package org.apache.maven.model.inheritance;
   
   /*
    * 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.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.maven.model.Model;
  import org.apache.maven.model.Plugin;
  import org.apache.maven.model.PluginContainer;
  import org.apache.maven.model.ReportPlugin;
  import org.apache.maven.model.Reporting;
  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 inheritance of model values.
   *
   * @author Benjamin Bentmann
   */
  @Component( role = InheritanceAssembler.class )
  public class DefaultInheritanceAssembler
      implements InheritanceAssembler
  {
  
      private InheritanceModelMerger merger = new InheritanceModelMerger();
  
      public void assembleModelInheritance( Model child, Model parent, ModelBuildingRequest request,
                                            ModelProblemCollector problems )
      {
          Map<Object, Object> hints = new HashMap<Object, Object>();
          hints.put( MavenModelMerger.CHILD_PATH_ADJUSTMENT, getChildPathAdjustment( child, parent ) );
          merger.merge( child, parent, false, hints );
      }
  
      /**
       * Calculates the relative path from the base directory of the parent to the parent directory of the base directory
       * of the child. The general idea is to adjust inherited URLs to match the project layout (in SCM). This calculation
       * is only a heuristic based on our conventions. In detail, the algo relies on the following assumptions. The parent
       * uses aggregation and refers to the child via the modules section. The module path to the child is considered to
       * point at the POM rather than its base directory if the path ends with ".xml" (ignoring case). The name of the
       * child's base directory matches the artifact id of the child. Note that for the sake of independence from the user
       * environment, the filesystem is intentionally not used for the calculation.
       *
       * @param child The child model, must not be <code>null</code>.
       * @param parent The parent model, may be <code>null</code>.
       * @return The path adjustment, can be empty but never <code>null</code>.
       */
      private String getChildPathAdjustment( Model child, Model parent )
      {
          String adjustment = "";
  
          if ( parent != null )
          {
              String childArtifactId = child.getArtifactId();
  
              for ( String module : parent.getModules() )
              {
                  module = module.replace( '\\', '/' );
  
                  if ( module.regionMatches( true, module.length() - 4, ".xml", 0, 4 ) )
                  {
                      module = module.substring( 0, module.lastIndexOf( '/' ) + 1 );
                  }
  
                  String moduleName = module;
                  if ( moduleName.endsWith( "/" ) )
                  {
                      moduleName = moduleName.substring( 0, moduleName.length() - 1 );
                  }
  
                  int lastSlash = moduleName.lastIndexOf( '/' );
  
                  moduleName = moduleName.substring( lastSlash + 1 );
  
                  if ( moduleName.equals( childArtifactId ) && lastSlash >= 0 )
                  {
                     adjustment = module.substring( 0, lastSlash );
                     break;
                 }
             }
         }
 
         return adjustment;
     }
 
     private static class InheritanceModelMerger
         extends MavenModelMerger
     {
 
         @Override
         protected void mergePluginContainer_Plugins( PluginContainer target, PluginContainer source,
                                                      boolean sourceDominant, Map<Object, Object> context )
         {
             List<Plugin> src = source.getPlugins();
             if ( !src.isEmpty() )
             {
                 List<Plugin> tgt = target.getPlugins();
                 Map<Object, Plugin> master = new LinkedHashMap<Object, Plugin>( src.size() * 2 );
 
                 for ( Plugin element : src )
                 {
                     if ( element.isInherited() || !element.getExecutions().isEmpty() )
                     {
                         // NOTE: Enforce recursive merge to trigger merging/inheritance logic for executions
                         Plugin plugin = new Plugin();
                         plugin.setGroupId( null );
                         mergePlugin( plugin, element, sourceDominant, context );
 
                         Object key = getPluginKey( element );
 
                         master.put( key, plugin );
                     }
                 }
 
                 Map<Object, List<Plugin>> predecessors = new LinkedHashMap<Object, List<Plugin>>();
                 List<Plugin> pending = new ArrayList<Plugin>();
                 for ( Plugin element : tgt )
                 {
                     Object key = getPluginKey( element );
                     Plugin existing = master.get( key );
                     if ( existing != null )
                     {
                         mergePlugin( element, existing, sourceDominant, context );
 
                         master.put( key, element );
 
                         if ( !pending.isEmpty() )
                         {
                             predecessors.put( key, pending );
                             pending = new ArrayList<Plugin>();
                         }
                     }
                     else
                     {
                         pending.add( element );
                     }
                 }
 
                 List<Plugin> result = new ArrayList<Plugin>( src.size() + tgt.size() );
                 for ( Map.Entry<Object, Plugin> entry : master.entrySet() )
                 {
                     List<Plugin> pre = predecessors.get( entry.getKey() );
                     if ( pre != null )
                     {
                         result.addAll( pre );
                     }
                     result.add( entry.getValue() );
                 }
                 result.addAll( pending );
 
                 target.setPlugins( result );
             }
         }
 
         @Override
         protected void mergePlugin( Plugin target, Plugin source, boolean sourceDominant, Map<Object, Object> context )
         {
             if ( source.isInherited() )
             {
                 mergeConfigurationContainer( target, source, sourceDominant, context );
             }
             mergePlugin_GroupId( target, source, sourceDominant, context );
             mergePlugin_ArtifactId( target, source, sourceDominant, context );
             mergePlugin_Version( target, source, sourceDominant, context );
             mergePlugin_Extensions( target, source, sourceDominant, context );
             mergePlugin_Dependencies( target, source, sourceDominant, context );
             mergePlugin_Executions( target, source, sourceDominant, context );
         }
 
         @Override
         protected void mergeReporting_Plugins( Reporting target, Reporting source, boolean sourceDominant,
                                                Map<Object, Object> context )
         {
             List<ReportPlugin> src = source.getPlugins();
             if ( !src.isEmpty() )
             {
                 List<ReportPlugin> tgt = target.getPlugins();
                 Map<Object, ReportPlugin> merged =
                     new LinkedHashMap<Object, ReportPlugin>( ( src.size() + tgt.size() ) * 2 );
 
                 for ( ReportPlugin element :  src )
                 {
                     Object key = getReportPluginKey( element );
                     if ( element.isInherited() )
                     {
                         // NOTE: Enforce recursive merge to trigger merging/inheritance logic for executions as well
                         ReportPlugin plugin = new ReportPlugin();
                         plugin.setGroupId( null );
                         mergeReportPlugin( plugin, element, sourceDominant, context );
 
                         merged.put( key, plugin );
                     }
                 }
 
                 for ( ReportPlugin element : tgt )
                 {
                     Object key = getReportPluginKey( element );
                     ReportPlugin existing = merged.get( key );
                     if ( existing != null )
                     {
                         mergeReportPlugin( element, existing, sourceDominant, context );
                     }
                     merged.put( key, element );
                 }
 
                 target.setPlugins( new ArrayList<ReportPlugin>( merged.values() ) );
             }
         }
     }
 
 }