/*
    * 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.util.mvc.utils;
  
  import fr.paris.lutece.portal.util.mvc.commons.annotations.Action;
  import fr.paris.lutece.portal.util.mvc.commons.annotations.View;
  
  import org.apache.log4j.Logger;
  
  import java.lang.reflect.Method;
  
  import java.util.Enumeration;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  
  /**
   * Utils for MVC components
   */
  public final class MVCUtils
  {
      public static final String PARAMETER_VIEW = "view";
      public static final String PARAMETER_ACTION = "action";
      public static final String PARAMETER_PAGE = "page";
      private static final String PREFIX_VIEW = "view_";
      private static final String PREFIX_ACTION = "action_";
      private static Logger _logger = Logger.getLogger( "lutece.mvc" );
  
      /**
       * Private constructor
       */
      private MVCUtils(  )
      {
      }
  
      /**
       * Get the view parameter
       * @param request The HTTP request
       * @return The view parameter or null if not found
       */
      public static String getView( HttpServletRequest request )
      {
          String strView = request.getParameter( PARAMETER_VIEW );
  
          if ( strView != null )
          {
              return strView;
          }
  
          Enumeration<String> parameters = request.getParameterNames(  );
  
          while ( parameters.hasMoreElements(  ) )
          {
              String strParameter = parameters.nextElement(  );
  
              if ( strParameter.startsWith( PREFIX_VIEW ) )
              {
                  strView = strParameter.substring( PREFIX_VIEW.length(  ) );
  
                  break;
              }
          }
  
          return strView;
      }
  
      /**
      * Get the action parameter or any parameter with the prefix 'action_'
      * @param request The HTTP request
      * @return The action parameter or null if not found
      */
     public static String getAction( HttpServletRequest request )
     {
         String strAction = request.getParameter( PARAMETER_ACTION );
 
         if ( strAction != null )
         {
             return strAction;
         }
 
         Enumeration<String> parameters = request.getParameterNames(  );
 
         while ( parameters.hasMoreElements(  ) )
         {
             String strParameter = parameters.nextElement(  );
 
             if ( strParameter.startsWith( PREFIX_ACTION ) )
             {
                 strAction = strParameter.substring( PREFIX_ACTION.length(  ) );
 
                 break;
             }
         }
 
         return strAction;
     }
 
     /**
      * Find the method that provide a given view
      * @param request The HTTP request
      * @param methods The methods list
      * @return The method
      */
     public static Method findViewAnnotedMethod( HttpServletRequest request, Method[] methods )
     {
         String strView = getView( request );
 
         if ( strView != null )
         {
             for ( Method m : methods )
             {
                 if ( m.isAnnotationPresent( View.class ) && strView.equals( m.getAnnotation( View.class ).value(  ) ) )
                 {
                     _logger.debug( "MVC controller - process view : '" + strView + "'" );
 
                     return m;
                 }
             }
 
             _logger.warn( "MVC controller - No method found to process view : '" + strView + "'" );
         }
 
         return null;
     }
 
     /**
      * Find the method that provide a given action
      * @param request The HTTP request
      * @param methods The methods list
      * @return The method
      */
     public static Method findActionAnnotedMethod( HttpServletRequest request, Method[] methods )
     {
         String strAction = getAction( request );
 
         if ( strAction != null )
         {
             for ( Method m : methods )
             {
                 if ( m.isAnnotationPresent( Action.class ) &&
                         strAction.equals( m.getAnnotation( Action.class ).value(  ) ) )
                 {
                     _logger.debug( "MVC controller - process action : '" + strAction + "'" );
 
                     return m;
                 }
             }
 
             _logger.warn( "MVC controller - No method found to process action : '" + strAction + "'" );
         }
 
         return null;
     }
 
     /**
      * Find the method that provide the default view
      * @param methods The methods list
      * @return The method
      */
     public static Method findDefaultViewMethod( Method[] methods )
     {
         for ( Method m : methods )
         {
             if ( m.isAnnotationPresent( View.class ) && m.getAnnotation( View.class ).defaultView(  ) )
             {
                 _logger.debug( "MVC controller - process default view" );
 
                 return m;
             }
         }
 
         _logger.error( "MVC controller - No default view found" );
 
         return null;
     }
 
     /**
      * Add download headers to the response
      * @param response The response
      * @param strFilename The name of the file to download
      * @param strContentType The content type of the downloaded file
      */
     public static void addDownloadHeaderToResponse( HttpServletResponse response, String strFilename,
         String strContentType )
     {
         response.setHeader( "Content-Disposition", "attachment; filename=\"" + strFilename + "\";" );
         response.setHeader( "Content-type", strContentType );
         response.addHeader( "Content-Encoding", "UTF-8" );
         response.addHeader( "Pragma", "public" );
         response.addHeader( "Expires", "0" );
         response.addHeader( "Cache-Control", "must-revalidate,post-check=0,pre-check=0" );
     }
 
     /**
      * Return the MVC logger
      * @return THe logger
      */
     public static Logger getLogger(  )
     {
         return _logger;
     }
 }