package dev.kske.chess.board;

import java.util.ArrayList;
import java.util.List;

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>Knight.java</strong><br>
 * Created: <strong>01.07.2019</strong><br>
 *
 * @since Chess v0.1-alpha
 * @author Kai S. K. Engelbart
 */
public class Knight extends Piece {

	/**
	 * Creates knight {@link Piece}.
	 *
	 * @param color the color of this knight
	 * @param board the board on which this knight will be placed
	 */
	public Knight(Color color, Board board) {
		super(color, board);
	}

	@Override
	public boolean isValidMove(Move move) {
		return Math.abs(move.getxDist() - move.getyDist()) == 1
			&& (move.getxDist() == 1 && move.getyDist() == 2
				|| move.getxDist() == 2 && move.getyDist() == 1)
			&& checkDestination(move);
	}

	private void checkAndInsertMove(
		List<Move> moves, Position pos, int offsetX, int offsetY
	) {
		if (
			pos.x + offsetX >= 0 && pos.x + offsetX < 8 && pos.y + offsetY >= 0
				&& pos.y + offsetY < 8
		) {
			Move move
				= new Move(pos, new Position(pos.x + offsetX, pos.y + offsetY));
			if (checkDestination(move))
				moves.add(move);
		}
	}

	@Override
	protected List<Move> getPseudolegalMoves(Position pos) {
		List<Move> moves = new ArrayList<>();
		checkAndInsertMove(moves, pos, -2, 1);
		checkAndInsertMove(moves, pos, -1, 2);
		checkAndInsertMove(moves, pos, 1, 2);
		checkAndInsertMove(moves, pos, 2, 1);
		checkAndInsertMove(moves, pos, -2, -1);
		checkAndInsertMove(moves, pos, -1, -2);
		checkAndInsertMove(moves, pos, 1, -2);
		checkAndInsertMove(moves, pos, 2, -1);
		return moves;
	}

	@Override
	public int getValue() { return 35; }

	@Override
	public char firstChar() {
		return 'n';
	}
}