package org.apache.maven.plugin.plugin;
   
   /*
    * 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 org.apache.maven.artifact.Artifact;
  import org.apache.maven.artifact.repository.ArtifactRepository;
  import org.apache.maven.artifact.resolver.filter.ArtifactFilter;
  import org.apache.maven.artifact.resolver.filter.IncludesArtifactFilter;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.descriptor.InvalidPluginDescriptorException;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.tools.plugin.DefaultPluginToolsRequest;
  import org.apache.maven.tools.plugin.PluginToolsRequest;
  import org.apache.maven.tools.plugin.extractor.ExtractionException;
  import org.apache.maven.tools.plugin.generator.Generator;
  import org.apache.maven.tools.plugin.generator.GeneratorException;
  import org.apache.maven.tools.plugin.generator.GeneratorUtils;
  import org.apache.maven.tools.plugin.scanner.MojoScanner;
  import org.codehaus.plexus.component.repository.ComponentDependency;
  import org.codehaus.plexus.util.ReaderFactory;
  
  import java.io.File;
  import java.util.Arrays;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Abstract class for this Plugin.
   *
   * @author <a href="mailto:jason@maven.org">Jason van Zyl</a>
   *
   */
  public abstract class AbstractGeneratorMojo
      extends AbstractMojo
  {
      /**
       * The project currently being built.
       */
      @Parameter( defaultValue = "${project}", readonly = true )
      protected MavenProject project;
  
      /**
       * The component used for scanning the source tree for mojos.
       */
      @Component
      protected MojoScanner mojoScanner;
  
      /**
       * The file encoding of the source files.
       *
       * @since 2.5
       */
      @Parameter( property = "encoding", defaultValue = "${project.build.sourceEncoding}" )
      protected String encoding;
  
      /**
       * The goal prefix that will appear before the ":".
       */
      @Parameter
      protected String goalPrefix;
  
      /**
       * By default an exception is throw if no mojo descriptor is found. As the maven-plugin is defined in core, the
       * descriptor generator mojo is bound to generate-resources phase.
       * But for annotations, the compiled classes are needed, so skip error
       *
       * @since 3.0
       */
      @Parameter( property = "maven.plugin.skipErrorNoDescriptorsFound", defaultValue = "false" )
      protected boolean skipErrorNoDescriptorsFound;
  
      /**
       * <p>
       * The role names of mojo extractors to use.
       * </p>
       * <p>
       * If not set, all mojo extractors will be used. If set to an empty extractor name, no mojo extractors
      * will be used.
      * </p>
      * Example:
      * <pre>
      *  &lt;!-- Use all mojo extractors --&gt;
      *  &lt;extractors/&gt;
      *
      *  &lt;!-- Use no mojo extractors --&gt;
      *  &lt;extractors&gt;
      *      &lt;extractor/&gt;
      *  &lt;/extractors&gt;
      *
      *  &lt;!-- Use only bsh mojo extractor --&gt;
      *  &lt;extractors&gt;
      *      &lt;extractor&gt;bsh&lt;/extractor&gt;
      *  &lt;/extractors&gt;
      * </pre>
      */
     @Parameter
     protected Set<String> extractors;
 
     /**
      * Set this to "true" to skip invoking any goals or reports of the plugin.
      *
      * @since 2.8
      */
     @Parameter( defaultValue = "false", property = "maven.plugin.skip" )
     protected boolean skip;
 
     /**
      * The set of dependencies for the current project
      *
      * @since 3.0
      */
     @Parameter( defaultValue = "${project.artifacts}", required = true, readonly = true )
     protected Set<Artifact> dependencies;
     
     /**
      * Specify the dependencies as {@code groupId:artifactId} containing (abstract) Mojos, to filter
      * dependencies scanned at runtime and focus on dependencies that are really useful to Mojo analysis.
      * By default, the value is {@code null} and all dependencies are scanned (as before this parameter was added).
      * If specified in the configuration with no children, no dependencies are scanned.
      * 
      * @since 3.5
      */
     @Parameter
     private List<String> mojoDependencies;
 
     /**
      * List of Remote Repositories used by the resolver
      *
      * @since 3.0
      */
     @Parameter( defaultValue = "${project.remoteArtifactRepositories}", required = true, readonly = true )
     protected List<ArtifactRepository> remoteRepos;
 
     /**
      * Location of the local repository.
      *
      * @since 3.0
      */
     @Parameter( defaultValue = "${localRepository}", required = true, readonly = true )
     protected ArtifactRepository local;
 
     /**
      * Maven plugin packaging types. Default is single "maven-plugin".
      * 
      * @since 3.3
      */
     @Parameter
     protected List<String> packagingTypes = Arrays.asList( "maven-plugin" );
 
     /**
      * @return the output directory where files will be generated.
      */
     protected abstract File getOutputDirectory();
 
