overreactive scala

import java.util.{Collections, UUID}

import reactor.core.publisher.{Flux, Mono}

class Overreactive {

  class POC {
    def ws = new WS()

    def db = new DB()

    def doIt(name: String): Flux[String] = {
      val paid: Mono[(java.util.List[Item], UUID)] = for {
        user <- ws.findUserByName(name)
        contains <- db.contains(user.getSsn)
        persistentUser <- if (!contains) db.save(user) else Mono.just(user)
        cart <- loadCart(persistentUser)
        total <- Mono.just(cart.stream().mapToDouble(_.getPrice).sum())
        uuid <- pay(total)
      } yield ((cart, uuid))

      for {
          allPaidItems <- paid.flux()
          paidItem <- Flux.fromIterable(allPaidItems._1)
          sent <- sendEmail(paidItem, allPaidItems._2)
      } yield (sent)

    }

    private def sendEmail(item: Item, id: UUID) = Mono.just("aa")

    private def pay(total: Double) = Mono.just(UUID.randomUUID)

    private def loadCart(user: User): Mono[java.util.List[Item]]
    = Flux.fromIterable(Collections.emptyList[Item]).collectList()

  }

  class WS {
    def findUserByName(name: String): Mono[User] = ???
  }

  class DB {
    def contains(ssn: String): Mono[Boolean] = Mono.just(false)

    def save(user: User): Mono[User] = Mono.just(user)
  }

  class Item {
    def getPrice = 0
  }

  class User {
    def getSsn = "ssn"
  }

}