package org.apache.maven.reporting.exec;
   
   /*
    * 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 javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Objects;
  import java.util.Set;
  
  import org.apache.maven.lifecycle.LifecycleExecutor;
  import org.apache.maven.model.Build;
  import org.apache.maven.model.Plugin;
  import org.apache.maven.plugin.MavenPluginManager;
  import org.apache.maven.plugin.Mojo;
  import org.apache.maven.plugin.MojoExecution;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoNotFoundException;
  import org.apache.maven.plugin.PluginConfigurationException;
  import org.apache.maven.plugin.PluginContainerException;
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.apache.maven.plugin.version.DefaultPluginVersionRequest;
  import org.apache.maven.plugin.version.PluginVersionRequest;
  import org.apache.maven.plugin.version.PluginVersionResolutionException;
  import org.apache.maven.plugin.version.PluginVersionResolver;
  import org.apache.maven.plugin.version.PluginVersionResult;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.reporting.MavenReport;
  import org.codehaus.plexus.configuration.PlexusConfiguration;
  import org.codehaus.plexus.util.StringUtils;
  import org.codehaus.plexus.util.xml.Xpp3Dom;
  import org.codehaus.plexus.util.xml.Xpp3DomUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * <p>
   * This component will build some {@link MavenReportExecution} from {@link MavenReportExecutorRequest}. If a
   * {@link MavenReport} needs to fork a lifecycle, this fork is executed here. It will ask the core to get some
   * informations in order to correctly setup {@link MavenReport}.
   * </p>
   * <p>
   * <b>Note</b> if no version is defined in the report plugin, the version will be searched with
   * {@link #resolvePluginVersion(ReportPlugin, MavenReportExecutorRequest) resolvePluginVersion(...)} method:
   * </p>
   * <ol>
   * <li>use the one defined in the reportPlugin configuration,</li>
   * <li>search similar (same groupId and artifactId) plugin in the build/plugins section of the pom,</li>
   * <li>search similar (same groupId and artifactId) plugin in the build/pluginManagement section of the pom,</li>
   * <li>ask {@link PluginVersionResolver} to get a fallback version (display a warning as it's not a recommended use).
   * </li>
   * </ol>
   * <p>
   * Following steps are done:
   * </p>
   * <ul>
   * <li>get {@link PluginDescriptor} from the {@link MavenPluginManager} (through
   * {@link MavenPluginManagerHelper#getPluginDescriptor(Plugin, org.apache.maven.execution.MavenSession)
   * MavenPluginManagerHelper.getPluginDescriptor(...)} to protect from core API change)</li>
   * <li>setup a {@link ClassLoader}, with the Site plugin classloader as parent for the report execution. <br>
   * Notice that some classes are imported from the current Site plugin ClassRealm: see {@link #IMPORTS}. Corresponding
   * artifacts are excluded from the artifact resolution: <code>doxia-site-renderer</code>, <code>doxia-sink-api</code>
   *  and <code>maven-reporting-api</code>.<br>
   * Work is done using {@link MavenPluginManager} (through
   * {@link MavenPluginManagerHelper#setupPluginRealm(PluginDescriptor, MavenSession, ClassLoader, List, List)
   * MavenPluginManagerHelper.setupPluginRealm(...)} to protect from core API change)</li>
   * <li>setup the mojo using {@link MavenPluginManager#getConfiguredMojo(Class, MavenSession, MojoExecution)
   * MavenPluginManager.getConfiguredMojo(...)}</li>
   * <li>verify with {@link LifecycleExecutor#calculateForkedExecutions(MojoExecution, MavenSession)
   * LifecycleExecutor.calculateForkedExecutions(...)} if any forked execution is needed: if yes, execute the forked
   * execution here</li>
   * </ul>
   *
  * @author Olivier Lamy
  */
 @Singleton
 @Named
 public class DefaultMavenReportExecutor
     implements MavenReportExecutor
 {
     private static final Logger LOGGER = LoggerFactory.getLogger( DefaultMavenReportExecutor.class );
 
