/*

  * 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.config;

 import java.io.File;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import javax.faces.context.ExternalContext;

 import org.apache.myfaces.config.element.ManagedBean;

 import org.apache.myfaces.config.element.NavigationCase;

 import org.apache.myfaces.config.element.NavigationRule;

 import org.apache.myfaces.shared_impl.util.ClassUtils;

 public class FacesConfigValidator

 {

     public static final String VALIDATE_CONTEXT_PARAM = "org.apache.myfaces.VALIDATE";

     private FacesConfigValidator(){

         // hidden 

     }

     public static List<String> validate(ExternalContext ctx, String ctxPath){

         RuntimeConfig runtimeConfig = RuntimeConfig.getCurrentInstance(ctx);

         Map managedBeansMap = runtimeConfig.getManagedBeans();

         Iterator managedBeans = managedBeansMap == null ? null : 

                                 managedBeansMap.values() == null ? null :

                                     managedBeansMap.values().iterator();

         Iterator<NavigationRule> navRules = runtimeConfig.getNavigationRules() == null ? 

                             null : runtimeConfig.getNavigationRules().iterator();

         return validate(managedBeans, navRules, ctxPath);

     }

     public static List<String> validate(Iterator managedBeans, Iterator<NavigationRule> navRules, String ctxPath){

         List<String> list = new ArrayList<String>();

         if(navRules != null)

             validateNavRules(navRules, list, ctxPath);

         if(managedBeans != null)

             validateManagedBeans(managedBeans, list);

         return list;

     }

     private static void validateNavRules(Iterator<NavigationRule> navRules, List<String> list, String ctxPath){

         while(navRules.hasNext()){

             NavigationRule navRule = navRules.next();

             validateNavRule(navRule, list, ctxPath);

         }

     }

     private static void validateNavRule(NavigationRule navRule, List<String> list, String ctxPath){

         String fromId = navRule.getFromViewId();

         String filePath = ctxPath + fromId;

         if(fromId != null && ! "*".equals(fromId) && ! new File(filePath).exists())

             list.add("File for navigation 'from id' does not exist " + filePath);

         Collection cases = navRule.getNavigationCases();

         Iterator iterator = cases.iterator();

         while(iterator.hasNext()){

             NavigationCase caze = (NavigationCase) iterator.next();

             String toViewPath = ctxPath + caze.getToViewId();

             if(! new File(toViewPath).exists())

                 list.add("File for navigation 'to id' does not exist " + toViewPath);

         }

     }

     private static void validateManagedBeans(Iterator managedBeans, List<String> list){

         while(managedBeans.hasNext()){

             ManagedBean managedBean = (ManagedBean) managedBeans.next();

             validateManagedBean(managedBean, list);

         }

     }

     private static void validateManagedBean(ManagedBean managedBean, List<String> list){

         String className = managedBean.getManagedBeanClassName();

         try

         {

             ClassUtils.classForName(className);

         }

         catch (ClassNotFoundException e)

         { 

             String msg = "Could not locate class " 

                 + className + " for managed bean '" + managedBean.getManagedBeanName() + "'";

             list.add(msg);

         }

     }

 }