bowling.rb

# @abstract Representation of a bowling frame. It can be any number of "throws" but a frame is complete if it is either                         
# open, a strike, or spare. Open frames occur when the player does not knock down all the pins within two throws. Closed                      
# frames mean all the pins were knocked down either with a strike or spare.                                                                  
class Frame

  attr_accessor :throws

  def initialize
    @throws = []
  end

  def closed?
    strike? || spare?
  end
   
  def strike?
    @throws[0] == 10
  end

  def spare?
    @throws[0..1].sum == 10
  end

  def open?
    @throws.count == 2 && !closed?
  end

  def score
    if closed?
      @throws[0..2].sum
    else
      @throws[0..1].sum
    end
  end
end

class Game

  # @param throws [Array<Integer>] Listing of every ball rolled expressed as the number of pins knocked down.
  # @param total_frames [Integer] Total number of frames in the game, defaults to 10.
  def initialize(throws:, total_frames: 10)
    @throws = throws
    @total_frames = total_frames
  end

  def frames
    accumulator = []
    frame = Frame.new
    throws.map.with_index do |shot, index|
      frame.throws << shot

      next unless (frame.open? || frame.closed?)

      if frame.strike?
        frame.throws += throws.slice((index + 1), 2)
      elsif frame.spare?
        frame.throws << throws[(index + 1)]
      end

      accumulator << frame
      break if accumulator.count == total_frames

      frame = Frame.new
    end
    accumulator
  end

  def tally
    frames.map(&:score).sum
  end

  private

  attr_reader :throws, :total_frames
end


game = Game.new(throws: [ 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10 ])
puts game.tally

game = Game.new(throws: [5, 3, 7, 2, 10, 9, 0, 8, 1, 4, 4, 8, 2, 10, 9, 0, 9, 1, 7])
puts game.tally

game = Game.new(throws: [10, 7, 3, 7, 2, 9, 1, 10, 10, 10, 2, 3, 6, 4, 7, 3, 3])
puts game.tally