#!/usr/bin/env ruby

# build double dabble in ruby so I can feel how it works

number = 999

puts "Binary: #{number.to_s(2)}"

binary_registers = number.to_s(2).split('').map(&:to_i)

scratch_size = 4 * (binary_registers.count / 3).ceil
scratch_space = Array.new(binary_registers.count + scratch_size) { 0 }

binary_registers.each_with_index do |reg, i|
  scratch_space[-(binary_registers.count - i)] = reg
end

pp (scratch_space.count / 4).to_i

binary_registers.count.times do
  (scratch_size / 4).to_i.times do |j|
    value = scratch_space[j * 4..j * 4 + 3].join.to_i(2)

    next unless value > 4

    value += 3

    scratch_space[j * 4..j * 4 + 3] = value.to_s(2).split('').map(&:to_i)
  end

  (scratch_space.count - 1).times do |j|
    scratch_space[j] = scratch_space[j + 1]
  end
  scratch_space[-1] = 0

  pp scratch_space
end