/*
    * 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.model.management;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.api.model.Build;
  import org.apache.maven.api.model.Model;
  import org.apache.maven.api.model.Plugin;
  import org.apache.maven.api.model.PluginContainer;
  import org.apache.maven.api.model.PluginExecution;
  import org.apache.maven.api.model.PluginManagement;
  import org.apache.maven.model.building.ModelBuildingRequest;
  import org.apache.maven.model.building.ModelProblemCollector;
  import org.apache.maven.model.merge.MavenModelMerger;
  
  /**
   * Handles injection of plugin management into the model.
   *
   * @author Benjamin Bentmann
   */
  @SuppressWarnings({"checkstyle:methodname"})
  @Named
  @Singleton
  public class DefaultPluginManagementInjector implements PluginManagementInjector {
  
      private ManagementModelMerger merger = new ManagementModelMerger();
  
      @Override
      public void injectManagement(
              org.apache.maven.model.Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
          model.update(merger.mergeManagedBuildPlugins(model.getDelegate()));
      }
  
      /**
       * ManagementModelMerger
       */
      protected static class ManagementModelMerger extends MavenModelMerger {
  
          public Model mergeManagedBuildPlugins(Model model) {
              Build build = model.getBuild();
              if (build != null) {
                  PluginManagement pluginManagement = build.getPluginManagement();
                  if (pluginManagement != null) {
                      return model.withBuild(mergePluginContainerPlugins(build, pluginManagement));
                  }
              }
              return model;
          }
  
          private Build mergePluginContainerPlugins(Build target, PluginContainer source) {
              List<Plugin> src = source.getPlugins();
              if (!src.isEmpty()) {
                  Map<Object, Plugin> managedPlugins = new LinkedHashMap<>(src.size() * 2);
  
                  Map<Object, Object> context = Collections.emptyMap();
  
                  for (Plugin element : src) {
                      Object key = getPluginKey().apply(element);
                      managedPlugins.put(key, element);
                  }
  
                  List<Plugin> newPlugins = new ArrayList<>();
                  for (Plugin element : target.getPlugins()) {
                      Object key = getPluginKey().apply(element);
                      Plugin managedPlugin = managedPlugins.get(key);
                      if (managedPlugin != null) {
                          element = mergePlugin(element, managedPlugin, false, context);
                      }
                      newPlugins.add(element);
                  }
                  return target.withPlugins(newPlugins);
              }
              return target;
          }
  
         @Override
         protected void mergePlugin_Executions(
                 Plugin.Builder builder,
                 Plugin target,
                 Plugin source,
                 boolean sourceDominant,
                 Map<Object, Object> context) {
             List<PluginExecution> src = source.getExecutions();
             if (!src.isEmpty()) {
                 List<PluginExecution> tgt = target.getExecutions();
 
                 Map<Object, PluginExecution> merged = new LinkedHashMap<>((src.size() + tgt.size()) * 2);
 
                 for (PluginExecution element : src) {
                     Object key = getPluginExecutionKey().apply(element);
                     merged.put(key, element);
                 }
 
                 for (PluginExecution element : tgt) {
                     Object key = getPluginExecutionKey().apply(element);
                     PluginExecution existing = merged.get(key);
                     if (existing != null) {
                         element = mergePluginExecution(element, existing, sourceDominant, context);
                     }
                     merged.put(key, element);
                 }
 
                 builder.executions(merged.values());
             }
         }
     }
 }