/**
    * This file Copyright (c) 2010-2011 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.module.blossom.support;
  
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.springframework.beans.factory.DisposableBean;
  import org.springframework.beans.factory.config.BeanPostProcessor;
  import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  import org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor;
  import org.springframework.beans.factory.support.AbstractBeanFactory;
  import org.springframework.beans.factory.support.BeanDefinitionBuilder;
  import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
  import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  
  /**
   * Utility methods for BeanFactory.
   *
   * @since 1.2
   */
  public class BeanFactoryUtils {
  
      private static final Log logger = LogFactory.getLog(BeanFactoryUtils.class);
  
      /**
       * Destroys a bean by applying destruction aware post processors and invoking destroy methods.
       */
      public static void destroyBean(Object bean, String beanName, AbstractBeanFactory beanFactory) {
          applyBeanPostProcessorsBeforeDestruction(bean, beanName, beanFactory);
          disposeBean(bean, beanName);
      }
  
      /**
       * Invokes destroy method on the bean if it implements DisposableBean.
       */
      public static void disposeBean(Object bean, String beanName) {
          if (bean instanceof DisposableBean) {
              try {
                  ((DisposableBean) bean).destroy();
              } catch (Throwable ex) {
                  String msg = "Invocation of destroy method failed on bean with name '" + beanName + "'";
                  if (logger.isDebugEnabled()) {
                      logger.warn(msg, ex);
                  } else {
                      logger.warn(msg + ": " + ex);
                  }
              }
          }
      }
  
      /**
       * Applies destruction aware post processors on the supplied bean.
       */
      public static void applyBeanPostProcessorsBeforeDestruction(Object bean, String beanName, AbstractBeanFactory beanFactory) {
          List<BeanPostProcessor> beanPostProcessors = beanFactory.getBeanPostProcessors();
          if (beanPostProcessors != null && !beanPostProcessors.isEmpty()) {
              for (int i = beanPostProcessors.size() - 1; i >= 0; i--) {
                  Object postProcessor = beanPostProcessors.get(i);
                  if (postProcessor instanceof DestructionAwareBeanPostProcessor) {
                      ((DestructionAwareBeanPostProcessor) postProcessor).postProcessBeforeDestruction(bean, beanName);
                  }
              }
          }
      }
  
      /**
      * Registers a bean definition for the specified class if no bean definition already exists for the class. The bean
      * definition is given a generated name unique within the bean factory.
      */
     public static void registerBeanIfMissing(ConfigurableListableBeanFactory beanFactory, BeanDefinitionRegistry registry, Class<?> beanClass) {
         if (beanFactory.getBeanNamesForType(beanClass).length == 0) {
             BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(beanClass);
             BeanDefinitionReaderUtils.registerWithGeneratedName(builder.getBeanDefinition(), registry);
         }
     }
 }