public static async Task <ChessBoard> FromStreamAsync(Stream stream)
{
bool?hasStarted = null;
string[] playerNames = new string[2];
PlayerColor[] playerColors = new PlayerColor[2];
int playersReceived = 0;
string winner = null;
double? turnTimeLeft = null;
List <string> moves = new List <string>();
var settings = new XmlReaderSettings()
{
Async = true
};
using (var xml = XmlReader.Create(stream, settings))
while (await xml.ReadAsync())
{
if (!xml.IsStartElement())
{
continue;
}
if (xml.Name == "Game")
{
if (hasStarted != null)
{
throw new InvalidDataException();
}
hasStarted = xml.GetAttribute("HasStarted") == "true";
winner = xml.GetAttribute("Winner");
}
else if (xml.Name == "Player")
{
if (playersReceived >= 2)
{
throw new InvalidDataException();
}
playerNames[playersReceived] = xml.GetAttribute("Name");
playerColors[playersReceived] = xml.GetAttribute("Color") == "Black" ? PlayerColor.Black : PlayerColor.White;
playersReceived++;
}
else if (xml.Name == "Turn")
{
if (turnTimeLeft != null)
{
throw new InvalidDataException();
}
string timeLeftString = xml.GetAttribute("TimeLeft");
if (!double.TryParse(timeLeftString, out double timeLeftDouble))
{
throw new InvalidDataException("Invalid turn element!");
}
turnTimeLeft = timeLeftDouble;
}
else if (xml.Name == "Board")
{
while (await xml.ReadAsync())
{
if (!xml.IsStartElement("Move"))
{
break;
}
moves.Add(await xml.ReadElementContentAsStringAsync());
}
}
else
{
throw new InvalidDataException("Invalid ChessBoard xml!");
}
}
if (hasStarted == null)
{
throw new InvalidDataException();
}
//If the game hasn't started, just return an empty ChessBoard
if (!hasStarted.Value)
{
return(new ChessBoard());
}
//Validate input when the game has started...
if (playersReceived != 2)
{
throw new InvalidDataException();
}
if (playerNames.Any(name => string.IsNullOrWhiteSpace(name)))
{
throw new InvalidDataException();
}
if (!playerColors.Any(color => color == PlayerColor.White) || !playerColors.Any(color => color == PlayerColor.Black))
{
throw new InvalidDataException();
}
string whiteName = playerColors[0] == PlayerColor.White ? playerNames[0] : playerNames[1];
string blackName = playerColors[0] == PlayerColor.White ? playerNames[1] : playerNames[0];
if (!string.IsNullOrWhiteSpace(winner))
{
return(new ChessBoard(whiteName, blackName, winner, moves.ToArray()));
}
//Validate input when the game hasn't ended yet...
if (turnTimeLeft == null)
{
throw new InvalidDataException();
}
return(new ChessBoard(whiteName, blackName, turnTimeLeft.Value, moves.ToArray()));
}
