// ========================================================================
   // Copyright (c) 2003-2009 Mort Bay Consulting Pty. Ltd.
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
   // The Apache License v2.0 is available at
  // http://www.opensource.org/licenses/apache2.0.php
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.webapp;
  
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.Collections;
  
  import org.eclipse.jetty.security.ConstraintAware;
  import org.eclipse.jetty.security.ConstraintMapping;
  import org.eclipse.jetty.security.SecurityHandler;
  import org.eclipse.jetty.servlet.ErrorPageErrorHandler;
  import org.eclipse.jetty.servlet.ServletHandler;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.resource.Resource;
  
  /* ------------------------------------------------------------------------------- */
  /**
   * Configure by parsing default web.xml and web.xml
   * 
   */
  public class WebXmlConfiguration implements Configuration
  {
      
      /* ------------------------------------------------------------------------------- */
      /**
       * Process webdefaults.xml
       * 
       * 
       */
      public void preConfigure (WebAppContext context) throws Exception
      {
          // cannot configure if the context is already started
          if (context.isStarted())
          {
              if (Log.isDebugEnabled())
              {
                  Log.debug("Cannot configure webapp after it is started");
              }
              return;
          }
          
          //Get or create a processor to handle webdefaults, web.xml and the fragments
          WebXmlProcessor processor = (WebXmlProcessor)context.getAttribute(WebXmlProcessor.WEB_PROCESSOR); 
          if (processor == null)
          {
              processor = new WebXmlProcessor (context);
              context.setAttribute(WebXmlProcessor.WEB_PROCESSOR, processor);
          }
          
          //handle webdefault.xml
          String defaultsDescriptor = context.getDefaultsDescriptor();
          if (defaultsDescriptor != null && defaultsDescriptor.length() > 0)
          {
              Resource dftResource = Resource.newSystemResource(defaultsDescriptor);
              if (dftResource == null) 
                  dftResource = context.newResource(defaultsDescriptor);
              processor.parseDefaults (dftResource);
              processor.processDefaults();
          }
          
          //parse, but don't process web.xml
          Resource webxml = findWebXml(context);
          if (webxml != null) 
          {      
              processor.parseWebXml(webxml);
          }
      }
  
      /* ------------------------------------------------------------------------------- */
      /**
       * Process web.xml, web-fragment.xml(s), override-web.xml
       * 
       */
      public void configure (WebAppContext context) throws Exception
      {
          // cannot configure if the context is already started
          if (context.isStarted())
          {
              if (Log.isDebugEnabled()) Log.debug("Cannot configure webapp after it is started");
              return;
          }
          
          WebXmlProcessor processor = (WebXmlProcessor)context.getAttribute(WebXmlProcessor.WEB_PROCESSOR); 
          if (processor == null)
          {
              processor = new WebXmlProcessor (context);
              context.setAttribute(WebXmlProcessor.WEB_PROCESSOR, processor);
         }
 
         //process web.xml (the effective web.xml???)
         processor.processWebXml();
         
         //process override-web.xml
         String overrideDescriptor = context.getOverrideDescriptor();
         if (overrideDescriptor != null && overrideDescriptor.length() > 0)
         {
             Resource orideResource = Resource.newSystemResource(overrideDescriptor);
             if (orideResource == null) 
                 orideResource = context.newResource(overrideDescriptor);
             processor.parseOverride(orideResource);
             processor.processOverride();
         }
     }
 
     public void postConfigure(WebAppContext context) throws Exception
     {
         context.setAttribute(WebXmlProcessor.WEB_PROCESSOR, null); 
         context.setAttribute(WebXmlProcessor.METADATA_COMPLETE, null);
         context.setAttribute(WebXmlProcessor.WEBXML_VERSION, null);
         context.setAttribute(WebXmlProcessor.WEBXML_CLASSNAMES, null); 
     }
 
     /* ------------------------------------------------------------------------------- */
     protected Resource findWebXml(WebAppContext context) throws IOException, MalformedURLException
     {
         String descriptor = context.getDescriptor();
         if (descriptor != null)
         {
             Resource web = context.newResource(descriptor);
             if (web.exists() && !web.isDirectory()) return web;
         }
 
         Resource web_inf = context.getWebInf();
         if (web_inf != null && web_inf.isDirectory())
         {
             // do web.xml file
             Resource web = web_inf.addPath("web.xml");
             if (web.exists()) return web;
             Log.debug("No WEB-INF/web.xml in " + context.getWar() + ". Serving files and default/dynamic servlets only");
         }
         return null;
     }
 
 
     /* ------------------------------------------------------------------------------- */
     public void deconfigure (WebAppContext context) throws Exception
     {
         // TODO preserve any configuration that pre-existed.
 
         ServletHandler _servletHandler = context.getServletHandler();
         SecurityHandler _securityHandler = (SecurityHandler)context.getSecurityHandler();
        
         _servletHandler.setFilters(null);
         _servletHandler.setFilterMappings(null);
         _servletHandler.setServlets(null);
         _servletHandler.setServletMappings(null);
 
         context.setEventListeners(null);
         context.setWelcomeFiles(null);
         if (_securityHandler instanceof ConstraintAware) 
             ((ConstraintAware) _securityHandler).setConstraintMappings(new ConstraintMapping[]{}, Collections.EMPTY_SET);
 
         if (context.getErrorHandler() instanceof ErrorPageErrorHandler)
             ((ErrorPageErrorHandler) 
                     context.getErrorHandler()).setErrorPages(null);
 
 
         // TODO remove classpaths from classloader
 
     }
 }