/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.myfaces.webapp;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.config.FacesConfigValidator;
  import org.apache.myfaces.config.FacesConfigurator;
  import org.apache.myfaces.context.servlet.ServletExternalContextImpl;
  import org.apache.myfaces.shared_impl.util.StateUtils;
  import org.apache.myfaces.shared_impl.webapp.webxml.WebXml;
  
  import javax.faces.FactoryFinder;
  import javax.faces.context.ExternalContext;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletContextEvent;
  import javax.servlet.ServletContextListener;
  import java.util.Iterator;
  import java.util.List;
  
  /**
   * Initialise the MyFaces system.
   * <p>
   * This context listener is registered by the JSP TLD file for the standard
   * JSF "f" components. Normally, servlet containers will automatically load
   * and process .tld files at startup time, and therefore register and run
   * this class automatically.
   * <p>
   * Some very old servlet containers do not do this correctly, so in those
   * cases this listener may be registered manually in web.xml. Registering
   * it twice (ie in both .tld and web.xml) will result in a harmless warning
   * message being generated. Very old versions of MyFaces Core do not register
   * the listener in the .tld file, so those also need a manual entry in web.xml.
   * However all versions since at least 1.1.2 have this entry in the tld.
   * 
   * @author Manfred Geiler (latest modification by $Author: lu4242 $)
   * @version $Revision: 952074 $ $Date: 2010-06-06 22:14:18 -0500 (Sun, 06 Jun 2010) $
   */
  public class StartupServletContextListener
          implements ServletContextListener
  {
      private static final Log log = LogFactory.getLog(StartupServletContextListener.class);
  
      static final String FACES_INIT_DONE
              = StartupServletContextListener.class.getName() + ".FACES_INIT_DONE";
  
      public void contextInitialized(ServletContextEvent event)
      {
          initFaces(event.getServletContext());
      }
  
      public static void initFaces(ServletContext servletContext)
      {
          try
          {
              Boolean b = (Boolean)servletContext.getAttribute(FACES_INIT_DONE);
  
              if (b == null || b.booleanValue() == false)
              {
                  log.trace("Initializing MyFaces");
  
                  //Load the configuration
                  ExternalContext externalContext = new ServletExternalContextImpl(servletContext, null, null);
  
                  //And configure everything
                  new FacesConfigurator(externalContext).configure();
  
                  if ("true".equals(servletContext
                                  .getInitParameter(FacesConfigValidator.VALIDATE_CONTEXT_PARAM)) || "true".equals(servletContext
                                  .getInitParameter(FacesConfigValidator.VALIDATE_CONTEXT_PARAM.toLowerCase())))
                  {
                      List list = FacesConfigValidator.validate(externalContext,
                              servletContext.getRealPath("/"));
  
                      Iterator iterator = list.iterator();
  
                      while (iterator.hasNext())
                          log.warn(iterator.next());
  
                  }
                  
                  // parse web.xml
                  WebXml.init(externalContext);
 
                 servletContext.setAttribute(FACES_INIT_DONE, Boolean.TRUE);
             }
             else
             {
                 log.info("MyFaces already initialized");
             }
         }
         catch (Exception ex)
         {
             log.error("Error initializing ServletContext", ex);
             ex.printStackTrace();
         }
         log.info("ServletContext '" + servletContext.getRealPath("/") + "' initialized.");
         
         String useEncryption = servletContext.getInitParameter(StateUtils.USE_ENCRYPTION);
         if (!"false".equals(useEncryption)){ // the default value is true
             StateUtils.initSecret(servletContext);
         }
 
     }
 
 
     public void contextDestroyed(ServletContextEvent e)
     {
         FactoryFinder.releaseFactories();
     }
 }