package org.apache.maven.plugin.changes;
   
   /*
    * 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.
   */
  
  import com.sun.syndication.feed.synd.SyndContent;
  import com.sun.syndication.feed.synd.SyndContentImpl;
  import com.sun.syndication.feed.synd.SyndEntry;
  import com.sun.syndication.feed.synd.SyndEntryImpl;
  import com.sun.syndication.feed.synd.SyndFeed;
  import com.sun.syndication.feed.synd.SyndFeedImpl;
  import com.sun.syndication.io.FeedException;
  import com.sun.syndication.io.SyndFeedOutput;
  
  import java.io.IOException;
  import java.io.Writer;
  
  import java.text.DateFormat;
  import java.text.ParseException;
  
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;
  import java.util.Locale;
  import java.util.ResourceBundle;
  
  import org.apache.maven.doxia.util.HtmlTools;
  
  import org.apache.maven.plugins.changes.model.Release;
  
  
  /**
   *
   * @author ltheussl
   */
  public class FeedGenerator
  {
      private final ResourceBundle rbundle;
      private final SyndFeed feed;
  
      private String link;
      private String title;
      private String author;
      private DateFormat dateFormat;
  
      /**
       * Initialize feedGenerator for a given locale.
       *
       * @param locale a locale for i18n.
       */
      public FeedGenerator( final Locale locale )
      {
          this.feed = new SyndFeedImpl();
          this.rbundle = ResourceBundle.getBundle( "changes-report", locale, this.getClass().getClassLoader() );
      }
  
      /**
       * The author of the feed.
       *
       * @return the author.
       */
      public String getAuthor()
      {
          return author;
      }
  
      /**
       * Set the author of the feed.
       *
       * @param author not null.
       */
      public void setAuthor( final String author )
      {
          this.author = author.trim(); // this also assures that author is not null.
      }
  
      /**
       * The title of the feed.
       *
       * @return the title.
       */
      public String getTitle()
      {
         return title;
     }
 
     /**
      * Set the title of the feed.
      *
      * @param title not null.
      */
     public void setTitle( final String title )
     {
         this.title = title.trim(); // this also assures that title is not null.
     }
 
     /**
      * The DateFormat.
      *
      * @return may be null.
      */
     public DateFormat getDateFormat()
     {
         return dateFormat;
     }
 
     /**
      * Set the date format.
      * This should match the date format used for the release dates in changes.xml.
      *
      * @param dateFormat may be null.
      */
     public void setDateFormat( final DateFormat dateFormat )
     {
         this.dateFormat = dateFormat;
     }
 
     /**
      * The main link of the feed.
      *
      * @return the link.
      */
     public String getLink()
     {
         return link;
     }
 
     /**
      * Set the main link of the feed.
      *
      * @param link not null.
      */
     public void setLink( final String link )
     {
         this.link = link.trim(); // this also assures that link is not null.
     }
 
     /**
      * Determine if a given feed type is supported. The currently supported values are:
      * <code>"rss_0.9", "rss_0.91N" (RSS 0.91 Netscape), "rss_0.91U" (RSS 0.91 Userland),
      * "rss_0.92", "rss_0.93", "rss_0.94", "rss_1.0", "rss_2.0", "atom_0.3", "atom_1.0"</code>.
      *
      * @param type the feed type to check. May be null.
      *
      * @return true if if the given type is supported by the rome library, false otherwise.
      */
     public boolean isSupportedFeedType( final String type )
     {
         return getSupportedFeedTypes().contains( type );
     }
 
     /**
      * A List of supported feed types.
      *
      * @return a List of supported feed types.
      *
      * @see #isSupportedFeedType(java.lang.String)
      */
     @SuppressWarnings( "unchecked" )
     public List<String> getSupportedFeedTypes()
     {
         return feed.getSupportedFeedTypes();
     }
 
     /**
      * Extract a feed and export it to a Writer.
      *
      * @param releases the List of Releases. Only the last release is used in the feed.
      * @param feedType The type of the feed to generate.
      *      See {@link #isSupportedFeedType(java.lang.String)} for supported values.
      *
      * @param writer a Writer. Note that this is not flushed nor closed upon exit.
      *
      * @throws IOException if an error occurs during export.
      */
     public void export( final List<Release> releases, final String feedType, final Writer writer )
         throws IOException
     {
         feed.setFeedType( feedType );
         feed.setTitle( title );
         feed.setAuthor( author );
         feed.setPublishedDate( new Date() );
         feed.setLink( link );
         feed.setDescription( rbundle.getString( "report.changes.text.rssfeed.description" ) );
         feed.setLanguage( rbundle.getLocale().getLanguage() );
         //feed.setCopyright(  );
         //feed.setEncoding();
         feed.setEntries( getEntries( releases ) );
 
         try
         {
             new SyndFeedOutput().output( feed, writer );
         }
         catch ( FeedException ex )
         {
             IOException ioex = new IOException( ex.getMessage() );
             ioex.initCause( ex );
             throw ioex;
         }
     }
 
     private List<SyndEntry> getEntries( final List<Release> releases )
     {
         final List<SyndEntry> entries = new ArrayList<SyndEntry>( 1 );
 
         if ( releases.size() > 0 )
         {
             final Release release = releases.get( 0 ); // TODO: is this guaranteed to be the latest?
 
             final SyndEntry entry = new SyndEntryImpl();
             entry.setTitle( release.getVersion() );
             entry.setLink( link + "#" + HtmlTools.encodeId( release.getVersion() ) );
             entry.setDescription( getSyndContent( release ) );
             entry.setPublishedDate( getDate( release.getDateRelease(), dateFormat ) );
 
             entries.add( entry );
         }
 
         return entries;
     }
 
     private static SyndContent getSyndContent( final Release release )
     {
         final SyndContent syndContent = new SyndContentImpl();
         syndContent.setType( "text/html" );
 
         final StringBuilder sb = new StringBuilder( 512 );
 
         final String description = release.getDescription();
 
         if ( description != null && description.trim().length() > 0 )
         {
             sb.append( "<p>" ).append( description ).append( "</p>" );
         }
 
         // TODO: localize?
         sb.append( "<p>Version " )
             .append( release.getVersion() ).append( " is available with " )
             .append( release.getActions().size() ).append( " fixed issues.</p>" );
 
         syndContent.setValue( sb.toString() );
 
         return syndContent;
     }
 
     private static Date getDate( final String dateRelease, final DateFormat dateFormat )
     {
         if ( dateFormat == null )
         {
             return new Date();
         }
 
         try
         {
             return dateFormat.parse( dateRelease );
         }
         catch ( ParseException ex )
         {
             return new Date();
         }
     }
 }