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.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.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.scanner.MojoScanner;

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

 import org.codehaus.plexus.util.ReaderFactory;

 import java.io.File;

 import java.io.IOException;

 import java.util.Set;

 /**

  * Abstract class for this Plugin.

  *

  * @author <a href="mailto:jason@maven.org">Jason van Zyl</a>

  * @version $Id: AbstractGeneratorMojo.java 1133737 2011-06-09 09:20:50Z stephenc $

  * 

  * @threadSafe

  */

 public abstract class AbstractGeneratorMojo

     extends AbstractMojo

 {

     /**

      * The project currently being built.

      *

      * @parameter default-value="${project}"

      * @required

      * @readonly

      */

     protected MavenProject project;

     /**

      * The component used for scanning the source tree for mojos.

      *

      * @component

      * @required

      */

     protected MojoScanner mojoScanner;

     /**

      * The file encoding of the source files.

      * 

      * @parameter expression="${encoding}" default-value="${project.build.sourceEncoding}"

      * @since 2.5

      */

     protected String encoding;

     /**

      * The goal prefix that will appear before the ":".

      *

      * @parameter

      */

     protected String goalPrefix;

     /**

      * The role names of mojo extractors to use.

      * <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:

      * <p/>

      * <pre>

      *  <!-- Use all mojo extractors -->

      *  <extractors/>

      *  

      *  <!-- Use no mojo extractors -->

      *  <extractors>

      *      <extractor/>

      *  </extractors>

      *  

      *  <!-- Use only bsh mojo extractor -->

      *  <extractors>

      *      <extractor>bsh</extractor>

      *  </extractors>

      * </pre>

      *

      * @parameter

      */

     protected Set<String> extractors;

     /**

      * Set this to "true" to skip invoking any goals or reports of the plugin.

      *

      * @parameter default-value="false" expression="${maven.plugin.skip}"

      * @since 2.8

      */

     protected boolean skip;

     /**

      * @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 ( !"maven-plugin".equals( project.getPackaging() ) )

         {

             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 metadata, i.e. build is platform dependent!" );

         }

         else

         {

             getLog().info( "Using '" + encoding + "' encoding to read mojo metadata." );

         }

         try

         {

             pluginDescriptor.setDependencies( PluginUtils.toComponentDependencies( project.getRuntimeDependencies() ) );

             PluginToolsRequest request = new DefaultPluginToolsRequest( project, pluginDescriptor );

             request.setEncoding( encoding );

             mojoScanner.populatePluginDescriptor( request );

             getOutputDirectory().mkdirs();

             createGenerator().execute( getOutputDirectory(), request );

         }

         catch ( IOException 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 );

         }

     }

 }