     private final MavenPluginManager mavenPluginManager;
 
     private final MavenPluginManagerHelper mavenPluginManagerHelper;
 
     private final LifecycleExecutor lifecycleExecutor;
 
     private final PluginVersionResolver pluginVersionResolver;
 
     private static final List<String> IMPORTS = Arrays.asList( "org.apache.maven.reporting.MavenReport",
                                                                "org.apache.maven.reporting.MavenMultiPageReport",
                                                                "org.apache.maven.doxia.siterenderer.Renderer",
                                                                "org.apache.maven.doxia.sink.SinkFactory",
                                                                // TODO Will be removed with Doxia 2.0.0-M1
                                                                "org.codehaus.doxia.sink.Sink",
                                                                "org.apache.maven.doxia.sink.Sink",
                                                                "org.apache.maven.doxia.sink.SinkEventAttributes",
                                                                // TODO Will be removed with Doxia 2.0.0-M1
                                                                "org.apache.maven.doxia.logging.LogEnabled",
                                                                // TODO Will be removed with Doxia 2.0.0-M1
                                                                "org.apache.maven.doxia.logging.Log" );
 
     private static final List<String> EXCLUDES = Arrays.asList( "doxia-site-renderer", "doxia-sink-api",
                                                                 "maven-reporting-api" );
 
     @Inject
     public DefaultMavenReportExecutor( MavenPluginManager mavenPluginManager,
                                        MavenPluginManagerHelper mavenPluginManagerHelper,
                                        LifecycleExecutor lifecycleExecutor,
                                        PluginVersionResolver pluginVersionResolver )
     {
         this.mavenPluginManager = requireNonNull( mavenPluginManager );
         this.mavenPluginManagerHelper = requireNonNull( mavenPluginManagerHelper );
         this.lifecycleExecutor = requireNonNull( lifecycleExecutor );
         this.pluginVersionResolver = requireNonNull( pluginVersionResolver );
     }
 
     @Override
     public List<MavenReportExecution> buildMavenReports( MavenReportExecutorRequest mavenReportExecutorRequest )
         throws MojoExecutionException
     {
         if ( mavenReportExecutorRequest.getReportPlugins() == null )
         {
             return Collections.emptyList();
         }
 
         Set<String> reportPluginKeys = new HashSet<>();
         List<MavenReportExecution> reportExecutions = new ArrayList<>();
 
         String pluginKey = "";
         try
         {
             for ( ReportPlugin reportPlugin : mavenReportExecutorRequest.getReportPlugins() )
             {
                 pluginKey = reportPlugin.getGroupId() + ':' + reportPlugin.getArtifactId();
 
                 if ( !reportPluginKeys.add( pluginKey ) )
                 {
                     LOGGER.info( "Plugin {} will be executed more than one time", pluginKey );
                 }
 
                 reportExecutions.addAll( buildReportPlugin( mavenReportExecutorRequest, reportPlugin ) );
             }
         }
         catch ( Exception e )
         {
             throw new MojoExecutionException( "Failed to get report for " + pluginKey, e );
         }
 
         return reportExecutions;
     }
 
     protected List<MavenReportExecution> buildReportPlugin( MavenReportExecutorRequest mavenReportExecutorRequest,
                                                             ReportPlugin reportPlugin )
         throws Exception
     {
         // step 1: prepare the plugin
         Plugin plugin = new Plugin();
         plugin.setGroupId( reportPlugin.getGroupId() );
         plugin.setArtifactId( reportPlugin.getArtifactId() );
         plugin.setVersion( resolvePluginVersion( reportPlugin, mavenReportExecutorRequest ) );
         LOGGER.info( "Configuring report plugin {}", plugin.getId() );
 
         mergePluginToReportPlugin( mavenReportExecutorRequest, plugin, reportPlugin );
 
         PluginDescriptor pluginDescriptor =
             mavenPluginManagerHelper.getPluginDescriptor( plugin, mavenReportExecutorRequest.getMavenSession() );
 
