/*

  * 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 javax.faces.FacesException;

 import javax.faces.application.Application;

 import javax.faces.application.ViewExpiredException;

 import javax.faces.application.ViewHandler;

 import javax.faces.component.UIViewRoot;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 import javax.faces.event.PhaseId;

 import javax.portlet.PortletRequest;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.myfaces.portlet.MyFacesGenericPortlet;

 import org.apache.myfaces.portlet.PortletUtil;

 import org.apache.myfaces.util.DebugUtils;

 /**

  * Implements the Restore View Phase (JSF Spec 2.2.1)

  * 

  * @author Nikolay Petrov

  * @author Bruno Aranda (JSF 1.2)

  * @version $Revision: 673926 $ $Date: 2008-07-04 02:03:53 -0500 (Fri, 04 Jul 2008) $

  * 

  */

 class RestoreViewExecutor implements PhaseExecutor

 {

     private static final Log log = LogFactory.getLog(RestoreViewExecutor.class);

     private RestoreViewSupport _restoreViewSupport;

     public boolean execute(FacesContext facesContext)

     {

         if (facesContext == null)

         {

             throw new FacesException("FacesContext is null");

         }

         // init the View

         Application application = facesContext.getApplication();

         ViewHandler viewHandler = application.getViewHandler();

         viewHandler.initView(facesContext);

         UIViewRoot viewRoot = facesContext.getViewRoot();

         RestoreViewSupport restoreViewSupport = getRestoreViewSupport();

         if (viewRoot != null)

         {

             if (log.isTraceEnabled())

                 log.trace("View already exists in the FacesContext");

             viewRoot.setLocale(facesContext.getExternalContext().getRequestLocale());

             restoreViewSupport.processComponentBinding(facesContext, viewRoot);

             return false;

         }

         String viewId = restoreViewSupport.calculateViewId(facesContext);

         // Determine if this request is a postback or initial request

         if (restoreViewSupport.isPostback(facesContext))

         {

             if (log.isTraceEnabled())

                 log.trace("Request is a postback");

             viewRoot = viewHandler.restoreView(facesContext, viewId);

             if (viewRoot == null)

             {

                 throw new ViewExpiredException(

                     "No saved view state could be found for the view identifier: "

                         + viewId, viewId);

             }

             restoreViewSupport.processComponentBinding(facesContext, viewRoot);

         }

         else

         {

             if (log.isTraceEnabled())

                 log.trace("Request is not a postback. New UIViewRoot will be created");

             viewRoot = viewHandler.createView(facesContext, viewId);

             facesContext.renderResponse();

         }

         facesContext.setViewRoot(viewRoot);

         return false;

     }

     protected RestoreViewSupport getRestoreViewSupport()

     {

         if (_restoreViewSupport == null)

         {

             _restoreViewSupport = new DefaultRestoreViewSupport();

         }

         return _restoreViewSupport;

     }

     /**

      * @param restoreViewSupport

      *            the restoreViewSupport to set

      */

     public void setRestoreViewSupport(RestoreViewSupport restoreViewSupport)

     {

         _restoreViewSupport = restoreViewSupport;

     }

     public PhaseId getPhase()

     {

         return PhaseId.RESTORE_VIEW;

     }

     /**

      * TODO place that stuff into the default view handler implementation.

      */

     private static String deriveViewId(FacesContext facesContext)

     {

         ExternalContext externalContext = facesContext.getExternalContext();

         if (PortletUtil.isPortletRequest(facesContext))

         {

             PortletRequest request = (PortletRequest) externalContext.getRequest();

             return request.getParameter(MyFacesGenericPortlet.VIEW_ID);

         }

         String viewId = externalContext.getRequestPathInfo(); // getPathInfo

         if (viewId == null)

         {

             // No extra path info found, so it is probably extension mapping

             viewId = externalContext.getRequestServletPath(); // getServletPath

             DebugUtils.assertError(viewId != null, log,

                     "RequestServletPath is null, cannot determine viewId of current page.");

             if (viewId == null)

                 return null;

             // TODO: JSF Spec 2.2.1 - what do they mean by "if the default

             // ViewHandler implementation is used..." ?

             // - probably that this should use DefaultViewHandlerSupport.calculateServletFacesMapping

             // rather than duplicating the logic here.

             String defaultSuffix = externalContext.getInitParameter(ViewHandler.DEFAULT_SUFFIX_PARAM_NAME);

             String suffix = defaultSuffix != null ? defaultSuffix : ViewHandler.DEFAULT_SUFFIX;

             DebugUtils.assertError(suffix.charAt(0) == '.', log, "Default suffix must start with a dot!");

             int slashPos = viewId.lastIndexOf('/');

             int extensionPos = viewId.lastIndexOf('.');

             if (extensionPos == -1 || extensionPos <= slashPos)

             {

                 log.error("Assumed extension mapping, but there is no extension in " + viewId);

                 viewId = null;

             }

             else

             {

                 viewId = viewId.substring(0, extensionPos) + suffix;

             }

         }

         return viewId;

     }

 }