package org.apache.maven.plugin.doap;

 /*

  * 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 java.io.File;

 import java.io.IOException;

 import java.io.Writer;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.text.DateFormat;

 import java.text.ParseException;

 import java.text.SimpleDateFormat;

 import java.util.Collections;

 import java.util.Comparator;

 import java.util.Date;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Locale;

 import java.util.TimeZone;

 import org.apache.maven.artifact.Artifact;

 import org.apache.maven.artifact.factory.ArtifactFactory;

 import org.apache.maven.artifact.repository.ArtifactRepository;

 import org.apache.maven.artifact.repository.metadata.ArtifactRepositoryMetadata;

 import org.apache.maven.artifact.repository.metadata.RepositoryMetadata;

 import org.apache.maven.artifact.repository.metadata.RepositoryMetadataManager;

 import org.apache.maven.artifact.repository.metadata.RepositoryMetadataResolutionException;

 import org.apache.maven.model.Contributor;

 import org.apache.maven.model.Developer;

 import org.apache.maven.model.License;

 import org.apache.maven.model.MailingList;

 import org.apache.maven.model.Scm;

 import org.apache.maven.plugin.AbstractMojo;

 import org.apache.maven.plugin.MojoExecutionException;

 import org.apache.maven.plugin.doap.options.ASFExtOptions;

 import org.apache.maven.plugin.doap.options.DoapOptions;

 import org.apache.maven.plugin.doap.options.Standard;

 import org.apache.maven.project.MavenProject;

 import org.apache.maven.scm.manager.NoSuchScmProviderException;

 import org.apache.maven.scm.manager.ScmManager;

 import org.apache.maven.scm.provider.cvslib.repository.CvsScmProviderRepository;

 import org.apache.maven.scm.provider.svn.repository.SvnScmProviderRepository;

 import org.apache.maven.scm.repository.ScmRepository;

 import org.apache.maven.scm.repository.ScmRepositoryException;

 import org.codehaus.plexus.i18n.I18N;

 import org.codehaus.plexus.util.FileUtils;

 import org.codehaus.plexus.util.StringUtils;

 import org.codehaus.plexus.util.WriterFactory;

 import org.codehaus.plexus.util.xml.PrettyPrintXMLWriter;

 import org.codehaus.plexus.util.xml.XMLWriter;

 import org.codehaus.plexus.util.xml.XmlWriterUtil;

 /**

  * Generate a <a href="http://usefulinc.com/ns/doap">Description of a Project (DOAP)</a>

  * file from the main information found in a POM.

  * <br/>

  * <b>Note</b>: The generated file is tailored for use by projects at

  * <a href="http://projects.apache.org/doap.html">Apache</a>.

  *

  * @author Jason van Zyl

  * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>

  * @version $Id: org.apache.maven.plugin.doap.DoapMojo.html 815332 2012-05-01 21:25:03Z hboutemy $

  * @since 1.0-beta-1

  * @goal generate

  */

 public class DoapMojo

     extends AbstractMojo

 {

     /** UTC Time Zone */

     private static final TimeZone UTC_TIME_ZONE = TimeZone.getTimeZone( "UTC" );

     /** Date format for <lastUpdated/> tag in the repository metadata, i.e.: yyyyMMddHHmmss */

     private static final DateFormat REPOSITORY_DATE_FORMAT;

     /** Date format for DOAP file, i.e. ISO-8601 YYYY-MM-DD */

     private static final DateFormat DOAP_DATE_FORMAT;

     static

     {

         REPOSITORY_DATE_FORMAT = new SimpleDateFormat( "yyyyMMddHHmmss", Locale.ENGLISH );

         REPOSITORY_DATE_FORMAT.setTimeZone( UTC_TIME_ZONE );

         DOAP_DATE_FORMAT = new SimpleDateFormat( "yyyy-MM-dd", Locale.ENGLISH );

         DOAP_DATE_FORMAT.setTimeZone( UTC_TIME_ZONE );

     }

     // ----------------------------------------------------------------------

     // Mojo components

     // ----------------------------------------------------------------------

     /**

      * Maven SCM Manager.

      *

      * @parameter expression="${component.org.apache.maven.scm.manager.ScmManager}"

      * @required

      * @readonly

      * @since 1.0

      */

     private ScmManager scmManager;

     /**

      * Artifact factory.

      *

      * @component

      * @since 1.0

      */

     private ArtifactFactory artifactFactory;

     /**

      * Used to resolve artifacts.

      *

      * @component

      * @since 1.0

      */

     private RepositoryMetadataManager repositoryMetadataManager;

     /**

      * Internationalization component.

      *

      * @component

      * @since 1.0

      */

     private I18N i18n;

     // ----------------------------------------------------------------------

     // Mojo parameters

     // ----------------------------------------------------------------------

     /**

      * The POM from which information will be extracted to create a DOAP file.

      *

      * @parameter expression="${project}"

      * @required

      */

     private MavenProject project;

     /**

      * The name of the DOAP file that will be generated.

