Authentication with DI

authmanager.scala

class AuthenticationManager {
  // inject db: Database, repo: Users
  def authenticateWithToken(token: String): Option[User] = {
    db withTransaction { implicit session =>
      repo.authenticateWithToken(token)
    }
  }
}

trait TokenAuthenticator {
  val apiTokenAuth = new ApiTokenAuthenticator()
}

class ApiTokenAuthenticator(implicit val executionContext: ExecutionContext) extends HttpAuthenticator[User] {
  // inject AuthenticationManager
  
  override def getChallengeHeaders(httpRequest: HttpRequest): List[HttpHeader] =
    `WWW-Authenticate`(HttpChallenge(scheme = "Token", realm = "Manta", params = Map.empty)) :: Nil

  override def authenticate(credentials: Option[HttpCredentials], ctx: RequestContext): Future[Option[User]] =
    Future.successful(
      credentials.flatMap {
        case GenericHttpCredentials(scheme, token, params) if scheme == "Token" =>  {
          authenticationManager.authenticateWithToken(token)
        }
        case _ => None
      }
    )
}