module FFaker::IdentificationBR

def document_verification_digits(verification_multipliers, document = nil)
  return false if document.nil?
  document_digits = document.to_s.scan(/[0-9]/).map(&:to_i)
  validation_digits = []
  if document_digits.size + 1 == verification_multipliers.size && document_digits.uniq.size > 1
    0.upto(1) do |i|
      sum = verification_multipliers.drop(1 - i).each_with_index.inject(0) do |val, (value, j)|
        val + document_digits[j] * value
      end
      validation_digits[i] = (sum %= 11) < 2 ? 0 : 11 - sum
      document_digits.push(validation_digits[i])
    end
    return validation_digits
  end
  []
end