internetee-registry/app/models/concerns/email_verifable.rb

module EmailVerifable
  extend ActiveSupport::Concern

  def email_verification
    EmailAddressVerification.find_or_create_by(email: unicode_email, domain: domain(email))
  end

  def billing_email_verification
    return unless attribute_names.include?('billing_email')

    EmailAddressVerification.find_or_create_by(email: unicode_billing_email,
                                               domain: domain(billing_email))
  end

  def email_verification_failed?
    email_verification&.failed?
  end

  class_methods do
    def domain(email)
      Mail::Address.new(email).domain&.downcase || 'not_found'
    rescue Mail::Field::IncompleteParseError
      'not_found'
    end

    def local(email)
      Mail::Address.new(email).local&.downcase || email
    rescue Mail::Field::IncompleteParseError
      email
    end

    def punycode_to_unicode(email)
      return email if domain(email) == 'not_found'

      local = local(email)
      domain = SimpleIDN.to_unicode(domain(email))
      "#{local}@#{domain}"&.downcase
    end

    def unicode_to_punycode(email)
      return email if domain(email) == 'not_found'

      local = local(email)
      domain = SimpleIDN.to_ascii(domain(email))
      "#{local}@#{domain}"&.downcase
    end
  end

  def unicode_billing_email
    self.class.punycode_to_unicode(billing_email)
  end

  def unicode_email
    self.class.punycode_to_unicode(email)
  end

  def domain(email)
    SimpleIDN.to_unicode(self.class.domain(email))
  end

  def punycode_to_unicode(email)
    self.class.punycode_to_unicode(email)
  end

  def correct_email_format
    return if email.blank?

    result = email_verification.verify
    process_result(result: result, field: :email)
  end

  def correct_billing_email_format
    return if email.blank?

    result = billing_email_verification.verify
    process_result(result: result, field: :billing_email)
  end

  # rubocop:disable Metrics/LineLength
  def process_result(result:, field:)
    case result[:errors].keys.first
    when :smtp
      errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_smtp_check_error'))
    when :mx
      errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_mx_check_error'))
    when :regex
      errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_regex_check_error'))
    end
  end
  # rubocop:enable Metrics/LineLength
end