/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2013, 2013 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.fmc.blockdiagram.editor.meta.features.update;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.fmc.blockdiagram.editor.meta.profile.IStereotypeProvider;
import org.eclipse.graphiti.features.IFeatureProvider;
import org.eclipse.graphiti.features.IReason;
import org.eclipse.graphiti.features.context.IUpdateContext;
import org.eclipse.graphiti.features.impl.Reason;
import org.eclipse.graphiti.mm.pictograms.Connection;
import org.eclipse.fmc.blockdiagram.editor.algorithm.connection.FMCConnectionAlgorithm;
import org.eclipse.fmc.blockdiagram.editor.util.FMCUtil;
import org.eclipse.fmc.mm.Access;
import org.eclipse.fmc.mm.AccessType;
import org.eclipse.fmc.mm.Agent;
import org.eclipse.fmc.mm.DataflowDirection;
import org.eclipse.fmc.mm.FMCConnection;
import org.eclipse.fmc.mm.Storage;

/**
 * Feature Class for updating the graphical representation and the business
 * model of an Access.
 * 
 * @author Patrick Jahnke
 * 
 */
public class AccessUpdateFeature extends FMCConnectionUpdateFeature {

	/**
	 * Constructor only calls the super constructor.
	 * 
	 * @param fp
	 *            The FeatureProvider
	 * @param stereotypeProvider
	 *            The StereotypeProvider Class.
	 */
	public AccessUpdateFeature(IFeatureProvider fp,
			IStereotypeProvider stereotypeProvider) {
		super(fp, stereotypeProvider);
	}

	/**
	 * Update the direction of the graphical representation.
	 */
	@Override
	public boolean update(IUpdateContext context) {
		Connection conShape = (Connection) context.getPictogramElement();
		FMCConnectionAlgorithm algorithm = factory.getAlgorithm(conShape);
		Access access = (Access) FMCUtil.getBO(context.getPictogramElement());
		EObject start = FMCUtil.getBO(conShape.getStart().getParent());
		if (!equalsAccessType(conShape, access)) {
			switch (access.getType()) {
			case UNSPECIFIED:
				algorithm.setDirection(conShape, DataflowDirection.UNSPECIFIED,
						getDiagram());
				break;
			case READ:
				algorithm.setDirection(conShape,
						start instanceof Agent ? DataflowDirection.OTHER
								: DataflowDirection.DEFAULT, getDiagram());
				break;
			case WRITE:
				algorithm.setDirection(conShape,
						start instanceof Storage ? DataflowDirection.OTHER
								: DataflowDirection.DEFAULT, getDiagram());
				break;
			case RW:
				// TODO
				break;
			}
		}
		return false;
	}

	/**
	 * Check if update needed because of when the access type property of the
	 * graphical representation is not synch with the domain.
	 */
	@Override
	protected IReason updateNeeded(Connection conShape, FMCConnection connection) {
		Access access = (Access) connection;
		if (!equalsAccessType(conShape, access))
			return Reason
					.createTrueReason("The access type property is not in synch with domain model");
		return Reason.createFalseReason();
	}

	/**
	 * Equals access type between graphical representation and business object.
	 * 
	 * @param conShape
	 *            The graphical representation.
	 * @param access
	 *            The business object.
	 * @return true if equals otherwiese false
	 */
	private boolean equalsAccessType(Connection conShape, Access access) {
		EObject start = FMCUtil.getBO(conShape.getStart().getParent());
		FMCConnectionAlgorithm algorithm = factory.getAlgorithm(conShape);
		DataflowDirection direction = algorithm.getDirection(conShape);
		boolean write = false;
		if (direction == DataflowDirection.UNSPECIFIED)
			return access.getType() == AccessType.UNSPECIFIED;
		if (direction == DataflowDirection.DEFAULT)
			write = start instanceof Agent;
		if (direction == DataflowDirection.OTHER)
			write = start instanceof Storage;
		return access.getType() == AccessType.WRITE == write;
	}

}