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.FileNotFoundException;
  import java.io.IOException;
  import java.io.InputStream;
  import java.lang.reflect.Method;
  import java.net.MalformedURLException;
  import java.net.SocketTimeoutException;
  import java.net.URL;
  import java.text.DateFormat;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.StringTokenizer;
  import java.util.WeakHashMap;
  import java.util.Map.Entry;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import java.util.Set;
  import java.util.Properties;
  
  import org.apache.commons.httpclient.Credentials;
  import org.apache.commons.httpclient.HttpClient;
  import org.apache.commons.httpclient.HttpStatus;
  import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
  import org.apache.commons.httpclient.UsernamePasswordCredentials;
  import org.apache.commons.httpclient.auth.AuthScope;
  import org.apache.commons.httpclient.methods.GetMethod;
  import org.apache.commons.httpclient.params.HttpClientParams;
  import org.apache.commons.httpclient.params.HttpMethodParams;
  import org.apache.maven.model.Contributor;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.settings.Proxy;
  import org.apache.maven.settings.Settings;
  import org.apache.maven.wagon.proxy.ProxyInfo;
  import org.apache.maven.wagon.proxy.ProxyUtils;
  import org.codehaus.plexus.i18n.I18N;
  import org.codehaus.plexus.interpolation.EnvarBasedValueSource;
  import org.codehaus.plexus.interpolation.InterpolationException;
  import org.codehaus.plexus.interpolation.ObjectBasedValueSource;
  import org.codehaus.plexus.interpolation.PrefixedObjectValueSource;
  import org.codehaus.plexus.interpolation.PropertiesBasedValueSource;
  import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.StringUtils;
  import org.codehaus.plexus.util.introspection.ClassMap;
  import org.codehaus.plexus.util.xml.XMLWriter;
  import org.codehaus.plexus.util.xml.XmlWriterUtil;
  
  import com.hp.hpl.jena.rdf.model.Model;
  import com.hp.hpl.jena.rdf.model.ModelFactory;
  import com.hp.hpl.jena.rdf.model.RDFReader;
  import com.hp.hpl.jena.rdf.model.impl.RDFDefaultErrorHandler;
  
  /**
   * Utility class for {@link DoapMojo} class.
   *
   * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
   * @version $Id: DoapUtil.java 1642247 2014-11-27 23:17:01Z hboutemy $
   * @since 1.0
   */
  public class DoapUtil
  {
      /** Email regex */
      private static final String EMAIL_REGEX =
          "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
  
      /** Email pattern */
      private static final Pattern EMAIL_PATTERN = Pattern.compile( EMAIL_REGEX );
  
      /** Magic number to repeat '=' */
      private static final int REPEAT_EQUALS = 21;
  
      /** The default timeout used when fetching url, i.e. 2000. */
     public static final int DEFAULT_TIMEOUT = 2000;
 
     /** RDF resource attribute */
     protected static final String RDF_RESOURCE = "rdf:resource";
 
     /** RDF nodeID attribute */
     protected static final String RDF_NODE_ID = "rdf:nodeID";
 
     /** DoaP Organizations stored by name */
     private static Map<String, DoapUtil.Organization> organizations = new HashMap<String, DoapUtil.Organization>();
 
     /**
      * Write comments in the DOAP file header
      *
      * @param writer not null
      */
     public static void writeHeader( XMLWriter writer )
     {
         XmlWriterUtil.writeLineBreak( writer );
 
         XmlWriterUtil.writeCommentLineBreak( writer );
         XmlWriterUtil.writeComment( writer, StringUtils.repeat( "=", REPEAT_EQUALS ) + " - DO NOT EDIT THIS FILE! - "
             + StringUtils.repeat( "=", REPEAT_EQUALS ) );
         XmlWriterUtil.writeCommentLineBreak( writer );
         XmlWriterUtil.writeComment( writer, " " );
         XmlWriterUtil.writeComment( writer, "Any modifications will be overwritten." );
         XmlWriterUtil.writeComment( writer, " " );
         DateFormat dateFormat = DateFormat.getDateTimeInstance( DateFormat.SHORT, DateFormat.SHORT, Locale.US );
         XmlWriterUtil.writeComment( writer, "Generated by Maven Doap Plugin " + getPluginVersion() + " on "
             + dateFormat.format( new Date( System.currentTimeMillis() ) ) );
         XmlWriterUtil.writeComment( writer, "See: http://maven.apache.org/plugins/maven-doap-plugin/" );
         XmlWriterUtil.writeComment( writer, " " );
         XmlWriterUtil.writeCommentLineBreak( writer );
 
