/*

  * 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.mc.test.core.mock;

 import java.beans.BeanInfo;

 import java.io.IOException;

 import javax.faces.FacesException;

 import javax.faces.FactoryFinder;

 import javax.faces.application.Application;

 import javax.faces.application.Resource;

 import javax.faces.application.ViewHandler;

 import javax.faces.component.UIViewRoot;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 import javax.faces.context.ResponseWriter;

 import javax.faces.render.RenderKit;

 import javax.faces.render.RenderKitFactory;

 import javax.faces.view.StateManagementStrategy;

 import javax.faces.view.ViewDeclarationLanguage;

 import javax.faces.view.ViewMetadata;

 import javax.servlet.http.HttpServletResponse;

 import org.apache.myfaces.shared.application.InvalidViewIdException;

 /**

  * It is a vdl that is just provided as fallback, to ensure if

  * viewHandler.createView(context, null) is called, an instance

  * is retrieved just like with jsp vdl, and it provides some methods

  * to hook a view instance for createView() and restoreView() methods.

  * 

  * In this way, it is possible to create view instance programatically

  * and simulate that it is generated by the vdl. 

  * 

  * @author Leonardo Uribe

  *

  */

 public class MockDefaultViewDeclarationLanguage extends ViewDeclarationLanguage

 {

     public static final String DUMMY_VIEW_CREATE_HOOK = "oam.dummy.create.UIViewRoot";

     public static final String DUMMY_VIEW_RESTORE_HOOK = "oam.dummy.restore.UIViewRoot";

     @Override

     public void buildView(FacesContext context, UIViewRoot view)

             throws IOException

     {

     }

     @Override

     public UIViewRoot createView(FacesContext context, String viewId)

     {

         if (context.getAttributes().containsKey(DUMMY_VIEW_CREATE_HOOK))

         {

             UIViewRoot root = (UIViewRoot) context.getAttributes().remove(DUMMY_VIEW_CREATE_HOOK);

             Application application = context.getApplication();

             ViewHandler handler = application.getViewHandler();

             root.setLocale(handler.calculateLocale(context));

             root.setRenderKitId(handler.calculateRenderKitId(context));

             root.setViewId(viewId);

             return root;

         }

         else

         {

             try

             {

                 viewId = calculateViewId(context, viewId);

                 Application application = context.getApplication();

                 // Create a new UIViewRoot object instance using Application.createComponent(UIViewRoot.COMPONENT_TYPE).

                 UIViewRoot newViewRoot = (UIViewRoot) application.createComponent(UIViewRoot.COMPONENT_TYPE);

                 UIViewRoot oldViewRoot = context.getViewRoot();

                 if (oldViewRoot == null)

                 {

                     // If not, this method must call calculateLocale() and calculateRenderKitId(), and store the results

                     // as the values of the locale and renderKitId, proeprties, respectively, of the newly created

                     // UIViewRoot.

                     ViewHandler handler = application.getViewHandler();

                     newViewRoot.setLocale(handler.calculateLocale(context));

                     newViewRoot.setRenderKitId(handler.calculateRenderKitId(context));

                 }

                 else

                 {

                     // If there is an existing UIViewRoot available on the FacesContext, 

                     //this method must copy its locale

                     // and renderKitId to this new view root

                     newViewRoot.setLocale(oldViewRoot.getLocale());

                     newViewRoot.setRenderKitId(oldViewRoot.getRenderKitId());

                 }

                 // TODO: VALIDATE - The spec is silent on the following line, but I feel bad if I don't set it

                 newViewRoot.setViewId(viewId);

                 return newViewRoot;

             }

             catch (InvalidViewIdException e)

             {

                 // If no viewId could be identified, or the viewId is exactly equal to the servlet mapping, 

                 // send the response error code SC_NOT_FOUND with a suitable message to the client.

                 sendSourceNotFound(context, e.getMessage());

                 // TODO: VALIDATE - Spec is silent on the return value when an error was sent

                 return null;

             }

         }

     }

     /**

      * Calculates the effective view identifier for the specified raw view identifier.