      *

      * @parameter expression="${doapFile}"

      * default-value="${project.reporting.outputDirectory}/doap_${project.artifactId}.rdf"

      * @required

      */

     private File doapFile;

     /**

      * The local repository where the artifacts are located.

      *

      * @parameter expression="${localRepository}"

      * @required

      * @readonly

      * @since 1.0

      */

     private ArtifactRepository localRepository;

     /**

      * The remote repositories where the artifacts are located.

      *

      * @parameter expression="${project.remoteArtifactRepositories}"

      * @required

      * @readonly

      * @since 1.0

      */

     private List remoteRepositories;

     // ----------------------------------------------------------------------

     // Doap options

     // ----------------------------------------------------------------------

     /**

      * The category which should be displayed in the DOAP file.

      *

      * @parameter expression="${category}"

      * @deprecated Since 1.0. Instead of, configure <code>category</code> property in <code>doapOptions</code>

      * parameter.

      */

     private String category;

     /**

      * The programming language which should be displayed in the DOAP file.

      *

      * @parameter expression="${language}"

      * @deprecated Since 1.0. Instead of, configure <code>programmingLanguage</code> property in

      * <code>doapOptions</code> parameter.

      */

     private String language;

     /**

      * Specific DOAP parameters, i.e. options that POM doesn't have any notions.

      * <br/>

      * Example:

      * <pre>

      * <doapOptions>

      *   <programmingLanguage>java</programmingLanguage>

      * </doapOptions>

      * </pre>

      * <br/>

      * See <a href="./apidocs/org/apache/maven/plugin/doap/options/DoapOptions.html">Javadoc</a>

      * <br/>

      *

      * @parameter expression="${doapOptions}"

      * @since 1.0

      * @see <a href="http://usefulinc.com/ns/doap#">http://usefulinc.com/ns/doap#</a>

      */

     private DoapOptions doapOptions;

     /**

      * Specific ASF extensions parameters, i.e. options that POM doesn't have any notions but required by ASF DOAP

      * requirements.

      * <br/>

      * Example:

      * <pre>

      * <asfExtOptions>

      *   <included>true</included>

      *   <charter>The mission of the Apache XXX project is to create and maintain software

      *   libraries that provide ...</charter>

      *   ...

      * </asfExtOptions>

      * </pre>

      * <b>Note</b>: By default, <code>asfExtOptions/included</code> is set to <code>true</code> to include the ASF

      * extensions.

      * <br/>

      * See <a href="./apidocs/org/apache/maven/plugin/doap/options/ASFExtOptions.html">Javadoc</a>

      * <br/>

      *

      * @parameter expression="${asfExtOptions}"

      * @since 1.0

      * @see <a href="http://svn.apache.org/repos/asf/infrastructure/site-tools/trunk/projects/asfext">

      * http://svn.apache.org/repos/asf/infrastructure/site-tools/trunk/projects/asfext</a>

      * @see <a href="http://projects.apache.org/docs/pmc.html">http://projects.apache.org/docs/pmc.html</a>

      * @see <a href="http://projects.apache.org/docs/standards.html">http://projects.apache.org/docs/standards.html</a>

      */

     private ASFExtOptions asfExtOptions;

     /**

      * The value for the <code>xml:lang</code> attribute used by the <code>&lt;rdf:RDF/&gt;<code>,

      * <code>&lt;description/&gt;</code> and <code>&lt;shortdesc/&gt;</code> elements.

      * <br/>

      * POM doesn't have any notions about language.

      * <br/>

      * See <a href="http://www.w3.org/TR/REC-xml/#sec-lang-tag">http://www.w3.org/TR/REC-xml/#sec-lang-tag</a>

      * <br/>

      *

      * @parameter expression="${lang}" default-value="en"

      * @required

      * @since 1.0

      */

     private String lang;

     /**

      * The <code>about</code> URI-reference which should be displayed in the DOAP file.

      * Example:

      * <pre>

      * <rdf:RDF>

      *   <Project rdf:about="http://maven.apache.org/">

      *   ...

      *   </Project>

      * </rdf:RDF>

      * </pre>

      * See <a href="http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/#aboutAttr">

      * http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/#aboutAttr</a>

      * <br/>

      *

      * @parameter expression="${about}" default-value="${project.url}"

      * @required

      * @since 1.0

      */

     private String about;

     // ----------------------------------------------------------------------

     // Public methods

     // ----------------------------------------------------------------------

     /** {@inheritDoc} */

     public void execute()

         throws MojoExecutionException

     {

         // ----------------------------------------------------------------------------

         // setup pretty print xml writer

         // ----------------------------------------------------------------------------

         Writer w;

         try

         {

             if ( !doapFile.getParentFile().exists() )

             {

                 FileUtils.mkdir( doapFile.getParentFile().getAbsolutePath() );

             }

             w = WriterFactory.newXmlWriter( doapFile );

         }

         catch ( IOException e )

         {

             throw new MojoExecutionException( "Error creating DOAP file.", e );

         }

         if ( asfExtOptions.isIncluded() )

