/*
    * 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.annotation;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.Map;
  import java.util.WeakHashMap;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.faces.FacesException;
  import javax.faces.context.ExternalContext;
  import javax.faces.context.FacesContext;
  import javax.naming.NamingException;
  
  import org.apache.myfaces.shared.util.ClassUtils;
  import org.apache.tomcat.InstanceManager;
  
  /**
   * An annotation lifecycle provider for Tomcat 7.
   */
  public class Tomcat7AnnotationLifecycleProvider implements
          DiscoverableLifecycleProvider, LifecycleProvider2
  {
  
      private static Logger log = Logger.getLogger(Tomcat7AnnotationLifecycleProvider.class.getName());
      
      private WeakHashMap<ClassLoader, InstanceManager> instanceManagers = null;
  
      public Tomcat7AnnotationLifecycleProvider(ExternalContext externalContext)
      {
          instanceManagers = new WeakHashMap<ClassLoader, InstanceManager>();
      }
  
      public Object newInstance(String className)
              throws ClassNotFoundException, IllegalAccessException,
              InstantiationException, NamingException, InvocationTargetException
      {
          Class<?> clazz = ClassUtils.classForName(className);
          if (log.isLoggable(Level.FINEST))
          {
              log.finest("Creating instance of " + className);
          }
          Object object = clazz.newInstance();
  
          return object;
      }
  
      public void destroyInstance(Object instance)
              throws IllegalAccessException, InvocationTargetException
      {
          InstanceManager manager = instanceManagers
                  .get(ClassUtils.getContextClassLoader());
  
          if (manager != null)
          {
              manager.destroyInstance(instance);
          }
      }
  
      public void postConstruct(Object instance)
              throws IllegalAccessException, InvocationTargetException
      {
          InstanceManager manager = instanceManagers
                  .get(ClassUtils.getContextClassLoader());
          if (manager == null)
          {
              //Initialize manager
              manager = initManager();
          }
  
          //Is initialized
          if (manager != null)
          {
              //Inject resources
              try 
              {
                  manager.newInstance(instance);
              }
              catch (NamingException e)
              {
                  throw new FacesException(e);
              }
         }
     }
 
     public boolean isAvailable()
     {
         try
         {
             Class.forName("org.apache.tomcat.InstanceManager",
                     true, ClassUtils.getContextClassLoader());
             return true;
         }
         catch (Exception e)
         {
             // ignore
         }
 
         return false;
     }
 
     private InstanceManager initManager()
     {
         FacesContext context = FacesContext.getCurrentInstance();
         if (context == null)
         {
             return null;
         }
 
         ExternalContext extCtx = context.getExternalContext();
         if (extCtx == null)
         {
             return null;
         }
 
         // get application map to access ServletContext attributes
         Map<String, Object> applicationMap = extCtx.getApplicationMap();
 
         InstanceManager instanceManager = (InstanceManager)
                 applicationMap.get(InstanceManager.class.getName());
         if (instanceManager != null)
         {
             instanceManagers.put(ClassUtils.getContextClassLoader(),
                     instanceManager);
         }
 
         return instanceManager;
     }
 
 }