      * 

      * @param context le current FacesContext

      * @param viewId the raw view identifier

      * 

      * @return the effective view identifier

      */

     protected String calculateViewId(FacesContext context, String viewId)

     {

         if (viewId != null)

         {

             throw new InvalidViewIdException();

         }

         return null;

     }

     protected void sendSourceNotFound(FacesContext context, String message)

     {

         HttpServletResponse response = (HttpServletResponse) context.getExternalContext().getResponse();

         try

         {

             context.responseComplete();

             response.sendError(HttpServletResponse.SC_NOT_FOUND, message);

         }

         catch (IOException ioe)

         {

             throw new FacesException(ioe);

         }

     }

     /**

      * Hook the passed instance on UIViewRoot, storing into facesContext attribute map,

      * so the next call to createView() will return that value.

      * 

      * @param context

      * @param root

      */

     public static void hookCreateView(FacesContext context, UIViewRoot root)

     {

         context.getAttributes().put(DUMMY_VIEW_CREATE_HOOK, root);

     }

     /**

      * Hook the passed instance on UIViewRoot, storing into facesContext attribute map,

      * so the next call to createView() will return that value.

      * 

      * @param context

      * @param root

      */

     public static void hookRestoreView(FacesContext context, UIViewRoot root)

     {

         context.getAttributes().put(DUMMY_VIEW_RESTORE_HOOK, root);

     }

     @Override

     public BeanInfo getComponentMetadata(FacesContext context,

             Resource componentResource)

     {

         return null;

     }

     @Override

     public Resource getScriptComponentResource(FacesContext context,

             Resource componentResource)

     {

         return null;

     }

     @Override

     public StateManagementStrategy getStateManagementStrategy(

             FacesContext context, String viewId)

     {

         return null;

     }

     @Override

     public ViewMetadata getViewMetadata(FacesContext context, String viewId)

     {

         return null;

     }

     @Override

     public void renderView(FacesContext context, UIViewRoot view)

             throws IOException

     {

         checkNull(context, "context");

         checkNull(view, "view");

         ExternalContext externalContext = context.getExternalContext();

         ResponseWriter responseWriter = context.getResponseWriter();

         if (responseWriter == null)

         {

             RenderKitFactory renderFactory = (RenderKitFactory) 

                 FactoryFinder.getFactory(FactoryFinder.RENDER_KIT_FACTORY);

             RenderKit renderKit = renderFactory.getRenderKit(context, view.getRenderKitId());

             responseWriter = renderKit.createResponseWriter(externalContext.getResponseOutputWriter(), 

                     null, externalContext.getRequestCharacterEncoding());

             context.setResponseWriter(responseWriter);

         }

         // Now we actually render the document

         // Call startDocument() on the ResponseWriter.

         responseWriter.startDocument();

         view.encodeAll(context);

         // Call endDocument() on the ResponseWriter

         responseWriter.endDocument();

         responseWriter.flush();

     }

     @Override

     public UIViewRoot restoreView(FacesContext context, String viewId)

     {

         checkNull(context, "context");

         //checkNull(viewId, "viewId");

         if (context.getAttributes().containsKey(DUMMY_VIEW_RESTORE_HOOK))

         {

             UIViewRoot root = (UIViewRoot) context.getAttributes().remove(DUMMY_VIEW_RESTORE_HOOK);

             root.setViewId(viewId);

             return root;

         }

         else

         {

             Application application = context.getApplication();

             ViewHandler applicationViewHandler = application.getViewHandler();

             String renderKitId = applicationViewHandler.calculateRenderKitId(context);

             UIViewRoot viewRoot = application.getStateManager().restoreView(context, viewId, renderKitId);

             return viewRoot;

         }

     }

     protected void checkNull(final Object o, final String param)

     {

         if (o == null)

         {

             throw new NullPointerException(param + " can not be null.");

         }

     }

 }