/*
    * 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.analyze;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import org.apache.maven.model.Dependency;
  import org.apache.maven.model.Model;
  import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
  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.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.util.xml.XmlStreamReader;
  import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
  
  /**
   * Analyzes the <code>&lt;dependencies/&gt;</code> and <code>&lt;dependencyManagement/&gt;</code> tags in the
   * <code>pom.xml</code> and determines the duplicate declared dependencies.
   *
   * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
   */
  @Mojo(name = "analyze-duplicate", aggregator = false, threadSafe = true)
  public class AnalyzeDuplicateMojo extends AbstractMojo {
      public static final String MESSAGE_DUPLICATE_DEP_IN_DEPENDENCIES =
              "List of duplicate dependencies defined in <dependencies/> in your pom.xml:\n";
  
      public static final String MESSAGE_DUPLICATE_DEP_IN_DEPMGMT =
              "List of duplicate dependencies defined in <dependencyManagement/> in your pom.xml:\n";
  
      /**
       * Skip plugin execution completely.
       *
       * @since 2.7
       */
      @Parameter(property = "mdep.analyze.skip", defaultValue = "false")
      private boolean skip;
  
      /**
       * The Maven project to analyze.
       */
      @Component
      private MavenProject project;
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void execute() throws MojoExecutionException, MojoFailureException {
          if (skip) {
              getLog().info("Skipping plugin execution");
              return;
          }
  
          MavenXpp3Reader pomReader = new MavenXpp3Reader();
          Model model;
          try (Reader reader = new XmlStreamReader(project.getFile())) {
              model = pomReader.read(reader);
          } catch (IOException | XmlPullParserException e) {
              throw new MojoExecutionException("Exception: " + e.getMessage(), e);
          }
  
          Set<String> duplicateDependencies = Collections.emptySet();
          if (model.getDependencies() != null) {
              duplicateDependencies = findDuplicateDependencies(model.getDependencies());
          }
  
          Set<String> duplicateDependenciesManagement = Collections.emptySet();
          if (model.getDependencyManagement() != null
                  && model.getDependencyManagement().getDependencies() != null) {
              duplicateDependenciesManagement =
                      findDuplicateDependencies(model.getDependencyManagement().getDependencies());
         }
 
         if (getLog().isInfoEnabled()) {
             StringBuilder sb = new StringBuilder();
 
             createMessage(duplicateDependencies, sb, MESSAGE_DUPLICATE_DEP_IN_DEPENDENCIES);
             createMessage(duplicateDependenciesManagement, sb, MESSAGE_DUPLICATE_DEP_IN_DEPMGMT);
 
             if (sb.length() > 0) {
                 getLog().info(sb.toString());
             } else {
                 getLog().info("No duplicate dependencies found in <dependencies/> or in <dependencyManagement/>");
             }
         }
     }
 
     private void createMessage(
             Set<String> duplicateDependencies, StringBuilder sb, String messageDuplicateDepInDependencies) {
         if (!duplicateDependencies.isEmpty()) {
             if (sb.length() > 0) {
                 sb.append("\n");
             }
             sb.append(messageDuplicateDepInDependencies);
             for (Iterator<String> it = duplicateDependencies.iterator(); it.hasNext(); ) {
                 String dup = it.next();
 
                 sb.append("\to ").append(dup);
                 if (it.hasNext()) {
                     sb.append("\n");
                 }
             }
         }
     }
 
     private Set<String> findDuplicateDependencies(List<Dependency> modelDependencies) {
         List<String> modelDependencies2 =
                 modelDependencies.stream().map(Dependency::getManagementKey).collect(Collectors.toList());
         // remove one instance of each element from the list
         modelDependencies2.removeIf(new HashSet<>(modelDependencies2)::remove);
         // keep a single instance of each duplicate
         return new LinkedHashSet<>(modelDependencies2);
     }
 }