package org.apache.maven.artifact.resolver;

/*
 * 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.artifact.factory.ArtifactFactory;
import org.apache.maven.artifact.metadata.ArtifactMetadataRetrievalException;
import org.apache.maven.artifact.metadata.ArtifactMetadataSource;
import org.apache.maven.artifact.metadata.ResolutionGroup;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.resolver.filter.ArtifactFilter;
import org.apache.maven.artifact.resolver.filter.ExclusionSetFilter;
import org.apache.maven.artifact.resolver.filter.ScopeArtifactFilter;
import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
import org.apache.maven.artifact.versioning.InvalidVersionSpecificationException;
import org.apache.maven.artifact.versioning.OverConstrainedVersionException;
import org.apache.maven.artifact.versioning.VersionRange;
import org.codehaus.plexus.PlexusTestCase;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Test the default artifact collector.
 *
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 * @version $Id: DefaultArtifactCollectorTest.java 675087 2008-07-09 02:23:29Z jdcasey $
 */
public class DefaultArtifactCollectorTest
    extends PlexusTestCase
{
    private ArtifactCollector artifactCollector;

    private ArtifactFactory artifactFactory;

    private ArtifactSpec projectArtifact;

    private Source source;

    private static final String GROUP_ID = "test";

    protected void setUp()
        throws Exception
    {
        super.setUp();

        source = new Source();
        artifactFactory = (ArtifactFactory) lookup( ArtifactFactory.ROLE );
        artifactCollector = new DefaultArtifactCollector();

        projectArtifact = createArtifactSpec( "project", "1.0", null );
    }

    // works, but we don't fail on cycles presently
    public void disabledtestCircularDependencyNotIncludingCurrentProject()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        b.addDependency( "a", "1.0" );
        try
        {
            collect( a );
            fail( "Should have failed on cyclic dependency not involving project" );
        }
        catch ( CyclicDependencyException expected )
        {
            assertTrue( true );
        }
    }

    // works, but we don't fail on cycles presently
    public void disabledtestCircularDependencyIncludingCurrentProject()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        b.addDependency( "project", "1.0" );
        try
        {
            collect( a );
            fail( "Should have failed on cyclic dependency involving project" );
        }
        catch ( CyclicDependencyException expected )
        {
            assertTrue( true );
        }
    }

    public void testResolveWithFilter()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c = a.addDependency( "c", "3.0" );

        b.addDependency( "c", "2.0" );
        ArtifactSpec d = b.addDependency( "d", "4.0" );

        ArtifactResolutionResult res = collect( a );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact, c.artifact, d.artifact} ),
                      res.getArtifacts() );

        ArtifactFilter filter = new ExclusionSetFilter( new String[]{"b"} );
        res = collect( a, filter );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, c.artifact} ), res.getArtifacts() );
    }

    public void testResolveCorrectDependenciesWhenDifferentDependenciesOnNearest()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c2 = b.addDependency( "c", "2.0" );
        c2.addDependency( "d", "1.0" );

        ArtifactSpec e = createArtifactSpec( "e", "1.0" );
        ArtifactSpec c1 = e.addDependency( "c", "1.0" );
        ArtifactSpec f = c1.addDependency( "f", "1.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, e.artifact} ) );
        assertEquals( "Check artifact list",
                      createSet( new Object[]{a.artifact, b.artifact, e.artifact, c1.artifact, f.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "1.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void disabledtestResolveCorrectDependenciesWhenDifferentDependenciesOnNewest()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        // TODO: use newest conflict resolver
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c2 = b.addDependency( "c", "2.0" );
        ArtifactSpec d = c2.addDependency( "d", "1.0" );

        ArtifactSpec e = createArtifactSpec( "e", "1.0" );
        ArtifactSpec c1 = e.addDependency( "c", "1.0" );
        c1.addDependency( "f", "1.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, e.artifact} ) );
        assertEquals( "Check artifact list",
                      createSet( new Object[]{a.artifact, b.artifact, e.artifact, c2.artifact, d.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "2.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void disabledtestResolveCorrectDependenciesWhenDifferentDependenciesOnNewestVersionReplaced()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        // TODO: use newest conflict resolver
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b1 = a.addDependency( "b", "1.0" );
        ArtifactSpec c = a.addDependency( "c", "1.0" );
        ArtifactSpec d2 = b1.addDependency( "d", "2.0" );
        d2.addDependency( "h", "1.0" );
        ArtifactSpec d1 = c.addDependency( "d", "1.0" );
        ArtifactSpec b2 = c.addDependency( "b", "2.0" );
        ArtifactSpec e = b2.addDependency( "e", "1.0" );
        ArtifactSpec g = d1.addDependency( "g", "1.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact} ) );
        Object[] artifacts = new Object[]{a.artifact, c.artifact, d1.artifact, b2.artifact, e.artifact, g.artifact};
        assertEquals( "Check artifact list", createSet( artifacts ), res.getArtifacts() );
        assertEquals( "Check version", "1.0", getArtifact( "d", res.getArtifacts() ).getVersion() );
        assertEquals( "Check version", "2.0", getArtifact( "b", res.getArtifacts() ).getVersion() );
    }

