package org.apache.maven.plugins.enforcer;
   
   /*
    * 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 org.apache.maven.artifact.Artifact;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.shared.dependency.graph.DependencyGraphBuilder;
  import org.apache.maven.shared.dependency.graph.DependencyGraphBuilderException;
  import org.apache.maven.shared.dependency.graph.DependencyNode;
  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
  import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
  import java.util.HashSet;
  import java.util.Set;
  
  /**
   * Abstract Rule for banning dependencies.
   *
   * @author <a href="mailto:brianf@apache.org">Brian Fox</a>
   * @version $Id$
   */
  public abstract class AbstractBanDependencies
      extends AbstractNonCacheableEnforcerRule
  {
  
      /** Specify if transitive dependencies should be searched (default) or only look at direct dependencies. */
      private boolean searchTransitive = true;
  
      private transient DependencyGraphBuilder graphBuilder;
  
      @Override
      public void execute( EnforcerRuleHelper helper )
          throws EnforcerRuleException
      {
  
          // get the project
          MavenProject project = null;
          try
          {
              project = (MavenProject) helper.evaluate( "${project}" );
          }
          catch ( ExpressionEvaluationException eee )
          {
              throw new EnforcerRuleException( "Unable to retrieve the MavenProject: ", eee );
          }
  
          try
          {
              graphBuilder = (DependencyGraphBuilder) helper.getComponent( DependencyGraphBuilder.class );
          }
          catch ( ComponentLookupException e )
          {
              // real cause is probably that one of the Maven3 graph builder could not be initiated and fails with a
              // ClassNotFoundException
              try
              {
                  graphBuilder =
                      (DependencyGraphBuilder) helper.getComponent( DependencyGraphBuilder.class.getName(), "maven2" );
              }
              catch ( ComponentLookupException e1 )
              {
                  throw new EnforcerRuleException( "Unable to lookup DependencyGraphBuilder: ", e );
              }
          }
  
          // get the correct list of dependencies
          Set<Artifact> dependencies = getDependenciesToCheck( project );
  
          // look for banned dependencies
          Set<Artifact> foundExcludes = checkDependencies( dependencies, helper.getLog() );
  
          // if any are found, fail the check but list all of them
          if ( foundExcludes != null && !foundExcludes.isEmpty() )
          {
              String message = getMessage();
  
              StringBuilder buf = new StringBuilder();
              if ( message != null )
              {
                  buf.append( message + "\n" );
             }
             for ( Artifact artifact : foundExcludes )
             {
                 buf.append( getErrorMessage( artifact ) );
             }
             message = buf.toString() + "Use 'mvn dependency:tree' to locate the source of the banned dependencies.";
 
             throw new EnforcerRuleException( message );
         }
 
     }
 
     protected CharSequence getErrorMessage( Artifact artifact )
     {
         return "Found Banned Dependency: " + artifact.getId() + "\n";
     }
 
     protected Set<Artifact> getDependenciesToCheck( MavenProject project )
     {
         Set<Artifact> dependencies = null;
         try
         {
             DependencyNode node = graphBuilder.buildDependencyGraph( project, null );
             if ( searchTransitive )
             {
                 dependencies = getAllDescendants( node );
             }
             else if ( node.getChildren() != null )
             {
                 dependencies = new HashSet<Artifact>();
                 for ( DependencyNode depNode : node.getChildren() )
                 {
                     dependencies.add( depNode.getArtifact() );
                 }
             }
         }
         catch ( DependencyGraphBuilderException e )
         {
             // otherwise we need to change the signature of this protected method
             throw new RuntimeException( e );
         }
         return dependencies;
     }
 
     private Set<Artifact> getAllDescendants( DependencyNode node )
     {
         Set<Artifact> children = null;
         if ( node.getChildren() != null )
         {
             children = new HashSet<Artifact>();
             for ( DependencyNode depNode : node.getChildren() )
             {
                 children.add( depNode.getArtifact() );
                 Set<Artifact> subNodes = getAllDescendants( depNode );
                 if ( subNodes != null )
                 {
                     children.addAll( subNodes );
                 }
             }
         }
         return children;
     }
 
     /**
      * Checks the set of dependencies against the list of excludes.
      *
      * @param dependencies the dependencies
      * @param log the log
      * @return the sets the
      * @throws EnforcerRuleException the enforcer rule exception
      */
     protected abstract Set<Artifact> checkDependencies( Set<Artifact> dependencies, Log log )
         throws EnforcerRuleException;
 
     /**
      * Checks if is search transitive.
      *
      * @return the searchTransitive
      */
     public boolean isSearchTransitive()
     {
         return this.searchTransitive;
     }
 
     /**
      * Sets the search transitive.
      *
      * @param theSearchTransitive the searchTransitive to set
      */
     public void setSearchTransitive( boolean theSearchTransitive )
     {
         this.searchTransitive = theSearchTransitive;
     }
 
 }