/*

  * 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.spi.impl;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import java.util.Map;

 import java.util.WeakHashMap;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 import javax.naming.NamingException;

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

 import org.apache.myfaces.spi.InjectionProvider;

 import org.apache.myfaces.spi.InjectionProviderException;

 import org.apache.myfaces.util.ExternalSpecifications;

 import org.apache.tomcat.InstanceManager;

 /**

  * An annotation lifecycle provider for Tomcat 7.

  */

 public class Tomcat7AnnotationInjectionProvider extends InjectionProvider

 {

     private WeakHashMap<ClassLoader, InstanceManager> instanceManagers = null;

     public Tomcat7AnnotationInjectionProvider(ExternalContext externalContext)

     {

         instanceManagers = new WeakHashMap<ClassLoader, InstanceManager>();

     }

     @Override

     public Object inject(Object instance) throws InjectionProviderException

     {

         return null;

     }

     @Override

     public void preDestroy(Object instance, Object creationMetaData) throws InjectionProviderException

     {

         InstanceManager manager = instanceManagers

                 .get(ClassUtils.getContextClassLoader());

         if (manager != null)

         {

             try

             {

                 manager.destroyInstance(instance);

             }

             catch (IllegalAccessException ex)

             {

                 throw new InjectionProviderException(ex);

             }

             catch (InvocationTargetException ex)

             {

                 throw new InjectionProviderException(ex);

             }

         }

     }

     @Override

     public void postConstruct(Object instance, Object creationMetaData) throws InjectionProviderException

     {

         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 (IllegalAccessException ex)

             {

                 throw new InjectionProviderException(ex);

             }

             catch (InvocationTargetException ex)

             {

                 throw new InjectionProviderException(ex);

             }

             catch (NamingException e)

             {

                 throw new InjectionProviderException(e);

             }

         }

     }

     @Override

     public boolean isAvailable()

     {

         try

         {

             Class c = Class.forName("org.apache.tomcat.InstanceManager",

                     true, ClassUtils.getContextClassLoader());

             if (c != null)

             {

                 // Tomcat 7 Available, check CDI integration. If there is no CDI available,

                 // things goes as usual just connect to the server. If CDI is available,

                 // the injection provider should check if we can inject a bean through tomcat

                 // otherwise, we need to prefer an integration against CDI, and from CDI to

                 // the underlying server.

                 FacesContext facesContext = FacesContext.getCurrentInstance();

                 if (ExternalSpecifications.isCDIAvailable(facesContext.getExternalContext()))

                 {

                     ExternalContext extCtx = facesContext.getExternalContext();

                     Map<String, Object> applicationMap = extCtx.getApplicationMap();

                     InstanceManager instanceManager = (InstanceManager)

                             applicationMap.get(InstanceManager.class.getName());                    

                     Class clazz = ClassUtils.classForName(

                         "org.apache.myfaces.cdi.checkenv.DummyInjectableBean");

                     Object dummyInjectableBean = clazz.newInstance();

                     instanceManager.newInstance(dummyInjectableBean);

                     Method m = clazz.getDeclaredMethod("isDummyBeanInjected");

                     Object value = m.invoke(dummyInjectableBean);

                     if (Boolean.TRUE.equals(value))

                     {

                         // Bean is injectable. We can use this approach.

                         return true;

                     }

                     else

                     {

                         // Bean is not injectable with this method. We should try to 

                         // inject using CDI Injection Provider. Theorically CDI 

                         // has a similar code to integrate with the underlying web server.

                         return false;

                     }

                 }

             }

             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;

     }

 }