         {

             getLog().info( "Generating an ASF DOAP file..." );

         }

         else

         {

             getLog().info( "Generating a pure DOAP file..." );

         }

         XMLWriter writer = new PrettyPrintXMLWriter( w, project.getModel().getModelEncoding(), null );

         // ----------------------------------------------------------------------------

         // Convert POM to DOAP

         // ----------------------------------------------------------------------------

         DoapUtil.writeHeader( writer );

         // Heading

         writer.startElement( "rdf:RDF" );

         writer.addAttribute( "xml:lang", lang );

         writer.addAttribute( "xmlns", "http://usefulinc.com/ns/doap#" );

         writer.addAttribute( "xmlns:rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#" );

         writer.addAttribute( "xmlns:foaf", "http://xmlns.com/foaf/0.1/" );

         if ( asfExtOptions.isIncluded() )

         {

             writer.addAttribute( "xmlns:asfext", ASFExtOptions.ASFEXT_NAMESPACE );

         }

         // Project

         writer.startElement( "Project" );

         if ( StringUtils.isNotEmpty( about ) )

         {

             writer.addAttribute( "rdf:about", about );

         }

         else

         {

             getLog().warn( "rdf:about should be required" );

         }

         // name

         writeName( writer );

         // description

         writeDescription( writer );

         // created

         writeCreated( writer );

         // homepage and old-homepage

         writeHomepage( writer );

         // licenses

         writeLicenses( writer );

         // programming-language

         writeProgrammingLanguage( writer );

         // category

         writeCategory( writer );

         // os

         writeOS( writer );

         // SCM

         writeSourceRepositories( writer );

         // bug-database

         writeBugDatabase( writer );

         // mailing list

         writeMailingList( writer );

         // download-page and download-mirror

         writeDownloadPage( writer );

         // screenshots

         writeScreenshots( writer );

         // wiki

         writeWiki( writer );

         // Releases

         writeReleases( writer );

         // Developers

         writeDevelopersOrContributors( writer, project.getDevelopers() );

         // Contributors

         writeDevelopersOrContributors( writer, project.getContributors() );

         // ASFext

         if ( asfExtOptions.isIncluded() )

         {

             writeASFext( writer );

         }

         writer.endElement(); // Project

         writer.endElement(); // rdf:RDF

         try

         {

             w.close();

         }

         catch ( IOException e )

         {

             throw new MojoExecutionException( "Error when closing the writer.", e );

         }

     }

     // ----------------------------------------------------------------------

     // Private methods

     // ----------------------------------------------------------------------

     /**

      * Write DOAP name.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#name">http://usefulinc.com/ns/doap#name</a>

      */

     private void writeName( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( project.getName() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "A name of something.", 2 );

         if ( asfExtOptions.isIncluded()

             && !project.getName().toLowerCase( Locale.ENGLISH ).trim().startsWith( "apache" ) )

         {

             DoapUtil.writeRdfResourceElement( writer, "name", "Apache " + project.getName() );

         }

         else

         {

             DoapUtil.writeRdfResourceElement( writer, "name", project.getName() );

         }

     }

     /**

      * Write DOAP description.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#description">http://usefulinc.com/ns/doap#description</a>

      * @see <a href="http://usefulinc.com/ns/doap#shortdesc">http://usefulinc.com/ns/doap#shortdesc</a>

      */

     private void writeDescription( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( project.getDescription() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Plain text description of a project, of 2-4 sentences in length.", 2 );

         DoapUtil.writeElement( writer, "description", project.getDescription(), lang );

         if ( StringUtils.isNotEmpty( doapOptions.getShortdesc() ) )

         {

             DoapUtil.writeElement( writer, "shortdesc", doapOptions.getShortdesc(), lang );

         }

         else

         {

             DoapUtil.writeElement( writer, "shortdesc", project.getDescription(), lang );

         }

     }

     /**

      * Write DOAP created.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#created">http://usefulinc.com/ns/doap#created</a>

      */

     private void writeCreated( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( project.getInceptionYear() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Date when something was created, in YYYY-MM-DD form. e.g. 2004-04-05",

                                         2 );

         DoapUtil.writeElement( writer, "created", project.getInceptionYear() + "-01-01" );

     }

     /**

      * Write DOAP homepage and old-homepage.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#homepage">http://usefulinc.com/ns/doap#homepage</a>

      * @see <a href="http://usefulinc.com/ns/doap#old-homepage">http://usefulinc.com/ns/doap#old-homepage</a>

      */

     private void writeHomepage( XMLWriter writer )

     {

         if ( StringUtils.isNotEmpty( project.getUrl() ) )

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText( writer,

                                             "URL of a project's homepage, associated with exactly one project.", 2 );

             DoapUtil.writeRdfResourceElement( writer, "homepage", project.getUrl() );

         }

         if ( StringUtils.isNotEmpty( doapOptions.getOldHomepage() ) )

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText(

                                             writer,

                                             "URL of a project's past homepage, associated with exactly one project.",

                                             2 );

