package dev.kske.chess.board;

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

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>King.java</strong><br>
 * Created: <strong>01.07.2019</strong><br>
 * Author: <strong>Kai S. K. Engelbart</strong>
 */
public class King extends Piece {

	public King(Color color, Board board) {
		super(color, board);
	}

	@Override
	public boolean isValidMove(Move move) {
		// Castling
		if (getMoveCounter() == 0 && move.xDist == 2 && move.yDist == 0) {

			// Kingside
			if (board.getBoardArr()[7][move.pos.y] != null && board.getBoardArr()[7][move.pos.y].getType() == Type.ROOK
					&& isFreePath(new Move(new Position(5, move.pos.y), new Position(7, move.pos.y)))) {
				move.type = Move.Type.CASTLING;
				return true;
			}

			// Queenside
			if (board.getBoardArr()[0][move.pos.y] != null && board.getBoardArr()[0][move.pos.y].getType() == Type.ROOK
					&& isFreePath(new Move(new Position(1, move.pos.y), new Position(4, move.pos.y)))) {
				move.type = Move.Type.CASTLING;
				return true;
			}

		}

		return move.xDist <= 1 && move.yDist <= 1 && checkDestination(move);
	}

	@Override
	protected List<Move> getPseudolegalMoves(Position pos) {
		List<Move> moves = new ArrayList<>();
		for (int i = Math.max(0, pos.x - 1); i < Math.min(8, pos.x + 2); i++)
			for (int j = Math.max(0, pos.y - 1); j < Math.min(8, pos.y + 2); j++)
				if (i != pos.x || j != pos.y) {
					Move move = new Move(pos, new Position(i, j));
					if (board.getDest(move) == null || board.getDest(move).getColor() != getColor()) moves.add(move);
				}

		// Castling
		// TODO: Check attacked squares in between
		// TODO: Castling out of check?
		if (getMoveCounter() == 0) {

			// Kingside
			if (board.getBoardArr()[7][pos.y] != null && board.getBoardArr()[7][pos.y].getType() == Type.ROOK
					&& isFreePath(new Move(new Position(5, pos.y), new Position(7, pos.y))))
				moves.add(new Move(pos, new Position(6, pos.y), Move.Type.CASTLING));

			// Queenside
			if (board.getBoardArr()[0][pos.y] != null && board.getBoardArr()[0][pos.y].getType() == Type.ROOK
					&& isFreePath(new Move(new Position(1, pos.y), new Position(4, pos.y))))
				moves.add(new Move(pos, new Position(2, pos.y), Move.Type.CASTLING));
		}

		return moves;
	}

	@Override
	protected boolean isFreePath(Move move) {
		for (int i = move.pos.x, j = move.pos.y; i != move.dest.x || j != move.dest.y; i += move.xSign, j += move.ySign)
			if (board.getBoardArr()[i][j] != null) return false;
		return true;
	}

	@Override
	public Type getType() { return Type.KING; }
}