package snake

class Snake (
  val initPos: Pos,
  val initDir: Dir,
  val headColor: java.awt.Color,
  val tailColor: java.awt.Color,
  val game: SnakeGame,
  var points: Int = 0
) extends CanMove {
  var dir: Dir = initDir

  val initBody: List[Pos] = List(initPos + initDir, initPos)

  val body: scala.collection.mutable.Buffer[Pos] = initBody.toBuffer

  val initTailSize: Int = 10 // välj själv vad som är lagom svårt

  var nbrOfSteps = 1
  val growEvery = 100


  def reset(): Unit = {   // återställ starttillstånd, ge rätt svanslängd
    while (body.length > initBody.length) shrink()
  }

  def grow(): Unit = body.prepend(body.head + dir)  // väx i rätt riktning med extra svansposition

  def shrink(): Unit = if (body.length > 2) body.remove(body.length - 1) // krymp svansen om kroppslängden är större än 2

  def isOccupyingBlockAt(p: Pos): Boolean = body contains p      // kolla om p finns i kroppen

  def isHeadCollision(other: Snake): Boolean = body.head == other.body.head
  def isTailCollision(other: Snake): Boolean = other.body.tail.contains(body.head)

  def move(): Unit = {
    grow()
    shrink()

    if (nbrOfSteps % growEvery == 0) grow(); nbrOfSteps += 1

    game.entities.foreach{
      ent => if (ent.isOccupyingBlockAt(body.head)) {
        ent match {
          case c: CanTeleport => grow(); points += 1; ent.reset()
          case _ =>
        }
      }
    }
  }

   // väx och krymp enl. regler; action om äter frukt

  def draw(): Unit =
    body.foreach(pos => if (pos == body.head) game.drawBlock(pos.x, pos.y, headColor) else game.drawBlock(pos.x, pos.y, tailColor))

  def erase(): Unit = game.eraseBlock(body.last.x, body.last.y)

  override def toString: String =  // bra vid println-debugging
    body.map(p => (p.x, p.y)).mkString(">:)", "~", s" going $dir")
}