package org.apache.maven.shared.dependency.tree.filter;

 /*

  * 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.Collections;

 import java.util.List;

 import org.apache.maven.shared.dependency.tree.DependencyNode;

 /**

  * A dependency node filter than only accepts nodes that are ancestors of, or equal to, a given list of nodes.

  * 

  * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>

  * @version $Id: AncestorOrSelfDependencyNodeFilter.java 1100703 2011-05-08 08:27:33Z hboutemy $

  * @since 1.1

  */

 public class AncestorOrSelfDependencyNodeFilter

     implements DependencyNodeFilter

 {

     // fields -----------------------------------------------------------------

     /**

      * The list of nodes that this filter accepts ancestors-or-self of.

      */

     private final List<DependencyNode> descendantNodes;

     // constructors -----------------------------------------------------------

     public AncestorOrSelfDependencyNodeFilter( DependencyNode descendantNode )

     {

         this( Collections.singletonList( descendantNode ) );

     }

     /**

      * Creates a dependency node filter that only accepts nodes that are ancestors of, or equal to, the specified list

      * of nodes.

      * 

      * @param descendantNodes

      *            the list of nodes to accept ancestors-or-self of

      */

     public AncestorOrSelfDependencyNodeFilter( List<DependencyNode> descendantNodes )

     {

         this.descendantNodes = descendantNodes;

     }

     // DependencyNodeFilter methods -------------------------------------------

     /**

      * {@inheritDoc}

      */

     public boolean accept( DependencyNode node )

     {

         for ( DependencyNode descendantNode : descendantNodes )

         {

             if ( isAncestorOrSelf( node, descendantNode ) )

             {

                 return true;

             }

         }

         return false;

     }

     // private methods --------------------------------------------------------

     /**

      * Gets whether the first dependency node is an ancestor-or-self of the second.

      * 

      * @param ancestorNode

      *            the ancestor-or-self dependency node

      * @param descendantNode

      *            the dependency node to test

      * @return <code>true</code> if <code>ancestorNode</code> is an ancestor, or equal to,

      *         <code>descendantNode</code>

      */

     private boolean isAncestorOrSelf( DependencyNode ancestorNode, DependencyNode descendantNode )

     {

         boolean ancestor = false;

         while ( !ancestor && descendantNode != null )

         {

             ancestor = ancestorNode.equals( descendantNode );

             descendantNode = descendantNode.getParent();

         }

         return ancestor;

     }

 }