FlagsRegistry.scala

object FlagsRegistry {

  private val flagsRegistry = new FlagsRegistry(config, dao, executorService)

  def check(serviceId: Long, flag: FlagEnum) = flagsRegistry.check(serviceId, flag)
}


class FlagsRegistry(conf, dao, executorService) {

  private val UpdateInterval: Long = conf.get("bla.bla.update-interval")

  @volatile private var flags: Map[Long, Map[FlagEnum, Flag]] = fetchAllFlags()

  sheduleNextTimer(UpdateInterval)
  
  def check(serviceId: Long, flag: FlagEnum) = 
    flags.get(serviceId).flatMap(_.get(flag)).exists(_.value == true)

  private def fetchAllFlags(): Map[Long, Map[FlagEnum, Flag]] = 
    dao.getAllServiceFlags() map { result ⇒
      ???
    }
  
  private def sheduleNextTimer(timeout: Long) {
    executorService.schedule(new Runnable {
        def run() {
          flags = fetchAllFlags()
          sheduleNextTimer(math.min(UpdateInterval, findNextExpiredTimeout))
        }
      },
      timeout,
      TimeUnit.MILLISECONDS
    )
  }
  
  private def findNextExpiredTimeout: Long = ???
}