/**
    * Copyright 2005-2011 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.core.impl.lifecycle;
  
  import javax.xml.namespace.QName;
  
  import org.kuali.rice.core.api.lifecycle.BaseLifecycle;
  import org.kuali.rice.core.api.lifecycle.Lifecycle;
  import org.kuali.rice.core.api.resourceloader.GlobalResourceLoader;
  
  /**
   * A lifecycle that wraps a service.  This fetches and calls a lifecycle available
   * in the GRL and calls lifecycle methods on that.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ServiceDelegatingLifecycle extends BaseLifecycle {
  	
  	private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(BaseLifecycle.class);
  
  	private QName serviceName;
  
  	public ServiceDelegatingLifecycle(QName serviceName) {
  		this.serviceName = serviceName;
  	}
  
  	public ServiceDelegatingLifecycle(String serviceName) {
  		this(new QName(serviceName));
  	}
  
  	public void start() throws Exception {
  	    if (!isStarted()) {
  	        loadService(this.serviceName).start();
  	    }
  		super.start();
  	}
  
  	public void stop() throws Exception {
  	    if (isStarted()) {
  	    	try {
  	    		Lifecycle lifecycle = loadService(this.serviceName);
  	    		if (lifecycle == null) {
  	    			LOG.warn("Couldn't stop service, failed to locate service with name " + serviceName);
  	    		} else {
  	    			lifecycle.stop();
  	    		}
  	    	} catch (Exception e) {
  	    		LOG.warn("couldn't stop service " + this.serviceName);
  	    		throw e;
  	    	}
  	    }
  		super.stop();
  	}
  
  	protected Lifecycle loadService(QName serviceName) {
  	    Object service = GlobalResourceLoader.getService(serviceName);
  	    if (service == null) {
  	        return null;
  	    }
  	    if (!(service instanceof Lifecycle)) {
  	        throw new RuntimeException("Service with name " + serviceName + " does not implement the Lifecycle interface!");
  	    }
  	    return (Lifecycle) service;
  	}
  
  }