package org.apache.maven.tools.plugin.extractor.java;

 /*

  * 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.thoughtworks.qdox.JavaDocBuilder;

 import com.thoughtworks.qdox.model.DocletTag;

 import com.thoughtworks.qdox.model.JavaClass;

 import com.thoughtworks.qdox.model.JavaField;

 import com.thoughtworks.qdox.model.Type;

 import org.apache.maven.plugin.descriptor.InvalidParameterException;

 import org.apache.maven.plugin.descriptor.InvalidPluginDescriptorException;

 import org.apache.maven.plugin.descriptor.MojoDescriptor;

 import org.apache.maven.plugin.descriptor.Parameter;

 import org.apache.maven.plugin.descriptor.PluginDescriptor;

 import org.apache.maven.plugin.descriptor.Requirement;

 import org.apache.maven.project.MavenProject;

 import org.apache.maven.tools.plugin.DefaultPluginToolsRequest;

 import org.apache.maven.tools.plugin.ExtendedMojoDescriptor;

 import org.apache.maven.tools.plugin.PluginToolsRequest;

 import org.apache.maven.tools.plugin.extractor.MojoDescriptorExtractor;

 import org.apache.maven.tools.plugin.extractor.ExtractionException;

 import org.apache.maven.tools.plugin.util.PluginUtils;

 import org.codehaus.plexus.component.annotations.Component;

 import org.codehaus.plexus.logging.AbstractLogEnabled;

 import org.codehaus.plexus.util.StringUtils;

 import java.io.File;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Map;

 import java.util.TreeMap;

 /**

  * Extracts Mojo descriptors from <a href="http://java.sun.com/">Java</a> sources.

  * <br/>

  * For more information about the usage tag, have a look to:

  * <a href="http://maven.apache.org/developers/mojo-api-specification.html">

  * http://maven.apache.org/developers/mojo-api-specification.html</a>

  *

  * @todo need to add validation directives so that systems embedding maven2 can

  * get validation directives to help users in IDEs.

  * @version $Id: JavaMojoDescriptorExtractor.java 1343166 2012-05-28 08:54:25Z hboutemy $

  * @see org.apache.maven.plugin.descriptor.MojoDescriptor

  */

 @Component( role = MojoDescriptorExtractor.class, hint = "java" )

 public class JavaMojoDescriptorExtractor

     extends AbstractLogEnabled

     implements MojoDescriptorExtractor, JavaMojoAnnotation

 {

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#INSTANTIATION_STRATEGY} instead of. */

     public static final String MAVEN_PLUGIN_INSTANTIATION = JavaMojoAnnotation.INSTANTIATION_STRATEGY;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#CONFIGURATOR} instead of. */

     public static final String CONFIGURATOR = JavaMojoAnnotation.CONFIGURATOR;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PARAMETER} instead of. */

     public static final String PARAMETER = JavaMojoAnnotation.PARAMETER;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PARAMETER_EXPRESSION} instead of. */

     public static final String PARAMETER_EXPRESSION = JavaMojoAnnotation.PARAMETER_EXPRESSION;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PARAMETER_DEFAULT_VALUE} instead of. */

     public static final String PARAMETER_DEFAULT_VALUE = JavaMojoAnnotation.PARAMETER_DEFAULT_VALUE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PARAMETER_ALIAS} instead of. */

     public static final String PARAMETER_ALIAS = JavaMojoAnnotation.PARAMETER_ALIAS;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#SINCE} instead of. */

     public static final String SINCE = JavaMojoAnnotation.SINCE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PARAMETER_IMPLEMENTATION} instead of. */

     public static final String PARAMETER_IMPLEMENTATION = JavaMojoAnnotation.PARAMETER_IMPLEMENTATION;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRED} instead of. */

     public static final String REQUIRED = JavaMojoAnnotation.REQUIRED;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#DEPRECATED} instead of. */

     public static final String DEPRECATED = JavaMojoAnnotation.DEPRECATED;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#READONLY} instead of. */

     public static final String READONLY = JavaMojoAnnotation.READONLY;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#GOAL} instead of. */

     public static final String GOAL = JavaMojoAnnotation.GOAL;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#PHASE} instead of. */

     public static final String PHASE = JavaMojoAnnotation.PHASE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#EXECUTE} instead of. */

     public static final String EXECUTE = JavaMojoAnnotation.EXECUTE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#EXECUTE_LIFECYCLE} instead of. */

