package at.asitplus.eidas.specific.connector;

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

import org.slf4j.Logger;
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.context.event.EventListener;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;

import at.gv.egiz.components.spring.api.IDestroyableObject;
import eu.eidas.auth.cache.IgniteInstanceInitializerSpecificCommunication;

/**
 * SpringContext CloseHandler.
 *
 * @author tlenz
 *
 */

public class SpringContextCloseHandler
    implements ApplicationListener<ContextClosedEvent>, ApplicationContextAware, BeanPostProcessor {

  private static final Logger log =
      org.slf4j.LoggerFactory.getLogger(SpringContextCloseHandler.class);

  private ApplicationContext context;

  /*
   * (non-Javadoc)
   *
   * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.
   * springframework.context. ApplicationEvent)
   */
  @Override
  @EventListener
  public void onApplicationEvent(final ContextClosedEvent arg0) {
    log.info("MS-specific eIDAS-Node shutdown process started ...");

    try {
      log.debug("CleanUp objects with implements the IDestroyable interface ... ");
      final Map<String, IDestroyableObject> objectsToDestroy =
          context.getBeansOfType(IDestroyableObject.class);
      internalIDestroyableObject(objectsToDestroy);
      log.info("Object cleanUp complete");

      log.debug("Stopping Spring Thread-Pools ... ");
      // shut-down task schedulers
      final Map<String, ThreadPoolTaskScheduler> schedulers =
          context.getBeansOfType(ThreadPoolTaskScheduler.class);
      internalThreadPoolTaskScheduler(schedulers);

      // shut-down task executors
      final Map<String, ThreadPoolTaskExecutor> executers =
          context.getBeansOfType(ThreadPoolTaskExecutor.class);
      internalThreadPoolTaskExecutor(executers);
      log.debug("Spring Thread-Pools stopped");
      
      
      //clean-up eIDAS node
      Map<String, IgniteInstanceInitializerSpecificCommunication> nodeIgnite = 
          context.getBeansOfType(IgniteInstanceInitializerSpecificCommunication.class);
      log.info("Find #{} Apache Ignite instances from eIDAS Ref. impl.", nodeIgnite.size());
      for (Entry<String, IgniteInstanceInitializerSpecificCommunication> el : nodeIgnite.entrySet()) {
        if (el.getValue().getInstance() != null) {
          el.getValue().getInstance().close();
          el.getValue().destroyInstance();
          log.debug("Shutdown Apache-Ignite: {}", el.getKey());
          
        }        
      }
            
      log.info("MS-specific eIDAS-Node shutdown process finished");

    } catch (final Exception e) {
      log.warn("MS-specific eIDAS-Node shutdown process has an error.", e);

    }

  }

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

  }

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

  }

  private void internalThreadPoolTaskExecutor(final Map<String, ThreadPoolTaskExecutor> executers) {
    for (final ThreadPoolTaskExecutor executor : executers.values()) {
      executor.shutdown();
      log.debug("Executer {} with active {} work has killed", executor.getThreadNamePrefix(),
          executor.getActiveCount());

    }

  }

  // Not required at the moment
  private void internalThreadPoolTaskScheduler(
      final Map<String, ThreadPoolTaskScheduler> schedulers) {
    log.trace("Stopping #{} task-schedulers", schedulers.size());
    
  }

  private void internalIDestroyableObject(final Map<String, IDestroyableObject> objectsToDestroy) {
    if (objectsToDestroy != null) {
      final Iterator<Entry<String, IDestroyableObject>> interator =
          objectsToDestroy.entrySet().iterator();
      while (interator.hasNext()) {
        final Entry<String, IDestroyableObject> object = interator.next();
        try {
          object.getValue().fullyDestroy();
          log.debug("Object with ID: {} is destroyed", object.getKey());

        } catch (final Exception e) {
          log.warn("Destroing object with ID: {} FAILED!", object.getKey(), null, e);

        }
      }
    }

  }

}