package org.apache.maven.settings.merge;
   
   /*
    * 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.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.settings.IdentifiableBase;
  import org.apache.maven.settings.Settings;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
   * @author Benjamin Bentmann
   */
  public class MavenSettingsMerger
  {
  
      /**
       * @param dominant
       * @param recessive
       * @param recessiveSourceLevel
       */
      public void merge( Settings dominant, Settings recessive, String recessiveSourceLevel )
      {
          if ( dominant == null || recessive == null )
          {
              return;
          }
  
          recessive.setSourceLevel( recessiveSourceLevel );
  
          List<String> dominantActiveProfiles = dominant.getActiveProfiles();
          List<String> recessiveActiveProfiles = recessive.getActiveProfiles();
  
          if ( recessiveActiveProfiles != null )
          {
              if ( dominantActiveProfiles == null )
              {
                  dominantActiveProfiles = new ArrayList<String>();
                  dominant.setActiveProfiles( dominantActiveProfiles );
              }
  
              for ( String profileId : recessiveActiveProfiles )
              {
                  if ( !dominantActiveProfiles.contains( profileId ) )
                  {
                      dominantActiveProfiles.add( profileId );
                  }
              }
          }
  
          List<String> dominantPluginGroupIds = dominant.getPluginGroups();
  
          List<String> recessivePluginGroupIds = recessive.getPluginGroups();
  
          if ( recessivePluginGroupIds != null )
          {
              if ( dominantPluginGroupIds == null )
              {
                  dominantPluginGroupIds = new ArrayList<String>();
                  dominant.setPluginGroups( dominantPluginGroupIds );
              }
  
              for ( String pluginGroupId : recessivePluginGroupIds )
              {
                  if ( !dominantPluginGroupIds.contains( pluginGroupId ) )
                  {
                      dominantPluginGroupIds.add( pluginGroupId );
                  }
              }
          }
  
          if ( StringUtils.isEmpty( dominant.getLocalRepository() ) )
          {
              dominant.setLocalRepository( recessive.getLocalRepository() );
          }
  
          shallowMergeById( dominant.getMirrors(), recessive.getMirrors(), recessiveSourceLevel );
          shallowMergeById( dominant.getServers(), recessive.getServers(), recessiveSourceLevel );
         shallowMergeById( dominant.getProxies(), recessive.getProxies(), recessiveSourceLevel );
         shallowMergeById( dominant.getProfiles(), recessive.getProfiles(), recessiveSourceLevel );
 
     }
 
     /**
      * @param dominant
      * @param recessive
      * @param recessiveSourceLevel
      */
     private static <T extends IdentifiableBase> void shallowMergeById( List<T> dominant, List<T> recessive,
                                                                        String recessiveSourceLevel )
     {
         Map<String, T> dominantById = mapById( dominant );
 
         for ( T identifiable : recessive )
         {
             if ( !dominantById.containsKey( identifiable.getId() ) )
             {
                 identifiable.setSourceLevel( recessiveSourceLevel );
 
                 dominant.add( identifiable );
             }
         }
     }
 
     /**
      * @param identifiables
      * @return a map
      */
     private static <T extends IdentifiableBase> Map<String, T> mapById( List<T> identifiables )
     {
         Map<String, T> byId = new HashMap<String, T>();
 
         for ( T identifiable : identifiables )
         {
             byId.put( identifiable.getId(), identifiable );
         }
 
         return byId;
     }
 
 }