Scala - arbitrary length chained futures where each depends on the result of the previous

gistfile1.txt

  def pieceOfWork(i: Int): Int = new Random().nextInt(10) + i
  def eventualWork(i: Int): Future[Int] = Future {
    println(s"eventualWork $i")
    Thread.sleep(500)
    val r = pieceOfWork(i)
    println(s"returning $r")
    r
  }
  def findMoreThan(total: Int): Future[Int] = {
    val promise = Promise[Int]()

    def r(i: Int): Unit = {
      println("r")
      eventualWork(i).map(t => {
        if (t > total) promise.success(t)
        else r(t)
      })
    }
    r(0)
    promise.future
  }