/*
 * Copyright 2014 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */
package at.gv.egovernment.moa.id.auth;

import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.TimeUnit;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import org.springframework.stereotype.Component;

import at.gv.egiz.eaaf.core.api.IDestroyableObject;
import at.gv.egovernment.moa.logging.Logger;

/**
 * @author tlenz
 *
 */
@Component
public class MOAContextCloseHandler implements ApplicationListener<ContextClosedEvent>, ApplicationContextAware, BeanPostProcessor {

	private ApplicationContext context;
	
	/* (non-Javadoc)
	 * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
	 */
	@Override
	public void onApplicationEvent(ContextClosedEvent arg0) {
		Logger.info("MOA-ID-Auth shutdown process started ...");		
		
		try {			
			Logger.debug("CleanUp objects with implements the IDestroyable interface ... ");
			Map<String, IDestroyableObject> objectsToDestroy = context.getBeansOfType(IDestroyableObject.class);
			if (objectsToDestroy != null) {
				Iterator<Entry<String, IDestroyableObject>> interator = 
						objectsToDestroy.entrySet().iterator();				
				while (interator.hasNext()) {
					Entry<String, IDestroyableObject> object = interator.next();
					try {
						object.getValue().fullyDestroy();
						Logger.debug("Object with ID:" + object.getKey() + " is destroyed");
						
					} catch (Exception e) {
						Logger.warn("Destroing object with ID:" + object.getKey() + " FAILED!", e);
						
					}										
				}				
			}						
			Logger.info("Object cleanUp complete");
					
			Logger.debug("Stopping Spring Thread-Pools ... ");		
			//shut-down task schedulers
			Map<String, ThreadPoolTaskScheduler> schedulers = context.getBeansOfType(ThreadPoolTaskScheduler.class);
		    for (ThreadPoolTaskScheduler scheduler : schedulers.values()) {         
		        scheduler.getScheduledExecutor().shutdown();
		        try {
		            scheduler.getScheduledExecutor().awaitTermination(20000, TimeUnit.MILLISECONDS);
		            if(scheduler.getScheduledExecutor().isTerminated() || scheduler.getScheduledExecutor().isShutdown())
		                Logger.debug("Scheduler "+scheduler.getThreadNamePrefix() + " has stoped");
		            else{
		            	Logger.debug("Scheduler "+scheduler.getThreadNamePrefix() + " has not stoped normally and will be shut down immediately");
		                scheduler.getScheduledExecutor().shutdownNow();
		                Logger.info("Scheduler "+scheduler.getThreadNamePrefix() + " has shut down immediately");
		            }
		        } catch (IllegalStateException e) {
		            e.printStackTrace();
		        } catch (InterruptedException e) {
		            e.printStackTrace();
		            
		        } finally {
					scheduler.shutdown();
		        	
				}
		    }
			
		  //shut-down task executors
		    Map<String, ThreadPoolTaskExecutor> executers = context.getBeansOfType(ThreadPoolTaskExecutor.class);
		    for (ThreadPoolTaskExecutor executor: executers.values()) {
		        int retryCount = 0;
		        while(executor.getActiveCount()>0 && ++retryCount<51){
		            try {
		            	Logger.debug("Executer "+executor.getThreadNamePrefix()+" is still working with active " + executor.getActiveCount()+" work. Retry count is "+retryCount);
		                Thread.sleep(1000);
		            } catch (InterruptedException e) {
		                e.printStackTrace();
		            }
		        }
		        if(!(retryCount<51))
		        	Logger.debug("Executer "+executor.getThreadNamePrefix()+" is still working.Since Retry count exceeded max value "+retryCount+", will be killed immediately");
		        executor.shutdown();
		        Logger.debug("Executer "+executor.getThreadNamePrefix()+" with active " + executor.getActiveCount()+" work has killed");
		    }
			
			Logger.debug("Spring Thread-Pools stopped");
			
			Logger.info("MOA-ID-Auth shutdown process finished");
			
		} catch (Exception e) {
			Logger.warn("MOA-ID-Auth shutdown process has an error.", e);
			
		}
		
		//System.exit(0);
		//Thread.currentThread().interrupt();		
		
	}

	/* (non-Javadoc)
	 * @see org.springframework.beans.factory.config.BeanPostProcessor#postProcessAfterInitialization(java.lang.Object, java.lang.String)
	 */
	@Override
	public Object postProcessAfterInitialization(Object arg0, String arg1) throws BeansException {
		if(arg0 instanceof ThreadPoolTaskScheduler)
	        ((ThreadPoolTaskScheduler)arg0).setWaitForTasksToCompleteOnShutdown(true);
	    if(arg0 instanceof ThreadPoolTaskExecutor)
	        ((ThreadPoolTaskExecutor)arg0).setWaitForTasksToCompleteOnShutdown(true);
	    return arg0;
	    
	}

	/* (non-Javadoc)
	 * @see org.springframework.beans.factory.config.BeanPostProcessor#postProcessBeforeInitialization(java.lang.Object, java.lang.String)
	 */
	@Override
	public Object postProcessBeforeInitialization(Object arg0, String arg1) throws BeansException {
		return arg0;
		
	}

	/* (non-Javadoc)
	 * @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.ApplicationContext)
	 */
	@Override
	public void setApplicationContext(ApplicationContext arg0) throws BeansException {
		this.context = arg0;
		
	}

}