// try to do a movement of piece
public MovementResult MovePiece(char column, int row, char targetColumn, int targetRow)
{
MovementResult result = new MovementResult();
var selectPiece = GetPiece(column, row);
// check if there is a piece at start position
if (selectPiece == null)
{
result.IsSuccess = false;
result.Description = String.Format("No piece is present at position {0}{1}", column, row.ToString());
return(result);
}
var targetPiece = GetPiece(targetColumn, targetRow);
// check it is a valid movement for piece (rules piece validator)
if (!selectPiece.IsValidMovement(
(targetPiece != null && !selectPiece.ChessColor.Equals(targetPiece.ChessColor)),
row - 1, Columns[column], targetRow - 1, Columns[targetColumn]))
{
result.IsSuccess = false;
result.Description =
String.Format("The {0} {1} at position {2}{3} cannot move to {4}{5}",
selectPiece.ChessColor.ToString(), selectPiece.GetType().Name,
column, row.ToString(), targetColumn, targetRow.ToString());
return(result);
}
// check if the path is free if piece is not a knight
if (!(selectPiece is Knight) && !checkIfPathIsFree(column, row, targetColumn, targetRow))
{
result.IsSuccess = false;
result.Description =
String.Format("The path from {0}{1} to {2}{3} for {4}{5} is not free.",
column, row.ToString(), targetColumn, targetRow.ToString(),
selectPiece.ChessColor.ToString(), selectPiece.GetType().Name);
return(result);
}
// check if target position there is already present a piece with same color
if (targetPiece != null && selectPiece.ChessColor.Equals(targetPiece.ChessColor))
{
result.IsSuccess = false;
result.Description =
String.Format("There is already present a {0} piece at position {1}{2}",
selectPiece.ChessColor.ToString(), targetColumn, targetRow);
return(result);
}
// set result information after capture
result.Capture = (targetPiece != null && !selectPiece.ChessColor.Equals(targetPiece.ChessColor));
if (result.Capture)
{
result.CapturedPiece = targetPiece;
}
// change position of piece
putPiece(selectPiece, targetColumn, targetRow);
clearBoardPosition(column, row);
return(result);
}
private MovementResult MovePiece(char column, int row, char targetColumn, int targetRow, bool forTest)
{
MovementResult result = new MovementResult();
var selectPiece = GetPiece(column, row);
// check if there is a piece at start position
if (selectPiece == null)
{
result.IsSuccess = false;
result.Description = String.Format("No piece is present at position {0}{1}", column, row.ToString());
return(result);
}
Piece targetPiece = null;
var isEnPassant = EnPassant != null && selectPiece is Pawn && targetColumn == EnPassant.Item1 && targetRow == EnPassant.Item2;
if (!isEnPassant)
{
targetPiece = GetPiece(targetColumn, targetRow);
}
else
{
targetPiece = GetPiece(targetColumn, row);
}
// check it is a valid movement for piece (rules piece validator)
if (!selectPiece.IsValidMovement(
(targetPiece != null && !selectPiece.ChessColor.Equals(targetPiece.ChessColor)),
row - 1, Columns[column], targetRow - 1, Columns[targetColumn]))
{
result.IsSuccess = false;
result.Description =
String.Format("The {0} {1} at position {2}{3} cannot move to {4}{5}",
selectPiece.ChessColor.ToString(), selectPiece.GetType().Name,
column, row.ToString(), targetColumn, targetRow.ToString());
return(result);
}
// check if the path is free if piece is not a knight
if (!(selectPiece is Knight) && !checkIfPathIsFree(column, row, targetColumn, targetRow))
{
result.IsSuccess = false;
result.Description =
String.Format("The path from {0}{1} to {2}{3} for {4}{5} is not free.",
column, row.ToString(), targetColumn, targetRow.ToString(),
selectPiece.ChessColor.ToString(), selectPiece.GetType().Name);
return(result);
}
// check if target position there is already present a piece with same color
if (targetPiece != null && selectPiece.ChessColor.Equals(targetPiece.ChessColor))
{
result.IsSuccess = false;
result.Description =
String.Format("There is already present a {0} piece at position {1}{2}",
selectPiece.ChessColor.ToString(), targetColumn, targetRow);
return(result);
}
//En passant done
if (isEnPassant && !forTest)
{
