class OrderStatus(models.Model):
    """
    An order will have multiple statuses as it moves its way through processing.
    """
    order = models.ForeignKey(Order, verbose_name=_("Order"), edit_inline=models.STACKED, num_in_admin=1)
    status = models.CharField(_("Status"),
        max_length=20, choices=ORDER_STATUS, core=True, blank=True)
    notes = models.CharField(_("Notes"), max_length=100, blank=True)
    timestamp = models.DateTimeField(_("Timestamp"))

    def __unicode__(self):
        return self.status

    def save(self):
        super(OrderStatus, self).save()
        self.order.status = self.status
        self.order.save()

    class Meta:
        verbose_name = _("Order Status")
        verbose_name_plural = _("Order Statuses")