package org.apache.maven.toolchain;
   
   /*
    * 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.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.plugin.descriptor.PluginDescriptor;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.toolchain.model.ToolchainModel;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * @author mkleint
   */
  @Named
  @Singleton
  public class DefaultToolchainManager
      implements ToolchainManager
  {
      protected final Logger logger; // TODO this class is extended, needs refactoring
  
      final Map<String, ToolchainFactory> factories;
  
      @Inject
      public DefaultToolchainManager( Map<String, ToolchainFactory> factories )
      {
          this.factories = factories;
          this.logger = LoggerFactory.getLogger( DefaultToolchainManager.class );
      }
  
      /**
       * Ctor needed for UT.
       */
      DefaultToolchainManager( Map<String, ToolchainFactory> factories, Logger logger )
      {
          this.factories = factories;
          this.logger = requireNonNull( logger );
      }
  
      @Override
      public Toolchain getToolchainFromBuildContext( String type, MavenSession session )
      {
          Map<String, Object> context = retrieveContext( session );
  
          ToolchainModel model = (ToolchainModel) context.get( getStorageKey( type ) );
  
          if ( model != null )
          {
              List<Toolchain> toolchains = selectToolchains( Collections.singletonList( model ), type, null );
  
              if ( !toolchains.isEmpty() )
              {
                  return toolchains.get( 0 );
              }
          }
  
          return null;
      }
  
      @Override
      public List<Toolchain> getToolchains( MavenSession session, String type, Map<String, String> requirements )
      {
          List<ToolchainModel> models = session.getRequest().getToolchains().get( type );
  
          return selectToolchains( models, type, requirements );
      }
  
      private List<Toolchain> selectToolchains( List<ToolchainModel> models, String type,
                                                Map<String, String> requirements )
      {
         List<Toolchain> toolchains = new ArrayList<>();
 
         if ( models != null )
         {
             ToolchainFactory fact = factories.get( type );
 
             if ( fact == null )
             {
                 logger.error( "Missing toolchain factory for type: " + type
                     + ". Possibly caused by misconfigured project." );
             }
             else
             {
                 for ( ToolchainModel model : models )
                 {
                     try
                     {
                         ToolchainPrivate toolchain = fact.createToolchain( model );
                         if ( requirements == null || toolchain.matchesRequirements( requirements ) )
                         {
                             toolchains.add( toolchain );
                         }
                     }
                     catch ( MisconfiguredToolchainException ex )
                     {
                         logger.error( "Misconfigured toolchain.", ex );
                     }
                 }
             }
         }
         return toolchains;
     }
 
     Map<String, Object> retrieveContext( MavenSession session )
     {
         Map<String, Object> context = null;
 
         if ( session != null )
         {
             PluginDescriptor desc = new PluginDescriptor();
             desc.setGroupId( PluginDescriptor.getDefaultPluginGroupId() );
             desc.setArtifactId( PluginDescriptor.getDefaultPluginArtifactId( "toolchains" ) );
 
             MavenProject current = session.getCurrentProject();
 
             if ( current != null )
             {
                 //TODO why is this using the context
                 context = session.getPluginContext( desc, current );
             }
         }
 
         return ( context != null ) ? context : new HashMap<>();
     }
 
     public static final String getStorageKey( String type )
     {
         return "toolchain-" + type; // NOI18N
     }
 
 }