package PP_Lab.Lab11

class Queue[+T] private (val l1: List[T], val l2: List[T]) {

  //Exception
  class QueueException(message: String) extends Exception(message)

  def this() = this(Nil, Nil)

//  def enqueue[T](elem: T) : Queue[T] = {
//    (l1, l2) match {
//      case (Nil, Nil) => new Queue(List(elem), Nil)
//      case (_, _) => new Queue(l1, elem :: l2)
//    }
//  }

  def enqueue[S >: T](elem: S) = {
    (l1, l2) match {
      case (Nil, Nil) => new Queue[S](List(elem), Nil)
      case (_, _) => new Queue[S](l1, elem :: l2)
    }
  }

  def dequeue() : Queue[T] = {
    (l1, l2) match {
      case (Nil, Nil) => this
      case (List(_), l) => new Queue(l.reverse, Nil)
      case (_ :: t, l) => new Queue(t, l)
    }
  }

  def first() : T = {
    (l1, l2) match {
      case (Nil, Nil) => throw new QueueException("empty")
      case (h :: _, _) => h
      case _ => throw new QueueException("sth gone wrong")
    }
  }

  def isEmpty : Boolean = {
    l1 == Nil
  }

  override def toString : String = {
    var res = ""

    var qTemp = this

    while (!qTemp.isEmpty) {
      res += qTemp.first() + "\n"
      qTemp = qTemp.dequeue()
    }

    res
  }

  override def hashCode(): Int = 2137

}

object QueueTests extends App {

  var q1 = new Queue[Number]()
  q1 = q1.enqueue(10)
  q1 = q1.enqueue(20.4)
  q1 = q1.enqueue(0.5f)

  println(q1)

  var qPoints = new Queue[Point]()
  qPoints = qPoints.enqueue(new Point(0.0))
  qPoints = qPoints.enqueue(new Point(2.2))
  qPoints = qPoints.enqueue(new Pixel())

  println("punkty:")
  println(qPoints)

  var qPixels = new Queue[Pixel]()
  //qPixels = qPixels.enqueue(new Point(0,-1))
  qPixels = qPixels.enqueue(new Pixel())
  qPixels = qPixels.enqueue(new Pixel(2, 2))
  println("pixels:")
  println(qPixels)


  var qPixels2 = qPixels.enqueue(new Point(0, -1))
  println("pixele z punktami:")
  println(qPixels2)


  //rzutowanie:
  var element = qPixels2.first()
  println("kolejka")
  println(qPixels2.getClass.toGenericString)

  println()
  println("element: ")
  println(element.isInstanceOf[Point])
  println(element.isInstanceOf[Pixel])
  println(element.getClass.toGenericString)

  println()
  qPoints = qPixels
  //qPixels = qPoints //nie kompiluje się
  println(qPoints)

}