     public static final String EXECUTE_LIFECYCLE = JavaMojoAnnotation.EXECUTE_LIFECYCLE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#EXECUTE_PHASE} instead of. */

     public static final String EXECUTE_PHASE = JavaMojoAnnotation.EXECUTE_PHASE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#EXECUTE_GOAL} instead of. */

     public static final String EXECUTE_GOAL = JavaMojoAnnotation.EXECUTE_GOAL;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#DESCRIPTION} instead of. */

     public static final String GOAL_DESCRIPTION = JavaMojoAnnotation.DESCRIPTION;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRES_DEPENDENCY_RESOLUTION} instead of. */

     public static final String GOAL_REQUIRES_DEPENDENCY_RESOLUTION = JavaMojoAnnotation.REQUIRES_DEPENDENCY_RESOLUTION;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRES_PROJECT} instead of. */

     public static final String GOAL_REQUIRES_PROJECT = JavaMojoAnnotation.REQUIRES_PROJECT;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRES_REPORTS} instead of. */

     public static final String GOAL_REQUIRES_REPORTS = JavaMojoAnnotation.REQUIRES_REPORTS;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#AGGREGATOR} instead of. */

     public static final String GOAL_IS_AGGREGATOR = JavaMojoAnnotation.AGGREGATOR;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRES_ONLINE} instead of. */

     public static final String GOAL_REQUIRES_ONLINE = JavaMojoAnnotation.REQUIRES_ONLINE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#INHERIT_BY_DEFAULT} instead of. */

     public static final String GOAL_INHERIT_BY_DEFAULT = JavaMojoAnnotation.INHERIT_BY_DEFAULT;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#MULTI_EXECUTION_STRATEGY} instead of. */

     public static final String GOAL_MULTI_EXECUTION_STRATEGY = JavaMojoAnnotation.MULTI_EXECUTION_STRATEGY;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#REQUIRES_DIRECT_INVOCATION} instead of. */

     public static final String GOAL_REQUIRES_DIRECT_INVOCATION = JavaMojoAnnotation.REQUIRES_DIRECT_INVOCATION;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#COMPONENT} instead of. */

     public static final String COMPONENT = JavaMojoAnnotation.COMPONENT;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#COMPONENT_ROLE} instead of. */

     public static final String COMPONENT_ROLE = JavaMojoAnnotation.COMPONENT_ROLE;

     /** @deprecated since 2.4, use {@link JavaMojoAnnotation#COMPONENT_ROLEHINT} instead of. */

     public static final String COMPONENT_ROLEHINT = JavaMojoAnnotation.COMPONENT_ROLEHINT;

     /**

      * @param parameter not null

      * @param i positive number

      * @throws InvalidParameterException if any

      */

     protected void validateParameter( Parameter parameter, int i )

         throws InvalidParameterException

     {

         // TODO: remove when backward compatibility is no longer an issue.

         String name = parameter.getName();

         if ( name == null )

         {

             throw new InvalidParameterException( "name", i );

         }

         // TODO: remove when backward compatibility is no longer an issue.

         String type = parameter.getType();

         if ( type == null )

         {

             throw new InvalidParameterException( "type", i );

         }

         // TODO: remove when backward compatibility is no longer an issue.

         String description = parameter.getDescription();

         if ( description == null )

         {

             throw new InvalidParameterException( "description", i );

         }

     }

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

     // Mojo descriptor creation from @tags

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

     /**

      * @param javaClass not null

      * @return a mojo descriptor

      * @throws InvalidPluginDescriptorException if any

      */

     protected MojoDescriptor createMojoDescriptor( JavaClass javaClass )

         throws InvalidPluginDescriptorException

     {

         ExtendedMojoDescriptor mojoDescriptor = new ExtendedMojoDescriptor();

         mojoDescriptor.setLanguage( "java" );

         mojoDescriptor.setImplementation( javaClass.getFullyQualifiedName() );

         mojoDescriptor.setDescription( javaClass.getComment() );

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

         // Mojo annotations in alphabetical order

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

         // Aggregator flag

         DocletTag aggregator = findInClassHierarchy( javaClass, JavaMojoAnnotation.AGGREGATOR );

         if ( aggregator != null )

         {

             mojoDescriptor.setAggregator( true );

         }

         // Configurator hint

         DocletTag configurator = findInClassHierarchy( javaClass, JavaMojoAnnotation.CONFIGURATOR );

         if ( configurator != null )