     /**
      * @return the wanted <code>Generator</code> implementation.
      */
     protected abstract Generator createGenerator();
 
     /**
      * {@inheritDoc}
      */
     public void execute()
         throws MojoExecutionException
     {
         if ( !packagingTypes.contains( project.getPackaging() ) )
         {
             getLog().warn( "Unsupported packaging type " + project.getPackaging() + ", execution skipped" );
             return;
         }
         if ( skip )
         {
             getLog().warn( "Execution skipped" );
             return;
         }
 
         if ( project.getArtifactId().toLowerCase().startsWith( "maven-" )
             && project.getArtifactId().toLowerCase().endsWith( "-plugin" ) && !"org.apache.maven.plugins".equals(
             project.getGroupId() ) )
         {
             getLog().error( "\n\nArtifact Ids of the format maven-___-plugin are reserved for \n"
                                 + "plugins in the Group Id org.apache.maven.plugins\n"
                                 + "Please change your artifactId to the format ___-maven-plugin\n"
                                 + "In the future this error will break the build.\n\n" );
         }
 
         String defaultGoalPrefix = PluginDescriptor.getGoalPrefixFromArtifactId( project.getArtifactId() );
         if ( goalPrefix == null )
         {
             goalPrefix = defaultGoalPrefix;
         }
         else if ( !goalPrefix.equals( defaultGoalPrefix ) )
         {
             getLog().warn(
                 "\n\nGoal prefix is specified as: '" + goalPrefix + "'. " + "Maven currently expects it to be '"
                     + defaultGoalPrefix + "'.\n" );
         }
 
         mojoScanner.setActiveExtractors( extractors );
 
         // TODO: could use this more, eg in the writing of the plugin descriptor!
         PluginDescriptor pluginDescriptor = new PluginDescriptor();
 
         pluginDescriptor.setGroupId( project.getGroupId() );
 
         pluginDescriptor.setArtifactId( project.getArtifactId() );
 
         pluginDescriptor.setVersion( project.getVersion() );
 
         pluginDescriptor.setGoalPrefix( goalPrefix );
 
         pluginDescriptor.setName( project.getName() );
 
         pluginDescriptor.setDescription( project.getDescription() );
 
         if ( encoding == null || encoding.length() < 1 )
         {
             getLog().warn( "Using platform encoding (" + ReaderFactory.FILE_ENCODING
                                + " actually) to read mojo source files, i.e. build is platform dependent!" );
         }
         else
         {
             getLog().info( "Using '" + encoding + "' encoding to read mojo source files." );
         }
 
         try
         {
             List<ComponentDependency> deps = GeneratorUtils.toComponentDependencies( project.getRuntimeDependencies() );
             pluginDescriptor.setDependencies( deps );
 
             PluginToolsRequest request = new DefaultPluginToolsRequest( project, pluginDescriptor );
             request.setEncoding( encoding );
             request.setSkipErrorNoDescriptorsFound( skipErrorNoDescriptorsFound );
             request.setDependencies( filterMojoDependencies() );
             request.setLocal( this.local );
             request.setRemoteRepos( this.remoteRepos );
 
             mojoScanner.populatePluginDescriptor( request );
 
             getOutputDirectory().mkdirs();
 
             createGenerator().execute( getOutputDirectory(), request );
         }
         catch ( GeneratorException e )
         {
             throw new MojoExecutionException( "Error writing plugin descriptor", e );
         }
         catch ( InvalidPluginDescriptorException e )
         {
             throw new MojoExecutionException( "Error extracting plugin descriptor: \'" + e.getLocalizedMessage() + "\'",
                                               e );
         }
         catch ( ExtractionException e )
         {
             throw new MojoExecutionException( "Error extracting plugin descriptor: \'" + e.getLocalizedMessage() + "\'",
                                               e );
         }
         catch ( LinkageError e )
         {
             throw new MojoExecutionException( "The API of the mojo scanner is not compatible with this plugin version."
                 + " Please check the plugin dependencies configured in the POM and ensure the versions match.", e );
         }
     }
 
     /**
      * Get dependencies filtered with mojoDependencies configuration.
      * 
      * @return eventually filtered dependencies, or even <code>null</code> if configured with empty mojoDependencies
      * list
      * @see #mojoDependencies
      */
     private Set<Artifact> filterMojoDependencies()
     {
         Set<Artifact> filteredDependencies;
         if ( mojoDependencies == null )
         {
             filteredDependencies = dependencies;
         }
         else if ( mojoDependencies.size() == 0 )
         {
             filteredDependencies = null;
         }
         else
         {
             filteredDependencies = new LinkedHashSet<>();
             
             ArtifactFilter filter = new IncludesArtifactFilter( mojoDependencies );
 
             for ( Artifact artifact : dependencies )
             {
                 if ( filter.include( artifact ) )
                 {
                     filteredDependencies.add( artifact );
                 }
             }
         }
 
         return filteredDependencies;
     }
 }