clearBoardPosition(targetColumn, row);
}
// set result information after ate
result.Ate = (targetPiece != null && !selectPiece.ChessColor.Equals(targetPiece.ChessColor));
if (result.Ate)
{
result.AtePiece = targetPiece;
}
// set EnPassant Information
EnPassant = null;
if ((selectPiece is Pawn) && (Math.Abs(row - targetRow) == 2))
{
//En passant possibilities
var pieceLeft = TryGetPiece(Columns[targetColumn], targetRow);
var pieceRigth = TryGetPiece(Columns[targetColumn] + 2, targetRow);
if ((pieceLeft != null && pieceLeft.ChessColor != selectPiece.ChessColor && pieceLeft is Pawn)
||
(pieceRigth != null && pieceRigth.ChessColor != selectPiece.ChessColor && pieceRigth is Pawn))
{
EnPassant = new Tuple <char, int>(targetColumn, (targetRow + row) / 2);
}
}
//Castling rules
bool isCastling = false;
if ((selectPiece is King) && Math.Abs(Columns[column] - Columns[targetColumn]) == 2)
{
//1-The king should not have moved yet
var king = (King)selectPiece;
if (king.HasAlreadyMoved || !(column == 'E' && (row == 1 || row == 8)))
{
result.IsSuccess = false;
result.Description =
String.Format("You cannot do the Castling because your king has already moved.");
return(result);
}
//2-The Rook should not have moved yet either
var rookColumn = (targetColumn == 'G') ? 'H' : 'A';
var pieceFound = GetPiece(rookColumn, targetRow);
if (pieceFound == null || pieceFound.ChessColor != king.ChessColor || !(pieceFound is Rook))
{
result.IsSuccess = false;
result.Description =
String.Format("You cannot do the Castling because there is no Rook at position {0}{1}.", rookColumn, targetRow);
return(result);
}
var goodRook = (Rook)pieceFound;
if (goodRook.HasAlreadyMoved)
{
result.IsSuccess = false;
result.Description =
String.Format("You cannot do the Castling as your rook has already moved at position {0}{1}.", rookColumn, targetRow);
return(result);
}
//3-The King should not be chess or passing on a echec position
var canMoveOnTheKing = CheckKingEchec(king.ChessColor);
if (canMoveOnTheKing != null)
{
result.IsSuccess = false;
result.Description =
String.Format("You cannot do the Castling because you are echec {0}{1}.", canMoveOnTheKing.Item1, canMoveOnTheKing.Item2);
return(result);
}
//4-Can do one step :
var oneStepColumn = (targetColumn == 'G') ? 'F' : 'D';
var canDoOne = this.MovePiece(column, row, oneStepColumn, targetRow);
if (!canDoOne.IsSuccess)
{
result.IsSuccess = false;
result.Description =
String.Format("You cannot do the Castling because you would be echec at the position {0}{1}.", oneStepColumn, targetRow);
return(result);
}
else
{
//One step is posible, so rollback, and test two step :
PutPiece(king, column, row);
clearBoardPosition(oneStepColumn, row);
king.HasAlreadyMoved = false;
isCastling = true;
}
}
// change position of piece
if (!forTest)
{
PutPiece(selectPiece, targetColumn, targetRow);
clearBoardPosition(column, row);
//Pawn reach the opposite side, can be promoted
if (selectPiece is Pawn && (targetRow == 1 || targetRow == 8))
{
PawnPromoted = true;
PawnPromotedColor = selectPiece.ChessColor;
}
// check if the move does not make our king in chess
Tuple <char, int> pieceWitchMakeChess = CheckKingEchec(selectPiece.ChessColor);
if (pieceWitchMakeChess != null)
{
//RollBack
PutPiece(selectPiece, column, row);
clearBoardPosition(targetColumn, targetRow);
PawnPromoted = false;
if (result.Ate == true)
{
var pieceEaten = result.AtePiece;
this.PutPiece(pieceEaten, targetColumn, targetRow);
result.AtePiece = null;
result.Ate = false;
}
result.IsSuccess = false;
result.Description =
String.Format("Your king is in echec from the piece {0} ({1}{2}).",
selectPiece.GetType().Name, pieceWitchMakeChess.Item1, pieceWitchMakeChess.Item2);
return(result);
}
if (selectPiece is IHasAlreadyMoved)
{
((IHasAlreadyMoved)selectPiece).HasAlreadyMoved = true;
//TODO : Move the rook in case of castling
if (isCastling)
{
var rookColumnOrigin = (targetColumn == 'G') ? 'H' : 'A';
var rookColumnTarget = (targetColumn == 'G') ? 'F' : 'D';
var pieceFound = GetPiece(rookColumnOrigin, row);
PutPiece(pieceFound, rookColumnTarget, row);
clearBoardPosition(rookColumnOrigin, row);
}
}
}
return(result);
}