    public void testResolveNearestNewestIsNearest()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c = a.addDependency( "c", "3.0" );

        b.addDependency( "c", "2.0" );

        ArtifactResolutionResult res = collect( a );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact, c.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "3.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testResolveNearestOldestIsNearest()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c = a.addDependency( "c", "2.0" );

        b.addDependency( "c", "3.0" );

        ArtifactResolutionResult res = collect( a );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact, c.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "2.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testResolveLocalNewestIsLocal()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        a.addDependency( "b", "2.0" );
        ArtifactSpec b = createArtifactSpec( "b", "3.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
        assertEquals( "Check version", "3.0", getArtifact( "b", res.getArtifacts() ).getVersion() );
    }

    public void testResolveLocalOldestIsLocal()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        a.addDependency( "b", "3.0" );
        ArtifactSpec b = createArtifactSpec( "b", "2.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
        assertEquals( "Check version", "2.0", getArtifact( "b", res.getArtifacts() ).getVersion() );
    }

    public void testResolveLocalWithNewerVersionButLesserScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "commons-logging", "1.0" );
        a.addDependency( "junit", "3.7" );
        ArtifactSpec b = createArtifactSpec( "junit", "3.8.1", Artifact.SCOPE_TEST );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
        assertEquals( "Check version", "3.8.1", getArtifact( "junit", res.getArtifacts() ).getVersion() );
        assertEquals( "Check scope", Artifact.SCOPE_TEST, getArtifact( "junit", res.getArtifacts() ).getScope() );
    }

    public void testResolveLocalWithNewerVersionButLesserScopeResolvedFirst()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec b = createArtifactSpec( "junit", "3.8.1", Artifact.SCOPE_TEST );
        ArtifactSpec a = createArtifactSpec( "commons-logging", "1.0" );
        a.addDependency( "junit", "3.7" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
        assertEquals( "Check version", "3.8.1", getArtifact( "junit", res.getArtifacts() ).getVersion() );
        assertEquals( "Check scope", Artifact.SCOPE_TEST, getArtifact( "junit", res.getArtifacts() ).getScope() );
    }

    public void testResolveNearestWithRanges()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec c = a.addDependency( "c", "2.0" );

        b.addDependency( "c", "[1.0,3.0]" );

        ArtifactResolutionResult res = collect( a );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact, c.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "2.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testResolveRangeWithManagedVersion()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "[1.0,3.0]" );

        ArtifactSpec managedB = createArtifactSpec( "b", "5.0" );

        ArtifactResolutionResult res = collect( a, managedB.artifact );
        assertEquals( "Check artifact list", createSet( new Object[] { a.artifact, managedB.artifact } ),
                      res.getArtifacts() );
        assertEquals( "Check version", "5.0", getArtifact( "b", res.getArtifacts() ).getVersion() );
    }

    public void testCompatibleRanges()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        a.addDependency( "c", "[2.0,2.5]" );
        b.addDependency( "c", "[1.0,3.0]" );
        ArtifactSpec c = createArtifactSpec( "c", "2.5" );

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact, c.artifact} ),
                      res.getArtifacts() );
        assertEquals( "Check version", "2.5", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testCompatibleRecommendedVersion()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {

        //this test puts two dependencies on C with 3.2 and [1.0,3.0] as the version.
        //it puts 2.5 in the pretend repo...we should get back 2.5
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec b1 = a.addDependency( "b1", "1.0" );
        b.addDependency( "c", "3.2" );
        b1.addDependency( "c", "[1.0,3.0]" );

        //put it in the repo
        ArtifactSpec c = createArtifactSpec( "c", "2.5" );
        source.addArtifact( createArtifactSpec( "c", "2.5" ));

