/*
    * 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.
   */
  package org.apache.maven.plugin.plugin;
  
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  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 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();
  
      /**
       * The project currently being built.
       */
      protected final MavenProject project;
  
      protected AbstractGeneratorMojo(MavenProject project) {
          this.project = project;
      }
  
      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;
          }
  
          if (goalPrefix == null || goalPrefix.isEmpty()) {
              goalPrefix = getDefaultGoalPrefix(project);
          }
          if (goalPrefix == null || goalPrefix.isEmpty()) {
              throw new MojoExecutionException("You need to specify a goalPrefix as it can not be correctly computed");
          }
  
          generate();
      }
  
      static String getDefaultGoalPrefix(MavenProject project) {
          String artifactId = project.getArtifactId();
          if (artifactId.endsWith("-maven-plugin")) {
             return artifactId.substring(0, artifactId.length() - "-maven-plugin".length());
         } else if (artifactId.startsWith("maven-") && artifactId.endsWith("-plugin")) {
             return artifactId.substring("maven-".length(), artifactId.length() - "-plugin".length());
         } else {
             return null;
         }
     }
 }