public void Capture(IPieceBag pieceBag, IPiece startingPiece, Direction direction)
{
foreach (var piece in GetCapturablePieces(pieceBag, startingPiece, direction))
{
piece.Flip();
}
}
private IEnumerable<IPiece> GetContiguousOpponentPieces(IPieceBag pieceBag, IPiece startingPiece, Direction direction)
{
var piece = GetNextPieceFrom(pieceBag, startingPiece, direction);
while (piece != null)
{
if (piece.Side == startingPiece.Side)
{
yield break;
}
yield return piece;
piece = GetNextPieceFrom(pieceBag, piece, direction);
}
}
private IEnumerable<IPiece> GetCapturablePieces(IPieceBag pieceBag, IPiece startingPiece, Direction direction)
{
var opponents = GetContiguousOpponentPieces(pieceBag, startingPiece, direction)
.ToArray();
if (!opponents.Any())
{
return Enumerable.Empty<IPiece>();
}
var nextPiece = GetNextPieceFrom(pieceBag, opponents.Last(), direction);
if (nextPiece == null || nextPiece.Side != startingPiece.Side)
{
return Enumerable.Empty<IPiece>();
}
return opponents;
}
public PiecesInLine(Board board, Piece piece, Direction direction)
{
this.board = board;
this.piece = piece;
this.direction = direction;
}
private IPiece GetNextPieceFrom(IPieceBag pieceBag, IPiece piece, Direction direction)
{
return pieceBag.GetPiece(direction.AwayFrom(piece.Position));
}
public bool HasCapturablePieces(IPieceBag pieceBag, IPiece startingPiece, Direction direction)
{
return GetCapturablePieces(pieceBag, startingPiece, direction).Any();
}