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list", createSet( new Object[] { a.artifact, b.artifact,b1.artifact,c.artifact } ),
                      res.getArtifacts() );
        assertEquals( "Check version", "2.5", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testCompatibleRecommendedVersionWithChildren()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {

        // this test puts two dependencies on C with 3.2 and [1.0,3.0] as the version.
        // it puts 2.5 in the pretend repo...we should get back c2.5 and d1.0
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec e = a.addDependency( "e", "1.0" );
        ArtifactSpec c1 = b.addDependency( "c", "3.2" );
        ArtifactSpec d1 = c1.addDependency( "d","1.1" );
        e.addDependency( "c", "[1.0,3.0]" );

        // put it in the repo
        ArtifactSpec c = createArtifactSpec( "c", "2.5" );
        ArtifactSpec d = c.addDependency( "d","1.0" );

        source.addArtifact( c );
        source.addArtifact( d );
        source.addArtifact( c1 );
        source.addArtifact( d1 );

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list",
                      createSet( new Object[] { a.artifact, b.artifact, e.artifact, c.artifact,d.artifact } ), res.getArtifacts() );
        assertEquals( "Check version", "2.5", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testInCompatibleRecommendedVersion()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {

        // this test puts two dependencies on C with 3.2 and [1.0,3.0] as the version.
        // it puts 2.5 and 3.0 in the pretend repo...we should get back 3.0
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec b1 = a.addDependency( "b1", "1.0" );
        b.addDependency( "c", "3.2" );
        b1.addDependency( "c", "[1.0,3.0]" );

        // put it in the repo
        ArtifactSpec c = createArtifactSpec( "c", "3.0" );
        source.addArtifact( createArtifactSpec( "c", "2.5" ) );
        source.addArtifact( createArtifactSpec( "c", "3.0" ) );
        source.addArtifact( createArtifactSpec( "c", "3.2" ) );

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list",
                      createSet( new Object[] { a.artifact, b.artifact, b1.artifact, c.artifact } ), res.getArtifacts() );
        assertEquals( "Check version", "3.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    //MNG-2123: this version of the test caused the crash seen in the IT. It was
    //only happening if the first dependency was not a range but the second one was.
    public void testInCompatibleRecommendedVersion2()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {

        // this test puts two dependencies on C with 3.2 and [1.0,3.0] as the version.
        // it puts 2.5 and 3.0 in the pretend repo...we should get back 3.0
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        ArtifactSpec b1 = a.addDependency( "b1", "1.0" );
        b1.addDependency( "c", "3.2" );
        b.addDependency( "c", "[1.0,3.0]" );

        // put it in the repo
        ArtifactSpec c = createArtifactSpec( "c", "3.0" );
        source.addArtifact( createArtifactSpec( "c", "2.5" ) );
        source.addArtifact( createArtifactSpec( "c", "3.0" ) );
        source.addArtifact( createArtifactSpec( "c", "3.2" ) );

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list",
                      createSet( new Object[] { a.artifact, b.artifact, b1.artifact, c.artifact } ), res.getArtifacts() );
        assertEquals( "Check version", "3.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testIncompatibleRanges()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        a.addDependency( "c", "[2.4,3.0]" );

        b.addDependency( "c", "[1.0,2.0]" );

        try
        {
            ArtifactResolutionResult res = collect( a );
            fail( "Should not succeed collecting, got: " + res.getArtifacts() );
        }
        catch ( ArtifactResolutionException expected )
        {
        }
    }

    public void testUnboundedRangeWhenVersionUnavailable()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = a.addDependency( "b", "1.0" );
        a.addDependency( "c", "[2.0,]" );
        b.addDependency( "c", "[1.0,]" );

        try
        {
            ArtifactResolutionResult res = collect( a );
            fail( "Should not succeed collecting, got: " + res.getArtifacts() );
        }
        catch ( ArtifactResolutionException expected )
        {
            assertTrue( true );
        }
    }

    public void testUnboundedRangeBelowLastRelease()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        createArtifactSpec( "c", "1.5" );
        ArtifactSpec c = createArtifactSpec( "c", "2.0" );
        createArtifactSpec( "c", "1.1" );
        a.addDependency( "c", "[1.0,)" );

        ArtifactResolutionResult res = collect( a );

