttpContext;
  import org.apache.http.protocol.HttpCoreContext;
  
  public class OutgoingRequestContext extends HttpClientContext {
      private static final String PROXY = "PROXY";
      private static final String OUTGOING_REQUEST = "OUTGOING_REQUEST";
      private static final String PHYSICAL_HOST = "PHYSICAL_HOST";
  
      public static OutgoingRequestContext adapt(final HttpContext context) {
          if (context instanceof OutgoingRequestContext) {
              return (OutgoingRequestContext) context;
          } else {
              return new OutgoingRequestContext(context);
          }
      }
  
      private OutgoingRequestContext(final HttpContext context) {
          super(context);
      }
  
      OutgoingRequestContext() {
          super();
      }
  
      public boolean isProxy() {
          Boolean proxy = getAttribute(PROXY, Boolean.class);
          return proxy != null && proxy;
      }
  
      void setProxy(boolean proxy) {
          setAttribute(PROXY, proxy);
      }
  
      public OutgoingRequest getOutgoingRequest() {
          return getAttribute(OUTGOING_REQUEST, OutgoingRequest.class);
      }
  
      void setOutgoingRequest(OutgoingRequest outgoingRequest) {
          setAttribute(OUTGOING_REQUEST, outgoingRequest);
      }
  
      /**
       * 
       * @return physical host
       */
      HttpHost getPhysicalHost() {
          return getAttribute(PHYSICAL_HOST, HttpHost.class);
      }
  
      /**
       * 
       * @param httpHost
       *            host
       */
      void setPhysicalHost(HttpHost httpHost) {
          setAttribute(PHYSICAL_HOST, httpHost);
      }
  
      /**
       * Set attribute and save previous attribute value
       * 
       * @param id
       *            attribute name
       * @param obj
       *            value
       * @param save
       *            save previous attribute value to restore later
       */
      public void setAttribute(String id, Object obj, boolean save) {
          if (save) {
              String historyAttribute = id + "history";
              Queue<Object> history = (Queue<Object>) getAttribute(historyAttribute);
              if (history == null) {
                  history = new LinkedList<>();
                  setAttribute(historyAttribute, history);
              }
             if (this.getAttribute(id) != null) {
                 history.add(getAttribute(id));
             }
         }
         setAttribute(id, obj);
     }
 
     /**
      * remove attribute and restore previous attribute value
      * 
      * @param id
      *            attribute name
      * @param restore
      *            restore previous attribute value
      * @return attribute value
      */
     public Object removeAttribute(String id, boolean restore) {
         Object value = removeAttribute(id);
         if (restore) {
             String historyAttribute = id + "history";
             Queue<Object> history = (Queue<Object>) getAttribute(historyAttribute);
             if (history != null && !history.isEmpty()) {
                 Object previous = history.remove();
                 setAttribute(id, previous);
             }
         }
         return value;
     }
 
     /**
      * @return the actual request sent by th HttpClient.
      */
     public HttpRequest getSentRequest() {
         return (HttpRequest) getAttribute(HttpCoreContext.HTTP_REQUEST);
     }
 }