             DoapUtil.writeRdfResourceElement( writer, "old-homepage", doapOptions.getOldHomepage() );

         }

     }

     /**

      * Write DOAP programming-language.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#programming-language">

      * http://usefulinc.com/ns/doap#programming-language</a>

      */

     private void writeProgrammingLanguage( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getProgrammingLanguage() ) && StringUtils.isEmpty( language ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Programming language.", 2 );

         if ( StringUtils.isNotEmpty( language ) ) // backward compatible

         {

             if ( asfExtOptions.isIncluded() && !ASFExtOptions.isProgrammingLanguageSupportedByASF( language ) )

             {

                 getLog().warn(

                                "The programming language '" + language + "' is not supported by ASF. "

                                    + "Refer you to http://projects.apache.org/languages.html" );

             }

             DoapUtil.writeRdfResourceElement( writer, "programming-language", language );

         }

         if ( StringUtils.isNotEmpty( doapOptions.getProgrammingLanguage() ) )

         {

             String[] languages = StringUtils.split( doapOptions.getProgrammingLanguage(), "," );

             for ( int i = 0; i < languages.length; i++ )

             {

                 if ( asfExtOptions.isIncluded()

                     && !ASFExtOptions.isProgrammingLanguageSupportedByASF( languages[i].trim() ) )

                 {

                     getLog().warn(

                                    "The programming language '" + languages[i].trim() + "' is not supported by ASF. "

                                        + "Refer you to http://projects.apache.org/languages.html" );

                 }

                 DoapUtil.writeRdfResourceElement( writer, "programming-language", languages[i].trim() );

             }

         }

     }

     /**

      * Write DOAP category.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#category">http://usefulinc.com/ns/doap#category</a>

      */

     private void writeCategory( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getCategory() ) && StringUtils.isEmpty( category ) )

         {

             return;

         }

         //TODO: how to lookup category, map it, or just declare it.

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "A category of project.", 2 );

         if ( StringUtils.isNotEmpty( category ) ) // backward compatible

         {

             if ( asfExtOptions.isIncluded() && !ASFExtOptions.isCategorySupportedByASF( category ) )

             {

                 getLog().warn(

                                "The given category '" + category + "' is not supported by ASF. "

                                    + "Refer you to http://projects.apache.org/categories.html" );

             }

             if ( asfExtOptions.isIncluded() )

             {

                 DoapUtil

                     .writeRdfResourceElement( writer, "category", "http://projects.apache.org/category/" + category );

             }

             else

             {

                 DoapUtil.writeRdfResourceElement( writer, "category", category );

             }

         }

         if ( StringUtils.isNotEmpty( doapOptions.getCategory() ) )

         {

             String[] categories = StringUtils.split( doapOptions.getCategory(), "," );

             for ( int i = 0; i < categories.length; i++ )

             {

                 if ( asfExtOptions.isIncluded() && !ASFExtOptions.isCategorySupportedByASF( categories[i] ) )

                 {

                     getLog().warn(

                                    "The given category '" + categories[i] + "' is not supported by ASF. "

                                        + "Refer you to http://projects.apache.org/categories.html" );

                 }

                 if ( asfExtOptions.isIncluded() )

                 {

                     DoapUtil.writeRdfResourceElement( writer, "category", "http://projects.apache.org/category/"

                         + categories[i].trim() );

                 }

                 else

                 {

                     DoapUtil.writeRdfResourceElement( writer, "category", categories[i].trim() );

                 }

             }

         }

     }

     /**

      * Write DOAP download-page and download-mirror.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#download-page">http://usefulinc.com/ns/doap#download-page</a>

      * @see <a href="http://usefulinc.com/ns/doap#download-mirror">http://usefulinc.com/ns/doap#download-mirror</a>

      */

     private void writeDownloadPage( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getDownloadPage() ) )

         {

             if ( StringUtils.isNotEmpty( project.getUrl() ) )

             {

                 doapOptions.setDownloadPage( composeUrl( project.getUrl(), "/download.html" ) );

             }

         }

         if ( StringUtils.isNotEmpty( doapOptions.getDownloadPage() ) )

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText( writer, "Download page.", 2 );

             DoapUtil.writeRdfResourceElement( writer, "download-page", doapOptions.getDownloadPage() );

         }

         if ( StringUtils.isNotEmpty( doapOptions.getDownloadMirror() ) )

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText( writer, "Mirror of software download web page.", 2 );

             String[] downloadMirrors = StringUtils.split( doapOptions.getDownloadMirror(), "," );

             for ( int i = 0; i < downloadMirrors.length; i++ )

             {

                 DoapUtil.writeRdfResourceElement( writer, "download-mirror", downloadMirrors[i].trim() );

             }

         }

     }

     /**

      * Write DOAP OS.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#os">http://usefulinc.com/ns/doap#os</a>

      */

     private void writeOS( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getOs() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Operating system that a project is limited to.", 2 );

         String[] oses = StringUtils.split( doapOptions.getOs(), "," );

         for ( int i = 0; i < oses.length; i++ )

