/*=============================================================================#
 # Copyright (c) 2012, 2021 Original NatTable authors and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0
 # 
 # Contributors:
 #     Original NatTable authors and others - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.waltable.coordinate;

import static org.eclipse.statet.ecommons.waltable.coordinate.Orientation.HORIZONTAL;
import static org.eclipse.statet.ecommons.waltable.coordinate.Orientation.VERTICAL;


public enum Direction {
	
	
	LEFT (HORIZONTAL),
	RIGHT (HORIZONTAL),
	UP (VERTICAL),
	DOWN (VERTICAL);
	
	
	public static Direction backward(final Orientation orientation) {
		if (orientation == null) {
			throw new NullPointerException("orientation"); //$NON-NLS-1$
		}
		return (orientation == HORIZONTAL) ? LEFT : UP;
	}
	
	public static Direction forward(final Orientation orientation) {
		if (orientation == null) {
			throw new NullPointerException("orientation"); //$NON-NLS-1$
		}
		return (orientation == HORIZONTAL) ? RIGHT : LEFT;
	}
	
	
	private final Orientation orientation;
	
	
	private Direction(final Orientation orientation) {
		this.orientation= orientation;
	}
	
	
	public Orientation getOrientation() {
		return this.orientation;
	}
	
	public boolean isBackward() {
		switch (this) {
		case LEFT:
		case UP:
			return true;
		case RIGHT:
		case DOWN:
		default:
			return false;
		}
	}
	
	public boolean isForward() {
		switch (this) {
		case RIGHT:
		case DOWN:
			return true;
		case LEFT:
		case UP:
		default:
			return false;
		}
	}
	
	public Direction getOpposite() {
		switch (this) {
		case LEFT:
			return RIGHT;
		case RIGHT:
			return LEFT;
		case UP:
			return DOWN;
		case DOWN:
		default:
			return UP;
		}
	}
	
}