        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, c.artifact} ), res.getArtifacts() );
        assertEquals( "Check version", "2.0", getArtifact( "c", res.getArtifacts() ).getVersion() );
    }

    public void testUnboundedRangeAboveLastRelease()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        createArtifactSpec( "c", "2.0" );
        a.addDependency( "c", "[10.0,)" );

        try
        {
            ArtifactResolutionResult res = collect( a );
            fail( "Should not succeed collecting, got: " + res.getArtifacts() );
        }
        catch ( ArtifactResolutionException expected )
        {
            assertTrue( true );
        }
    }

    public void testResolveManagedVersion()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        a.addDependency( "b", "3.0", Artifact.SCOPE_RUNTIME );

        Artifact managedVersion = createArtifactSpec( "b", "5.0" ).artifact;
        Artifact modifiedB = createArtifactSpec( "b", "5.0", Artifact.SCOPE_RUNTIME ).artifact;

        ArtifactResolutionResult res = collect( a, managedVersion );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, modifiedB} ), res.getArtifacts() );
    }

    public void testCollectChangesVersionOfOriginatingArtifactIfInDependencyManagementHasDifferentVersion()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );

        Artifact artifact = projectArtifact.artifact;
        Artifact managedVersion = createArtifactSpec( artifact.getArtifactId(), "2.0" ).artifact;

        ArtifactResolutionResult result = collect( a, managedVersion );

        assertEquals( "collect has modified version in originating artifact", "1.0", artifact.getVersion() );

        Artifact resolvedArtifact = (Artifact) result.getArtifacts().iterator().next();

        assertEquals( "Resolved version don't match original artifact version", "1.0", resolvedArtifact.getVersion() );
    }

    public void testResolveCompileScopeOverTestScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec c = createArtifactSpec( "c", "3.0", Artifact.SCOPE_TEST );

        a.addDependency( "c", "2.0", Artifact.SCOPE_COMPILE );

        Artifact modifiedC = createArtifactSpec( "c", "3.0", Artifact.SCOPE_COMPILE ).artifact;

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, c.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, modifiedC} ), res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        // local wins now, and irrelevant if not local as test/provided aren't transitive
//        assertEquals( "Check scope", Artifact.SCOPE_COMPILE, artifact.getScope() );
        assertEquals( "Check scope", Artifact.SCOPE_TEST, artifact.getScope() );
    }

    public void testResolveRuntimeScopeOverTestScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec c = createArtifactSpec( "c", "3.0", Artifact.SCOPE_TEST );

        a.addDependency( "c", "2.0", Artifact.SCOPE_RUNTIME );

        Artifact modifiedC = createArtifactSpec( "c", "3.0", Artifact.SCOPE_RUNTIME ).artifact;

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, c.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, modifiedC} ), res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        // local wins now, and irrelevant if not local as test/provided aren't transitive
//        assertEquals( "Check scope", Artifact.SCOPE_RUNTIME, artifact.getScope() );
        assertEquals( "Check scope", Artifact.SCOPE_TEST, artifact.getScope() );
    }

    public void testResolveCompileScopeOverRuntimeScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec root = createArtifactSpec( "root", "1.0" );
        ArtifactSpec a = root.addDependency( "a", "1.0" );
        root.addDependency( "c", "3.0", Artifact.SCOPE_RUNTIME );

        a.addDependency( "c", "2.0", Artifact.SCOPE_COMPILE );

        Artifact modifiedC = createArtifactSpec( "c", "3.0", Artifact.SCOPE_COMPILE ).artifact;

        ArtifactResolutionResult res = collect( createSet( new Object[]{root.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, root.artifact, modifiedC} ),
                      res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        assertEquals( "Check scope", Artifact.SCOPE_COMPILE, artifact.getScope() );
    }

    public void testResolveCompileScopeOverProvidedScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec c = createArtifactSpec( "c", "3.0", Artifact.SCOPE_PROVIDED );

        a.addDependency( "c", "2.0", Artifact.SCOPE_COMPILE );

        Artifact modifiedC = createArtifactSpec( "c", "3.0", Artifact.SCOPE_COMPILE ).artifact;

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, c.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, modifiedC} ), res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        // local wins now, and irrelevant if not local as test/provided aren't transitive
//        assertEquals( "Check scope", Artifact.SCOPE_COMPILE, artifact.getScope() );
        assertEquals( "Check scope", Artifact.SCOPE_PROVIDED, artifact.getScope() );
    }

    public void testResolveRuntimeScopeOverProvidedScope()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec c = createArtifactSpec( "c", "3.0", Artifact.SCOPE_PROVIDED );

        a.addDependency( "c", "2.0", Artifact.SCOPE_RUNTIME );

