private static async Task Execute(
InMemoryEventStore store,
string streamName,
Func <EventData[], IEvent[]> f,
Func <IEvent[], Task> pub)
{
var r = await store.LoadEventStreamAsync(streamName, 0);
var events = f(r.Events.ToArray());
_ = await store.AppendToStreamAsync(streamName, r.Version, events);
await pub(events);
}
public async Task Dispatch(ICommand command)
{
async Task subsciption(IEvent[] events)
{
_ = await store.AppendToStreamAsync("games", events);
await pub(events);
};
Func <InMemoryEventStore, Task> commandHandler = command switch
{
CreateGame cmd => (store) => Execute(store, $"game-{cmd.GameId}", events => Game.Handle(cmd, events).ToArray(), subsciption),
JoinGame cmd => (store) => Execute <GameState>(store, $"game-{cmd.GameId}", state => Game.Handle(cmd, state).ToArray(), subsciption),
_ => (store) => throw new ArgumentException($"Could not dispatch {command.GetType()}")
};
await commandHandler(store);
}