fab-manager/app/workers/invoice_worker.rb

class InvoiceWorker
  include Sidekiq::Worker

  def perform(invoice_id, subscription_expiration_date)
    # generate a invoice
    invoice = Invoice.find invoice_id
    pdf = ::PDF::Invoice.new(invoice, subscription_expiration_date).render

    # store invoice on drive
    File.binwrite(invoice.file, pdf)

    # notify user + send invoice by mail
    if invoice.is_a?(Avoir)
      NotificationCenter.call type: 'notify_user_when_avoir_ready',
                              receiver: invoice.user,
                              attached_object: invoice
    else
      NotificationCenter.call type: 'notify_user_when_invoice_ready',
                              receiver: invoice.user,
                              attached_object: invoice
    end
  end

end