001package org.apache.maven.graph;
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 java.util.ArrayList;
023import java.util.Collection;
024import java.util.HashSet;
025import java.util.List;
026import java.util.Set;
027
028import org.apache.maven.execution.ProjectDependencyGraph;
029import org.apache.maven.project.DuplicateProjectException;
030import org.apache.maven.project.MavenProject;
031import org.apache.maven.project.ProjectSorter;
032import org.codehaus.plexus.util.dag.CycleDetectedException;
033
034/**
035 * Describes the inter-dependencies between projects in the reactor.
036 *
037 * @author Benjamin Bentmann
038 */
039public class DefaultProjectDependencyGraph
040    implements ProjectDependencyGraph
041{
042
043    private ProjectSorter sorter;
044
045    /**
046     * Creates a new project dependency graph based on the specified projects.
047     *
048     * @param projects The projects to create the dependency graph with
049     * @throws DuplicateProjectException
050     * @throws CycleDetectedException
051     */
052    public DefaultProjectDependencyGraph( Collection<MavenProject> projects )
053        throws CycleDetectedException, DuplicateProjectException
054    {
055        this.sorter = new ProjectSorter( projects );
056    }
057
058    public List<MavenProject> getSortedProjects()
059    {
060        return new ArrayList<MavenProject>( sorter.getSortedProjects() );
061    }
062
063    public List<MavenProject> getDownstreamProjects( MavenProject project, boolean transitive )
064    {
065        if ( project == null )
066        {
067            throw new IllegalArgumentException( "project missing" );
068        }
069
070        Set<String> projectIds = new HashSet<String>();
071
072        getDownstreamProjects( ProjectSorter.getId( project ), projectIds, transitive );
073
074        return getSortedProjects( projectIds );
075    }
076
077    private void getDownstreamProjects( String projectId, Set<String> projectIds, boolean transitive )
078    {
079        for ( String id : sorter.getDependents( projectId ) )
080        {
081            if ( projectIds.add( id ) && transitive )
082            {
083                getDownstreamProjects( id, projectIds, transitive );
084            }
085        }
086    }
087
088    public List<MavenProject> getUpstreamProjects( MavenProject project, boolean transitive )
089    {
090        if ( project == null )
091        {
092            throw new IllegalArgumentException( "project missing" );
093        }
094
095        Set<String> projectIds = new HashSet<String>();
096
097        getUpstreamProjects( ProjectSorter.getId( project ), projectIds, transitive );
098
099        return getSortedProjects( projectIds );
100    }
101
102    private void getUpstreamProjects( String projectId, Collection<String> projectIds, boolean transitive )
103    {
104        for ( String id : sorter.getDependencies( projectId ) )
105        {
106            if ( projectIds.add( id ) && transitive )
107            {
108                getUpstreamProjects( id, projectIds, transitive );
109            }
110        }
111    }
112
113    private List<MavenProject> getSortedProjects( Set<String> projectIds )
114    {
115        List<MavenProject> result = new ArrayList<MavenProject>( projectIds.size() );
116
117        for ( MavenProject mavenProject : sorter.getSortedProjects() )
118        {
119            if ( projectIds.contains( ProjectSorter.getId( mavenProject ) ) )
120            {
121                result.add( mavenProject );
122            }
123        }
124
125        return result;
126    }
127
128    @Override
129    public String toString()
130    {
131        return sorter.getSortedProjects().toString();
132    }
133
134}