/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
    *
   * 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.argeo.slc.unit;
  
  import java.util.Map;
  
  import junit.framework.TestCase;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.argeo.slc.SlcException;
  import org.springframework.beans.factory.BeanFactoryUtils;
  import org.springframework.beans.factory.ListableBeanFactory;
  import org.springframework.context.ConfigurableApplicationContext;
  import org.springframework.context.support.ClassPathXmlApplicationContext;
  
  /** Helper for tests using a Spring application co,text. */
  public abstract class AbstractSpringTestCase extends TestCase {
  	protected final Log log = LogFactory.getLog(getClass());
  	private ConfigurableApplicationContext context;
  
  	/**
  	 * Gets (and create if necessary) the application context to use. Default
  	 * implementation uses a class path xml application context and calls
  	 * {@link #getApplicationContextLocation()}.
  	 */
  	protected ConfigurableApplicationContext getContext() {
  		if (context == null) {
  			context = new ClassPathXmlApplicationContext(
  					getApplicationContextLocation());
  			if (getIsStartContext())
  				context.start();
  		}
  		return context;
  	}
  
  	@Override
  	protected void tearDown() throws Exception {
  		if (context != null && context.isActive())
  			context.close();
  		super.tearDown();
  	}
  
  	/** Whether the context should be started after being created. */
  	protected Boolean getIsStartContext() {
  		return false;
  	}
  
  	/** Returns a bean from the underlying context */
  	@SuppressWarnings(value = { "unchecked" })
  	protected <T> T getBean(String beanId) {
  		return (T) getContext().getBean(beanId);
  	}
  
  	protected <T> T getBean(Class<? extends T> clss) {
  		T bean = loadSingleFromContext(getContext(), clss);
  		if (bean == null) {
  			throw new SlcException("Cannot retrieve a unique bean of type "
  					+ clss);
  		} else {
  			return bean;
  		}
  	}
  
  	/**
  	 * Th location of the application to load. The default implementation
  	 * returns <i>applicationContext.xml</i> found in the same package as the
  	 * test.
  	 */
  	protected String getApplicationContextLocation() {
  		return inPackage("applicationContext.xml");
  	}
  
  	/**
  	 * Prefixes the package of the class after converting the '.' to '/' in
  	 * order to have a resource path.
  	 */
  	protected String inPackage(String suffix) {
  		String prefix = getClass().getPackage().getName().replace('.', '/');
  		return prefix + '/' + suffix;
  	}
  
  	@SuppressWarnings(value = { "unchecked" })
  	protected <T> T loadSingleFromContext(ListableBeanFactory context,
  			Class<T> clss) {
  		Map<String, T> beans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
 				context, clss, false, false);
 		if (beans.size() == 1) {
 			return beans.values().iterator().next();
 		} else if (beans.size() > 1) {
 			if (log.isDebugEnabled()) {
 				log
 						.debug(("Found more that on bean for type " + clss
 								+ ": " + beans.keySet()));
 			}
 			return null;
 		} else {
 			return null;
 		}
 	}
 
 }