/*
    * 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.settings.merge;
  
  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<>();
                  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<>();
                  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<>();
 
         for (T identifiable : identifiables) {
             byId.put(identifiable.getId(), identifiable);
         }
 
         return byId;
     }
 }