/*******************************************************************************
 * Copyright (c) 2014, 2016 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *     Semantum Oy
 *******************************************************************************/
package org.simantics.r;

import org.rosuda.REngine.Rserve.RserveException;
import org.simantics.databoard.Bindings;
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.StandardGraphChildVariable;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.db.layer0.variable.VariableNode;
import org.simantics.layer0.Layer0;
import org.simantics.r.scl.RSession;
import org.simantics.r.scl.RSessionConfiguration;
import org.simantics.r.scl.RSessionManager;
import org.simantics.r.scl.variable.RVariableNode;
import org.simantics.simulator.variable.NodeManager;

public class RVariableBuilder extends NodeManagerVariableBuilder {

    @Override
    public Variable buildChild(ReadGraph graph, Variable parent, VariableNode node, Resource child) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        RResource R = RResource.getInstance(graph);
        String name = graph.getRelatedValue(child, L0.HasName, Bindings.STRING);
        RSession session = RSessionManager.getSession(name);
        if(session == null) {
            Resource conf = graph.getSingleObject(child, L0.PartOf);
            RSessionConfiguration configuration = new RSessionConfiguration(
                    graph.<String>getRelatedValue(conf, R.SessionConfiguration_host, Bindings.STRING),
                    graph.<Integer>getRelatedValue(conf, R.SessionConfiguration_port, Bindings.INTEGER),
                    graph.<String>getRelatedValue(conf, R.SessionConfiguration_username, Bindings.STRING),
                    graph.<String>getRelatedValue(conf, R.SessionConfiguration_password, Bindings.STRING));
            try {
                session = RSessionManager.getOrCreateSession(configuration, name);
            } catch (RserveException e) {
                throw new DatabaseException(e);
            }
        }
        
        NodeSupport<?> support = getNodeSupport(graph, name);
        NodeManager<RVariableNode> nodeManager = session.getNodeManager();
        return new StandardGraphChildVariable(parent, new VariableNode(support, nodeManager), child);
    }

    @Override
    protected NodeSupport<?> getNodeSupport(ReadGraph graph, String sessionName) throws DatabaseException {
        return RSessionManager.getOrCreateNodeSupport(sessionName);
    }

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

}