        Artifact modifiedC = createArtifactSpec( "c", "3.0", Artifact.SCOPE_RUNTIME ).artifact;

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, c.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, modifiedC} ), res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        // local wins now, and irrelevant if not local as test/provided aren't transitive
//        assertEquals( "Check scope", Artifact.SCOPE_RUNTIME, artifact.getScope() );
        assertEquals( "Check scope", Artifact.SCOPE_PROVIDED, artifact.getScope() );
    }

    public void testProvidedScopeNotTransitive()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0", Artifact.SCOPE_PROVIDED );
        ArtifactSpec b = createArtifactSpec( "b", "1.0" );
        b.addDependency( "c", "3.0", Artifact.SCOPE_PROVIDED );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
    }

    public void testOptionalNotTransitive()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = createArtifactSpec( "b", "1.0" );
        b.addDependency( "c", "3.0", true );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
    }

    public void testOptionalIncludedAtRoot()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );

        ArtifactSpec b = createArtifactSpec( "b", "1.0", true );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
    }

    public void testScopeUpdate()
        throws InvalidVersionSpecificationException, ArtifactResolutionException
    {
        /* farthest = compile */
        checkScopeUpdate( Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_COMPILE, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_COMPILE, Artifact.SCOPE_RUNTIME, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_COMPILE, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_COMPILE, Artifact.SCOPE_TEST, Artifact.SCOPE_COMPILE );

        /* farthest = provided */
        checkScopeUpdate( Artifact.SCOPE_PROVIDED, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_PROVIDED, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_PROVIDED );
        checkScopeUpdate( Artifact.SCOPE_PROVIDED, Artifact.SCOPE_RUNTIME, Artifact.SCOPE_RUNTIME );
        checkScopeUpdate( Artifact.SCOPE_PROVIDED, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM );
        checkScopeUpdate( Artifact.SCOPE_PROVIDED, Artifact.SCOPE_TEST, Artifact.SCOPE_TEST );

        /* farthest = runtime */
        checkScopeUpdate( Artifact.SCOPE_RUNTIME, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_RUNTIME, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_RUNTIME );
        checkScopeUpdate( Artifact.SCOPE_RUNTIME, Artifact.SCOPE_RUNTIME, Artifact.SCOPE_RUNTIME );
        checkScopeUpdate( Artifact.SCOPE_RUNTIME, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM );
        checkScopeUpdate( Artifact.SCOPE_RUNTIME, Artifact.SCOPE_TEST, Artifact.SCOPE_RUNTIME );

        /* farthest = system */
        checkScopeUpdate( Artifact.SCOPE_SYSTEM, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_SYSTEM, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_PROVIDED );
        checkScopeUpdate( Artifact.SCOPE_SYSTEM, Artifact.SCOPE_RUNTIME, Artifact.SCOPE_RUNTIME );
        checkScopeUpdate( Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM );
        checkScopeUpdate( Artifact.SCOPE_SYSTEM, Artifact.SCOPE_TEST, Artifact.SCOPE_TEST );

        /* farthest = test */
        checkScopeUpdate( Artifact.SCOPE_TEST, Artifact.SCOPE_COMPILE, Artifact.SCOPE_COMPILE );
        checkScopeUpdate( Artifact.SCOPE_TEST, Artifact.SCOPE_PROVIDED, Artifact.SCOPE_PROVIDED );
        checkScopeUpdate( Artifact.SCOPE_TEST, Artifact.SCOPE_RUNTIME, Artifact.SCOPE_RUNTIME );
        checkScopeUpdate( Artifact.SCOPE_TEST, Artifact.SCOPE_SYSTEM, Artifact.SCOPE_SYSTEM );
        checkScopeUpdate( Artifact.SCOPE_TEST, Artifact.SCOPE_TEST, Artifact.SCOPE_TEST );
    }

    private void checkScopeUpdate( String farthestScope, String nearestScope, String expectedScope )
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        checkScopeUpdateDirect( farthestScope, nearestScope, expectedScope );
        checkScopeUpdateTransitively( farthestScope, nearestScope, expectedScope );
    }

    private void checkScopeUpdateTransitively( String farthestScope, String nearestScope, String expectedScope )
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = createArtifactSpec( "b", "1.0", nearestScope );
        ArtifactSpec c = createArtifactSpec( "c", "1.0" );
        a.addDependency( c );
        ArtifactSpec dNearest = createArtifactSpec( "d", "2.0" );
        b.addDependency( dNearest );
        ArtifactSpec dFarthest = createArtifactSpec( "d", "3.0", farthestScope );
        c.addDependency( dFarthest );