         XmlWriterUtil.writeLineBreak( writer );
     }
 
     /**
      * Write comment.
      *
      * @param writer not null
      * @param comment not null
      * @throws IllegalArgumentException if comment is null or empty
      * @since 1.1
      */
     public static void writeComment( XMLWriter writer, String comment )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( comment ) )
         {
             throw new IllegalArgumentException( "comment should be defined" );
         }
 
         XmlWriterUtil.writeLineBreak( writer );
         XmlWriterUtil.writeCommentText( writer, comment, 2 );
     }
 
     /**
      * @param writer not null
      * @param xmlnsPrefix could be null
      * @param name not null
      * @param value could be null. In this case, the element is not written.
      * @throws IllegalArgumentException if name is null or empty
      */
     public static void writeElement( XMLWriter writer, String xmlnsPrefix, String name, String value )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( name ) )
         {
             throw new IllegalArgumentException( "name should be defined" );
         }
 
         if ( value != null )
         {
             writeStartElement( writer, xmlnsPrefix, name );
             writer.writeText( value );
             writer.endElement();
         }
     }
 
     /**
      * @param writer not null
      * @param xmlnsPrefix could be null
      * @param name not null
      * @param lang not null
      * @param value could be null. In this case, the element is not written.
      * @throws IllegalArgumentException if name is null or empty
      */
     public static void writeElement( XMLWriter writer, String xmlnsPrefix, String name, String value, String lang )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( lang ) )
         {
             writeElement( writer, xmlnsPrefix, name, value );
             return;
         }
 
         if ( StringUtils.isEmpty( name ) )
         {
             throw new IllegalArgumentException( "name should be defined" );
         }
 
         if ( value != null )
         {
             writeStartElement( writer, xmlnsPrefix, name );
             writer.addAttribute( "xml:lang", lang );
             writer.writeText( value );
             writer.endElement();
         }
     }
 
     /**
      * @param writer not null
      * @param xmlnsPrefix could be null
      * @param name not null
      * @throws IllegalArgumentException if name is null or empty
      * @since 1.1
      */
     public static void writeStartElement( XMLWriter writer, String xmlnsPrefix, String name )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( name ) )
         {
             throw new IllegalArgumentException( "name should be defined" );
         }
 
         if ( StringUtils.isNotEmpty( xmlnsPrefix ) )
         {
             writer.startElement( xmlnsPrefix + ":" + name );
         }
         else
         {
             writer.startElement( name );
         }
     }
 
     /**
      * @param writer not null
      * @param xmlnsPrefix could be null
      * @param name not null
      * @param value could be null. In this case, the element is not written.
      * @throws IllegalArgumentException if name is null or empty
      */
     public static void writeRdfResourceElement( XMLWriter writer, String xmlnsPrefix, String name, String value )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( name ) )
         {
             throw new IllegalArgumentException( "name should be defined" );
         }
 
         if ( value != null )
         {
             writeStartElement( writer, xmlnsPrefix, name );
             writer.addAttribute( RDF_RESOURCE, value );
             writer.endElement();
         }
     }
 
     /**
      * @param writer not null
      * @param name not null
      * @param value could be null. In this case, the element is not written.
      * @throws IllegalArgumentException if name is null or empty
      */
     public static void writeRdfNodeIdElement( XMLWriter writer, String xmlnsPrefix, String name, String value )
         throws IllegalArgumentException
     {
         if ( StringUtils.isEmpty( name ) )
         {
             throw new IllegalArgumentException( "name should be defined" );
         }
 
         if ( value != null )
         {
             writeStartElement( writer, xmlnsPrefix, name );
             writer.addAttribute( RDF_NODE_ID, value );
             writer.endElement();
         }
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have a <code>developer</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithDeveloperRole( I18N i18n,
                                                                       List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "developers" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have a <code>documenter</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithDocumenterRole( I18N i18n,
                                                                        List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "documenters" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have an <code>helper</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithHelperRole( I18N i18n,
                                                                    List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "helpers" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have a <code>maintainer</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithMaintainerRole( I18N i18n,
                                                                        List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "maintainers" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have a <code>tester</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithTesterRole( I18N i18n,
                                                                    List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "testers" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have a <code>translator</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithTranslatorRole( I18N i18n,
                                                                        List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "translators" );
     }
 
