/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.myfaces.lifecycle;
  
  import java.util.Map;
  
  import javax.el.ValueExpression;
  import javax.faces.FacesException;
  import javax.faces.application.ViewHandler;
  import javax.faces.component.UIComponent;
  import javax.faces.context.ExternalContext;
  import javax.faces.context.FacesContext;
  import javax.faces.render.ResponseStateManager;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.shared_impl.renderkit.RendererUtils;
  import org.apache.myfaces.shared_impl.util.Assert;
  import org.apache.myfaces.shared_impl.util.RestoreStateUtils;
  
  /**
   * @author Mathias Broekelmann (latest modification by $Author: lu4242 $)
   * @version $Revision: 825575 $ $Date: 2009-10-15 12:18:20 -0500 (Thu, 15 Oct 2009) $
   */
  public class DefaultRestoreViewSupport implements RestoreViewSupport
  {
      private static final String JAVAX_SERVLET_INCLUDE_SERVLET_PATH = "javax.servlet.include.servlet_path";
  
      private static final String JAVAX_SERVLET_INCLUDE_PATH_INFO = "javax.servlet.include.path_info";
      
      /**
       * Constant defined on javax.portlet.faces.Bridge class that helps to 
       * define if the current request is a portlet request or not.
       */
      private static final String PORTLET_LIFECYCLE_PHASE = "javax.portlet.faces.phase";
  
      private final Log log = LogFactory.getLog(DefaultRestoreViewSupport.class);
  
      public void processComponentBinding(FacesContext facesContext, UIComponent component)
      {
          ValueExpression binding = component.getValueExpression("binding");
          if (binding != null)
          {
              binding.setValue(facesContext.getELContext(), component);
          }
          
          //This part is for make compatibility with t:aliasBean, because
          //this components has its own code before and after binding is 
          //set for child components.
          RestoreStateUtils.recursivelyHandleComponentReferencesAndSetValid(facesContext,component);
  
          //The required behavior for the spec is call recursively this method
          //for walk the component tree. 
          //for (Iterator<UIComponent> iter = component.getFacetsAndChildren(); iter.hasNext();)
          //{
          //    processComponentBinding(facesContext, iter.next());
          //}
      }
  
      public String calculateViewId(FacesContext facesContext)
      {
          Assert.notNull(facesContext);
          ExternalContext externalContext = facesContext.getExternalContext();
          Map<String, Object> requestMap = externalContext.getRequestMap();
  
          String viewId = null;
          boolean traceEnabled = log.isTraceEnabled();
          
          if (requestMap.containsKey(PORTLET_LIFECYCLE_PHASE))
          {
              viewId = (String) externalContext.getRequestPathInfo();
          }
          else
          {
              viewId = (String) requestMap.get(JAVAX_SERVLET_INCLUDE_PATH_INFO);
              if (viewId != null)
              {
                  if (traceEnabled)
                  {
                      log.trace("Calculated viewId '" + viewId + "' from request param '" + JAVAX_SERVLET_INCLUDE_PATH_INFO
                              + "'");
                  }
              }
             else
             {
                 viewId = externalContext.getRequestPathInfo();
                 if (viewId != null && traceEnabled)
                 {
                     log.trace("Calculated viewId '" + viewId + "' from request path info");
                 }
             }
     
             if (viewId == null)
             {
                 viewId = (String) requestMap.get(JAVAX_SERVLET_INCLUDE_SERVLET_PATH);
                 if (viewId != null && traceEnabled)
                 {
                     log.trace("Calculated viewId '" + viewId + "' from request param '"
                             + JAVAX_SERVLET_INCLUDE_SERVLET_PATH + "'");
                 }
             }
         }
         
         if (viewId == null)
         {
             viewId = externalContext.getRequestServletPath();
             if (viewId != null && traceEnabled)
             {
                 log.trace("Calculated viewId '" + viewId + "' from request servlet path");
             }
         }
 
         if (viewId == null)
         {
             throw new FacesException("Could not determine view id.");
         }
 
         return viewId;
     }
 
     public boolean isPostback(FacesContext facesContext)
     {
         ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
         String renderkitId = viewHandler.calculateRenderKitId(facesContext);
         ResponseStateManager rsm = RendererUtils.getResponseStateManager(facesContext, renderkitId);
         return rsm.isPostback(facesContext);
     }
 }