001package org.apache.maven.repository.metadata;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import org.apache.maven.artifact.versioning.ArtifactVersion;
023import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
024import org.codehaus.plexus.component.annotations.Component;
025import org.codehaus.plexus.component.annotations.Configuration;
026
027/**
028 * @author <a href="mailto:oleg@codehaus.org">Oleg Gusakov</a>
029 *
030 */
031@Component( role = GraphConflictResolutionPolicy.class )
032public class DefaultGraphConflictResolutionPolicy
033    implements GraphConflictResolutionPolicy
034{
035    /**
036     * artifact, closer to the entry point, is selected
037     */
038    @Configuration( name = "closer-first", value = "true" )
039    private boolean closerFirst = true;
040
041    /**
042     * newer artifact is selected
043     */
044    @Configuration( name = "newer-first", value = "true" )
045    private boolean newerFirst = true;
046
047    public MetadataGraphEdge apply( MetadataGraphEdge e1, MetadataGraphEdge e2 )
048    {
049        int depth1 = e1.getDepth();
050        int depth2 = e2.getDepth();
051
052        if ( depth1 == depth2 )
053        {
054            ArtifactVersion v1 = new DefaultArtifactVersion( e1.getVersion() );
055            ArtifactVersion v2 = new DefaultArtifactVersion( e2.getVersion() );
056
057            if ( newerFirst )
058            {
059                return v1.compareTo( v2 ) > 0 ? e1 : e2;
060            }
061
062            return v1.compareTo( v2 ) > 0 ? e2 : e1;
063        }
064
065        if ( closerFirst )
066        {
067            return depth1 < depth2 ? e1 : e2;
068        }
069
070        return depth1 < depth2 ? e2 : e1;
071    }
072
073}