public bool PerformCastlingIfCastlingMove(ChessMove chessMove,
IEnumerable <IChessPiece> pieces)
{
if (chessMove.PawnPromotion != ChessPieceType.Pawn)
{
return(false);
}
var movedPiece = pieces
.First(p => p.Position == chessMove.StartingPosition);
if (movedPiece.PieceType != ChessPieceType.King)
{
return(false);
}
if (CalculateDifference(chessMove.StartingPosition, chessMove.FinishedPosition) == 1)
{
return(false);
}
var rook = pieces
.First(p => p.Position == chessMove.FinishedPosition);
rook.Position = CalculateRookPositionAfterCastling(rook.Position,
movedPiece.Position);
movedPiece.Position = CalculateKingPositionAfterCastling(rook.Position,
movedPiece.Position);
rook.IncrementMoveCounter();
movedPiece.IncrementMoveCounter();
history.Add(chessMove);
return(true);
}
public IChessPiece PerformEnPassantIfApplicable(ChessMove chessMove,
IEnumerable <IChessPiece> pieces)
{
if (chessMove.PawnPromotion != ChessPieceType.Pawn)
{
return(null);
}
var pieceToMove = pieces
.First(p => p.Position == chessMove.StartingPosition);
if (pieceToMove.PieceType != ChessPieceType.Pawn)
{
return(null);
}
if (!IsDiagonalMove(chessMove))
{
return(null);
}
if (IsFinishedPositionTaken(chessMove, pieces))
{
return(null);
}
pieceToMove.IncrementMoveCounter();
pieceToMove.Position = chessMove.FinishedPosition;
history.Add(chessMove.ReturnWithCaptureAsTrue());
return(FindPawnToRemove(chessMove, pieces));
}
public IChessPiece Move(ChessMove chessMove, IEnumerable <IChessPiece> pieces)
{
if (piecePromoter.PromoteIfPromotionMove(chessMove, pieces))
{
return(null);
}
if (castlingMover.PerformCastlingIfCastlingMove(chessMove, pieces))
{
return(null);
}
var pieceToRemove = enPassantMover.PerformEnPassantIfApplicable(chessMove, pieces);
if (pieceToRemove != null)
{
return(pieceToRemove);
}
var pieceToMove = pieces
.First(p => p.Position == chessMove.StartingPosition);
pieceToRemove = pieces
.FirstOrDefault(p => p.Position == chessMove.FinishedPosition);
pieceToMove.Position = chessMove.FinishedPosition;
pieceToMove.IncrementMoveCounter();
if (pieceToRemove != null)
{
chessMove = chessMove.ReturnWithCaptureAsTrue();
}
history.Add(chessMove);
return(pieceToRemove);
}