package org.cristalise.gui.lifecycle.instance;

import org.cristalise.kernel.graph.model.DirectedEdge;
import org.cristalise.kernel.graph.model.EdgeFactory;
import org.cristalise.kernel.graph.model.GraphModelManager;
import org.cristalise.kernel.graph.model.TypeNameAndConstructionInfo;
import org.cristalise.kernel.graph.model.Vertex;
import org.cristalise.kernel.lifecycle.instance.WfVertex;

public class WfEdgeFactory implements EdgeFactory
{
    @Override
	public void create
    (
        GraphModelManager           graphModelManager,
        Vertex                      origin,
        Vertex                      terminus,
        TypeNameAndConstructionInfo typeNameAndConstructionInfo
    )
    {
		if ( validCreation( graphModelManager, origin, terminus ) )
			((WfVertex)origin).addNext((WfVertex)terminus);

    }

    private static boolean validCreation( GraphModelManager graphModelManager, Vertex origin, Vertex terminus )
    {
        DirectedEdge[] connectingEdgesAToB = graphModelManager.getModel().getConnectingEdges( origin.getID()  , terminus.getID() );
        DirectedEdge[] connectingEdgesBToA = graphModelManager.getModel().getConnectingEdges( terminus.getID(), origin.getID() );


        return ( origin != terminus ) && ( connectingEdgesAToB.length == 0 ) && ( connectingEdgesBToA.length == 0 );
    }
}