     /**
      * @param i18n the internationalization component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null list of <code>{@link Contributor}</code> which have an <code>unknown</code> DOAP role.
      */
     public static List<Contributor> getContributorsWithUnknownRole( I18N i18n,
                                                                     List<Contributor> developersOrContributors )
     {
         return filterContributorsByDoapRoles( i18n, developersOrContributors ).get( "unknowns" );
     }
 
     /**
      * Utility class for keeping track of DOAP organizations in the DoaP mojo.
      *
      * @author <a href="mailto:t.fliss@gmail.com">Tim Fliss</a>
      * @version $Id: DoapUtil.java 1642247 2014-11-27 23:17:01Z hboutemy $
      * @since 1.1
      */
     public static class Organization
     {
         private String name;
 
         private String url;
 
         private List<String> members = new LinkedList<String>();
 
         public Organization( String name, String url )
         {
             this.name = name;
             this.url = url;
         }
 
         public void setName( String name )
         {
             this.name = name;
         }
 
         public String getName()
         {
             return name;
         }
 
         public void setUrl( String url )
         {
             this.url = url;
         }
 
         public String getUrl()
         {
             return url;
         }
 
         public void addMember( String nodeId )
         {
             members.add( nodeId );
         }
 
         public List<String> getMembers()
         {
             return members;
         }
     }
 
     /**
      * put an organization from the pom file in the organization list.
      *
      * @param name from the pom file (e.g. Yoyodyne)
      * @param url from the pom file (e.g. http://yoyodyne.example.org/about)
      * @return the existing organization if a duplicate, or a new one.
      */
     public static DoapUtil.Organization addOrganization( String name, String url )
     {
         Organization organization = organizations.get( name );
 
         if ( organization == null )
         {
             organization = new DoapUtil.Organization( name, url );
         }
 
         organizations.put( name, organization );
 
         return organization;
     }
 
     // unique RDF blank node index scoped internal to the DOAP file
     private static int nodeNumber = 1;
 
     /**
      * get a unique (within the DoaP file) RDF blank node ID
      *
      * @return the nodeID
      * @see <a href="http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-blank-nodes">
      *      http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-blank-nodes</a>
      */
     public static String getNodeId()
     {
         return "b" + nodeNumber++;
     }
 
     /**
      * get the set of Organizations that people are members of
      *
      * @return Map.EntrySet of DoapUtil.Organization
      */
     public static Set<Entry<String, DoapUtil.Organization>> getOrganizations()
     {
         return organizations.entrySet();
     }
 
     /**
      * Validate the given DOAP file.
      *
      * @param doapFile not null and should exists.
      * @return an empty list if the DOAP file is valid, otherwise a list of errors.
      * @since 1.1
      */
     public static List<String> validate( File doapFile )
     {
         if ( doapFile == null || !doapFile.isFile() )
         {
             throw new IllegalArgumentException( "The DOAP file should exist" );
         }
 
         Model model = ModelFactory.createDefaultModel();
         RDFReader r = model.getReader( "RDF/XML" );
         r.setProperty( "error-mode", "strict-error" );
         final List<String> errors = new ArrayList<String>();
         r.setErrorHandler( new RDFDefaultErrorHandler()
         {
             @Override
             public void error( Exception e )
             {
                 errors.add( e.getMessage() );
             }
         } );
 
         try
         {
             r.read( model, doapFile.toURI().toURL().toString() );
         }
         catch ( MalformedURLException e )
         {
             // ignored
         }
 
         return errors;
     }
 
     /**
      * @param str not null
      * @return <code>true</code> if the str parameter is a valid email, <code>false</code> otherwise.
      * @since 1.1
      */
     public static boolean isValidEmail( String str )
     {
         if ( StringUtils.isEmpty( str ) )
         {
             return false;
         }
 
         Matcher matcher = EMAIL_PATTERN.matcher( str );
         return matcher.matches();
     }
 