         {

             mojoDescriptor.setComponentConfigurator( configurator.getValue() );

         }

         // Additional phase to execute first

         DocletTag execute = findInClassHierarchy( javaClass, JavaMojoAnnotation.EXECUTE );

         if ( execute != null )

         {

             String executePhase = execute.getNamedParameter( JavaMojoAnnotation.EXECUTE_PHASE );

             String executeGoal = execute.getNamedParameter( JavaMojoAnnotation.EXECUTE_GOAL );

             if ( executePhase == null && executeGoal == null )

             {

                 throw new InvalidPluginDescriptorException( javaClass.getFullyQualifiedName()

                     + ": @execute tag requires either a 'phase' or 'goal' parameter" );

             }

             else if ( executePhase != null && executeGoal != null )

             {

                 throw new InvalidPluginDescriptorException( javaClass.getFullyQualifiedName()

                     + ": @execute tag can have only one of a 'phase' or 'goal' parameter" );

             }

             mojoDescriptor.setExecutePhase( executePhase );

             mojoDescriptor.setExecuteGoal( executeGoal );

             String lifecycle = execute.getNamedParameter( JavaMojoAnnotation.EXECUTE_LIFECYCLE );

             if ( lifecycle != null )

             {

                 mojoDescriptor.setExecuteLifecycle( lifecycle );

                 if ( mojoDescriptor.getExecuteGoal() != null )

                 {

                     throw new InvalidPluginDescriptorException( javaClass.getFullyQualifiedName()

                         + ": @execute lifecycle requires a phase instead of a goal" );

                 }

             }

         }

         // Goal name

         DocletTag goal = findInClassHierarchy( javaClass, JavaMojoAnnotation.GOAL );

         if ( goal != null )

         {

             mojoDescriptor.setGoal( goal.getValue() );

         }

         // inheritByDefault flag

         boolean value =

             getBooleanTagValue( javaClass, JavaMojoAnnotation.INHERIT_BY_DEFAULT,

                                 mojoDescriptor.isInheritedByDefault() );

         mojoDescriptor.setInheritedByDefault( value );

         // instantiationStrategy

         DocletTag tag = findInClassHierarchy( javaClass, JavaMojoAnnotation.INSTANTIATION_STRATEGY );

         if ( tag != null )

         {

             mojoDescriptor.setInstantiationStrategy( tag.getValue() );

         }

         // executionStrategy (and deprecated @attainAlways)

         tag = findInClassHierarchy( javaClass, JavaMojoAnnotation.MULTI_EXECUTION_STRATEGY );

         if ( tag != null )

         {

             getLogger().warn( "@" + JavaMojoAnnotation.MULTI_EXECUTION_STRATEGY + " in "

                                   + javaClass.getFullyQualifiedName() + " is deprecated: please use '@"

                                   + JavaMojoAnnotation.EXECUTION_STATEGY + " always' instead." );

             mojoDescriptor.setExecutionStrategy( MojoDescriptor.MULTI_PASS_EXEC_STRATEGY );

         }

         else

         {

             mojoDescriptor.setExecutionStrategy( MojoDescriptor.SINGLE_PASS_EXEC_STRATEGY );

         }

         tag = findInClassHierarchy( javaClass, JavaMojoAnnotation.EXECUTION_STATEGY );

         if ( tag != null )

         {

             mojoDescriptor.setExecutionStrategy( tag.getValue() );

         }

         // Phase name

         DocletTag phase = findInClassHierarchy( javaClass, JavaMojoAnnotation.PHASE );

         if ( phase != null )

         {

             mojoDescriptor.setPhase( phase.getValue() );

         }

         // Dependency resolution flag

         DocletTag requiresDependencyResolution =

             findInClassHierarchy( javaClass, JavaMojoAnnotation.REQUIRES_DEPENDENCY_RESOLUTION );

         if ( requiresDependencyResolution != null )

         {

             String v = requiresDependencyResolution.getValue();

             if ( StringUtils.isEmpty( v ) )

             {

                 v = "runtime";

             }

             mojoDescriptor.setDependencyResolutionRequired( v );

         }

         // Dependency collection flag

         DocletTag requiresDependencyCollection =

             findInClassHierarchy( javaClass, JavaMojoAnnotation.REQUIRES_DEPENDENCY_COLLECTION );

         if ( requiresDependencyCollection != null )

         {

             String v = requiresDependencyCollection.getValue();

             if ( StringUtils.isEmpty( v ) )

