public static MoveSummary CanKingMove(ChessGame game, Color kingColor, Board board, Square from, Square to)
{
var isSameColor = board[from].Color == board[to].Color;
var isCapturing = board[to].IsNone() ?
false :
!isSameColor;
var canDefaultMove = CanDefaultMove(from, to, isSameColor);
if (canDefaultMove)
{
return(MoveSummaryBuilder.KingSummary(isCapturing, true, false, false, to));
}
return
(CanCastle(game, kingColor, board, from, to));
}
private static MoveSummary CanCastle(ChessGame game, Color kingColor, Board board, Square from, Square to)
{
var isHorizontalLine = MoveProperty.IsHorizontalLine(from, to);
if (isHorizontalLine)
{
var isAnyPieceBetween = Checker.IsAnyPieceBetween(board, from, to);
if (!isAnyPieceBetween)
{
var isKingWhite = kingColor.IsWhite();
var hasKingMoved =
isKingWhite ?
game.HasWhiteKingMoved :
game.HasBlackKingMoved;
if (hasKingMoved)
{
return
(MoveSummaryBuilder.DefaultMoveSummary(false, false, Square.NoneSquare));
}
var kingStartSquare = GetKingStartSquare(isKingWhite);
if (kingStartSquare == from)
{
var isQueensideDirection = IsQueensideDirection(isKingWhite, to);
var isKingsideDirection = IsKingsideDirection(isKingWhite, to);
Square rookStartSquare;
bool hasRookMoved;
if (isQueensideDirection)
{
rookStartSquare = GetQueensideRookStartSquare(isKingWhite);
hasRookMoved = isKingWhite ?
game.HasWhiteQueensideRookMoved :
game.HasBlackQueensideRookMoved;
}
else if (isKingsideDirection)
{
rookStartSquare = GetKingsideRookStartSquare(isKingWhite);
hasRookMoved = isKingWhite ?
game.HasWhiteKingsideRookMoved :
game.HasBlackKingsideRookMoved;
}
else
{
return(MoveSummaryBuilder.DefaultMoveSummary(false, false, Square.NoneSquare));
}
var piece = board[rookStartSquare];
if (piece.IsNone())
{
return
(MoveSummaryBuilder.DefaultMoveSummary(false, false, Square.NoneSquare));
}
var isValid =
!hasRookMoved &&
piece.Color == kingColor &&
piece.Type == PieceType.Rook;
if (isValid)
{
return(MoveSummaryBuilder.
KingSummary(false, true, isQueensideDirection, isKingsideDirection, Square.NoneSquare));
}
}
}
}
return(MoveSummaryBuilder.DefaultMoveSummary(false, false, Square.NoneSquare));
}