/*
    * Copyright 2005-2008 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.resourceloader;
  
  import javax.xml.namespace.QName;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.config.ConfigurationException;
  import org.springframework.context.ApplicationContext;
  import org.springframework.context.ConfigurableApplicationContext;
  import org.springframework.context.support.ClassPathXmlApplicationContext;
  
  /**
   * A simple {@link ResourceLoader} which wraps a Spring {@link ConfigurableApplicationContext}.
   *
   * Starts and stops the {@link ConfigurableApplicationContext}.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class SpringResourceLoader extends BaseResourceLoader {
  
  	private static final Logger LOG = Logger.getLogger(SpringResourceLoader.class);
  
  	private SpringResourceLoader parentSpringResourceLoader;
  	
  	private ApplicationContext parentContext;
  	private ConfigurableApplicationContext context;
  
  	private final String[] fileLocs;
  
  	public SpringResourceLoader(QName name, String fileLoc) {
  	    this(name, new String[] { fileLoc });
  	}
  
  	public SpringResourceLoader(QName name, String[] fileLocs) {
  		super(name);
  		this.fileLocs = fileLocs;
  	}
  
  	public Object getService(QName serviceName) {
  	    	if (!isStarted()) {
  	    	    return null;
  	    	}
  		if (this.getContext().containsBean(serviceName.toString())) {
  			Object service = this.getContext().getBean(serviceName.toString());
  			return postProcessService(serviceName, service);
  		}
  		return super.getService(serviceName);
  	}
  
  	@Override
  	public void start() throws Exception {
  		if(!isStarted()){
  			LOG.info("Creating Spring context " + StringUtils.join(this.fileLocs, ","));
  			if (parentSpringResourceLoader != null && parentContext != null) {
  				throw new ConfigurationException("Both a parentSpringResourceLoader and parentContext were defined.  Only one can be defined!");
  			}
  			if (parentSpringResourceLoader != null) {
  				parentContext = parentSpringResourceLoader.getContext();
  			}
  			this.context = new ClassPathXmlApplicationContext(this.fileLocs, parentContext);
  			super.start();
  		}
  	}
  
  	@Override
  	public void stop() throws Exception {
  		LOG.info("Stopping Spring context " + StringUtils.join(this.fileLocs, ","));
  		this.context.close();
  		super.stop();
  	}
  
  	public ConfigurableApplicationContext getContext() {
  		return this.context;
  	}
  	
  	public void setParentContext(ApplicationContext parentContext) {
  		this.parentContext = parentContext;
  	}
  
  	public void setParentSpringResourceLoader(
  			SpringResourceLoader parentSpringResourceLoader) {
  		this.parentSpringResourceLoader = parentSpringResourceLoader;
  	}
 	
 	
 
 }