             {

                 v = "runtime";

             }

             mojoDescriptor.setDependencyCollectionRequired( v );

         }

         // requiresDirectInvocation flag

         value =

             getBooleanTagValue( javaClass, JavaMojoAnnotation.REQUIRES_DIRECT_INVOCATION,

                                 mojoDescriptor.isDirectInvocationOnly() );

         mojoDescriptor.setDirectInvocationOnly( value );

         // Online flag

         value =

             getBooleanTagValue( javaClass, JavaMojoAnnotation.REQUIRES_ONLINE, mojoDescriptor.isOnlineRequired() );

         mojoDescriptor.setOnlineRequired( value );

         // Project flag

         value =

             getBooleanTagValue( javaClass, JavaMojoAnnotation.REQUIRES_PROJECT, mojoDescriptor.isProjectRequired() );

         mojoDescriptor.setProjectRequired( value );

         // requiresReports flag

         value =

             getBooleanTagValue( javaClass, JavaMojoAnnotation.REQUIRES_REPORTS, mojoDescriptor.isRequiresReports() );

         mojoDescriptor.setRequiresReports( value );

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

         // Javadoc annotations in alphabetical order

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

         // Deprecation hint

         DocletTag deprecated = javaClass.getTagByName( JavaMojoAnnotation.DEPRECATED );

         if ( deprecated != null )

         {

             mojoDescriptor.setDeprecated( deprecated.getValue() );

         }

         // What version it was introduced in

         DocletTag since = findInClassHierarchy( javaClass, JavaMojoAnnotation.SINCE );

         if ( since != null )

         {

             mojoDescriptor.setSince( since.getValue() );

         }

         // Thread-safe mojo 

         value = getBooleanTagValue( javaClass, JavaMojoAnnotation.THREAD_SAFE, true, mojoDescriptor.isThreadSafe() );

         mojoDescriptor.setThreadSafe( value );

         extractParameters( mojoDescriptor, javaClass );

         return mojoDescriptor;

     }

     /**

      * @param javaClass not null

      * @param tagName not null

      * @param defaultValue the wanted default value

      * @return the boolean value of the given tagName

      * @see #findInClassHierarchy(JavaClass, String)

      */

     private static boolean getBooleanTagValue( JavaClass javaClass, String tagName, boolean defaultValue )

     {

         DocletTag tag = findInClassHierarchy( javaClass, tagName );

         if ( tag != null )

         {

             String value = tag.getValue();

             if ( StringUtils.isNotEmpty( value ) )

             {

                 defaultValue = Boolean.valueOf( value ).booleanValue();

             }

         }

         return defaultValue;

     }

     /**

      * @param javaClass     not null

      * @param tagName       not null

      * @param defaultForTag The wanted default value when only the tagname is present

      * @param defaultValue  the wanted default value when the tag is not specified

      * @return the boolean value of the given tagName

      * @see #findInClassHierarchy(JavaClass, String)

      */

     private static boolean getBooleanTagValue( JavaClass javaClass, String tagName, boolean defaultForTag,

                                                boolean defaultValue )

     {

         DocletTag tag = findInClassHierarchy( javaClass, tagName );

         if ( tag != null )

         {

             String value = tag.getValue();

             if ( StringUtils.isNotEmpty( value ) )

             {

                 return Boolean.valueOf( value ).booleanValue();

             }

             else

             {

                 return defaultForTag;

             }

         }

         return defaultValue;

     }

     /**

      * @param javaClass not null

      * @param tagName not null

      * @return docletTag instance

      */

     private static DocletTag findInClassHierarchy( JavaClass javaClass, String tagName )

     {

         DocletTag tag = javaClass.getTagByName( tagName );

         if ( tag == null )

         {

             JavaClass superClass = javaClass.getSuperJavaClass();

             if ( superClass != null )

             {

                 tag = findInClassHierarchy( superClass, tagName );

             }

         }

         return tag;

     }

     /**

      * @param mojoDescriptor not null

      * @param javaClass not null

      * @throws InvalidPluginDescriptorException if any

      */

     private void extractParameters( MojoDescriptor mojoDescriptor, JavaClass javaClass )

         throws InvalidPluginDescriptorException

     {

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

         // We're resolving class-level, ancestor-class-field, local-class-field order here.

