rubyforgood/casa

module PhoneNumberHelper
  VALID_PHONE_NUMBER_LENGTHS = [10, 11]
  VALID_COUNTRY_CODE = "+1"
  ERROR_MESSAGE = "must be 10 digits or 12 digits including country code (+1)"

  def valid_phone_number(number)
    if number.nil? || number.empty?
      return true, nil
    end

    number = strip_unnecessary_characters(number)

    if !VALID_PHONE_NUMBER_LENGTHS.include?(number.length)
      return false, ERROR_MESSAGE
    end

    if number.length == 11
      country_code = number[0..0]
      phone_number = number[1..number.length]
      valid_country_code = VALID_COUNTRY_CODE[1..1]

      if country_code != valid_country_code
        return false, ERROR_MESSAGE
      end
    else
      phone_number = number
    end

    if !phone_number.scan(/\D/).empty?
      return false, ERROR_MESSAGE
    end

    [true, nil]
  end

  def strip_unnecessary_characters(number)
    number.gsub(/[()\+\s\-\.]/, "")
  end
end