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 java.util.Collections;
  import java.util.List;
  
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.project.MavenProject;
  
  /**
   * 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 goal prefix that will appear before the ":".
       */
      @Parameter
      protected String goalPrefix;
  
      /**
       * Set this to "true" to skip invoking any goals or reports of the plugin.
       *
       * @since 2.8
       */
      @Parameter( defaultValue = "false", property = "maven.plugin.skip" )
      private boolean skip;
  
      /**
       * Maven plugin packaging types. Default is single "maven-plugin".
       * 
       * @since 3.3
       */
      @Parameter
      private List<String> packagingTypes = Collections.singletonList( "maven-plugin" );
  
      /**
       * System/OS line separator: used to format console messages.
       */
      protected static final String LS = System.lineSeparator();
  
      protected abstract void generate() throws MojoExecutionException;
  
      @Override
      public void execute()
          throws MojoExecutionException
      {
          if ( !packagingTypes.contains( project.getPackaging() ) )
          {
              getLog().info( "Unsupported packaging type " + project.getPackaging() + ", execution skipped" );
              return;
          }
  
          if ( skip )
          {
              getLog().warn( "Execution skipped" );
              return;
          }
  
          String defaultGoalPrefix = getDefaultGoalPrefix( project );
  
          if ( goalPrefix == null )
          {
              goalPrefix = defaultGoalPrefix;
          }
          else if ( !goalPrefix.equals( defaultGoalPrefix ) )
          {
              getLog().warn(
                 LS + LS + "Goal prefix is specified as: '" + goalPrefix + "'. " + "Maven currently expects it to be '"
                     + defaultGoalPrefix + "'." + LS );
         }
 
         generate();
     }
 
     static String getDefaultGoalPrefix( MavenProject project )
     {
         String defaultGoalPrefix;
         if ( "maven-plugin-report-plugin".equalsIgnoreCase( project.getArtifactId() ) )
         {
             defaultGoalPrefix = "plugin-report";
         }
         else if ( "maven-plugin".equalsIgnoreCase( project.getArtifactId() ) )
         {
             defaultGoalPrefix = project.getGroupId().substring( project.getGroupId().lastIndexOf( '.' ) + 1 );
         }
         else
         {
             defaultGoalPrefix = PluginDescriptor.getGoalPrefixFromArtifactId( project.getArtifactId() );
         }
         return defaultGoalPrefix;
     }
 }