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

         Map<String, JavaField> rawParams = extractFieldParameterTags( javaClass );

         for ( Map.Entry<String, JavaField> entry : rawParams.entrySet() )

         {

             JavaField field = entry.getValue();

             Type type = field.getType();

             Parameter pd = new Parameter();

             pd.setName( entry.getKey() );

             if ( !type.isArray() )

             {

                 pd.setType( type.getValue() );

             }

             else

             {

                 StringBuilder value = new StringBuilder( type.getValue() );

                 int remaining = type.getDimensions();

                 while ( remaining-- > 0 )

                 {

                     value.append( "[]" );

                 }

                 pd.setType( value.toString() );

             }

             pd.setDescription( field.getComment() );

             DocletTag componentTag = field.getTagByName( JavaMojoAnnotation.COMPONENT );

             if ( componentTag != null )

             {

                 String role = componentTag.getNamedParameter( JavaMojoAnnotation.COMPONENT_ROLE );

                 if ( role == null )

                 {

                     role = field.getType().toString();

                 }

                 String roleHint = componentTag.getNamedParameter( JavaMojoAnnotation.COMPONENT_ROLEHINT );

                 if ( roleHint == null )

                 {

                     // support alternate syntax for better compatibility with the Plexus CDC.

                     roleHint = componentTag.getNamedParameter( "role-hint" );

                 }

                 String expression = PluginUtils.MAVEN_COMPONENTS.get( role );

                 if ( expression == null )

                 {

                     pd.setRequirement( new Requirement( role, roleHint ) );

                 }

                 else

                 {

                     pd.setDefaultValue( expression );

                     pd.setImplementation( role );

                     pd.setType( role );

                 }

                 pd.setEditable( false );

                 /* TODO: or better like this? Need @component fields be editable for the user?

                 pd.setEditable( field.getTagByName( READONLY ) == null );

                 */

             }

             else

             {

                 DocletTag parameter = field.getTagByName( JavaMojoAnnotation.PARAMETER );

                 pd.setRequired( field.getTagByName( JavaMojoAnnotation.REQUIRED ) != null );

                 pd.setEditable( field.getTagByName( JavaMojoAnnotation.READONLY ) == null );

                 DocletTag deprecationTag = field.getTagByName( JavaMojoAnnotation.DEPRECATED );

                 if ( deprecationTag != null )

                 {

                     pd.setDeprecated( deprecationTag.getValue() );

                 }

                 DocletTag sinceTag = field.getTagByName( JavaMojoAnnotation.SINCE );

                 if ( sinceTag != null )

                 {

                     pd.setSince( sinceTag.getValue() );

                 }

                 String alias = parameter.getNamedParameter( JavaMojoAnnotation.PARAMETER_ALIAS );

                 if ( !StringUtils.isEmpty( alias ) )

                 {

                     pd.setAlias( alias );

                 }

                 String expression = parameter.getNamedParameter( JavaMojoAnnotation.PARAMETER_EXPRESSION );

                 String property = parameter.getNamedParameter( JavaMojoAnnotation.PARAMETER_PROPERTY );

                 if ( StringUtils.isNotEmpty( expression ) && StringUtils.isNotEmpty( property ) )

                 {

                     getLogger().error( javaClass.getFullyQualifiedName() + "#" + field.getName() + ":" );

                     getLogger().error( "  Cannot use both:" );

                     getLogger().error( "    @parameter expression=\"${property}\"" );

                     getLogger().error( "  and" );

                     getLogger().error( "    @parameter property=\"property\"" );

                     getLogger().error( "  Second syntax is preferred." );

                     throw new InvalidParameterException( javaClass.getFullyQualifiedName() + "#" + field.getName()

                         + ": cannot" + " use both @parameter expression and property", null );

                 }

                 if ( StringUtils.isNotEmpty( expression ) )

                 {

                     getLogger().warn( javaClass.getFullyQualifiedName() + "#" + field.getName() + ":" );

                     getLogger().warn( "  The syntax" );

                     getLogger().warn( "    @parameter expression=\"${property}\"" );

                     getLogger().warn( "  is deprecated, please use" );

                     getLogger().warn( "    @parameter property=\"property\"" );

                     getLogger().warn( "  instead." );

                 }

                 else if ( StringUtils.isNotEmpty( property ) )

                 {

                     expression = "${" + property + "}";

                 }

                 pd.setExpression( expression );

                 if ( StringUtils.isNotEmpty( expression ) && expression.startsWith( "${component." ) )

