public override async Task <FunctionResponse> ProcessMessageAsync(FunctionRequest request)
{
// get game state from DynamoDB table
LogInfo($"Loading game state: ID = {request.GameId}");
var gameRecord = await _table.GetAsync <GameRecord>(request.GameId);
if (gameRecord == null)
{
// game must have been stopped
return(new FunctionResponse {
GameId = request.GameId,
Status = GameStatus.Finished,
GameLoopType = request.GameLoopType
});
}
// compute next turn
var game = gameRecord.Game;
LogInfo($"Game turn {game.TotalTurns}");
var logic = new GameLogic(new GameDependencyProvider(
gameRecord.Game,
_random,
robot => GetRobotBuildAsync(game, robot, gameRecord.LambdaRobotArns[gameRecord.Game.Robots.IndexOf(robot)]),
robot => GetRobotActionAsync(game, robot, gameRecord.LambdaRobotArns[gameRecord.Game.Robots.IndexOf(robot)])
));
// determine game action to take
var messageCount = game.Messages.Count;
try {
// check game state
switch (gameRecord.Game.Status)
{
case GameStatus.Start:
// start game
LogInfo($"Start game: initializing {game.Robots.Count(robot => robot.Status == LambdaRobotStatus.Alive)} robots (total: {game.Robots.Count})");
await logic.StartAsync(gameRecord.LambdaRobotArns.Count);
game.Status = GameStatus.NextTurn;
LogInfo($"Done: {game.Robots.Count(robot => robot.Status == LambdaRobotStatus.Alive)} robots ready");
break;
case GameStatus.NextTurn:
// next turn
LogInfo($"Start turn {game.TotalTurns} (max: {game.MaxTurns}): invoking {game.Robots.Count(robot => robot.Status == LambdaRobotStatus.Alive)} robots (total: {game.Robots.Count})");
await logic.NextTurnAsync();
LogInfo($"End turn: {game.Robots.Count(robot => robot.Status == LambdaRobotStatus.Alive)} robots alive");
break;
case GameStatus.Finished:
// nothing further to do
break;
default:
game.Status = GameStatus.Error;
throw new ApplicationException($"unexpected game state: '{gameRecord.Game.Status}'");
}
} catch (Exception e) {
LogError(e, "error during game loop");
game.Status = GameStatus.Error;
}
// log new game messages
for (var i = messageCount; i < game.Messages.Count; ++i)
{
LogInfo($"Game message {i + 1}: {game.Messages[i].Text}");
}
// check if we need to update or delete the game from the game table
if (game.Status == GameStatus.NextTurn)
{
LogInfo($"Storing game: ID = {game.Id}");
// attempt to update the game record
try {
await _table.UpdateAsync(new GameRecord {
PK = game.Id,
Game = game
}, new[] { nameof(GameRecord.Game) });
} catch {
LogInfo($"Storing game failed: ID = {game.Id}");
// the record failed to updated, because the game was stopped
return(new FunctionResponse {
GameId = game.Id,
Status = GameStatus.Finished,
GameLoopType = request.GameLoopType
});
}
}
else
{
LogInfo($"Deleting game: ID = {game.Id}");
await _table.DeleteAsync <GameRecord>(game.Id);
}
// notify WebSocket of new game state
LogInfo($"Posting game update to connection: {game.Id}");
try {
await _amaClient.PostToConnectionAsync(new PostToConnectionRequest {
ConnectionId = gameRecord.ConnectionId,
Data = new MemoryStream(Encoding.UTF8.GetBytes(SerializeJson(new GameTurnNotification {
Game = game
})))
});
} catch (AmazonServiceException e) when(e.StatusCode == System.Net.HttpStatusCode.Gone)
{
// connection has been closed, stop the game
LogInfo($"Connection is gone");
game.Status = GameStatus.Finished;
await _table.DeleteAsync <GameRecord>(game.Id);
} catch (Exception e) {
LogErrorAsWarning(e, "PostToConnectionAsync() failed");
}
// check if we need to invoke the next game turn
if ((request.GameLoopType == GameLoopType.Recursive) && (game.Status == GameStatus.NextTurn))
{
await _lambdaClient.InvokeAsync(new InvokeRequest {
Payload = SerializeJson(request),
FunctionName = CurrentContext.FunctionName,
InvocationType = InvocationType.Event
});
}
return(new FunctionResponse {
GameId = game.Id,
Status = game.Status,
GameLoopType = request.GameLoopType
});
}
public async Task <StartGameResponse> StartGameAsync(StartGameRequest request)
{
LogInfo($"Starting a new game: ConnectionId = {CurrentRequest.RequestContext.ConnectionId}");
// create a new game
var game = new Game {
Id = Guid.NewGuid().ToString("N"),
Status = GameStatus.Start,
BoardWidth = request.BoardWidth ?? 1000.0,
BoardHeight = request.BoardHeight ?? 1000.0,
SecondsPerTurn = request.SecondsPerTurn ?? 0.5,
MaxTurns = request.MaxTurns ?? 300,
MaxBuildPoints = request.MaxBuildPoints ?? 8,
DirectHitRange = request.DirectHitRange ?? 5.0,
NearHitRange = request.NearHitRange ?? 20.0,
FarHitRange = request.FarHitRange ?? 40.0,
CollisionRange = request.CollisionRange ?? 8.0,
MinRobotStartDistance = request.MinRobotStartDistance ?? 50.0,
RobotTimeoutSeconds = request.RobotTimeoutSeconds ?? 15.0
};
var gameRecord = new GameRecord {
PK = game.Id,
Game = game,
LambdaRobotArns = request.RobotArns,
ConnectionId = CurrentRequest.RequestContext.ConnectionId
};
// store game record
await _table.CreateAsync(gameRecord);
// dispatch game loop
var gameTurnRequest = new {
GameId = game.Id,
Status = game.Status,
GameLoopType = request.GameLoopType
};
switch (request.GameLoopType)
{
case GameLoopType.Recursive:
LogInfo($"Kicking off Game Turn lambda: Name = {_gameTurnFunctionArn}");
await _lambdaClient.InvokeAsync(new InvokeRequest {
Payload = SerializeJson(gameTurnRequest),
FunctionName = _gameTurnFunctionArn,
InvocationType = InvocationType.Event
});
break;
case GameLoopType.StepFunction:
// kick off game step function
var startGameId = $"LambdaRobotsGame-{game.Id}";
LogInfo($"Kicking off Step Function: Name = {startGameId}");
var startGame = await _stepFunctionsClient.StartExecutionAsync(new StartExecutionRequest {
StateMachineArn = _gameStateMachine,
Name = startGameId,
Input = SerializeJson(gameTurnRequest)
});
// update execution ARN for game record
await _table.UpdateAsync(new GameRecord {
PK = game.Id,
GameLoopArn = startGame.ExecutionArn
}, new[] {
nameof(GameRecord.GameLoopArn)
});
break;
default:
throw new ApplicationException($"unsupported: GameLoopType = {request.GameLoopType}");
}
// return with kicked off game
return(new StartGameResponse {
Game = game
});
}