         {

             DoapUtil.writeRdfResourceElement( writer, "os", oses[i].trim() );

         }

     }

     /**

      * Write DOAP screenshots.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#screenshots">http://usefulinc.com/ns/doap#screenshots</a>

      */

     private void writeScreenshots( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getScreenshots() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Web page with screenshots of project.", 2 );

         DoapUtil.writeRdfResourceElement( writer, "screenshots", doapOptions.getScreenshots() );

     }

     /**

      * Write DOAP wiki.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#wiki">http://usefulinc.com/ns/doap#wiki</a>

      */

     private void writeWiki( XMLWriter writer )

     {

         if ( StringUtils.isEmpty( doapOptions.getWiki() ) )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "URL of Wiki for collaborative discussion of project.", 2 );

         DoapUtil.writeRdfResourceElement( writer, "wiki", doapOptions.getWiki() );

     }

     /**

      * Write DOAP licenses.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#license">http://usefulinc.com/ns/doap#license</a>

      */

     private void writeLicenses( XMLWriter writer )

     {

         if ( project.getLicenses() == null || project.getLicenses().isEmpty() )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "The URI of the license the software is distributed under.", 2 );

         //TODO: how to map to usefulinc site, or if this is necessary, the OSI page might

         //      be more appropriate.

         for ( Iterator it = project.getLicenses().iterator(); it.hasNext(); )

         {

             License license = (License) it.next();

             if ( StringUtils.isNotEmpty( license.getUrl() ) )

             {

                 DoapUtil.writeRdfResourceElement( writer, "license", license.getUrl() );

             }

             else

             {

                 getLog().warn( "No URL was specified for license " + license.getName() );

             }

         }

     }

     /**

      * Write DOAP bug-database.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#bug-database">http://usefulinc.com/ns/doap#bug-database</a>

      */

     private void writeBugDatabase( XMLWriter writer )

     {

         if ( project.getIssueManagement() == null )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "bug database.", 2 );

         if ( StringUtils.isNotEmpty( project.getIssueManagement().getUrl() ) )

         {

             DoapUtil.writeRdfResourceElement( writer, "bug-database", project.getIssueManagement().getUrl() );

         }

         else

         {

             getLog().warn( "No URL was specified for issue management" );

         }

     }

     /**

      * Write DOAP mailing-list.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#mailing-list">http://usefulinc.com/ns/doap#mailing-list</a>

      */

     private void writeMailingList( XMLWriter writer )

     {

         if ( project.getMailingLists() == null || project.getMailingLists().isEmpty() )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "mailing list.", 2 );

         for ( Iterator it = project.getMailingLists().iterator(); it.hasNext(); )

         {

             MailingList mailingList = (MailingList) it.next();

             if ( StringUtils.isNotEmpty( mailingList.getArchive() ) )

             {

                 DoapUtil.writeRdfResourceElement( writer, "mailing-list", mailingList.getArchive() );

             }

             else

             {

                 getLog().warn( "No archive was specified for mailing list " + mailingList.getName() );

             }

             if ( mailingList.getOtherArchives() != null )

             {

                 for ( Iterator it2 = mailingList.getOtherArchives().iterator(); it2.hasNext(); )

                 {

                     String otherArchive = (String) it2.next();

                     if ( StringUtils.isNotEmpty( otherArchive ) )

                     {

                         DoapUtil.writeRdfResourceElement( writer, "mailing-list", otherArchive );

                     }

                     else

                     {

                         getLog().warn( "No other archive was specified for mailing list " + mailingList.getName() );

                     }

                 }

             }

         }

     }

     /**

      * Write all DOAP releases.

      *

      * @param writer not null

      * @throws MojoExecutionException if any

      * @see <a href="http://usefulinc.com/ns/doap#release">http://usefulinc.com/ns/doap#release</a>

      * @see <a href="http://usefulinc.com/ns/doap#Version">http://usefulinc.com/ns/doap#Version</a>

      */

     private void writeReleases( XMLWriter writer )

         throws MojoExecutionException

     {

         Artifact artifact = artifactFactory.createArtifact( project.getGroupId(), project.getArtifactId(), project

             .getVersion(), null, project.getPackaging() );

         RepositoryMetadata metadata = new ArtifactRepositoryMetadata( artifact );

         for ( Iterator it = remoteRepositories.iterator(); it.hasNext(); )

         {

             ArtifactRepository repo = (ArtifactRepository) it.next();

             if ( repo.isBlacklisted() )

             {

                 continue;

             }

             if ( repo.getSnapshots().isEnabled() )

             {

                 continue;

             }

             if ( repo.getReleases().isEnabled() )

             {

                 try

                 {

                     repositoryMetadataManager.resolveAlways( metadata, localRepository, repo );

                     break;

                 }

                 catch ( RepositoryMetadataResolutionException e )

                 {

                     throw new MojoExecutionException( metadata

                         + " could not be retrieved from repositories due to an error: " + e.getMessage(), e );