     /**
      * Fetch an URL
      *
      * @param settings the user settings used to fetch the url with an active proxy, if defined.
      * @param url the url to fetch
      * @throws IOException if any
      * @see #DEFAULT_TIMEOUT
      * @since 1.1
      */
     public static void fetchURL( Settings settings, URL url )
         throws IOException
     {
         if ( url == null )
         {
             throw new IllegalArgumentException( "The url is null" );
         }
 
         if ( "file".equals( url.getProtocol() ) )
         {
             InputStream in = null;
             try
             {
                 in = url.openStream();
             }
             finally
             {
                 IOUtil.close( in );
             }
 
             return;
         }
 
         // http, https...
         HttpClient httpClient = new HttpClient( new MultiThreadedHttpConnectionManager() );
         httpClient.getHttpConnectionManager().getParams().setConnectionTimeout( DEFAULT_TIMEOUT );
         httpClient.getHttpConnectionManager().getParams().setSoTimeout( DEFAULT_TIMEOUT );
         httpClient.getParams().setBooleanParameter( HttpClientParams.ALLOW_CIRCULAR_REDIRECTS, true );
 
         // Some web servers don't allow the default user-agent sent by httpClient
         httpClient.getParams().setParameter( HttpMethodParams.USER_AGENT,
                                              "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)" );
 
         if ( settings != null && settings.getActiveProxy() != null )
         {
             Proxy activeProxy = settings.getActiveProxy();
 
             ProxyInfo proxyInfo = new ProxyInfo();
             proxyInfo.setNonProxyHosts( activeProxy.getNonProxyHosts() );
 
             if ( StringUtils.isNotEmpty( activeProxy.getHost() )
                 && !ProxyUtils.validateNonProxyHosts( proxyInfo, url.getHost() ) )
             {
                 httpClient.getHostConfiguration().setProxy( activeProxy.getHost(), activeProxy.getPort() );
 
                 if ( StringUtils.isNotEmpty( activeProxy.getUsername() ) && activeProxy.getPassword() != null )
                 {
                     Credentials credentials =
                         new UsernamePasswordCredentials( activeProxy.getUsername(), activeProxy.getPassword() );
 
                     httpClient.getState().setProxyCredentials( AuthScope.ANY, credentials );
                 }
             }
         }
 
         GetMethod getMethod = new GetMethod( url.toString() );
         try
         {
             int status;
             try
             {
                 status = httpClient.executeMethod( getMethod );
             }
             catch ( SocketTimeoutException e )
             {
                 // could be a sporadic failure, one more retry before we give up
                 status = httpClient.executeMethod( getMethod );
             }
 
             if ( status != HttpStatus.SC_OK )
             {
                 throw new FileNotFoundException( url.toString() );
             }
         }
         finally
         {
             getMethod.releaseConnection();
         }
     }
 
     /**
      * Interpolate a string with project and settings.
      *
      * @param value could be null
      * @param project not null
      * @param settings could be null
      * @return the value trimmed and interpolated or null if the interpolation doesn't work.
      * @since 1.1
      */
     public static String interpolate( String value, final MavenProject project, Settings settings )
     {
         if ( project == null )
         {
             throw new IllegalArgumentException( "project is required" );
         }
 
         if ( value == null )
         {
             return value;
         }
 
         if ( !value.contains( "${" ) )
         {
             return value.trim();
         }
 
         RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
         try
         {
             interpolator.addValueSource( new EnvarBasedValueSource() );
         }
         catch ( IOException e )
         {
             // ignore
         }
         interpolator.addValueSource( new PropertiesBasedValueSource( System.getProperties() ) );
         interpolator.addValueSource( new PropertiesBasedValueSource( project.getProperties() ) );
         interpolator.addValueSource( new PrefixedObjectValueSource( "project", project ) );
         interpolator.addValueSource( new PrefixedObjectValueSource( "pom", project ) );
         interpolator.addValueSource( new ObjectBasedValueSource( project )
         {
             @Override
             public Object getValue( String expression )
             {
                 try
                 {
                     return ReflectionValueExtractor.evaluate( expression, project, true );
                 }
                 catch ( Exception e )
                 {
                     addFeedback( "Failed to extract \'" + expression + "\' from: " + project, e );
                 }
 
                 return null;
             }
         } );
 
         if ( settings != null )
         {
             interpolator.addValueSource( new PrefixedObjectValueSource( "settings", settings ) );
         }
 
