package ch.epfl.maze.util;

import java.util.HashMap;
import java.util.Map;

/**
 * A trail keeping track on positional markings.
 *
 * @author Pacien TRAN-GIRARD
 */
public class Trail {

    public enum Marking {
        NO_MARKING,
        AVOID_MARKING,
        NO_GO_MARKING;

        public static Marking DEFAULT = NO_MARKING;
        public static Marking[] ALL = new Marking[]{NO_MARKING, AVOID_MARKING, NO_GO_MARKING};

        /**
         * Returns the next Marking.
         *
         * @return The next Marking
         */
        public Marking getNext() {
            switch (this) {
                case NO_MARKING:
                    return AVOID_MARKING;
                case AVOID_MARKING:
                    return NO_GO_MARKING;
                case NO_GO_MARKING:
                    return NO_GO_MARKING;
                default:
                    return AVOID_MARKING;
            }
        }
    }

    private final Map<Vector2D, Marking> trail;

    /**
     * Constructs a new blank Trail.
     */
    public Trail() {
        this.trail = new HashMap<>();
    }

    /**
     * Get the marking at the given position.
     *
     * @param position The positional Vector
     * @return The Marking
     */
    public Marking getMarking(Vector2D position) {
        Marking marking = this.trail.get(position);
        return marking != null ? marking : Marking.DEFAULT;
    }

    /**
     * Marks the given position with the given Marking.
     *
     * @param position The positional vector
     * @param marking  The Marking
     */
    public void markPosition(Vector2D position, Marking marking) {
        this.trail.put(position, marking);
    }

    /**
     * Marks the given position with the following Marking.
     *
     * @param position The positional vector
     */
    public void markPosition(Vector2D position) {
        this.markPosition(position, this.getMarking(position).getNext());
    }

}