         // step 2: prepare the goals
         List<GoalWithConf> goalsWithConfiguration = new ArrayList<>();
         boolean hasUserDefinedReports = prepareGoals( reportPlugin, pluginDescriptor, goalsWithConfiguration );
 
         // step 3: prepare the reports
         List<MavenReportExecution> reports = new ArrayList<>( goalsWithConfiguration.size() );
         for ( GoalWithConf report : goalsWithConfiguration )
         {
             MavenReportExecution mavenReportExecution =
                 prepareReportExecution( mavenReportExecutorRequest, report, hasUserDefinedReports );
 
             if ( mavenReportExecution != null )
             {
                 // ok, report is ready to generate
                 reports.add( mavenReportExecution );
             }
         }
 
         if ( !reports.isEmpty() )
         {
             // log reports, either configured or detected
             StringBuilder buff = new StringBuilder();
             for ( MavenReportExecution mre : reports )
             {
                 if ( buff.length() > 0 )
                 {
                     buff.append( ", " );
                 }
                 buff.append( mre.getGoal() );
             }
             LOGGER.info( "{} report{} {} for {}:{}: {}", reports.size(), ( reports.size() > 1 ? "s" : "" ),
                 ( hasUserDefinedReports ? "configured" : "detected" ), plugin.getArtifactId(),
                 plugin.getVersion(), buff );
         }
 
         return reports;
     }
 
     private boolean prepareGoals( ReportPlugin reportPlugin, PluginDescriptor pluginDescriptor,
                                List<GoalWithConf> goalsWithConfiguration )
     {
         if ( reportPlugin.getReportSets().isEmpty() && reportPlugin.getReports().isEmpty() )
         {
             // by default, use every goal, which will be filtered later to only keep reporting goals
             List<MojoDescriptor> mojoDescriptors = pluginDescriptor.getMojos();
             for ( MojoDescriptor mojoDescriptor : mojoDescriptors )
             {
                 goalsWithConfiguration.add( new GoalWithConf( reportPlugin, pluginDescriptor, mojoDescriptor.getGoal(),
                                                               mojoDescriptor.getConfiguration() ) );
             }
 
             return false;
         }
 
         Set<String> goals = new HashSet<>();
         for ( String report : reportPlugin.getReports() )
         {
             if ( goals.add( report ) )
             {
                 goalsWithConfiguration.add( new GoalWithConf( reportPlugin, pluginDescriptor, report,
                                                               reportPlugin.getConfiguration() ) );
             }
             else
             {
                 LOGGER.warn( "{} report is declared twice in default reports", report );
             }
         }
 
         for ( ReportSet reportSet : reportPlugin.getReportSets() )
         {
             goals = new HashSet<>();
             for ( String report : reportSet.getReports() )
             {
                 if ( goals.add( report ) )
                 {
                     goalsWithConfiguration.add( new GoalWithConf( reportPlugin, pluginDescriptor, report,
                                                                   reportSet.getConfiguration() ) );
                 }
                 else
                 {
                     LOGGER.warn( "{} report is declared twice in {} reportSet", report, reportSet.getId() );
                 }
             }
         }
 
         return true;
     }
 
     private MavenReportExecution prepareReportExecution( MavenReportExecutorRequest mavenReportExecutorRequest,
                                                          GoalWithConf report, boolean hasUserDefinedReports )
         throws Exception
     {
         ReportPlugin reportPlugin = report.getReportPlugin();
         PluginDescriptor pluginDescriptor = report.getPluginDescriptor();
 
         MojoDescriptor mojoDescriptor = pluginDescriptor.getMojo( report.getGoal() );
         if ( mojoDescriptor == null )
         {
             throw new MojoNotFoundException( report.getGoal(), pluginDescriptor );
         }
 
         MavenProject project = mavenReportExecutorRequest.getProject();
         if ( !hasUserDefinedReports && mojoDescriptor.isAggregator() && !canAggregate( project ) )
         {
             // aggregator mojos automatically added from plugin are only run at execution root
             return null;
         }
 
