package org.neo4j.kernel.impl.traversal;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;

import java.util.Iterator;

import org.junit.BeforeClass;
import org.junit.Test;
import org.neo4j.graphdb.DynamicRelationshipType;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.RelationshipExpander;
import org.neo4j.graphdb.RelationshipType;
import org.neo4j.kernel.OrderedByTypeExpander;
import org.neo4j.kernel.Traversal;

public class TestOrderByTypeExpander extends AbstractTestBase
{
    @BeforeClass
    public static void setup()
    {
        createGraph( "A1 NEXT A2", "A2 NEXT A3",
                "A1 FIRST_COMMENT C1", "C1 COMMENT C2", "C2 COMMENT C3",
                "A2 FIRST_COMMENT C4", "C4 COMMENT C5", "C5 COMMENT C6",
                "A3 FIRST_COMMENT C7", "C7 COMMENT C8", "C8 COMMENT C9" );
    }
    
    @Test
    public void makeSureNodesAreTraversedInCorrectOrder()
    {
        RelationshipType next = DynamicRelationshipType.withName( "NEXT" );
        RelationshipType firstComment = DynamicRelationshipType.withName( "FIRST_COMMENT" );
        RelationshipType comment = DynamicRelationshipType.withName( "COMMENT" );
        RelationshipExpander expander =
            new OrderedByTypeExpander().add( firstComment ).add( comment ).add( next );
        Iterator<Node> itr = Traversal.description().depthFirst().expand(
                expander ).traverse( referenceNode() ).nodes().iterator();
        assertOrder( itr, "A1", "C1", "C2", "C3", "A2", "C4", "C5", "C6", "A3", "C7", "C8", "C9" );

        expander = new OrderedByTypeExpander().add( next ).add( firstComment ).add( comment );
        itr = Traversal.description().depthFirst().expand(
                expander ).traverse( referenceNode() ).nodes().iterator();
        assertOrder( itr, "A1", "A2", "A3", "C7", "C8", "C9", "C4", "C5", "C6", "C1", "C2", "C3" );
    }
    
    private void assertOrder( Iterator<Node> itr, String... names )
    {
        for ( String name : names )
        {
            System.out.println( name );
            Node node = itr.next();
            assertEquals( "expected " + name + ", was " + node.getProperty( "name" ),
                    getNodeWithName( name ), node );
        }
        assertFalse( itr.hasNext() );
    }
}