private void UpdateGameState(Square from, Square to, Position newPosition, PieceColor playerWhoDidTheMove)
{
if (PlayerMovedPawnToPromotionRank(from, to))
{
State = GameState.Promotion;
}
else if (newPosition.WhiteKingIsInCheck() || newPosition.BlackKingIsInCheck())
{
State = newPosition.HasLegalMoves(PlayerToMove) ? GameState.Check : GameState.CheckMate;
}
else
{
State = newPosition.HasLegalMoves(PlayerToMove) &&
newPosition.HasLegalMoves(playerWhoDidTheMove)
? GameState.Normal
: GameState.StaleMate;
}
}
