package org.apache.maven.shared.transfer.dependencies.resolve.internal;
   
   /*
    * 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.Collection;
  
  import org.apache.maven.model.Dependency;
  import org.apache.maven.model.Model;
  import org.apache.maven.project.ProjectBuildingRequest;
  import org.apache.maven.shared.artifact.filter.resolve.TransformableFilter;
  import org.apache.maven.shared.transfer.artifact.resolve.ArtifactResult;
  import org.apache.maven.shared.transfer.dependencies.DependableCoordinate;
  import org.apache.maven.shared.transfer.dependencies.resolve.DependencyResolver;
  import org.apache.maven.shared.transfer.dependencies.resolve.DependencyResolverException;
  import org.codehaus.plexus.PlexusConstants;
  import org.codehaus.plexus.PlexusContainer;
  import org.codehaus.plexus.component.annotations.Component;
  import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
  import org.codehaus.plexus.context.Context;
  import org.codehaus.plexus.context.ContextException;
  import org.codehaus.plexus.personality.plexus.lifecycle.phase.Contextualizable;
  
  /**
   * 
   */
  @Component( role = DependencyResolver.class, hint = "default" )
  class DefaultDependencyResolver
      implements DependencyResolver, Contextualizable
  {
      private PlexusContainer container;
  
      @Override
      public Iterable<ArtifactResult> resolveDependencies( ProjectBuildingRequest buildingRequest,
                                                           Collection<Dependency> coordinates,
                                                           Collection<Dependency> managedDependencies,
                                                           TransformableFilter filter )
          throws DependencyResolverException
      {
          validateBuildingRequest( buildingRequest );
          
          try
          {
              String hint = isMaven31() ? "maven31" : "maven3";
  
              DependencyResolver effectiveArtifactResolver = container.lookup( DependencyResolver.class, hint );
  
              return effectiveArtifactResolver.resolveDependencies( buildingRequest, coordinates, managedDependencies,
                                                                    filter );
          }
          catch ( ComponentLookupException e )
          {
              throw new DependencyResolverException( e.getMessage(), e );
          }
      }
  
      @Override
      public Iterable<ArtifactResult> resolveDependencies( ProjectBuildingRequest buildingRequest,
                                                           DependableCoordinate coordinate, TransformableFilter filter )
          throws DependencyResolverException
      {
          validateParameters( buildingRequest, coordinate, filter );
          try
          {
              String hint = isMaven31() ? "maven31" : "maven3";
  
              DependencyResolver effectiveArtifactResolver = container.lookup( DependencyResolver.class, hint );
  
              return effectiveArtifactResolver.resolveDependencies( buildingRequest, coordinate, filter );
          }
          catch ( ComponentLookupException e )
          {
              throw new DependencyResolverException( e.getMessage(), e );
          }
      }
  
      @Override
      public Iterable<ArtifactResult> resolveDependencies( ProjectBuildingRequest buildingRequest, Model model,
                                                           TransformableFilter filter )
          throws DependencyResolverException
      {
          validateParameters( buildingRequest, model, filter );
          try
         {
             String hint = isMaven31() ? "maven31" : "maven3";
 
             DependencyResolver effectiveArtifactResolver = container.lookup( DependencyResolver.class, hint );
 
             return effectiveArtifactResolver.resolveDependencies( buildingRequest, model, filter );
         }
         catch ( ComponentLookupException e )
         {
             throw new DependencyResolverException( e.getMessage(), e );
         }
     }
 
     /**
      * @return true if the current Maven version is Maven 3.1.
      */
     private boolean isMaven31()
     {
         return canFindCoreClass( "org.eclipse.aether.artifact.Artifact" ); // Maven 3.1 specific
     }
 
     private boolean canFindCoreClass( String className )
     {
         try
         {
             Thread.currentThread().getContextClassLoader().loadClass( className );
 
             return true;
         }
         catch ( ClassNotFoundException e )
         {
             return false;
         }
     }
 
     /**
      * Injects the Plexus content.
      *
      * @param context Plexus context to inject.
      * @throws ContextException if the PlexusContainer could not be located.
      */
     public void contextualize( Context context )
         throws ContextException
     {
         container = (PlexusContainer) context.get( PlexusConstants.PLEXUS_KEY );
     }
 
     private void validateParameters( ProjectBuildingRequest buildingRequest, DependableCoordinate coordinate,
                                      TransformableFilter filter )
     {
         validateBuildingRequest( buildingRequest );
         if ( coordinate == null )
         {
             throw new IllegalArgumentException( "The parameter coordinate is not allowed to be null." );
         }
     }
 
     private void validateParameters( ProjectBuildingRequest buildingRequest, Model model,
                                      TransformableFilter filter )
     {
         validateBuildingRequest( buildingRequest );
         if ( model == null )
         {
             throw new IllegalArgumentException( "The parameter model is not allowed to be null." );
         }
 
     }
 
     private void validateBuildingRequest( ProjectBuildingRequest buildingRequest )
     {
         if ( buildingRequest == null )
         {
             throw new IllegalArgumentException( "The parameter buildingRequest is not allowed to be null." );
         }
     }
 
 }