// Adapt the code to your code kata primes.
// Important: Test and production code has to be
//            completely in this file.

import org.scalatest.junit.JUnitSuite
import org.scalatest.junit.ShouldMatchersForJUnit
import org.junit.Test

class BowlingGameTest extends JUnitSuite with ShouldMatchersForJUnit {

  val game = new BowlingGame()

  @Test
  def verifyThatAllGuttersScore0() = {
    for (i <- 1 to 20) game roll(0)
    (game score) should be(0)
  }

  @Test
  def verifyThatAllOnesScore20() = {
    for (i <- 1 to 20) game roll(1)
    (game score) should be(20)
  }
  
  @Test
  def verifyThatASpareFollowedByAllOnesScore29() = {
    game roll(5)
    game roll(5)
    for (i <- 1 to 18) game roll(1)
    (game score) should be(29)
  }
  
  @Test
  def verifyThatAStrikeFollowedByAllOnesScore30() = {
    game roll(10)
    for (i <- 1 to 18) game roll(1)
    (game score) should be(30)
  }
  
  @Test
  def verifyThatAPerfectGameScores300() = {
    for (i <- 1 to 12) game roll(10)
      (game score) should be(300)
  }
    
  @Test
  def verifyThatAStartingSpareAnd1Scores12() = {
    game roll(7)
    game roll(3)
    game roll(1)
    (game score) should be(12)
  }


  class BowlingGame {

    var rolls: List[Int] = List()

    def roll(pins: Int) = {
      rolls = rolls :+ pins
    }

    def score: Int = {
      scoreRecursive(0, 1, rolls)
    }

    def scoreRecursive(currentScore: Int, frame: Int, rolls: List[Int]): Int = {
      frame match {
        case 11 => currentScore
        case f => rolls match {
          case 10 :: rollsTail // strike
            => scoreRecursive(currentScore + (rolls take (3) sum), f + 1, rollsTail)
          case first :: second :: rollsTail if (first + second == 10) // spare
            => scoreRecursive(currentScore + (rolls take (3) sum), f + 1, rollsTail)
          case first :: second :: rollsTail // normal
            => scoreRecursive(currentScore + (rolls take (2) sum), f + 1, rollsTail)
          case last :: rollsTail // partial frame
            => currentScore + last
          case nil // partial game
            => currentScore
        }
      }
    }
  }
  
}