signup_inviter.rb

class SignupInviter
  include ActiveModel::Model

  EMAIL_REGEX = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/

  attr_accessor :recipients, :sender

  validates :sender, :recipients, presence: true
  validate  :ensure_recipient_emails

  def deliver
    return false unless valid?

    if recipients_without_users.any?
      create_invitations
      send_invitations
    end

    true
  end

  private

  def ensure_recipient_emails
    if has_any_invalid_recipient_email?
      errors.add(:recipients, "have invalid email format")
    end
  end

  def create_invitations
    recipients_without_users.each do |recipient_email|
      Invitation.create!(sender: sender, recipient_email: recipient_email)
    end
  end

  def send_invitations
    SendSignupInvitationsWorker.perform_async(sender.id, recipients_without_users)
  end

  def has_any_invalid_recipient_email?
    recipients && recipients.any? { |email| email !~ EMAIL_REGEX }
  end

  def recipients_without_users
    @recipients_without_users ||= begin
      emails = User.where(email: recipients).pluck(:email)
      recipients - emails
    end
  end
end