/**
    * 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.krad.config;
  
  import org.kuali.rice.core.api.config.ConfigurationException;
  import org.kuali.rice.core.api.resourceloader.GlobalResourceLoader;
  import org.springframework.beans.factory.FactoryBean;
  import org.springframework.beans.factory.InitializingBean;
  
  /**
   * Exports services in the {@link org.kuali.rice.core.api.resourceloader.GlobalResourceLoader} as beans available to Spring.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   *
   */
  public class GlobalResourceLoaderServiceFactoryBean implements FactoryBean<Object>, InitializingBean {
  
  	private String serviceName;
  	private boolean singleton;
  	private boolean mustExist;
  
  	// used to prevent a stack overflow when trying to get the service
  	private boolean isFetchingService = false;
  	
  	public GlobalResourceLoaderServiceFactoryBean() {
  		this.mustExist = true;
  	}
  	
  	public Object getObject() throws Exception {
  		if (isFetchingService) return null; // we already have been invoked, don't recurse, just return null.
  		isFetchingService = true;
  		try {
  			Object service = GlobalResourceLoader.getService(this.getServiceName());
  			if (mustExist && service == null) {
  				throw new IllegalStateException("Service must exist and no service could be located with name: " + this.getServiceName());
  			}
  			return service;
  		} finally {
  			isFetchingService = false;
  		}
  	}
  
  	public Class<?> getObjectType() {
  		return Object.class;
  	}
  
  	public boolean isSingleton() {
  		return singleton;
  	}
  
  	public String getServiceName() {
  		return serviceName;
  	}
  
  	public void setServiceName(String serviceName) {
  		this.serviceName = serviceName;
  	}
  
  	public void setSingleton(boolean singleton) {
  		this.singleton = singleton;
  	}
  	
  	public boolean isMustExist() {
  		return mustExist;
  	}
  	
  	public void setMustExist(boolean mustExist) {
  		this.mustExist = mustExist;
  	}
  	
  
  	public void afterPropertiesSet() throws Exception {
  		if (this.getServiceName() == null) {
  			throw new ConfigurationException("No serviceName given.");
  		}
  	}
  
  }