/// <summary>
/// The "main" method of this class, returns a correct move from a string essentially
/// <example>
/// <code>
/// Grid board = new Grid();
/// Move e4 = Move.FromUCI(board, "e2e4");
/// </code>
/// The example above will return a move with all the features that containst:
/// Good move printing
/// MoveType detection
/// Promotion pieces
/// Castltes
/// </example>
/// <see cref="Grid"/>
/// <see cref="Piece"/>
/// <see cref="Move.MoveTypeIdentifier(Grid, Tile, Tile)"
/// </summary>
/// <param name="board">The current board <see cref="Grid"/></param>
/// <param name="uci">A uci string <example>"e2e4"</example> (must be lower case)</param>
/// <param name="promotionPiece">Optional paramter for promotion piece, the MakeMove in <see cref="Grid"/> will handle it automatically</param>
/// <returns>A move <see cref="Move"/></returns>
/// <exception cref="ArgumentException">Will be thrown if the uci string length is different from 4</exception>
/// <exception cref="InvalidMoveException">
/// Will be thrown from a few reasons, mainly Invalid moves, like source tile has no piece etc'
/// And also from wrong promotion
/// </exception>
public static Move FromUCI(Grid board, string uci, Piece promotionPiece = null)
{
Move move = null;
if (uci.Length != 4)
{
throw new ArgumentException("UCI must be 4 characters");
}
int startX = (int)(uci[0] - 'a');
int startY = int.Parse(uci[1].ToString()) - 1;
int endX = (int)(uci[2] - 'a');
int endY = int.Parse(uci[3].ToString()) - 1;
Tile start = board.GetTile(startX, startY);
Tile end = board.GetTile(endX, endY);
if (start.Piece == null)
{
throw new InvalidMoveException("Source tile has no piece");
}
if (end.Piece != null)
{
if (start.Piece.IsWhite == end.Piece.IsWhite)
{
throw new InvalidMoveException("Source tile piece and destination tile piece are of the same team");
}
}
if (promotionPiece == null)
{
MoveType temp = MoveType.Normal;
move = new Move(start, end, board.CurrentPlayer, Move.MoveTypeIdentifier(board, start, end, ref temp));
move.additionalMoveType = temp;
return(move);
}
//promotion move
Pawn pawn = start.Piece as Pawn;
if (pawn == null)
{
throw new InvalidMoveException("Source tile must contain pawn");
}
if (pawn.IsWhite)
{
if (end.Y != 7)
{
throw new InvalidMoveException("Destination tile must be the last rank");
}
}
else
{
if (end.Y != 0)
{
throw new InvalidMoveException("Destination tile must be the first rank");
}
}
//check if promotion piece is not pawn
if (promotionPiece is Pawn)
{
throw new InvalidMoveException("Can't promote to pawn");
}
move = new Move(start, end, board.CurrentPlayer, MoveType.Promotion, promotionPiece);
return(move);
}
