Weekly Challenge - Secret Handshake

secret_handshake.rb

# A SecretHandshake class that decodes binary commands in a secret language
class SecretHandshake
  SECRETS = ['wink', 'double blink', 'close your eyes', 'jump'].freeze

  def initialize(num)
    @bits = to_binary(num).chars.reverse
  end

  def commands
    secrets = @bits.map.with_index { |bit, idx| SECRETS[idx] if bit == '1' }
    secrets.reverse! if @bits[4] == '1'

    secrets.compact
  end

  private

  def to_binary(num)
    return '0' if num =~ /[a-zA-Z]/

    indexes = ones_indexes(num)
    string = '0' * (Math.log2(num).to_i + 1)
    indexes.each { |digit| string[digit] = '1' }
    string
  end

  def ones_indexes(num)
    array = []
    while num > 0
      power = Math.log2(num).to_i
      array << -power - 1
      num = num.zero? ? num - 1 : num - (2**power)
    end
    array
  end
end