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 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.codehaus.plexus.component.annotations.Component;
  import org.codehaus.plexus.component.annotations.Requirement;
  import org.codehaus.plexus.logging.Logger;
  
  /**
   * @author mkleint
   */
  @Component( role = ToolchainManager.class )
  public class DefaultToolchainManager
      implements ToolchainManager
  {
      @Requirement
      Logger logger;
  
      @Requirement( role = ToolchainFactory.class )
      Map<String, ToolchainFactory> factories;
      
      @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<Toolchain>();
  
          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<String, Object>();
     }
 
     public static final String getStorageKey( String type )
     {
         return "toolchain-" + type; // NOI18N
     }
 
 }