module PoBox
  module Emailable
    extend ActiveSupport::Concern

    included do
      has_many :inboxes, as: :emailable, class_name: "PoBox::Inbox", dependent: :destroy

      after_create_commit :set_inbox

      accepts_nested_attributes_for :inboxes, allow_destroy: true

      private

      def set_inbox
        return if inboxes.any?

        inbox_address = if email.present?
          "#{email.split("@").first}##{SecureRandom.hex(2)}"
        else
          SecureRandom.hex(8)
        end

        inbox = inboxes.new
        loop do
          inbox.address = inbox_address
          break unless PoBox.emailable_class.joins(:inboxes).where(po_box_inboxes: {address: inbox.address}).exists?
        end

        save
      end
    end
  end
end