                 }

             }

         }

         if ( metadata.getMetadata().getVersioning() == null )

         {

             getLog().info( "No versioning was found - ignored writing <release/> tag." );

             return;

         }

         List versions = metadata.getMetadata().getVersioning().getVersions();

         // Recent releases in first

         Collections.reverse( versions );

         boolean addComment = false;

         int i = 0;

         for ( Iterator it = versions.iterator(); it.hasNext(); )

         {

             String version = (String) it.next();

             if ( !addComment )

             {

                 XmlWriterUtil.writeLineBreak( writer );

                 XmlWriterUtil.writeCommentText( writer, "Project releases.", 2 );

                 addComment = true;

             }

             writer.startElement( "release" );

             writer.startElement( "Version" );

             writer.startElement( "name" );

             if ( version.equals( metadata.getMetadata().getVersioning().getRelease() ) )

             {

                 writer.writeText( "Latest stable release" );

             }

             else

             {

                 writer.writeText( project.getName() + " - " + version );

             }

             writer.endElement(); // name

             writer.startElement( "revision" );

             writer.writeText( version );

             writer.endElement(); // revision

             // list all file release from all remote repos

             for ( Iterator it2 = remoteRepositories.iterator(); it2.hasNext(); )

             {

                 ArtifactRepository repo = (ArtifactRepository) it2.next();

                 Artifact artifactRelease = artifactFactory.createArtifact( project.getGroupId(), project

                     .getArtifactId(), version, null, project.getPackaging() );

                 if ( artifactRelease == null )

                 {

                     continue;

                 }

                 String fileRelease = repo.getUrl() + "/" + repo.pathOf( artifactRelease );

                 // try to ping the url

                 try

                 {

                     URL urlRelease = new URL( fileRelease );

                     urlRelease.openStream();

                 }

                 catch ( MalformedURLException e )

                 {

                     getLog().debug( e.getMessage(), e );

                     continue;

                 }

                 catch ( IOException e )

                 {

                     // Not found, ignored

                     getLog().debug( e.getMessage(), e );

                     continue;

                 }

                 writer.startElement( "file-release" );

                 writer.writeText( fileRelease );

                 writer.endElement(); // file-release

                 Date releaseDate = null;

                 try

                 {

                     releaseDate =

                         REPOSITORY_DATE_FORMAT.parse( metadata.getMetadata().getVersioning().getLastUpdated() );

                 }

                 catch ( ParseException e )

                 {

                     getLog().error(

                                     "Unable to parse date '"

                                         + metadata.getMetadata().getVersioning().getLastUpdated() + "'" );

                     continue;

                 }

                 // See MDOAP-11

                 if ( i == 0 )

                 {

                     writer.startElement( "created" );

                     writer.writeText( DOAP_DATE_FORMAT.format( releaseDate ) );

                     writer.endElement(); // created

                 }

             }

             writer.endElement(); // Version

             writer.endElement(); // release

             i++;

         }

     }

     /**

      * Write all DOAP repositories.

      *

      * @param writer not null

      * @see <a href="http://usefulinc.com/ns/doap#Repository">http://usefulinc.com/ns/doap#Repository</a>

      * @see <a href="http://usefulinc.com/ns/doap#CVSRepository">http://usefulinc.com/ns/doap#CVSRepository</a>

      * @see <a href="http://usefulinc.com/ns/doap#SVNRepository">http://usefulinc.com/ns/doap#SVNRepository</a>

      */

     private void writeSourceRepositories( XMLWriter writer )

     {

         Scm scm = project.getScm();

         if ( scm == null )

         {

             return;

         }

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Anonymous Source Repository", 2 );

         String anonymousConnection = scm.getConnection();

         writeSourceRepository( writer, anonymousConnection );

         XmlWriterUtil.writeLineBreak( writer );

         XmlWriterUtil.writeCommentText( writer, "Developer Source Repository", 2 );

         String developerConnection = scm.getDeveloperConnection();

         writeSourceRepository( writer, developerConnection );

     }

     /**

      * Write a DOAP repository, for instance:

      * <pre>

      *   <repository>

      *     <SVNRepository>

      *       <location rdf:resource="http://svn.apache.org/repos/asf/maven/components/trunk/"/>

      *       <browse rdf:resource="http://svn.apache.org/viewcvs.cgi/maven/components/trunk/"/>

      *     </SVNRepository>

      *   </repository>

      * </pre>

      *

      * @param writer not null

      * @param connection not null

      * @see <a href="http://usefulinc.com/ns/doap#Repository">http://usefulinc.com/ns/doap#Repository</a>

      * @see <a href="http://usefulinc.com/ns/doap#CVSRepository">http://usefulinc.com/ns/doap#CVSRepository</a>

      * @see <a href="http://usefulinc.com/ns/doap#SVNRepository">http://usefulinc.com/ns/doap#SVNRepository</a>

      */

     private void writeSourceRepository( XMLWriter writer, String connection )

     {

         ScmRepository repository = getScmRepository( connection );

         writer.startElement( "repository" );

         if ( isScmSystem( repository, "cvs" ) )

