/*
    * 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.plugins.dependency;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.LifecyclePhase;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.project.MavenProject;
  
  /**
   * Displays all ancestor POMs of the project. This may be useful in a continuous integration system where you want to
   * know all parent poms of the project.
   *
   * @author Mirko Friedenhagen
   * @since 2.9
   */
  @Mojo(name = "display-ancestors", threadSafe = true, requiresProject = true, defaultPhase = LifecyclePhase.VALIDATE)
  public class DisplayAncestorsMojo extends AbstractMojo {
  
      /**
       * POM
       */
      @Component
      private MavenProject project;
  
      @Override
      public void execute() throws MojoExecutionException, MojoFailureException {
          final List<String> ancestors = collectAncestors();
  
          if (ancestors.isEmpty()) {
              getLog().info("No Ancestor POMs!");
          } else {
              getLog().info("Ancestor POMs: " + String.join(" <- ", ancestors));
          }
      }
  
      private ArrayList<String> collectAncestors() {
          final ArrayList<String> ancestors = new ArrayList<>();
  
          MavenProject currentAncestor = project.getParent();
          while (currentAncestor != null) {
              ancestors.add(currentAncestor.getGroupId() + ":" + currentAncestor.getArtifactId() + ":"
                      + currentAncestor.getVersion());
  
              currentAncestor = currentAncestor.getParent();
          }
  
          return ancestors;
      }
  }