package ch.epfl.xblast;

/**
 * A Direction.
 *
 * @author Pacien TRAN-GIRARD (261948)
 * @author Timothée FLOURE (257420)
 */
public enum Direction {

    /**
     * North
     */
    N,

    /**
     * East
     */
    E,

    /**
     * South
     */
    S,

    /**
     * West
     */
    W;

    /**
     * Returns the opposite Direction.
     *
     * @return the opposite Direction
     */
    public Direction opposite() {
        switch (this) {
            case N:
                return S;
            case S:
                return N;
            case E:
                return W;
            case W:
                return E;
            default:
                return null;
        }
    }

    /**
     * T(the Direction is horizontal to the screen (East or West)).
     *
     * @return T(the Direction is horizontal to the screen)
     */
    public boolean isHorizontal() {
        return this == E || this == W;
    }

    /**
     * T(the current and given Directions are parallel (identical or opposite)).
     *
     * @param that a Direction to compare
     * @return T(the current and given Directions are parallel)
     */
    public boolean isParallelTo(Direction that) {
        return that == this || that == this.opposite();
    }

    /**
     * T(the current and given Directions are perpendicular).
     *
     * @param that a Direction to compare
     * @return T(the current and given Directions are perpendicular)
     */
    public boolean isPerpendicularTo(Direction that) {
        switch (this) {
            case N:
            case S:
                return that == E || that == W;
            case E:
            case W:
                return that == N || that == S;
            default:
                return false;
        }
    }

    /**
     * Returns the x-coordinate of the normed vector representation of the Direction.
     *
     * @return the x-coordinate
     */
    public int xVector() {
        switch (this) {
            case W:
                return -1;
            case E:
                return +1;
            default:
                return 0;
        }
    }

    /**
     * Returns the x-coordinate of the normed vector representation of the Direction.
     *
     * @return the y-coordinate
     */
    public int yVector() {
        switch (this) {
            case N:
                return -1;
            case S:
                return +1;
            default:
                return 0;
        }
    }

}