/**
    * Copyright 2005-2015 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.ksb.messaging.threadpool;
  
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.api.config.property.ConfigContext;
  import org.kuali.rice.ksb.util.KSBConstants;
  
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledThreadPoolExecutor;
  import java.util.concurrent.ThreadFactory;
  import java.util.concurrent.TimeUnit;
  
  public class KSBScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor implements KSBScheduledPool {
  
  	private static final Logger LOG = Logger.getLogger(KSBScheduledThreadPoolExecutor.class);
  
  	private boolean started;
  	private static final int DEFAULT_SIZE = 2;
  
  	public KSBScheduledThreadPoolExecutor() {
  		super(DEFAULT_SIZE, new KSBThreadFactory());
  	}
  
  	public boolean isStarted() {
  		return started;
  	}
  
  	public void start() throws Exception {
  		LOG.info("Starting the KSB scheduled thread pool...");
  		try {
  			Integer size = new Integer(ConfigContext.getCurrentContextConfig().getProperty(KSBConstants.Config.FIXED_POOL_SIZE));
  			this.setCorePoolSize(size);
  		} catch (NumberFormatException nfe) {
  			// ignore this, instead the pool will be set to DEFAULT_SIZE
  		}
  		LOG.info("...KSB scheduled thread pool successfully started.");
  	}
  
  	public void stop() throws Exception {
  		LOG.info("Stopping the KSB scheduled thread pool...");
  		try {
              int pendingTasks = this.shutdownNow().size();
              LOG.info(pendingTasks + " pending tasks...");
  			LOG.info("awaiting termination: " + this.awaitTermination(20, TimeUnit.SECONDS));
  			LOG.info("...KSB scheduled thread pool successfully stopped, isShutdown=" + this.isShutdown() + ", isTerminated=" + this.isTerminated());
  		} catch (Exception e) {
  			LOG.warn("Exception thrown shutting down " + KSBScheduledThreadPoolExecutor.class.getSimpleName(), e);
  		}
  
  	}
  	
  	private static class KSBThreadFactory implements ThreadFactory {
  		
  		private ThreadFactory defaultThreadFactory = Executors.defaultThreadFactory();
  		
  		public Thread newThread(Runnable runnable) {
  			Thread thread = defaultThreadFactory.newThread(runnable);
  			thread.setName("KSB-Scheduled-" + thread.getName());
  			return thread;
  	    }
  	}
  
  }