         MojoExecution mojoExecution = new MojoExecution( pluginDescriptor.getPlugin(), report.getGoal(), null );
 
         mojoExecution.setMojoDescriptor( mojoDescriptor );
 
         mavenPluginManagerHelper.setupPluginRealm( pluginDescriptor, mavenReportExecutorRequest.getMavenSession(),
                                                    Thread.currentThread().getContextClassLoader(), IMPORTS,
                                                    EXCLUDES );
 
         if ( !isMavenReport( mojoExecution, pluginDescriptor ) )
         {
             if ( hasUserDefinedReports )
             {
                 // reports were explicitly written in the POM
                 LOGGER.warn( "Ignoring {}:{}"
                     + " goal since it is not a report: should be removed from reporting configuration in POM",
                     mojoExecution.getPlugin().getId(), report.getGoal() );
             }
             return null;
         }
 
         Xpp3Dom pluginMgmtConfiguration = null;
         if ( project.getBuild() != null && project.getBuild().getPluginManagement() != null )
         {
             Plugin pluginMgmt = find( reportPlugin, project.getBuild().getPluginManagement().getPlugins() );
 
             if ( pluginMgmt != null )
             {
                 pluginMgmtConfiguration = (Xpp3Dom) pluginMgmt.getConfiguration();
             }
         }
 
         mojoExecution.setConfiguration( mergeConfiguration( mojoDescriptor.getMojoConfiguration(),
                                                             pluginMgmtConfiguration,
                                                             reportPlugin.getConfiguration(),
                                                             report.getConfiguration(),
                                                             mojoDescriptor.getParameterMap().keySet() ) );
 
         MavenReport mavenReport =
             getConfiguredMavenReport( mojoExecution, pluginDescriptor, mavenReportExecutorRequest );
 
         MavenReportExecution mavenReportExecution =
             new MavenReportExecution( report.getGoal(), mojoExecution.getPlugin(), mavenReport,
                                       pluginDescriptor.getClassRealm() );
 
         lifecycleExecutor.calculateForkedExecutions( mojoExecution,
                                                      mavenReportExecutorRequest.getMavenSession() );
 
         if ( !mojoExecution.getForkedExecutions().isEmpty() )
         {
             String reportDescription = pluginDescriptor.getArtifactId() + ":" + report.getGoal() + " report";
 
             String execution;
             if ( StringUtils.isNotEmpty( mojoDescriptor.getExecutePhase() ) )
             {
                 // forked phase
                 execution = "'"
                     + ( StringUtils.isEmpty( mojoDescriptor.getExecuteLifecycle() ) ? ""
                                     : ( '[' + mojoDescriptor.getExecuteLifecycle() + ']' ) )
                     + mojoDescriptor.getExecutePhase() + "' forked phase execution";
             }
             else
             {
                 // forked goal
                 execution = "'" + mojoDescriptor.getExecuteGoal() + "' forked goal execution";
             }
 
             LOGGER.info( "Preparing {} requires {}", reportDescription, execution );
 
             lifecycleExecutor.executeForkedExecutions( mojoExecution,
                                                        mavenReportExecutorRequest.getMavenSession() );
 
             LOGGER.info( "{} for {} preparation done", execution, reportDescription );
         }
 
         return mavenReportExecution;
     }
 
     private boolean canAggregate( MavenProject project )
     {
         return project.isExecutionRoot() && "pom".equals( project.getPackaging() ) && ( project.getModules() != null )
             && !project.getModules().isEmpty();
     }
 
     private MavenReport getConfiguredMavenReport( MojoExecution mojoExecution, PluginDescriptor pluginDescriptor,
                                                   MavenReportExecutorRequest mavenReportExecutorRequest )
         throws PluginContainerException, PluginConfigurationException
     {
         try
         {
             Mojo mojo =
                 mavenPluginManager.getConfiguredMojo( Mojo.class, mavenReportExecutorRequest.getMavenSession(),
                                                       mojoExecution );
 
