package org.simantics.spreadsheet.graph;

import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.variable.NodeManagerVariableBuilder;
import org.simantics.db.layer0.variable.NodeSupport;
import org.simantics.db.layer0.variable.ProxyChildVariable;
import org.simantics.db.layer0.variable.StandardGraphChildVariable;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.layer0.variable.VariableNode;
import org.simantics.spreadsheet.graph.function.SpreadsheetRootVariable;

public class SpreadsheetVariableBuilder extends NodeManagerVariableBuilder {

    @Override
    public Variable buildChild(ReadGraph graph, Variable parent, VariableNode node, Resource child) throws DatabaseException {
    	
    	// For proxies, return a variable with a node manager
    	if(parent instanceof ProxyChildVariable) {
            String sessionName = parent.getURI(graph);
            return createChild(graph, parent, sessionName, child);
    	}
    	//  For others return a standard variable
    	return new StandardGraphChildVariable(parent, node, child);
    	
    }

    @Override
    protected Variable createChild(ReadGraph graph, Variable parent, String sessionName, Resource child) throws DatabaseException {
        NodeSupport<?> support = getNodeSupport(graph, sessionName);
        return new SpreadsheetRootVariable(parent, new VariableNode(support, getRoot(graph, support, sessionName)), child);
    }
    

	@Override
	protected NodeSupport<?> getNodeSupport(ReadGraph graph, String sessionName) throws DatabaseException {
        return SpreadsheetSessionManager.getInstance().getOrCreateNodeSupport(graph, sessionName);
	}
	
	@Override
	protected Object getRoot(ReadGraph graph, NodeSupport<?> support, String sessionName) {
		SpreadsheetNodeManager manager = (SpreadsheetNodeManager)support.manager;
		return manager.getRoot();
	}
	
}