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 (move.xDist == 2 && move.yDist == 0) {
			if (canCastleKingside()) {
				move.type = Move.Type.CASTLING;
				return true;
			}
			if (canCastleQueenside()) {
				move.type = Move.Type.CASTLING;
				return true;
			}
		}

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

	public boolean canCastleKingside() {
		if (getMoveCounter() == 0) {
			int			y		= getColor() == Color.WHITE ? 7 : 0;
			Position	rookPos	= new Position(7, y);
			Piece		rook	= board.get(rookPos);
			return rook != null && rook.getType() == Type.ROOK && rook.getMoveCounter() == 0
					&& isFreePath(new Move(new Position(4, y), new Position(6, y)));
		} else return false;
	}

	public boolean canCastleQueenside() {
		if (getMoveCounter() == 0) {
			int			y		= getColor() == Color.WHITE ? 7 : 0;
			Position	rookPos	= new Position(0, y);
			Piece		rook	= board.get(rookPos);
			return rook != null && rook.getType() == Type.ROOK && rook.getMoveCounter() == 0
					&& isFreePath(new Move(new Position(4, y), new Position(1, y)));
		} else return false;
	}

	@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: Condition: cannot castle out of, through or into check
		if (canCastleKingside()) moves.add(new Move(pos, new Position(6, pos.y), Move.Type.CASTLING));
		if (canCastleQueenside()) moves.add(new Move(pos, new Position(2, pos.y), Move.Type.CASTLING));

		return moves;
	}

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