                 {

                     getLogger().warn( javaClass.getFullyQualifiedName() + "#" + field.getName() + ":" );

                     getLogger().warn( "  The syntax" );

                     getLogger().warn( "    @parameter expression=\"${component.<role>#<roleHint>}\"" );

                     getLogger().warn( "  is deprecated, please use" );

                     getLogger().warn( "    @component role=\"<role>\" roleHint=\"<roleHint>\"" );

                     getLogger().warn( "  instead." );

                 }

                 if ( "${reports}".equals( pd.getExpression() ) )

                 {

                     mojoDescriptor.setRequiresReports( true );

                 }

                 pd.setDefaultValue( parameter.getNamedParameter( JavaMojoAnnotation.PARAMETER_DEFAULT_VALUE ) );

                 pd.setImplementation( parameter.getNamedParameter( JavaMojoAnnotation.PARAMETER_IMPLEMENTATION ) );

             }

             mojoDescriptor.addParameter( pd );

         }

     }

     /**

      * extract fields that are either parameters or components.

      * 

      * @param javaClass not null

      * @return map with Mojo parameters names as keys

      */

     private Map<String, JavaField> extractFieldParameterTags( JavaClass javaClass )

     {

         Map<String, JavaField> rawParams;

         // we have to add the parent fields first, so that they will be overwritten by the local fields if

         // that actually happens...

         JavaClass superClass = javaClass.getSuperJavaClass();

         if ( superClass != null )

         {

             rawParams = extractFieldParameterTags( superClass );

         }

         else

         {

             rawParams = new TreeMap<String, JavaField>();

         }

         JavaField[] classFields = javaClass.getFields();

         if ( classFields != null )

         {

             for ( JavaField field : classFields )

             {

                 if ( field.getTagByName( JavaMojoAnnotation.PARAMETER ) != null

                     || field.getTagByName( JavaMojoAnnotation.COMPONENT ) != null )

                 {

                     rawParams.put( field.getName(), field );

                 }

             }

         }

         return rawParams;

     }

     /** {@inheritDoc} */

     public List<MojoDescriptor> execute( MavenProject project, PluginDescriptor pluginDescriptor )

         throws ExtractionException, InvalidPluginDescriptorException

     {

         return execute( new DefaultPluginToolsRequest( project, pluginDescriptor ) );

     }

     /** {@inheritDoc} */

     public List<MojoDescriptor> execute( PluginToolsRequest request )

         throws ExtractionException, InvalidPluginDescriptorException

     {

         JavaClass[] javaClasses = discoverClasses( request );

         List<MojoDescriptor> descriptors = new ArrayList<MojoDescriptor>();

         for ( JavaClass javaClass : javaClasses )

         {

             DocletTag tag = javaClass.getTagByName( GOAL );

             if ( tag != null )

             {

                 MojoDescriptor mojoDescriptor = createMojoDescriptor( javaClass );

                 mojoDescriptor.setPluginDescriptor( request.getPluginDescriptor() );

                 // Validate the descriptor as best we can before allowing it to be processed.

                 validate( mojoDescriptor );

                 descriptors.add( mojoDescriptor );

             }

         }

         return descriptors;

     }

     /**

      * @param request The plugin request.

      * @return an array of java class

      */

     @SuppressWarnings( "unchecked" )

     protected JavaClass[] discoverClasses( final PluginToolsRequest request )

     {

         JavaDocBuilder builder = new JavaDocBuilder();

         builder.setEncoding( request.getEncoding() );

         MavenProject project = request.getProject();

         for ( String source : (List<String>) project.getCompileSourceRoots() )

         {

             builder.addSourceTree( new File( source ) );

         }

         // TODO be more dynamic

         File generatedPlugin = new File( project.getBasedir(), "target/generated-sources/plugin" );

         if ( !project.getCompileSourceRoots().contains( generatedPlugin.getAbsolutePath() ) )

         {

             builder.addSourceTree( generatedPlugin );

         }

         return builder.getClasses();

     }

     /**

      * @param mojoDescriptor not null

      * @throws InvalidParameterException if any

      */

     protected void validate( MojoDescriptor mojoDescriptor )

         throws InvalidParameterException

     {

         @SuppressWarnings( "unchecked" )

         List<Parameter> parameters = mojoDescriptor.getParameters();

         if ( parameters != null )

         {

             for ( int j = 0; j < parameters.size(); j++ )

             {

                 validateParameter( parameters.get( j ), j );

             }

         }

     }

 }