package org.apache.maven.archiva.dependency.graph.walk;

 /*

  * 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.HashMap;

 import java.util.Map;

 import org.apache.commons.collections.Predicate;

 import org.apache.commons.collections.functors.NotPredicate;

 import org.apache.maven.archiva.dependency.graph.DependencyGraph;

 import org.apache.maven.archiva.dependency.graph.DependencyGraphEdge;

 import org.apache.maven.archiva.dependency.graph.DependencyGraphNode;

 import org.apache.maven.archiva.dependency.graph.functors.EdgeDisabledPredicate;

 import org.apache.maven.archiva.model.ArtifactReference;

 /**

  * Perform a walk of the graph using the DepthFirstSearch algorithm.

  * 

  * NOTE: Default edgePredicate is to NOT traverse disabled edges.

  *

  * @version $Id: WalkDepthFirstSearch.java 755277 2009-03-17 15:18:35Z brett $

  */

 public class WalkDepthFirstSearch

     implements DependencyGraphWalker

 {

     private Map<ArtifactReference, Integer> nodeVisitStates = new HashMap<ArtifactReference, Integer>();

     private Predicate edgePredicate;

     public WalkDepthFirstSearch()

     {

         this.edgePredicate = NotPredicate.getInstance( new EdgeDisabledPredicate() );

     }

     public Predicate getEdgePredicate()

     {

         return this.edgePredicate;

     }

     public void setEdgePredicate( Predicate edgePredicate )

     {

         this.edgePredicate = edgePredicate;

     }

     public Integer getNodeVisitState( DependencyGraphNode node )

     {

         if ( node == null )

         {

             return SEEN;

         }

         return (Integer) nodeVisitStates.get( node.getArtifact() );

     }

     public Integer getNodeVisitState( ArtifactReference artifact )

     {

         return (Integer) nodeVisitStates.get( artifact );

     }

     public void setNodeVisitState( DependencyGraphNode node, Integer state )

     {

         this.nodeVisitStates.put( node.getArtifact(), state );

     }

     public void setNodeVisitState( ArtifactReference artifact, Integer state )

     {

         this.nodeVisitStates.put( artifact, state );

     }

     private void visitEdge( DependencyGraph graph, DependencyGraphEdge e, DependencyGraphVisitor visitor )

     {

         visitor.discoverEdge( e );

         DependencyGraphNode node = graph.getNode( e.getNodeTo() );

         if ( getNodeVisitState( node ) == UNSEEN )

         {

             visitNode( graph, node, visitor );

         }

         visitor.finishEdge( e );

     }

     private void visitNode( DependencyGraph graph, DependencyGraphNode node, DependencyGraphVisitor visitor )

     {

         setNodeVisitState( node, PROCESSING );

         visitor.discoverNode( node );

         for ( DependencyGraphEdge e : graph.getEdgesFrom( node ) )

         {

             if ( this.edgePredicate.evaluate( e ) )

             {

                 visitEdge( graph, e, visitor );

             }

         }

         visitor.finishNode( node );

         setNodeVisitState( node, SEEN );

     }

     public void visit( DependencyGraph graph, DependencyGraphVisitor visitor )

     {

         visit( graph, graph.getRootNode(), visitor );

     }

     public void visit( DependencyGraph graph, DependencyGraphNode startNode, DependencyGraphVisitor visitor )

     {

         nodeVisitStates.clear();

         for ( DependencyGraphNode node : graph.getNodes() )

         {

             setNodeVisitState( node, UNSEEN );

         }

         visitor.discoverGraph( graph );

         visitNode( graph, startNode, visitor );

         visitor.finishGraph( graph );

     }

 }