/*
    * Copyright (c) 2002-2014, Mairie de Paris
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    *
    *  1. Redistributions of source code must retain the above copyright notice
   *     and the following disclaimer.
   *
   *  2. Redistributions in binary form must reproduce the above copyright notice
   *     and the following disclaimer in the documentation and/or other materials
   *     provided with the distribution.
   *
   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
   *     contributors may be used to endorse or promote products derived from
   *     this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * License 1.0
   */
  package fr.paris.lutece.portal.service.filter;
  
  import fr.paris.lutece.portal.service.util.AppLogService;
  import fr.paris.lutece.util.sql.TransactionManager;
  
  import java.io.IOException;
  
  import javax.servlet.Filter;
  import javax.servlet.FilterChain;
  import javax.servlet.FilterConfig;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  
  /**
   * MainFilter
   */
  public class MainFilter implements Filter
  {
      /**
       * {@inheritDoc}
       */
      public void init( FilterConfig config ) throws ServletException
      {
          FilterService.setServletContext( config.getServletContext(  ) );
      }
  
      /**
       * {@inheritDoc}
       */
      public void doFilter( ServletRequest requestServlet, ServletResponse responseServlet, FilterChain chain )
          throws IOException, ServletException
      {
          AppLogService.debug( "MainFilter : doFilter()" );
  
          HttpServletRequest request = (HttpServletRequest) requestServlet;
          HttpServletResponse response = (HttpServletResponse) responseServlet;
          LuteceFilterChain chainPluginsFilters = new LuteceFilterChain(  );
  
          for ( LuteceFilter filter : FilterService.getInstance(  ).getFilters(  ) )
          {
              AppLogService.debug( "PluginFilter : " + filter.getName(  ) + " - url pattern : " +
                  filter.getMappingUrlPattern(  ) );
  
              // Catch exception for each filter to execute all chain
              try
              {
                  // Checks mapping and plugin status
                  if ( matchMapping( filter, request ) && filter.getPlugin(  ).isInstalled(  ) )
                  {
                      chainPluginsFilters.setFollowChain( false );
                      filter.getFilter(  ).doFilter( request, response, chainPluginsFilters );
  
                      if ( !chainPluginsFilters.shouldFollowChain(  ) )
                      {
                          // The filter didn't call chain.doFilter so the chain should be interrupted
                          return;
                      }
  
                      // the filter may have changed (wrapped) the request [like CAS filter] or the response
                      request = (HttpServletRequest) chainPluginsFilters.getRequest(  );
                      response = (HttpServletResponse) chainPluginsFilters.getResponse(  );
                  }
             }
             catch ( Exception e )
             {
                 AppLogService.error( "Error execution doFilter method - Filter " + filter.getName(  ), e );
             }
         }
 
         // Follow the standard filters chain
         chain.doFilter( request, response );
         // We check that some transactions is not still running for the current thread
         TransactionManager.rollBackEveryTransaction(  );
     }
 
     /**
      * {@inheritDoc}
      */
     public void destroy(  )
     {
         for ( LuteceFilter filter : FilterService.getInstance(  ).getFilters(  ) )
         {
             // Catch exception for each filter to execute all chain
             try
             {
                 // Checks mapping and plugin status
                 if ( filter.getPlugin(  ).isInstalled(  ) )
                 {
                     filter.getFilter(  ).destroy(  );
                 }
             }
             catch ( Exception e )
             {
                 AppLogService.error( "Error execution destroy() method - Filter " + filter.getName(  ), e );
             }
         }
     }
 
     /**
      * Check the mapping of the request with an url pattern
      * @param filter The filter
      * @param request The request
      * @return True if the request match the url pattern
      */
     boolean matchMapping( LuteceFilter filter, HttpServletRequest request )
     {
         return matchFilterUrl( filter.getMappingUrlPattern(  ), request.getServletPath(  ) );
     }
 
     /**
      * Check the mapping of the request with an url pattern according servlet
      * specifications 2.3 rules
      * @param strUrlPattern The filter url pattern
      * @param strRequestUrl The request Url
      * @return True if the request match the url pattern
      *
      *         Algorithm comming from tomcat6
      */
     boolean matchFilterUrl( String strUrlPattern, String strRequestUrl )
     {
         if ( strUrlPattern == null )
         {
             return ( false ); // Case 1 - Exact Match
         }
 
         if ( strUrlPattern.equals( strRequestUrl ) )
         {
             return ( true ); // Case 2 - Path Match ("/.../*")
         }
 
         if ( strUrlPattern.equals( "/*" ) )
         {
             return ( true );
         }
 
         if ( strUrlPattern.endsWith( "/*" ) )
         {
             if ( strUrlPattern.regionMatches( 0, strRequestUrl, 0, strUrlPattern.length(  ) - 2 ) )
             {
                 if ( strRequestUrl.length(  ) == ( strUrlPattern.length(  ) - 2 ) )
                 {
                     return ( true );
                 }
                 else if ( '/' == strRequestUrl.charAt( strUrlPattern.length(  ) - 2 ) )
                 {
                     return ( true );
                 }
             }
 
             return ( false );
         }
 
         // Case 3 - Extension Match
         if ( strUrlPattern.startsWith( "*." ) )
         {
             int slash = strRequestUrl.lastIndexOf( '/' );
             int period = strRequestUrl.lastIndexOf( '.' );
 
             if ( ( slash >= 0 ) && ( period > slash ) && ( period != ( strRequestUrl.length(  ) - 1 ) ) &&
                     ( ( strRequestUrl.length(  ) - period ) == ( strUrlPattern.length(  ) - 1 ) ) )
             {
                 return ( strUrlPattern.regionMatches( 2, strRequestUrl, period + 1, strUrlPattern.length(  ) - 2 ) );
             }
         }
 
         // Case 4 - "Default" Match
         return ( false ); // NOTE - Not relevant for selecting filters
     }
 }