package Game;

import Pieces.BoardSquare;
import Pieces.MoveType;

public class MoveHandler {
/*
Helper functions for movement.
 */

    /**
    * Helper function invoked by a Piece's move function and validMove.
    *
    * @param startSquare: Starting square of the move.
    *
    * @return Pieces.MoveType containing:
    * Pieces.MoveType.type: enum: if the move was vertical, diagonal, horizontal, or other
    * Pieces.MoveType.dist: int: distance of the move.
    */
    public static MoveType DetermineType(BoardSquare startSquare, BoardSquare destSquare) {
        if (startSquare.x == destSquare.x) {//Is the move being attempted vertical only?

            int dist = moveSignedDist(startSquare.y, destSquare.y, startSquare.owner);
            return new MoveType(MoveType.Direction.VERT, dist);

        } else if (startSquare.y == destSquare.y) {//Is it horizontal?

            int dist = moveSignedDist(startSquare.x, destSquare.x, startSquare.owner);
            return new MoveType(MoveType.Direction.HORIZ, dist);

        } else if (Math.abs(startSquare.y - destSquare.y) == Math.abs(startSquare.x - destSquare.x)) {//Is it diagonal?

            int dist = moveSignedDist(startSquare.y, destSquare.y, startSquare.owner);
            return new MoveType(MoveType.Direction.DIAG, dist);

        } else {//Is the attempted move something else?
            return new MoveType(MoveType.Direction.OTHER, 0);
        }

    }

    /**
     * Helper function invoked by DetermineType
     *
     * @param start start location
     * @param end ending location
     * @param player owner id
     *
     * @return positive distance between start and end if moving towards opponent, negative otherwise.
     */
    private static int moveSignedDist(int start, int end, Player player){

        if(player == Player.WHITE)
            return end - start;
        else if(player == Player.BLACK)
            return start - end;

        return 0;
    }

}