         {

             writer.startElement( "CVSRepository" );

             CvsScmProviderRepository cvsRepo = (CvsScmProviderRepository) repository.getProviderRepository();

             DoapUtil.writeElement( writer, "anon-root", cvsRepo.getCvsRoot() );

             DoapUtil.writeElement( writer, "module", cvsRepo.getModule() );

         }

         else if ( isScmSystem( repository, "svn" ) )

         {

             writer.startElement( "SVNRepository" );

             SvnScmProviderRepository svnRepo = (SvnScmProviderRepository) repository.getProviderRepository();

             DoapUtil.writeRdfResourceElement( writer, "location", svnRepo.getUrl() );

         }

         else

         {

             /*

              * Supported DOAP repositories actually unsupported by SCM:

              *   BitKeeper (http://usefulinc.com/ns/doap#BKRepository)

              *   Arch (http://usefulinc.com/ns/doap#ArchRepository)

              * Other SCM repos are unsupported by DOAP.

              */

             writer.startElement( "Repository" );

             if ( connection.length() < 4 )

             {

                 throw new IllegalArgumentException( "The source repository connection is too short." );

             }

             DoapUtil.writeRdfResourceElement( writer, "location", connection.substring( 4 ) );

         }

         DoapUtil.writeRdfResourceElement( writer, "browse", project.getScm().getUrl() );

         writer.endElement(); // CVSRepository || SVNRepository || Repository

         writer.endElement(); // repository

     }

     /**

      * Write all DOAP persons.

      *

      * @param writer not null

      * @param developersOrContributors list of developers or contributors

      */

     private void writeDevelopersOrContributors( XMLWriter writer, List developersOrContributors )

     {

         if ( developersOrContributors == null || developersOrContributors.isEmpty() )

         {

             return;

         }

         boolean isDeveloper = Developer.class.isAssignableFrom( developersOrContributors.get( 0 ).getClass() );

         if ( isDeveloper )

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText( writer, "Main committers", 2 );

         }

         else

         {

             XmlWriterUtil.writeLineBreak( writer );

             XmlWriterUtil.writeCommentText( writer, "Contributed persons", 2 );

         }

         List maintainers =  DoapUtil.getDevelopersOrContributorsWithMaintainerRole( i18n, developersOrContributors );

         List developers = DoapUtil.getDevelopersOrContributorsWithDeveloperRole( i18n, developersOrContributors );

         List documenters = DoapUtil.getDevelopersOrContributorsWithDocumenterRole( i18n, developersOrContributors );

         List translators = DoapUtil.getDevelopersOrContributorsWithTranslatorRole( i18n, developersOrContributors );

         List testers = DoapUtil.getDevelopersOrContributorsWithTesterRole( i18n, developersOrContributors );

         List helpers = DoapUtil.getDevelopersOrContributorsWithHelperRole( i18n, developersOrContributors );

         List unknowns = DoapUtil.getDevelopersOrContributorsWithUnknownRole( i18n, developersOrContributors );

         // By default, all developers are maintainers and contributors are helpers

         if ( isDeveloper )

         {

             maintainers.addAll( unknowns );

         }

         else

         {

             helpers.addAll( unknowns );

         }

         // all alphabetical

         if ( developers.size() != 0 )

         {

             writeDeveloperOrContributor( writer, developers, "developer" );

         }

         if ( documenters.size() != 0 )

         {

             writeDeveloperOrContributor( writer, documenters, "documenter" );

         }

         if ( helpers.size() != 0 )

         {

             writeDeveloperOrContributor( writer, helpers, "helper" );

         }

         if ( maintainers.size() != 0 )

         {

             writeDeveloperOrContributor( writer, maintainers, "maintainer" );

         }

         if ( testers.size() != 0 )

         {

             writeDeveloperOrContributor( writer, testers, "tester" );

         }

         if ( translators.size() != 0 )

         {

             writeDeveloperOrContributor( writer, translators, "translator" );

         }

     }

     /**

      * Write a DOAP maintainer or developer or documenter or translator or tester or helper, for instance:

      * <pre>

      *   <maintainer>

      *     <foaf:Person>

      *       <foaf:name>Emmanuel Venisse</foaf:name>

      *       <foaf:mbox rdf:resource="mailto:evenisse@apache.org"/>

      *     </foaf:Person>

      *   </maintainer>

      * </pre>

      *

      * @param writer not null

      * @param developersOrContributors list of <code>{@link Developer}/{@link Contributor}</code>

      * @param doapType not null

      * @see #writeDeveloperOrContributor(XMLWriter, Object, String)

      */

     private void writeDeveloperOrContributor( XMLWriter writer, List developersOrContributors, String doapType )

     {

         if ( developersOrContributors == null || developersOrContributors.isEmpty() )

         {

             return;

         }

         // Sort list by names

         Collections.sort( developersOrContributors, new Comparator()

         {

             /**

              * {@inheritDoc}

              */

             public int compare( Object arg0, Object arg1 )

