package org.eclipse.aether.util.graph.traverser;

/*
 * 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 static java.util.Objects.requireNonNull;
import static org.junit.Assert.*;

import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.artifact.DefaultArtifact;
import org.eclipse.aether.collection.DependencyCollectionContext;
import org.eclipse.aether.collection.DependencyTraverser;
import org.eclipse.aether.graph.Dependency;
import org.eclipse.aether.internal.test.util.TestFileUtils;
import org.eclipse.aether.internal.test.util.TestUtils;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.util.Collections;

public class AndDependencyTraverserTest
{

    static class DummyDependencyTraverser
        implements DependencyTraverser
    {

        private final boolean traverse;

        private final DependencyTraverser child;

        public DummyDependencyTraverser()
        {
            this( true );
        }

        public DummyDependencyTraverser( boolean traverse )
        {
            this.traverse = traverse;
            this.child = this;
        }

        public DummyDependencyTraverser( boolean traverse, DependencyTraverser child )
        {
            this.traverse = traverse;
            this.child = child;
        }

        public boolean traverseDependency( Dependency dependency )
        {
            requireNonNull( dependency, "dependency cannot be null" );
            return traverse;
        }

        public DependencyTraverser deriveChildTraverser( DependencyCollectionContext context )
        {
            requireNonNull( context, "context cannot be null" );
            return child;
        }

    }

    private RepositorySystemSession session;
    private DependencyCollectionContext context;

    @Before
    public void setup()
    {
        session = TestUtils.newSession();
        context = TestUtils.newCollectionContext( session, null, Collections.emptyList() );
    }

    @After
    public void teardown() throws Exception
    {
        if ( session.getLocalRepository() != null )
        {
            TestFileUtils.deleteFile( session.getLocalRepository().getBasedir() );
        }
        session = null;
        context = null;
    }

    @Test
    public void testNewInstance()
    {
        assertNull( AndDependencyTraverser.newInstance( null, null ) );
        DependencyTraverser traverser = new DummyDependencyTraverser();
        assertSame( traverser, AndDependencyTraverser.newInstance( traverser, null ) );
        assertSame( traverser, AndDependencyTraverser.newInstance( null, traverser ) );
        assertSame( traverser, AndDependencyTraverser.newInstance( traverser, traverser ) );
        assertNotNull( AndDependencyTraverser.newInstance( traverser, new DummyDependencyTraverser() ) );
    }

    @Test
    public void testTraverseDependency()
    {
        Dependency dependency = new Dependency( new DefaultArtifact( "g:a:v:1" ), "runtime" );

        DependencyTraverser traverser = new AndDependencyTraverser();
        assertTrue( traverser.traverseDependency( dependency ) );

        traverser =
            new AndDependencyTraverser( new DummyDependencyTraverser( false ), new DummyDependencyTraverser( false ) );
        assertFalse( traverser.traverseDependency( dependency ) );

        traverser =
            new AndDependencyTraverser( new DummyDependencyTraverser( true ), new DummyDependencyTraverser( false ) );
        assertFalse( traverser.traverseDependency( dependency ) );

        traverser =
            new AndDependencyTraverser( new DummyDependencyTraverser( true ), new DummyDependencyTraverser( true ) );
        assertTrue( traverser.traverseDependency( dependency ) );
    }

    @Test
    public void testDeriveChildTraverser_Unchanged()
    {
        DependencyTraverser other1 = new DummyDependencyTraverser( true );
        DependencyTraverser other2 = new DummyDependencyTraverser( false );
        DependencyTraverser traverser = new AndDependencyTraverser( other1, other2 );
        assertSame( traverser, traverser.deriveChildTraverser( context ) );
    }

    @Test
    public void testDeriveChildTraverser_OneRemaining()
    {
        DependencyTraverser other1 = new DummyDependencyTraverser( true );
        DependencyTraverser other2 = new DummyDependencyTraverser( false, null );
        DependencyTraverser traverser = new AndDependencyTraverser( other1, other2 );
        assertSame( other1, traverser.deriveChildTraverser( context ) );
    }

    @Test
    public void testDeriveChildTraverser_ZeroRemaining()
    {
        DependencyTraverser other1 = new DummyDependencyTraverser( true, null );
        DependencyTraverser other2 = new DummyDependencyTraverser( false, null );
        DependencyTraverser traverser = new AndDependencyTraverser( other1, other2 );
        assertNull( traverser.deriveChildTraverser( context ) );
    }

    @Test
    public void testEquals()
    {
        DependencyTraverser other1 = new DummyDependencyTraverser( true );
        DependencyTraverser other2 = new DummyDependencyTraverser( false );
        DependencyTraverser traverser1 = new AndDependencyTraverser( other1, other2 );
        DependencyTraverser traverser2 = new AndDependencyTraverser( other2, other1 );
        DependencyTraverser traverser3 = new AndDependencyTraverser( other1 );
        assertEquals( traverser1, traverser1 );
        assertEquals( traverser1, traverser2 );
        assertNotEquals( traverser1, traverser3 );
        assertNotEquals( traverser1, this );
        assertNotEquals( traverser1, null );
    }

    @Test
    public void testHashCode()
    {
        DependencyTraverser other1 = new DummyDependencyTraverser( true );
        DependencyTraverser other2 = new DummyDependencyTraverser( false );
        DependencyTraverser traverser1 = new AndDependencyTraverser( other1, other2 );
        DependencyTraverser traverser2 = new AndDependencyTraverser( other2, other1 );
        assertEquals( traverser1.hashCode(), traverser2.hashCode() );
    }

}
