raffle.scala

import scala.util.Random

/**
 * @author Sebastian Nozzi
 */
object RaffleApp extends App with HelperMethods {

  lazy val numberCandidates: Set[Int] = {
    val allNumbers = (1 to 17).toSet
    val numbersThatWonSomething = Set[Int]()
    allNumbers.diff(numbersThatWonSomething)
  }

  lazy val peopleCandidates: Set[String] = {
    // Outcomment winners!
    val peopleThatDidNotWinAnythingYet =
      Seq(
        "Person1",
        "Person2",
        "Person3",
        //"Person4", // this guy already won something
        "Person5")

    assert(hasUniqueElements(peopleThatDidNotWinAnythingYet), "Should have unique names!")

    peopleThatDidNotWinAnythingYet.toSet
  }

  val chosenOne = chooseOne(numberCandidates)
  println(s"And the chosen one is... ${chosenOne}")

}

trait HelperMethods {

  protected def hasUniqueElements[A](a: Seq[A]): Boolean = {
    a.toSet.size == a.size
  }

  protected def chooseOne[A](candidates: Set[A]): A = {
    Random.shuffle(candidates.toSeq).head
  }

}