             return (MavenReport) mojo;
         }
         catch ( ClassCastException e )
         {
             if ( LOGGER.isDebugEnabled() )
             {
                 LOGGER.warn( "Skipping ClassCastException", e );
             }
             else
             {
                 LOGGER.warn( "Skipping ClassCastException" );
             }
             return null;
         }
         catch ( PluginContainerException e )
         {
             /*
              * ignore old plugin which are using removed PluginRegistry [INFO] Caused by:
              * java.lang.NoClassDefFoundError: org/apache/maven/plugin/registry/PluginRegistry
              */
             if ( e.getCause() != null && e.getCause() instanceof NoClassDefFoundError
                 && e.getMessage().contains( "PluginRegistry" ) )
             {
                 if ( LOGGER.isDebugEnabled() )
                 {
                     LOGGER.warn( "Skipping NoClassDefFoundError with PluginRegistry", e );
                 }
                 else
                 {
                     LOGGER.warn( "Skipping NoClassDefFoundError with PluginRegistry" );
                 }
                 return null;
             }
             throw e;
         }
     }
 
     private boolean isMavenReport( MojoExecution mojoExecution, PluginDescriptor pluginDescriptor )
     {
         ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
 
         // get the plugin's goal Mojo class
         Class<?> mojoClass;
         try
         {
             Thread.currentThread().setContextClassLoader( mojoExecution.getMojoDescriptor().getRealm() );
 
             mojoClass =
                 pluginDescriptor.getClassRealm().loadClass( mojoExecution.getMojoDescriptor().getImplementation() );
         }
         catch ( ClassNotFoundException e )
         {
             if ( LOGGER.isDebugEnabled() )
             {
                 LOGGER.warn( "Skipping ClassNotFoundException mojoExecution.goal {}", mojoExecution.getGoal(), e );
             }
             else
             {
                 LOGGER.warn( "Skipping ClassNotFoundException mojoExecution.goal {}", mojoExecution.getGoal() );
             }
             return false;
         }
         finally
         {
             Thread.currentThread().setContextClassLoader( originalClassLoader );
         }
 
         // check if it is a report
         try
         {
             Thread.currentThread().setContextClassLoader( mojoExecution.getMojoDescriptor().getRealm() );
             MojoDescriptor mojoDescriptor = pluginDescriptor.getMojo( mojoExecution.getGoal() );
 
             boolean isMavenReport = MavenReport.class.isAssignableFrom( mojoClass );
 
             if ( LOGGER.isDebugEnabled() )
             {
                 if ( mojoDescriptor != null && mojoDescriptor.getImplementationClass() != null )
                 {
                     LOGGER.debug( "Class {} is MavenReport: ",
                         mojoDescriptor.getImplementationClass().getName(), isMavenReport );
                 }
 
                 if ( !isMavenReport )
                 {
                     LOGGER.debug( "Skipping non MavenReport {}", mojoExecution.getMojoDescriptor().getId() );
                 }
             }
 
             return isMavenReport;
         }
         catch ( LinkageError e )
         {
             if ( LOGGER.isDebugEnabled() )
             {
                 LOGGER.warn( "Skipping LinkageError mojoExecution.goal {}", mojoExecution.getGoal(), e );
             }
             else
             {
                 LOGGER.warn( "Skipping LinkageError mojoExecution.goal {}", mojoExecution.getGoal() );
             }
             return false;
         }
         finally
         {
             Thread.currentThread().setContextClassLoader( originalClassLoader );
         }
     }
 
     /**
      * Merge plugin configuration and reportset configuration to mojo configuration to get effective
      * mojo configuration.
      *
      * @param mojoConf configuration done at mojo descriptor level
      * @param pluginMgmtConfig configuration done at build.pluginManagement level
      * @param pluginConf configuration done at reporting plugin level
      * @param reportSetConf configuration done at reportSet level
      * @param parameters set of supported parameters: any other parameter will be removed
      * @return the effective configuration to be used
      */
     private Xpp3Dom mergeConfiguration( PlexusConfiguration mojoConf, Xpp3Dom pluginMgmtConfig,
                                         PlexusConfiguration pluginConf, PlexusConfiguration reportSetConf,
                                         Set<String> parameters )
     {
         Xpp3Dom mojoConfig = ( mojoConf != null ) ? convert( mojoConf ) : new Xpp3Dom( "configuration" );
 
         if ( pluginMgmtConfig != null || pluginConf != null || reportSetConf != null )
         {
             Xpp3Dom pluginConfig = ( pluginConf == null ) ? new Xpp3Dom( "fake" ) : convert( pluginConf );
 
