package org.simantics.structural2.queries;

import java.util.Map;

import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.request.ResourceRead;
import org.simantics.db.common.uri.UnescapedChildMapOfResource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.structural.stubs.StructuralResource2;

public class StructuralChildMapOfResource extends ResourceRead<Map<String, Resource>> {

    public StructuralChildMapOfResource(Resource resource) {
        super(resource);
    }

    @Override
    public Map<String, Resource> perform(ReadGraph graph) throws DatabaseException {
        StructuralResource2 STR = StructuralResource2.getInstance(graph);
        Resource type = graph.getPossibleType(resource, STR.Component);
        if(type != null) {
            Resource definition = graph.getPossibleObject(type, STR.IsDefinedBy);
            if(definition != null) {
                Map<String, Resource> map = graph.syncRequest(new UnescapedChildMapOfResource(definition));
                if (!map.isEmpty())
                    return map;
            } 
        }
        Map<String, Resource> directChildren = graph.syncRequest(new UnescapedChildMapOfResource(resource));
        return directChildren;
    }

}