        /* system and provided dependencies are not transitive */
        if ( !Artifact.SCOPE_SYSTEM.equals( nearestScope ) && !Artifact.SCOPE_PROVIDED.equals( nearestScope ) )
        {
            checkScopeUpdate( a, b, expectedScope, "2.0" );
        }
    }

    private void checkScopeUpdateDirect( String farthestScope, String nearestScope, String expectedScope )
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = createArtifactSpec( "b", "1.0" );
        ArtifactSpec c = createArtifactSpec( "c", "1.0" );
        a.addDependency( c );
        ArtifactSpec dNearest = createArtifactSpec( "d", "2.0", nearestScope );
        b.addDependency( dNearest );
        ArtifactSpec dFarthest = createArtifactSpec( "d", "3.0", farthestScope );
        c.addDependency( dFarthest );

        checkScopeUpdate( a, b, expectedScope, "2.0" );
    }

    private void checkScopeUpdate( ArtifactSpec a, ArtifactSpec b, String expectedScope, String expectedVersion )
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ScopeArtifactFilter filter;
        if ( Artifact.SCOPE_PROVIDED.equals( expectedScope ) )
        {
            filter = new ScopeArtifactFilter( Artifact.SCOPE_COMPILE );
        }
        else if ( Artifact.SCOPE_SYSTEM.equals( expectedScope ) )
        {
            filter = new ScopeArtifactFilter( Artifact.SCOPE_COMPILE );
        }
        else
        {
            filter = new ScopeArtifactFilter( expectedScope );
        }

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ), filter );
        Artifact artifact = getArtifact( "d", res.getArtifacts() );
        assertNotNull( "MNG-1895 Dependency was not added to resolution", artifact );
        assertEquals( "Check scope", expectedScope, artifact.getScope() );
        assertEquals( "Check version", expectedVersion, artifact.getVersion() );

        ArtifactSpec d = createArtifactSpec( "d", "1.0" );
        res = collect( createSet( new Object[]{a.artifact, b.artifact, d.artifact} ), filter );
        artifact = getArtifact( "d", res.getArtifacts() );
        assertNotNull( "MNG-1895 Dependency was not added to resolution", artifact );
        assertEquals( "Check scope", d.artifact.getScope(), artifact.getScope() );
        assertEquals( "Check version", "1.0", artifact.getVersion() );
    }

    public void disabledtestOptionalNotTransitiveButVersionIsInfluential()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        ArtifactSpec b = createArtifactSpec( "b", "1.0" );
        b.addDependency( "c", "3.0", true );
        ArtifactSpec d = a.addDependency( "d", "1.0" );
        ArtifactSpec e = d.addDependency( "e", "1.0" );
        e.addDependency( "c", "2.0" );

        ArtifactSpec c = createArtifactSpec( "c", "3.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list",
                      createSet( new Object[]{a.artifact, b.artifact, c.artifact, d.artifact, e.artifact} ),
                      res.getArtifacts() );
        Artifact artifact = getArtifact( "c", res.getArtifacts() );
        assertEquals( "Check version", "3.0", artifact.getVersion() );
    }

    public void testTestScopeNotTransitive()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0", Artifact.SCOPE_TEST );
        ArtifactSpec b = createArtifactSpec( "b", "1.0" );
        b.addDependency( "c", "3.0", Artifact.SCOPE_TEST );

        ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact, b.artifact} ) );
        assertEquals( "Check artifact list", createSet( new Object[]{a.artifact, b.artifact} ), res.getArtifacts() );
    }

    public void testResolveOrder()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec m = createArtifactSpec( "m", "1.0" );
        ArtifactSpec n = createArtifactSpec( "n", "1.0" );

        ArtifactResolutionResult res = collect( createSet( new Object[]{m.artifact, n.artifact} ) );
        Iterator i = res.getArtifacts().iterator();
        assertEquals( "m should be first", m.artifact, i.next() );
        assertEquals( "n should be second", n.artifact, i.next() );

        res = collect( createSet( new Object[]{n.artifact, m.artifact} ) );
        i = res.getArtifacts().iterator();
        assertEquals( "n should be first", n.artifact, i.next() );
        assertEquals( "m should be second", m.artifact, i.next() );
    }

    public void testOverConstrainedVersionException()
        throws ArtifactResolutionException, InvalidVersionSpecificationException
    {
        ArtifactSpec a = createArtifactSpec( "a", "1.0" );
        a.addDependency( "b", "[1.0, 2.0)" );
        a.addDependency( "c", "[3.3.0,4.0.0)" );

