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();

         }

     }

 }