Shutdown code example with few or confusing comments

models.py

    # TODO 1.5 Does shutdown belong on Order?
    @defer_to_detail
    def shutdown(self, reason, comment, by_user):

        log.debug('Shutdown order (%s) for reason: %s' % (self, reason))
        if reason == self.Status.RETURN:
            # we're going to ignore deactivated and promo cards, and shutdown as long
            # as the primary cards are pristine
            deactivated_statuses = [gift_card.Certificate.Status.RETURN,
                gift_card.Certificate.Status.DELETED, gift_card.Certificate.Status.FRAUD]
            for vgc in self.primary_vgcs.exclude(status__in=deactivated_statuses):
                # some clients allow cashout, meaning partial refunds on
                # card is acceptable and able to be refunded
                
                # --> do some stuff, clipped for brevity <--

            self.refund()

            self.set_status(reason, comment, by_user, 'return')
            if self.product.is_bulk:
                self.order_detail.update_status(reason)

        elif reason == self.Status.FRAUD:
            self.set_status(reason, comment, by_user)

            # Prevent any unsent messages from being sent for this order
            self.notifications.cancel_pending_messages()

        else:
            raise ValueError('Unknown shutdown reason "%s"' % reason)

        # Create an api callback to notify users the order was shutdown
        self.activationcallback_set.new_callback(self)

        return True