         String interpolatedValue = value;
         try
         {
             interpolatedValue = interpolator.interpolate( value ).trim();
         }
         catch ( InterpolationException e )
         {
             // ignore
         }
 
         if ( interpolatedValue.startsWith( "${" ) )
         {
             return null;
         }
 
         return interpolatedValue;
     }
 
     // ----------------------------------------------------------------------
     // Private methods
     // ----------------------------------------------------------------------
 
     /**
      * Filter the developers/contributors roles by the keys from {@link I18N#getBundle()}. <br/>
      * I18N roles supported in DOAP, i.e. <code>maintainer</code>, <code>developer</code>, <code>documenter</code>,
      * <code>translator</code>, <code>tester</code>, <code>helper</code>. <br/>
      * <b>Note:</b> Actually, only English keys are used.
      *
      * @param i18n i18n component
      * @param developersOrContributors list of <code>{@link Contributor}</code>
      * @return a none null map with <code>maintainers</code>, <code>developers</code>, <code>documenters</code>,
      *         <code>translators</code>, <code>testers</code>, <code>helpers</code>, <code>unknowns</code> as keys and
      *         list of <code>{@link Contributor}</code> as value.
      */
     private static Map<String, List<Contributor>> filterContributorsByDoapRoles( I18N i18n,
                                                                            List<Contributor> developersOrContributors )
     {
         Map<String, List<Contributor>> returnMap = new HashMap<String, List<Contributor>>( 7 );
         returnMap.put( "maintainers", new ArrayList<Contributor>() );
         returnMap.put( "developers", new ArrayList<Contributor>() );
         returnMap.put( "documenters", new ArrayList<Contributor>() );
         returnMap.put( "translators", new ArrayList<Contributor>() );
         returnMap.put( "testers", new ArrayList<Contributor>() );
         returnMap.put( "helpers", new ArrayList<Contributor>() );
         returnMap.put( "unknowns", new ArrayList<Contributor>() );
 
         if ( developersOrContributors == null || developersOrContributors.isEmpty() )
         {
             return returnMap;
         }
 
         for ( Contributor contributor : developersOrContributors )
         {
             List<String> roles = contributor.getRoles();
 
             if ( roles != null && roles.size() != 0 )
             {
                 for ( String role : roles )
                 {
                     role = role.toLowerCase( Locale.ENGLISH );
                     if ( role.contains( getLowerCaseString( i18n, "doap.maintainer" ) ) )
                     {
                         if ( !returnMap.get( "maintainers" ).contains( contributor ) )
                         {
                             returnMap.get( "maintainers" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.developer" ) ) )
                     {
                         if ( !returnMap.get( "developers" ).contains( contributor ) )
                         {
                             returnMap.get( "developers" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.documenter" ) ) )
                     {
                         if ( !returnMap.get( "documenters" ).contains( contributor ) )
                         {
                             returnMap.get( "documenters" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.translator" ) ) )
                     {
                         if ( !returnMap.get( "translators" ).contains( contributor ) )
                         {
                             returnMap.get( "translators" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.tester" ) ) )
                     {
                         if ( !returnMap.get( "testers" ).contains( contributor ) )
                         {
                             returnMap.get( "testers" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.helper" ) ) )
                     {
                         if ( !returnMap.get( "helpers" ).contains( contributor ) )
                         {
                             returnMap.get( "helpers" ).add( contributor );
                         }
                     }
                     else if ( role.contains( getLowerCaseString( i18n, "doap.emeritus" ) ) )
                     {
                         // Don't add as developer nor as contributor as the person is no longer involved
                     }
                     else
                     {
                         if ( !returnMap.get( "unknowns" ).contains( contributor ) )
                         {
                             returnMap.get( "unknowns" ).add( contributor );
                         }
                     }
                 }
             }
             else
             {
                 if ( !returnMap.get( "unknowns" ).contains( contributor ) )
                 {
                     returnMap.get( "unknowns" ).add( contributor );
                 }
             }
         }
 
         return returnMap;
     }
 
     /**
      * @param i18n not null
      * @param key not null
      * @return lower case value for the key in the i18n bundle.
      */
     private static String getLowerCaseString( I18N i18n, String key )
     {
         return i18n.getString( "doap-person", Locale.ENGLISH, key ).toLowerCase( Locale.ENGLISH );
     }
 
