A little less cake

example.scala

object Main extends App {
  val system = ActorSystem("my-system")
  val ec = system.dispatcher
  //we don't use the actor system ec here, but let's ignore that
  val userService = new UserServiceImpl(ec)
  val foobarService = new FoobarServiceImpl(userService)
  val restActor = system.actorOf(Props(new RestActor(userService, foobarService)) "actor")
}

class RestActor(val userService:UserService, val foobarServiceFoobarService) extends Registry with UserRoutes {
  val userRoutes = new UserRoutes(userService)
  
  def receive = {
    userRoutes.userRoutesDef ~
    otherRoutesFromOtherMixins
  }
}

trait AccessDirectives extends Directives {
  //Here we still need user service, so do we self type to UserRoutes?
  //Or maybe a structural self-type?
  self: {val userService:UserService} =>
  
  val letMeIn:Directive1[Option[User]] = optionalHeaderByValueName("user_auth").hflatMap {
    case Some(id) :: HNil => onSuccess(userService.get(id))
    case _ => reject()
  }
}

class UserRoutes(val userService:UserService) with AccessDirectives {
  self: Registry =>
  
  val userRoutesDef = {
    path(Segment){ userId =>
      onSuccess(userService.get(userId)){ user =>
        complete(user)
      }
    }
  }
}