/*

  * Copyright 2004-2011 the Seasar Foundation and the Others.

  *

  * 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.seasar.teeda.core.lifecycle.impl;

 import java.util.Collections;

 import java.util.Locale;

 import java.util.Map;

 import javax.faces.FacesException;

 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.faces.internal.SubApplicationUtil;

 import javax.faces.internal.WindowIdUtil;

 import javax.faces.internal.scope.PageScope;

 import javax.faces.internal.scope.SubApplicationScope;

 import org.seasar.framework.util.LruHashMap;

 import org.seasar.teeda.core.JsfConstants;

 import org.seasar.teeda.core.lifecycle.AbstractPhase;

 import org.seasar.teeda.core.util.ExternalContextUtil;

 import org.seasar.teeda.core.util.FacesContextUtil;

 import org.seasar.teeda.core.util.PortletUtil;

 import org.seasar.teeda.core.util.PostbackUtil;

 import org.seasar.teeda.core.util.ServletExternalContextUtil;

 /**

  * @author shot

  * @author higa

  */

 public class RestoreViewPhase extends AbstractPhase {

     private static final String VIEW_ID_LRU_ATTR = RestoreViewPhase.class

             .getName() +

             ".VIEW_ID_LRU";

     private int viewIdLruSize = 16;

     public RestoreViewPhase() {

     }

     public int getViewIdLruSize() {

         return viewIdLruSize;

     }

     public void setViewIdLruSize(int viewIdLruSize) {

         this.viewIdLruSize = viewIdLruSize;

     }

     protected void executePhase(final FacesContext context)

             throws FacesException {

         final RestoreValueHolder holder = setUpRestoreViewPhase(context);

         final String viewId = holder.getCurrentViewId();

         final String wid = holder.getWid();

         final String previousViewId = holder.getPreviousViewId();

         if (previousViewId != null && !previousViewId.equals(viewId)) {

             PageScope.removeContext(context, wid);

         }

         String subAppPath = SubApplicationUtil.getSubApplicationPath(viewId);

         String previousSubAppPath = SubApplicationUtil

                 .getSubApplicationPath(previousViewId);

         if (previousSubAppPath != null &&

                 !previousSubAppPath.equals(subAppPath)) {

             SubApplicationScope.removeContext(context, wid);

         }

         final UIViewRoot viewRoot = composeViewRoot(context, viewId);

         context.setViewRoot(viewRoot);

         final ExternalContext externalContext = context.getExternalContext();

         saveViewIdToSession(externalContext.getSessionMap(), wid, viewId);

         initializeChildren(context, viewRoot);

         Map requestParameterMap = externalContext.getRequestParameterMap();

         if (requestParameterMap.isEmpty()) {

             context.renderResponse();

         }

     }

     protected RestoreValueHolder setUpRestoreViewPhase(

             final FacesContext context) {

         RestoreValueHolder holder = new RestoreValueHolder(context);

         final ExternalContext externalContext = context.getExternalContext();

         final String previousViewId = holder.getPreviousViewId();

         Map requestMap = externalContext.getRequestMap();

         requestMap.put(JsfConstants.PREVIOUS_VIEW_ID, previousViewId);

         boolean isPost = true;

         // PortletSupport

         if (!PortletUtil.isPortlet(context)) {

             isPost = ServletExternalContextUtil.isPost(externalContext);

         } else {

             isPost = !PortletUtil.isRender(context);

         }

         PostbackUtil.setPostback(requestMap, isPost);

         return holder;

     }

     private UIViewRoot composeViewRoot(final FacesContext context,

             final String viewId) {

         final ViewHandler viewHandler = FacesContextUtil

                 .getViewHandler(context);

         UIViewRoot viewRoot = viewHandler.restoreView(context, viewId);

         if (viewRoot != null) {

             final Locale locale = viewHandler.calculateLocale(context);

             if (locale != null) {

                 viewRoot.setLocale(locale);

             }

         } else {

             viewRoot = viewHandler.createView(context, viewId);

         }

         return viewRoot;

     }

     private String getViewId(final FacesContext context,

             final ExternalContext externalContext) {

         return ExternalContextUtil.getViewId(externalContext);

     }

     protected String getViewIdFromSession(final Map sessionMap,

             final String windowId) {

         Map lru = getViewIdLruFromSession(sessionMap);

         return (String) lru.get(windowId);

     }

     protected synchronized Map getViewIdLruFromSession(final Map sessionMap) {

         Map lru = (Map) sessionMap.get(VIEW_ID_LRU_ATTR);

         if (lru == null) {

             lru = Collections.synchronizedMap(new LruHashMap(viewIdLruSize));

             sessionMap.put(VIEW_ID_LRU_ATTR, lru);

         }

         return lru;

     }

     protected void saveViewIdToSession(final Map sessionMap,

             final String windowId, final String viewId) {

         Map lru = getViewIdLruFromSession(sessionMap);

         lru.put(windowId, viewId);

     }

     protected PhaseId getCurrentPhaseId() {

         return PhaseId.RESTORE_VIEW;

     }

     private class RestoreValueHolder {

         private String currentViewId;

         private String wid;

         private String previousViewId;

         public RestoreValueHolder(FacesContext context) {

             final ExternalContext externalContext = context

                     .getExternalContext();

             this.currentViewId = getViewId(context, externalContext);

             this.wid = WindowIdUtil.getWindowId(externalContext);

             this.previousViewId = getViewIdFromSession(externalContext

                     .getSessionMap(), this.wid);

         }

         public String getCurrentViewId() {

             return currentViewId;

         }

         public String getWid() {

             return wid;

         }

         public String getPreviousViewId() {

             return previousViewId;

         }

     }

 }