             {

                 if ( Developer.class.isAssignableFrom( arg0.getClass() ) )

                 {

                     Developer developer0 = (Developer) arg0;

                     Developer developer1 = (Developer) arg1;

                     if ( developer0.getName() == null )

                     {

                         return -1;

                     }

                     if ( developer1.getName() == null )

                     {

                         return +1;

                     }

                     return developer0.getName().compareTo( developer1.getName() );

                 }

                 Contributor contributor0 = (Contributor) arg0;

                 Contributor contributor1 = (Contributor) arg1;

                 if ( contributor0.getName() == null )

                 {

                     return -1;

                 }

                 if ( contributor1.getName() == null )

                 {

                     return +1;

                 }

                 return contributor0.getName().compareTo( contributor1.getName() );

             }

         } );

         for ( Iterator it = developersOrContributors.iterator(); it.hasNext(); )

         {

             Object obj = it.next();

             writeDeveloperOrContributor( writer, obj, doapType );

         }

     }

     /**

      * Writer a single developer or contributor

      *

      * @param writer not null

      * @param developerOrContributor not null, instance of <code>{@link Developer}/{@link Contributor}</code>

      * @param doapType not null

      * @see <a href="http://usefulinc.com/ns/doap#maintainer">http://usefulinc.com/ns/doap#maintainer</a>

      * @see <a href="http://usefulinc.com/ns/doap#developer">http://usefulinc.com/ns/doap#developer</a>

      * @see <a href="http://usefulinc.com/ns/doap#documenter">http://usefulinc.com/ns/doap#documenter</a>

      * @see <a href="http://usefulinc.com/ns/doap#translator">http://usefulinc.com/ns/doap#translator</a>

      * @see <a href="http://usefulinc.com/ns/doap#tester">http://usefulinc.com/ns/doap#tester</a>

      * @see <a href="http://usefulinc.com/ns/doap#helper">http://usefulinc.com/ns/doap#helper</a>

      * @see <a href="http://xmlns.com/foaf/0.1/Person">http://xmlns.com/foaf/0.1/Person</a>

      * @see <a href="http://xmlns.com/foaf/0.1/name">http://xmlns.com/foaf/0.1/name</a>

      * @see <a href="http://xmlns.com/foaf/0.1/mbox">http://xmlns.com/foaf/0.1/mbox</a>

      * @see <a href="http://xmlns.com/foaf/0.1/Organization">http://xmlns.com/foaf/0.1/Organization</a>

      * @see <a href="http://xmlns.com/foaf/0.1/homepage">http://xmlns.com/foaf/0.1/homepage</a>

      */

     private void writeDeveloperOrContributor( XMLWriter writer, Object developerOrContributor, String doapType )

     {

         if ( developerOrContributor == null )

         {

             return;

         }

         if ( StringUtils.isEmpty( doapType ) )

         {

             throw new IllegalArgumentException( "doapType is required." );

         }

         String name;

         String email;

         String organization;

         String homepage;

         if ( Developer.class.isAssignableFrom( developerOrContributor.getClass() ) )

         {

             Developer d = (Developer) developerOrContributor;

             name = d.getName();

             email = d.getEmail();

             organization = d.getOrganization();

             homepage = d.getUrl();

         }

         else

         {

             Contributor c = (Contributor) developerOrContributor;

             name = c.getName();

             email = c.getEmail();

             organization = c.getOrganization();

             homepage = c.getUrl();

         }

         // Name is required to write doap

         if ( StringUtils.isEmpty( name ) )

         {

             return;

         }

         writer.startElement( doapType );

         writer.startElement( "foaf:Person" );

         writer.startElement( "foaf:name" );

         writer.writeText( name );

         writer.endElement(); // foaf:name

         if ( StringUtils.isNotEmpty( email ) )

         {

             DoapUtil.writeRdfResourceElement( writer, "foaf:mbox", "mailto:" + email );

         }

         if ( StringUtils.isNotEmpty( organization ) )

         {

             DoapUtil.writeRdfResourceElement( writer, "foaf:Organization", organization );

         }

         if ( StringUtils.isNotEmpty( homepage ) )

         {

             DoapUtil.writeRdfResourceElement( writer, "foaf:homepage", homepage );

         }

         writer.endElement(); // foaf:Person

         writer.endElement(); // doapType

     }

     /**

      * Return a <code>SCM repository</code> defined by a given url

      *

      * @param scmUrl an SCM URL

      * @return a valid SCM repository or null

      */

     private ScmRepository getScmRepository( String scmUrl )

     {

         ScmRepository repo = null;

         if ( !StringUtils.isEmpty( scmUrl ) )

         {

             try

             {

                 repo = scmManager.makeScmRepository( scmUrl );

             }

             catch ( NoSuchScmProviderException e )

             {

                 if ( getLog().isDebugEnabled() )

                 {

                     getLog().debug( e.getMessage(), e );

                 }

             }

             catch ( ScmRepositoryException e )

             {

                 if ( getLog().isDebugEnabled() )

                 {