        ArtifactSpec b = createArtifactSpec( "b", "1.0.0" );
        b.addDependency( "c", "3.3.0-v3346" );

        ArtifactSpec c = createArtifactSpec( "c", "3.2.1-v3235e" );

        try
        {
            ArtifactResolutionResult res = collect( createSet( new Object[]{a.artifact} ) );
        }
        catch ( OverConstrainedVersionException e )
        {
            assertTrue( "Versions unordered", e.getMessage().indexOf( "[3.2.1-v3235e, 3.3.0-v3346]" ) != -1);
            assertTrue( "DependencyTrail not resolved", e.getMessage().indexOf( "Path to dependency:" ) != -1);
        }
    }

    private Artifact getArtifact( String id, Set artifacts )
    {
        for ( Iterator i = artifacts.iterator(); i.hasNext(); )
        {
            Artifact a = (Artifact) i.next();
            if ( a.getArtifactId().equals( id ) && a.getGroupId().equals( GROUP_ID ) )
            {
                return a;
            }
        }
        return null;
    }

    private ArtifactResolutionResult collect( Set artifacts )
        throws ArtifactResolutionException
    {
        return collect( artifacts, null );
    }

    private ArtifactResolutionResult collect( Set artifacts, ArtifactFilter filter )
        throws ArtifactResolutionException
    {
        return artifactCollector.collect( artifacts, projectArtifact.artifact, null, null, source, filter,
                                          Collections.EMPTY_LIST );
    }

    private ArtifactResolutionResult collect( ArtifactSpec a )
        throws ArtifactResolutionException
    {
        return artifactCollector.collect( Collections.singleton( a.artifact ), projectArtifact.artifact, null, null,
                                          source, null, Collections.EMPTY_LIST );
    }

    private ArtifactResolutionResult collect( ArtifactSpec a, ArtifactFilter filter )
        throws ArtifactResolutionException
    {
        return artifactCollector.collect( Collections.singleton( a.artifact ), projectArtifact.artifact, null, null,
                                          source, filter, Collections.EMPTY_LIST );
    }

    private ArtifactResolutionResult collect( ArtifactSpec a, Artifact managedVersion )
        throws ArtifactResolutionException
    {
        Map managedVersions = Collections.singletonMap( managedVersion.getDependencyConflictId(), managedVersion );
        return artifactCollector.collect( Collections.singleton( a.artifact ), projectArtifact.artifact,
                                          managedVersions, null, null, source, null, Collections.EMPTY_LIST );
    }

    private ArtifactSpec createArtifactSpec( String id, String version )
        throws InvalidVersionSpecificationException
    {
        return createArtifactSpec( id, version, Artifact.SCOPE_COMPILE );
    }

    private ArtifactSpec createArtifactSpec( String id, String version, boolean optional )
        throws InvalidVersionSpecificationException
    {
        return createArtifactSpec( id, version, Artifact.SCOPE_COMPILE, null, optional );
    }

    private ArtifactSpec createArtifactSpec( String id, String version, String scope )
        throws InvalidVersionSpecificationException
    {
        return createArtifactSpec( id, version, scope, null, false );
    }

    private ArtifactSpec createArtifactSpec( String id, String version, String scope, String inheritedScope,
                                         boolean optional )
        throws InvalidVersionSpecificationException
    {
        VersionRange versionRange = VersionRange.createFromVersionSpec( version );
        Artifact artifact = artifactFactory.createDependencyArtifact( GROUP_ID, id, versionRange, "jar", null, scope,
                                                                      inheritedScope, optional );
        ArtifactSpec spec = null;
        if ( artifact != null )
        {
            spec = new ArtifactSpec();
            spec.artifact = artifact;
            source.addArtifact( spec );
        }
        return spec;
    }

    private static Set createSet( Object[] x )
    {
        return new LinkedHashSet( Arrays.asList( x ) );
    }

    private class ArtifactSpec
    {
        private Artifact artifact;

        private Set dependencies = new HashSet();

        public ArtifactSpec addDependency( String id, String version )
            throws InvalidVersionSpecificationException
        {
            return addDependency( id, version, Artifact.SCOPE_COMPILE );
        }

        public ArtifactSpec addDependency( String id, String version, String scope )
            throws InvalidVersionSpecificationException
        {
            return addDependency( id, version, scope, false );
        }