     /**
      * @return the Maven artefact version.
      */
     private static String getPluginVersion()
     {
         Properties pomProperties = new Properties();
         InputStream is = null;
         try
         {
             is =
                 DoapUtil.class.getResourceAsStream( "/META-INF/maven/org.apache.maven.plugins/"
                     + "maven-doap-plugin/pom.properties" );
             if ( is == null )
             {
                 return "<unknown>";
             }
 
             pomProperties.load( is );
 
             return pomProperties.getProperty( "version", "<unknown>" );
         }
         catch ( IOException e )
         {
             return "<unknown>";
         }
         finally
         {
             IOUtil.close( is );
         }
     }
 
     /**
      * Fork of {@link org.codehaus.plexus.interpolation.reflection.ReflectionValueExtractor} to care of list or arrays.
      */
     static class ReflectionValueExtractor
     {
         @SuppressWarnings( "rawtypes" )
         private static final Class[] CLASS_ARGS = new Class[0];
 
         private static final Object[] OBJECT_ARGS = new Object[0];
 
         /**
          * Use a WeakHashMap here, so the keys (Class objects) can be garbage collected. This approach prevents permgen
          * space overflows due to retention of discarded classloaders.
          */
         @SuppressWarnings( "rawtypes" )
         private static final Map<Class, ClassMap> CLASS_MAPS = new WeakHashMap<Class, ClassMap>();
 
         private ReflectionValueExtractor()
         {
         }
 
         public static Object evaluate( String expression, Object root )
             throws Exception
         {
             return evaluate( expression, root, true );
         }
 
         // TODO: don't throw Exception
         public static Object evaluate( String expression, Object root, boolean trimRootToken )
             throws Exception
         {
             // if the root token refers to the supplied root object parameter, remove it.
             if ( trimRootToken )
             {
                 expression = expression.substring( expression.indexOf( '.' ) + 1 );
             }
 
             Object value = root;
 
             // ----------------------------------------------------------------------
             // Walk the dots and retrieve the ultimate value desired from the
             // MavenProject instance.
             // ----------------------------------------------------------------------
 
             StringTokenizer parser = new StringTokenizer( expression, "." );
 
             while ( parser.hasMoreTokens() )
             {
                 String token = parser.nextToken();
                 if ( value == null )
                 {
                     return null;
                 }
 
                 StringTokenizer parser2 = new StringTokenizer( token, "[]" );
                 int index = -1;
                 if ( parser2.countTokens() > 1 )
                 {
                     token = parser2.nextToken();
                     try
                     {
                         index = Integer.valueOf( parser2.nextToken() ).intValue();
                     }
                     catch ( NumberFormatException e )
                     {
                         // ignore
                     }
                 }
 
                 final ClassMap classMap = getClassMap( value.getClass() );
 
                 final String methodBase = StringUtils.capitalizeFirstLetter( token );
 
                 String methodName = "get" + methodBase;
 
                 Method method = classMap.findMethod( methodName, CLASS_ARGS );
 
                 if ( method == null )
                 {
                     // perhaps this is a boolean property??
                     methodName = "is" + methodBase;
 
                     method = classMap.findMethod( methodName, CLASS_ARGS );
                 }
 
                 if ( method == null )
                 {
                     return null;
                 }
 
                 value = method.invoke( value, OBJECT_ARGS );
                 if ( value == null )
                 {
                     return null;
                 }
                 if ( Collection.class.isAssignableFrom( value.getClass() ) )
                 {
                     ClassMap classMap2 = getClassMap( value.getClass() );
 
                     Method method2 = classMap2.findMethod( "toArray", CLASS_ARGS );
 
                     value = method2.invoke( value, OBJECT_ARGS );
                 }
                 if ( value.getClass().isArray() )
                 {
                     value = ( (Object[]) value )[index];
                 }
             }
 
             return value;
         }
 
         private static ClassMap getClassMap( Class<? extends Object> clazz )
         {
             ClassMap classMap = CLASS_MAPS.get( clazz );
 
             if ( classMap == null )
             {
                 classMap = new ClassMap( clazz );
 
                 CLASS_MAPS.put( clazz, classMap );
             }
 
             return classMap;
         }
     }
 }