package org.apache.maven.model.management;
   
   /*
    * 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.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.model.Dependency;
  import org.apache.maven.model.DependencyManagement;
  import org.apache.maven.model.Exclusion;
  import org.apache.maven.model.Model;
  import org.apache.maven.model.building.ModelBuildingRequest;
  import org.apache.maven.model.building.ModelProblemCollector;
  import org.apache.maven.model.merge.MavenModelMerger;
  import org.codehaus.plexus.component.annotations.Component;
  
  /**
   * Handles injection of dependency management into the model.
   *
   * @author Benjamin Bentmann
   */
  @SuppressWarnings( { "checkstyle:methodname" } )
  @Component( role = DependencyManagementInjector.class )
  public class DefaultDependencyManagementInjector
      implements DependencyManagementInjector
  {
  
      private ManagementModelMerger merger = new ManagementModelMerger();
  
      @Override
      public void injectManagement( Model model, ModelBuildingRequest request, ModelProblemCollector problems )
      {
          merger.mergeManagedDependencies( model );
      }
  
      /**
       * ManagementModelMerger
       */
      protected static class ManagementModelMerger
          extends MavenModelMerger
      {
  
          public void mergeManagedDependencies( Model model )
          {
              DependencyManagement dependencyManagement = model.getDependencyManagement();
              if ( dependencyManagement != null )
              {
                  Map<Object, Dependency> dependencies = new HashMap<>();
                  Map<Object, Object> context = Collections.emptyMap();
  
                  for ( Dependency dependency : model.getDependencies() )
                  {
                      Object key = getDependencyKey( dependency );
                      dependencies.put( key, dependency );
                  }
  
                  for ( Dependency managedDependency : dependencyManagement.getDependencies() )
                  {
                      Object key = getDependencyKey( managedDependency );
                      Dependency dependency = dependencies.get( key );
                      if ( dependency != null )
                      {
                          mergeDependency( dependency, managedDependency, false, context );
                      }
                  }
              }
          }
  
          @Override
          protected void mergeDependency_Optional( Dependency target, Dependency source, boolean sourceDominant,
                                                   Map<Object, Object> context )
          {
              // optional flag is not managed
          }
  
          @Override
          protected void mergeDependency_Exclusions( Dependency target, Dependency source, boolean sourceDominant,
                                                     Map<Object, Object> context )
          {
              List<Exclusion> tgt = target.getExclusions();
             if ( tgt.isEmpty() )
             {
                 List<Exclusion> src = source.getExclusions();
 
                 for ( Exclusion element : src )
                 {
                     Exclusion clone = element.clone();
                     target.addExclusion( clone );
                 }
             }
         }
 
     }
 
 }