             // merge pluginConf into reportSetConf
             Xpp3Dom mergedConfig = Xpp3DomUtils.mergeXpp3Dom( convert( reportSetConf ), pluginConfig );
             // then merge pluginMgmtConfig
             mergedConfig = Xpp3DomUtils.mergeXpp3Dom( mergedConfig, pluginMgmtConfig );
             // then merge mojoConf
             mergedConfig = Xpp3DomUtils.mergeXpp3Dom( mergedConfig, mojoConfig );
 
             // clean result
             Xpp3Dom cleanedConfig = new Xpp3Dom( "configuration" );
             if ( mergedConfig.getChildren() != null )
             {
                 for ( Xpp3Dom parameter : mergedConfig.getChildren() )
                 {
                     if ( parameters.contains( parameter.getName() ) )
                     {
                         cleanedConfig.addChild( parameter );
                     }
                 }
             }
 
             mojoConfig = cleanedConfig;
         }
 
         return mojoConfig;
     }
 
     private Xpp3Dom convert( PlexusConfiguration config )
     {
         if ( config == null )
         {
             return null;
         }
 
         Xpp3Dom dom = new Xpp3Dom( config.getName() );
         dom.setValue( config.getValue( null ) );
 
         for ( String attrib : config.getAttributeNames() )
         {
             dom.setAttribute( attrib, config.getAttribute( attrib, null ) );
         }
 
         for ( int n = config.getChildCount(), i = 0; i < n; i++ )
         {
             dom.addChild( convert( config.getChild( i ) ) );
         }
 
         return dom;
     }
 
     /**
      * Resolve report plugin version. Steps to find a plugin version stop after each step if a non <code>null</code>
      * value has been found:
      * <ol>
      * <li>use the one defined in the reportPlugin configuration,</li>
      * <li>search similar (same groupId and artifactId) mojo in the build/plugins section of the pom,</li>
      * <li>search similar (same groupId and artifactId) mojo in the build/pluginManagement section of the pom,</li>
      * <li>ask {@link PluginVersionResolver} to get a fallback version and display a warning as it's not a recommended
      * use.</li>
      * </ol>
      *
      * @param reportPlugin the report plugin to resolve the version
      * @param mavenReportExecutorRequest the current report execution context
      * @return the report plugin version
      * @throws PluginVersionResolutionException on plugin version resolution issue
      */
     protected String resolvePluginVersion( ReportPlugin reportPlugin,
                                            MavenReportExecutorRequest mavenReportExecutorRequest )
         throws PluginVersionResolutionException
     {
         String reportPluginKey = reportPlugin.getGroupId() + ':' + reportPlugin.getArtifactId();
         LOGGER.debug( "Resolving version for {}", reportPluginKey );
 
         // look for version defined in the reportPlugin configuration
         if ( reportPlugin.getVersion() != null )
         {
             LOGGER.debug( "Resolved {} version from the reporting.plugins section: {}",
                 reportPluginKey, reportPlugin.getVersion() );
             return reportPlugin.getVersion();
         }
 
         MavenProject project = mavenReportExecutorRequest.getProject();
 
         // search in the build section
         if ( project.getBuild() != null )
         {
             Plugin plugin = find( reportPlugin, project.getBuild().getPlugins() );
 
             if ( plugin != null && plugin.getVersion() != null )
             {
                 LOGGER.debug( "Resolved {} version from the build.plugins section: {}",
                     reportPluginKey, plugin.getVersion() );
                 return plugin.getVersion();
             }
         }
 
