/*
    * 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.cms.spring;
  
  import java.security.AccessController;
  import java.security.PrivilegedAction;
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.security.auth.Subject;
  
  import org.eclipse.gemini.blueprint.context.DependencyInitializationAwareBeanPostProcessor;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.factory.support.AbstractBeanFactory;
  import org.springframework.beans.factory.support.SecurityContextProvider;
  import org.springframework.beans.factory.support.SimpleSecurityContextProvider;
  import org.springframework.context.ApplicationContext;
  import org.springframework.context.ApplicationContextAware;
  
  /**
   * Executes with a system authentication the instantiation and initialization
   * methods of the application context where it has been defined.
   */
  public class AuthenticatedApplicationContextInitialization extends
  		AbstractSystemExecution implements
  		DependencyInitializationAwareBeanPostProcessor, ApplicationContextAware {
  	/** If non empty, restricts to these beans */
  	private List<String> beanNames = new ArrayList<String>();
  
  	public Object postProcessBeforeInitialization(Object bean, String beanName)
  			throws BeansException {
  		if (beanNames.size() == 0 || beanNames.contains(beanName))
  			authenticateAsSystem();
  		return bean;
  	}
  
  	public Object postProcessAfterInitialization(Object bean, String beanName)
  			throws BeansException {
  		if (beanNames.size() == 0 || beanNames.contains(beanName))
  			deauthenticateAsSystem();
  		return bean;
  	}
  
  	public void setBeanNames(List<String> beanNames) {
  		this.beanNames = beanNames;
  	}
  
  	@Override
  	public void setApplicationContext(ApplicationContext applicationContext)
  			throws BeansException {
  		if (applicationContext.getAutowireCapableBeanFactory() instanceof AbstractBeanFactory) {
  			final AbstractBeanFactory beanFactory = ((AbstractBeanFactory) applicationContext
  					.getAutowireCapableBeanFactory());
  			// retrieve subject's access control context
  			// and set it as the bean factory security context
  			Subject.doAs(getSubject(), new PrivilegedAction<Void>() {
  				@Override
  				public Void run() {
  					SecurityContextProvider scp = new SimpleSecurityContextProvider(
  							AccessController.getContext());
  					beanFactory.setSecurityContextProvider(scp);
  					return null;
  				}
  			});
  		}
  	}
  }