/**

  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.commons.inject.api;

 import java.lang.annotation.Annotation;

 import java.lang.reflect.Method;

 import javax.annotation.PostConstruct;

 import javax.annotation.PreDestroy;

 import org.apache.commons.inject.api.bind.IBinder;

 import org.apache.commons.inject.api.bind.IModule;

 import org.apache.commons.inject.api.bind.IBinder.IInjectionListener;

 import org.apache.commons.inject.impl.DefaultLifecycleController;

 import org.apache.commons.inject.util.Exceptions;

 public class PostConstructModule implements IModule {

         private ILifecycleController controller;

         public ILifecycleController getLifecycleController() {

                 if (controller == null) {

                         controller = new DefaultLifecycleController();

                 }

                 return controller;

         }

         public void setLifecycleController(ILifecycleController pController) {

                 controller = pController;

         }

         @Override

         public void configure(IBinder pBinder) {

                 pBinder.add(new IInjectionListener() {

                         @Override

                         public void initialized(IKey<?> pKey, Object pObject) {

                                 final ILifecycleListener listener = getListenerFor(pObject);

                                 if (listener != null  &&  listener != controller) {

                                         controller.add(listener);

                                 }

                         }

                 });

                 pBinder.bind(ILifecycleController.class).toInstance(controller);

         }

         protected ILifecycleListener getListenerFor(final Object pObject) {

                 if (pObject instanceof ILifecycleListener) {

                         return (ILifecycleListener) pObject;

                 }

                 final Method postConstructMethod = findMethod(PostConstruct.class, pObject.getClass());

                 final Method preDestroyMethod = findMethod(PreDestroy.class, pObject.getClass());

                 if (postConstructMethod == null  &&  preDestroyMethod == null) {

                         return null;

                 }

                 return new ILifecycleListener(){

                         @Override

                         public void start() {

                                 invoke(postConstructMethod, pObject);

                         }

                         @Override

                         public void shutdown() {

                                 invoke(preDestroyMethod, pObject);

                         }

                         private void invoke(Method pMethod, Object pObject) {

                                 if (pMethod == null) {

                                         return;

                                 }

                                 try {

                                         if (!pMethod.isAccessible()) {

                                                 pMethod.setAccessible(true);

                                         }

                                         pMethod.invoke(pObject);

                                 } catch (Throwable t) {

                                         throw Exceptions.show(t);

                                 }

                         }

                 };

         }

         private Method findMethod(Class<? extends Annotation> pAnnotationClass, Class<?> pType) {

                 final Method[] methods = pType.getDeclaredMethods();

                 for (Method method : methods) {

                         if (method.isAnnotationPresent(pAnnotationClass)) {

                                 return method;

                         }

                 }

                 return null;

         }

 }