         // search in pluginManagement section
         if ( project.getBuild() != null && project.getBuild().getPluginManagement() != null )
         {
             Plugin plugin = find( reportPlugin, project.getBuild().getPluginManagement().getPlugins() );
 
             if ( plugin != null && plugin.getVersion() != null )
             {
                 LOGGER.debug( "Resolved {} version from the build.pluginManagement.plugins section: {}",
                     reportPluginKey, plugin.getVersion() );
                 return plugin.getVersion();
             }
         }
 
         LOGGER.warn( "Report plugin {} has an empty version.", reportPluginKey );
         LOGGER.warn( "" );
         LOGGER.warn( "It is highly recommended to fix these problems"
             + " because they threaten the stability of your build." );
         LOGGER.warn( "" );
         LOGGER.warn( "For this reason, future Maven versions might no"
             + " longer support building such malformed projects." );
 
         Plugin plugin = new Plugin();
         plugin.setGroupId( reportPlugin.getGroupId() );
         plugin.setArtifactId( reportPlugin.getArtifactId() );
 
         PluginVersionRequest pluginVersionRequest =
             new DefaultPluginVersionRequest( plugin, mavenReportExecutorRequest.getMavenSession() );
 
         PluginVersionResult result = pluginVersionResolver.resolve( pluginVersionRequest );
         LOGGER.debug( "Resolved {} version from repository: {}", reportPluginKey, result.getVersion() );
         return result.getVersion();
     }
 
     /**
      * Search similar (same groupId and artifactId) plugin as a given report plugin.
      *
      * @param reportPlugin the report plugin to search for a similar plugin
      * @param plugins the candidate plugins
      * @return the first similar plugin
      */
     private Plugin find( ReportPlugin reportPlugin, List<Plugin> plugins )
     {
         if ( plugins == null )
         {
             return null;
         }
         for ( Plugin plugin : plugins )
         {
             if ( Objects.equals( plugin.getArtifactId(), reportPlugin.getArtifactId() )
                 && Objects.equals( plugin.getGroupId(), reportPlugin.getGroupId() ) )
             {
                 return plugin;
             }
         }
         return null;
     }
 
     /**
      * TODO other stuff to merge ?
      * <p>
      * this method will "merge" some part of the plugin declaration existing in the build section to the fake plugin
      * build for report execution:
      * <ul>
      * <li>dependencies</li>
      * </ul>
      * </p>
      * The plugin could only be present in the dependency management section.
      *
      * @param mavenReportExecutorRequest
      * @param buildPlugin
      * @param reportPlugin
      */
     private void mergePluginToReportPlugin( MavenReportExecutorRequest mavenReportExecutorRequest, Plugin buildPlugin,
                                             ReportPlugin reportPlugin )
     {
         Build build = mavenReportExecutorRequest.getProject().getBuild();
         Plugin configuredPlugin = find( reportPlugin, build.getPlugins() );
         if ( configuredPlugin == null && build.getPluginManagement() != null )
         {
             configuredPlugin = find( reportPlugin, build.getPluginManagement().getPlugins() );
         }
         if ( configuredPlugin != null )
         {
             if ( !configuredPlugin.getDependencies().isEmpty() )
             {
                 buildPlugin.getDependencies().addAll( configuredPlugin.getDependencies() );
             }
         }
     }
 
     private static class GoalWithConf
     {
         private final String goal;
 
         private final PlexusConfiguration configuration;
 
         private final ReportPlugin reportPlugin;
 
         private final PluginDescriptor pluginDescriptor;
 
         GoalWithConf( ReportPlugin reportPlugin, PluginDescriptor pluginDescriptor, String goal,
                              PlexusConfiguration configuration )
         {
             this.reportPlugin = reportPlugin;
             this.pluginDescriptor = pluginDescriptor;
             this.goal = goal;
             this.configuration = configuration;
         }
 
         public ReportPlugin getReportPlugin()
         {
             return reportPlugin;
         }
 
         public PluginDescriptor getPluginDescriptor()
         {
             return pluginDescriptor;
         }
 
         public String getGoal()
         {
             return goal;
         }
 
         public PlexusConfiguration getConfiguration()
         {
             return configuration;
         }
     }
 }