Wolfram Two Color Rule

two_color_rule.rb

class TwoColorRule
  attr_reader :rule, :colors
  def initialize(number:, colors:)
    @colors = colors
    @rule = create_rule_from_int(number)
  end

  def apply_rule(input)
    input.each_cons(3) do |triple|
      left, center, right = *triple
      sum = triple.inject(:+)
      white = colors[0]
      black = colors[1]
      idx = 0
      case sum
      when 3 * white
        idx = 7
      when 2 * white + black
        idx = left == center ? 5 : left == right ? 4 : 6
      when 2 * black + white
        idx = left == center ? 5 : left == right ? 4 : 6
      end
    end
  end

  private

  def create_rule_from_int(number)
    format("%08b", number).split('').map { |s| s.to_i }
  end
end