//Method to move valid piece to valid location
// returns (true, null) if move was successful and neither king was checked
// returns (true, " ... ") if enemy king was checked or checkmated
private static (bool, string) MovePiece(Piece piece, Point target)
{
string message = null;
Point oldPoint = piece.GetLoc();
Piece overwritten = Chess.GetBoard().MovePiece(piece, target);
bool blackChecked = blackKing.CheckCheck();
bool whiteChecked = whiteKing.CheckCheck();
Func <bool, char, char, bool> CheckSelf = (isChecked, mine, kings) => isChecked && (mine == kings);
bool checkSelf = CheckSelf(blackChecked, piece.GetColor(), 'b') || CheckSelf(whiteChecked, piece.GetColor(), 'w');
//Return false with error message 'That would check your own king!'
// return board to original state
if (checkSelf)
{
//Restoring board to original position
Chess.GetBoard().MovePiece(piece, oldPoint);
Chess.GetBoard().MovePiece(overwritten, target);
return(false, "That move would check your king!");
}
else
{
//Now that we know we are not checked, check if enemy is checkmated
bool enemyChecked;
King checkedKing;
(enemyChecked, checkedKing) = (blackChecked) ? (true, blackKing) : (whiteChecked, whiteKing);
//If the enemy is checked, check if they are also checkmated
if (enemyChecked)
{
message = "Enemy king checked!";
bool enemeyCheckMated = checkedKing.CheckMate();
if (enemeyCheckMated)
{
message = "Check mate!";
return(false, message);
}
}
}
return(true, message);
}
