/*
    * 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.plugins.rss.service;
  
  import fr.paris.lutece.plugins.rss.business.RssFeed;
  import fr.paris.lutece.plugins.rss.business.RssFeedHome;
  import fr.paris.lutece.portal.service.resource.Resource;
  import fr.paris.lutece.portal.service.resource.ResourceLoader;
  import fr.paris.lutece.portal.service.util.AppLogService;
  import fr.paris.lutece.portal.service.util.AppPathService;
  import fr.paris.lutece.util.httpaccess.HttpAccess;
  import fr.paris.lutece.util.httpaccess.HttpAccessException;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.FileReader;
  import java.io.IOException;
  
  import java.sql.Timestamp;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Date;
  import java.util.Iterator;
  
  
  /**
   *
   * This class delivers RSS contents loaded from Internet Feeds
   */
  public class RssContentLoader implements ResourceLoader
  {
      private static final String PROPERTY_CACHE_DIRECTORY = "rss.content.service.cache.directory";
      private static final String FILE_EXT = ".xml";
      private static final int FETCH_OK = 0;
      private static final int FETCH_ERROR = 1;
  
      /**
       * Implementation of the ResourceLoader interface
       * @return A collection of resources
       */
      public Collection getResources(  )
      {
          ArrayList listRssContents = new ArrayList(  );
          Collection colRssFeeds = RssFeedHome.getRssFeeds(  );
          Iterator i = colRssFeeds.iterator(  );
  
          while ( i.hasNext(  ) )
          {
              RssFeed="../../../../../../fr/paris/lutece/plugins/rss/business/RssFeed.html#RssFeed">RssFeed rss = (RssFeed) i.next(  );
              Resource resource = getResource( "" + rss.getId(  ) );
              listRssContents.add( resource );
          }
  
          return listRssContents;
      }
  
      /**
       * Implementation of the ResourceLoader interface
       * @param strId The resource Id
       * @return The Resource
       */
      public Resource getResource( String strId )
      {
          RssContentrvice/RssContent.html#RssContent">RssContent rssContent = new RssContent(  );
          String strContent = getFromCacheFile( strId );
 
         if ( strContent == null )
         {
             int nId = Integer.parseInt( strId );
 
             try
             {
                 strContent = fetchRssFeed( nId );
             }
             catch ( RssParsingException ex )
             {
                 AppLogService.error( ex.getMessage(  ), ex );
             }
         }
 
         rssContent.setContent( strContent );
 
         return rssContent;
     }
 
     /**
      * Fetch an active RSS feed
      * @param nId The RSS feed Id
      * @return The content of the RSS feed
      * @throws RssParsingException If a parsing exception occurs
      */
     public static String fetchRssFeed( int nId ) throws RssParsingException
     {
         String strContent = null;
         RssFeed rss = RssFeedHome.findByPrimaryKey( nId, true );
         HttpAccess httpAccess = new HttpAccess(  );
 
         try
         {
             strContent = httpAccess.doGet( rss.getUrl(  ) );
             rss.setLastFetchStatus( FETCH_OK );
             rss.setLastFetchError( "" );
             saveInCacheFile( rss.getId(  ), strContent );
         }
         catch ( HttpAccessException e )
         {
             rss.setLastFetchStatus( FETCH_ERROR );
             rss.setLastFetchError( e.getMessage(  ) );
         }
 
         rss.setLastFetchDate( new Timestamp( new Date(  ).getTime(  ) ) );
         RssFeedHome.updateLastFetchInfos( rss );
 
         return strContent;
     }
 
     /**
      * Gets the content of the RSS feed from a cache file
      * @param strId The RS feed Id
      * @return The content of the RSS feed
      */
     private static String getFromCacheFile( String strId )
     {
         String strContent = null;
         String strFilePath = AppPathService.getPath( PROPERTY_CACHE_DIRECTORY, strId + FILE_EXT );
         File file = new File( strFilePath );
         BufferedReader input = null;
 
         StringBuffer sbContent = new StringBuffer(  );
 
         try
         {
             //use buffering
             //this implementation reads one line at a time
             //FileReader always assumes default encoding is OK!
             input = new BufferedReader( new FileReader( file ) );
 
             String strLine = null;
 
             while ( ( strLine = input.readLine(  ) ) != null )
             {
                 sbContent.append( strLine );
             }
 
             strContent = sbContent.toString(  );
         }
         catch ( FileNotFoundException e )
         {
             AppLogService.error( e.getMessage(  ), e );
         }
         catch ( IOException e )
         {
             AppLogService.error( e.getMessage(  ), e );
         }
         finally
         {
             try
             {
                 if ( input != null )
                 {
                     //flush and close both "input" and its underlying FileReader
                     input.close(  );
                 }
             }
             catch ( IOException e )
             {
                 AppLogService.error( e.getMessage(  ), e );
             }
         }
 
         return strContent;
     }
 
     /**
      * Save the content of the RSS feed in a cache file
      * @param nId The RSS feed ID
      * @param strContent The content of the RSS feed to store
      */
     private static void saveInCacheFile( int nId, String strContent )
     {
         String strFilePath = AppPathService.getPath( PROPERTY_CACHE_DIRECTORY, "" + nId + FILE_EXT );
 
         try
         {
             File file = new File( strFilePath );
 
             if ( file.exists(  ) )
             {
                 file.delete(  );
             }
 
             FileOutputStream fos = new FileOutputStream( file );
             fos.flush(  );
             fos.write( strContent.getBytes(  ) );
             fos.close(  );
         }
         catch ( IOException io )
         {
             AppLogService.error( io.getMessage(  ), io );
         }
     }
 
     /**
      * Fetch all feeds
      * @return the log message
      */
     public static String fetchAllRssFeeds(  )
     {
         StringBuffer sbProcessingLog = new StringBuffer(  );
         Collection colRssFeeds = RssFeedHome.getRssFeeds(  );
         Iterator i = colRssFeeds.iterator(  );
 
         while ( i.hasNext(  ) )
         {
             RssFeed="../../../../../../fr/paris/lutece/plugins/rss/business/RssFeed.html#RssFeed">RssFeed rss = (RssFeed) i.next(  );
 
             try
             {
                 fetchRssFeed( rss.getId(  ) );
             }
             catch ( RssParsingException ex )
             {
                 AppLogService.error( ex.getMessage(  ), ex );
             }
 
             sbProcessingLog.append( "\nFetching " + rss.toString(  ) );
         }
 
         return sbProcessingLog.toString(  );
     }
 }