/**

  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.impl;

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.commons.inject.api.ILifecycleController;

 import org.apache.commons.inject.api.ILifecycleListener;

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

 public class DefaultLifecycleController implements ILifecycleController {

         private static final int NOT_STARTED = 0;

         private static final int STARTED = 1;

         private static final int TERMINATED = 2;

         private int state = NOT_STARTED;

         private List<ILifecycleListener> listeners = new ArrayList<ILifecycleListener>();

         private List<ILifecycleListener> initializedListeners = new ArrayList<ILifecycleListener>();

         @Override

         public synchronized void start() {

                 System.err.println("DefaultLifecycleController.start: -> " + state);

                 if (state == NOT_STARTED) {

                         for (ILifecycleListener listener : listeners) {

                                 try {

                                         listener.start();

                                         initializedListeners.add(listener);

                                 } catch (Throwable t) {

                                         throw Exceptions.show(t);

                                 }

                         }

                         state = STARTED;

                 }

                 System.err.println("DefaultLifecycleController.start: <- " + state);

         }

         @Override

         public synchronized void shutdown() {

                 System.err.println("DefaultLifecycleController.shutdown: -> " + state);

                 if (state == STARTED) {

                         Throwable th = null;

                         // Shutdown in reverse order.

                         for (int i = initializedListeners.size()-1;  i >= 0;  i--) {

                                 final ILifecycleListener listener = initializedListeners.get(i);

                                 try {

                                         listener.shutdown();

                                         listeners.remove(i);

                                 } catch (Throwable t) {

                                         if (th == null) {

                                                 th = t;

                                         }

                                 }

                                 if (th != null) {

                                         throw Exceptions.show(th);

                                 }

                         }

                         state = TERMINATED;

                 }

                 System.err.println("DefaultLifecycleController.shutdown: <- " + state);

         }

         @Override

         public synchronized boolean add(ILifecycleListener pListener) {

                 System.err.println("DefaultLifecycleController.add: -> " + pListener + ", " + state);

                 if (state == STARTED) {

                         try {

                                 pListener.start();

                                 initializedListeners.add(pListener);

                         } catch (Throwable t) {

                                 throw Exceptions.show(t);

                         }

                 }

                 System.err.println("DefaultLifecycleController.add: <- " + listeners.size() + ", " + initializedListeners.size());

                 return listeners.add(pListener);

         }

         @Override

         public synchronized boolean remove(ILifecycleListener pListener) {

                 System.err.println("DefaultLifecycleController.remove: -> " + pListener + ", " + state);

                 boolean result = initializedListeners.remove(pListener);

                 if (state == TERMINATED  &&  result) {

                         try {

                                 pListener.shutdown();

                         } catch (Throwable t) {

                                 throw Exceptions.show(t);

                         }

                 }

                 System.err.println("DefaultLifecycleController.remove: <- " + result + ", " + listeners.size() + ", " + initializedListeners.size());

                 return result;

         }

 }