CodeManager.scala

package se.picturizer.service.screen.internal

import java.time.Instant
import java.time.temporal.ChronoUnit
import java.util.UUID

import CodeManager._
import akka.actor.Actor

import scala.collection.immutable
import scala.util.Random

private[internal] class CodeManager extends Actor {

  private var codes: immutable.Map[UUID, RegistrationCode] = Map.empty

  override def receive: Receive = {
    case screenId: UUID =>
      val code = RegistrationCode(screenId)
      codes = codes.filterNot(_._2.expired) + (screenId -> code)
      sender() ! code
    case (screenId: UUID, code: String) =>
      sender() ! codeOk(screenId, code)
  }

  private def codeOk(screenId: UUID, code: String): Boolean =
    codes
      .get(screenId)
      .filterNot(_.expired)
      .filter(_.code == code)
      .filter(_.screen == screenId)
      .isDefined
}

object CodeManager {

  private[CodeManager] final case class RegistrationCode private[CodeManager$](screen: UUID, code: String, issued: Instant) {
    def expired: Boolean = issued.plus(1, ChronoUnit.DAYS).isBefore(Instant.now)
  }

  private[CodeManager] object RegistrationCode {
    def apply(screenId: UUID): RegistrationCode =
      RegistrationCode(screenId, Random.alphanumeric.take(6).mkString("").toUpperCase, Instant.now)
  }
}