/// <summary>
/// Makes the move, it doesn't check if it's a valid move.
/// The capture must be set before making the move, othewise it throws InvalidOperationException.
/// </summary>
/// <param name="board">The board</param>
internal override void Make(Board board)
{
if (promotionPiece != null)
{
// set the ending square
board[to] = promotionPiece;
}
else
{
// if the promotion was not set throw an exception
throw new InvalidOperationException("Resources.NoPromotionMsg");
}
promotedPiece = board[from];// set the promoted piece
board[from] = null;// empty the starting square
board.Status = after;// set the board status to the after board status
}
/// <summary>
/// Sets the captured piece.
/// </summary>
/// <param name="piece">The piece</param>
internal void SetCapture(Piece piece)
{
capture = piece;
}
/// <summary>
/// Gets a board from its FEN (Forsyth-Edwards notation).
/// Throws ArgumentException if it's not a valid position.
/// </summary>
/// <param name="fen">The FEN string</param>
/// <returns></returns>
public static Board GetFENBoard(string fen)
{
try
{
// the FEN string must not be null
if (fen == null) { throw new ArgumentNullException("fen", "Resources.NullFENMsg"); }
Piece[] squares = new Piece[Board.SquareNo];
BoardStatus status = new BoardStatus();
Piece piece;
int index = 0, pos = 0;
while (fen[index] != ' ')
{
// get the piece from its char representation
piece = GetPieceFromChar(fen[index]);
// if there is a piece
if (piece != null)
{
squares[pos++] = piece;// put the piece on board
}
// if there is a number
else if (fen[index] >= '1' && fen[index] <= '8')
{
pos += fen[index] - '0';// skip empty squares
}
// if there another char than '/' throw exception
else if (fen[index] != '/')
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
index++;
}
index++;
// set side to move
if (fen[index] == 'w')
{
status.WhiteTurn = true;
}
else if (fen[index] == 'b')
{
status.BlackTurn = true;
}
else
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
index += 2;
// set castling availability
if (fen[index] == '-')
{
index++;
}
else
{
do
{
switch (fen[index])
{
case 'K':
status.WhiteCouldCastleShort = true;
break;
case 'Q':
status.WhiteCouldCastleLong = true;
break;
case 'k':
status.BlackCouldCastleShort = true;
break;
case 'q':
status.BlackCouldCastleLong = true;
break;
default:
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
}
while (fen[++index] != ' ');
}
index++;
// set en passant target
if (fen[index] == '-')
{
status.EnPassantTarget = null;
index++;
}
else
{
// checks if the square notation is correct
if (fen[index] < 'a' || fen[index] > 'h' || fen[index + 1] < '1' || fen[index + 1] > '8')
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
status.EnPassantTarget = GetPosition(fen[index], fen[index + 1]);
index += 2;
}
index++;
// set ply
try
{
status.Ply = Int32.Parse(fen.Substring(index, fen.IndexOf(' ', index) - index), CultureInfo.InvariantCulture);
}
catch
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
index = fen.IndexOf(' ', index) + 1;
// set move number
try
{
status.Moves = Int32.Parse(fen.Substring(index), CultureInfo.InvariantCulture);
}
catch
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
Board board = new Board(squares, status);
// verfies if the board is in valid state, throws ArgumentException if it's not
VerifyState(board);
return board;
}
// if the FEN string was too short
catch (IndexOutOfRangeException)
{
throw new ArgumentException("Resources.IllegalFENFormatMsg", "fen");
}
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="squares"></param>
/// <param name="status"></param>
public Board(Piece[] squares, BoardStatus status)
{
this.squares = squares;
this.status = status;
}
/// <summary>
/// Gets a board in the starting position.
/// </summary>
/// <returns></returns>
public static Board GetStartingBoard()
{
Piece[] squares = new Piece[SquareNo];
BoardStatus status = new BoardStatus();
squares[A8] = new BlackRook();
squares[B8] = new BlackKnight();
squares[C8] = new BlackBishop();
squares[D8] = new BlackQueen();
squares[E8] = new BlackKing();
squares[F8] = new BlackBishop();
squares[G8] = new BlackKnight();
squares[H8] = new BlackRook();
for (int sqIndex = SideSquareNo; sqIndex < SideSquareNo * 2; sqIndex++)
{
squares[sqIndex] = new BlackPawn();
}
for (int sqIndex = SideSquareNo * (SideSquareNo - 2); sqIndex < SideSquareNo * (SideSquareNo - 1); sqIndex++)
{
squares[sqIndex] = new WhitePawn();
}
squares[A1] = new WhiteRook();
squares[B1] = new WhiteKnight();
squares[C1] = new WhiteBishop();
squares[D1] = new WhiteQueen();
squares[E1] = new WhiteKing();
squares[F1] = new WhiteBishop();
squares[G1] = new WhiteKnight();
squares[H1] = new WhiteRook();
status.WhiteTurn = true;
status.WhiteCouldCastleLong = status.WhiteCouldCastleShort = status.BlackCouldCastleLong = status.BlackCouldCastleShort = true;
status.EnPassantTarget = null;
status.Ply = 0;
status.Moves = 1;
return new Board(squares, status);
}
/// <summary>
/// Makes the move, it doesn't check if it's a valid move.
/// </summary>
/// <param name="board">The board</param>
internal virtual void Make(Board board)
{
capture = board[to];// set the capture
board[to] = board[from];// put the piece on ending square
board[from] = null;// empty the starting square
board.Status = after;// set the board status to the after board status
}