        private ArtifactSpec addDependency( ArtifactSpec dep )
            throws InvalidVersionSpecificationException
        {
            if ( dep != null )
            {
                dependencies.add( dep.artifact );
            }
            return dep;
        }

        private ArtifactSpec addDependency( String id, String version, String scope, boolean optional )
            throws InvalidVersionSpecificationException
        {
            ArtifactSpec dep = createArtifactSpec( id, version, scope, artifact.getScope(), optional );
            return addDependency( dep );
        }

        public ArtifactSpec addDependency( String id, String version, boolean optional )
            throws InvalidVersionSpecificationException
        {
            return addDependency( id, version, Artifact.SCOPE_COMPILE, optional );
        }
    }

    private class Source
        implements ArtifactMetadataSource
    {
        private Map artifacts = new HashMap();

        private Map versions = new HashMap();

        public ResolutionGroup retrieve( Artifact artifact, ArtifactRepository localRepository,
                                         List remoteRepositories )
            throws ArtifactMetadataRetrievalException
        {
            String key = getKey( artifact );

            ArtifactSpec a = (ArtifactSpec) artifacts.get( key );
            try
            {
                return new ResolutionGroup( artifact, createArtifacts( artifactFactory, a.dependencies,
                                                                       artifact.getScope(),
                                                                       artifact.getDependencyFilter() ),
                                                      Collections.EMPTY_LIST );
            }
            catch ( InvalidVersionSpecificationException e )
            {
                throw new ArtifactMetadataRetrievalException( "Invalid version creating artifacts", e, artifact );
            }
        }

        private String getKey( Artifact artifact )
        {
            return artifact.getDependencyConflictId() + ":" + artifact.getVersion();
            //return artifact.getDependencyConflictId();
        }

        private Set createArtifacts( ArtifactFactory artifactFactory, Set dependencies, String inheritedScope,
                                     ArtifactFilter dependencyFilter )
            throws InvalidVersionSpecificationException
        {
            Set projectArtifacts = new LinkedHashSet();

            for ( Iterator i = dependencies.iterator(); i.hasNext(); )
            {
                Artifact d = (Artifact) i.next();

                VersionRange versionRange;
                if ( d.getVersionRange() != null )
                {
                    versionRange = d.getVersionRange();
                }
                else
                {
                    versionRange = VersionRange.createFromVersionSpec( d.getVersion() );
                }
                Artifact artifact;
                if ( d.getScope().equals( Artifact.SCOPE_TEST ) || d.getScope().equals( Artifact.SCOPE_PROVIDED ) )
                {
                    /* don't call createDependencyArtifact as it'll ignore test and provided scopes */
                    artifact = artifactFactory.createArtifact( d.getGroupId(), d.getArtifactId(), d.getVersion(), d
                        .getScope(), d.getType() );
                }
                else
                {
                    artifact = artifactFactory.createDependencyArtifact( d.getGroupId(), d.getArtifactId(),
                                                                         versionRange, d.getType(), d.getClassifier(),
                                                                         d.getScope(), inheritedScope, d.isOptional() );
                }

                if ( artifact != null && ( dependencyFilter == null || dependencyFilter.include( artifact ) ) )
                {
                    artifact.setDependencyFilter( dependencyFilter );

                    projectArtifacts.add( artifact );
                }
            }

            return projectArtifacts;
        }

        public List retrieveAvailableVersions( Artifact artifact, ArtifactRepository localRepository,
                                               List remoteRepositories )
            throws ArtifactMetadataRetrievalException
        {
            List artifactVersions = (List) versions.get( artifact.getDependencyConflictId() );
            if ( artifactVersions == null )
            {
                artifactVersions = Collections.EMPTY_LIST;
            }
            return artifactVersions;
        }

        public void addArtifact( ArtifactSpec spec )
        {
            artifacts.put( getKey( spec.artifact ), spec );

            String key = spec.artifact.getDependencyConflictId();
            List artifactVersions = (List) versions.get( key );
            if ( artifactVersions == null )
            {
                artifactVersions = new ArrayList();
                versions.put( key, artifactVersions );
            }
            if ( spec.artifact.getVersion() != null )
            {
                artifactVersions.add( new DefaultArtifactVersion( spec.artifact.getVersion() ) );
            }
        }

        public Artifact retrieveRelocatedArtifact( Artifact artifact,
                                                   ArtifactRepository localRepository,
                                                   List remoteRepositories )
            throws ArtifactMetadataRetrievalException
        {
            return artifact;
        }
    }
}
