### Models 



class base(models.Model):

    created_by = models.ForeignKey(User, verbose_name=_("User"), on_delete=models.CASCADE, editable=False, null=True, blank=True)
    created = models.DateTimeField(_("created date"), auto_now=False, auto_now_add=True, editable=False)

    class Meta:
        abstract = True

# Level 1 model
class Building(base):
    name = models.CharField(_("Name"), max_length=50)
    managers = models.ManyToManyField(User, verbose_name=_("Admins"), related_name='buildingmanagers')


    class Meta:
        verbose_name = _("building")
        verbose_name_plural = _("buildings")

    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse("building_detail", kwargs={"pk": self.pk})

# Level 2
# list should be on /buildings/<building_id>/properties
# Details could be on either
# /buildings/<building_id>/properties/<property_id>
# /properties/<property_id>
class Property(base):

    name = models.CharField(_("Nombre de la propiedad"), max_length=50)
    building = models.ForeignKey("core.Building", verbose_name=_("Edificio"), on_delete=models.CASCADE)
    owner = models.CharField(_("Nombre propietario"), max_length=50, blank=True, null=True)

    class Meta:
        verbose_name = _("property")
        verbose_name_plural = _("propertys")

    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse("property_detail", kwargs={"pk": self.pk})

# Level 3
# list should be on 
# /buildings/<building_id>/properties/<property_id>/invoices
# or /properties/<property_id>/invoices
# Details could be on either
# /buildings/<building_id>/properties/<property_id>/invoices/<property_invoice_id>
# /property_invoices/<property_invoice_id>
class PropertyInvoice(invoice_base):

    prop = models.ForeignKey(Property, verbose_name=_("Property"), on_delete=models.CASCADE)

    class Meta:
        verbose_name = _("property invoice")
        verbose_name_plural = _("property invoices")

    def __str__(self):
        return self.concept

    def get_absolute_url(self):
        return reverse("propertyinvoice_detail", kwargs={"pk": self.pk})

    def get_building(self):
        return self.prop.building


# Level 4
# list should be on 
# /buildings/<building_id>/properties/<property_id>/invoices/<invoice_id>/payments
# or /property_invoices/<invoice_id>/payments
# Details could be on either
# /buildings/<building_id>/properties/<property_id>/invoices/<invoice_id>/payments/<payment_id>
# /property_payments/<payment_id>
class PropertyInvoicePayment(payment_base):
    invoice = models.ForeignKey("core.PropertyInvoice", verbose_name=_("Related Invoice"), on_delete=models.CASCADE)

    def get_building(self):
        return self.invoice.prop.building