symposion_app/registrasion/models/conditions.py

454 lines
15 KiB
Python
Raw Normal View History

import itertools
from . import inventory
from django.core.exceptions import ValidationError
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _
from model_utils.managers import InheritanceManager
# Condition Types
class TimeOrStockLimitCondition(models.Model):
''' Attributes for a condition that is limited by timespan or a count of
purchased or reserved items.
Attributes:
start_time (Optional[datetime]): When the condition should start being
true.
end_time (Optional[datetime]): When the condition should stop being
true.
limit (Optional[int]): How many items may fall under the condition
the condition until it stops being false -- for all users.
'''
class Meta:
abstract = True
start_time = models.DateTimeField(
null=True,
blank=True,
verbose_name=_("Start time"),
help_text=_("When the condition should start being true"),
)
end_time = models.DateTimeField(
null=True,
blank=True,
verbose_name=_("End time"),
help_text=_("When the condition should stop being true."),
)
limit = models.PositiveIntegerField(
null=True,
blank=True,
verbose_name=_("Limit"),
help_text=_(
"How many times this condition may be applied for all users."
),
)
class VoucherCondition(models.Model):
''' A condition is met when a voucher code is in the current cart. '''
class Meta:
abstract = True
voucher = models.OneToOneField(
inventory.Voucher,
on_delete=models.CASCADE,
verbose_name=_("Voucher"),
db_index=True,
)
class IncludedProductCondition(models.Model):
class Meta:
abstract = True
enabling_products = models.ManyToManyField(
inventory.Product,
verbose_name=_("Including product"),
help_text=_("If one of these products are purchased, this condition "
"is met."),
)
# Discounts
@python_2_unicode_compatible
class DiscountBase(models.Model):
''' Base class for discounts. This class is subclassed with special
attributes which are used to determine whether or not the given discount
is available to be added to the current cart.
Attributes:
description (str): Display text that appears on the attendee's Invoice
when the discount is applied to a Product on that invoice.
'''
class Meta:
app_label = "registrasion"
objects = InheritanceManager()
def __str__(self):
return "Discount: " + self.description
def effects(self):
''' Returns all of the effects of this discount. '''
products = self.discountforproduct_set.all()
categories = self.discountforcategory_set.all()
return itertools.chain(products, categories)
description = models.CharField(
max_length=255,
verbose_name=_("Description"),
help_text=_("A description of this discount. This will be included on "
"invoices where this discount is applied."),
)
@python_2_unicode_compatible
class DiscountForProduct(models.Model):
''' Represents a discount on an individual product. Each Discount can
contain multiple products and categories. Discounts can either be a
percentage or a fixed amount, but not both.
Attributes:
product (inventory.Product): The product that this discount line will
apply to.
percentage (Decimal): The percentage discount that will be *taken off*
this product if this discount applies.
price (Decimal): The currency value that will be *taken off* this
product if this discount applies.
quantity (int): The number of times that each user may apply this
discount line. This applies across every valid Invoice that
the user has.
'''
class Meta:
app_label = "registrasion"
def __str__(self):
if self.percentage:
return "%s%% off %s" % (self.percentage, self.product)
elif self.price:
return "$%s off %s" % (self.price, self.product)
def clean(self):
if self.percentage is None and self.price is None:
raise ValidationError(
_("Discount must have a percentage or a price."))
elif self.percentage is not None and self.price is not None:
raise ValidationError(
_("Discount may only have a percentage or only a price."))
prods = DiscountForProduct.objects.filter(
discount=self.discount,
product=self.product)
cats = DiscountForCategory.objects.filter(
discount=self.discount,
category=self.product.category)
if len(prods) > 1:
raise ValidationError(
_("You may only have one discount line per product"))
if len(cats) != 0:
raise ValidationError(
_("You may only have one discount for "
"a product or its category"))
discount = models.ForeignKey(DiscountBase, on_delete=models.CASCADE)
product = models.ForeignKey(inventory.Product, on_delete=models.CASCADE)
percentage = models.DecimalField(
max_digits=4, decimal_places=1, null=True, blank=True)
price = models.DecimalField(
max_digits=8, decimal_places=2, null=True, blank=True)
quantity = models.PositiveIntegerField()
@python_2_unicode_compatible
class DiscountForCategory(models.Model):
''' Represents a discount for a category of products. Each discount can
contain multiple products. Category discounts can only be a percentage.
Attributes:
category (inventory.Category): The category whose products that this
discount line will apply to.
percentage (Decimal): The percentage discount that will be *taken off*
a product if this discount applies.
quantity (int): The number of times that each user may apply this
discount line. This applies across every valid Invoice that the
user has.
'''
class Meta:
app_label = "registrasion"
def __str__(self):
return "%s%% off %s" % (self.percentage, self.category)
def clean(self):
prods = DiscountForProduct.objects.filter(
discount=self.discount,
product__category=self.category)
cats = DiscountForCategory.objects.filter(
discount=self.discount,
category=self.category)
if len(prods) != 0:
raise ValidationError(
_("You may only have one discount for "
"a product or its category"))
if len(cats) > 1:
raise ValidationError(
_("You may only have one discount line per category"))
discount = models.ForeignKey(DiscountBase, on_delete=models.CASCADE)
category = models.ForeignKey(inventory.Category, on_delete=models.CASCADE)
percentage = models.DecimalField(
max_digits=4,
decimal_places=1)
quantity = models.PositiveIntegerField()
class TimeOrStockLimitDiscount(TimeOrStockLimitCondition, DiscountBase):
''' Discounts that are generally available, but are limited by timespan or
usage count. This is for e.g. Early Bird discounts.
Attributes:
start_time (Optional[datetime]): When the discount should start being
offered.
end_time (Optional[datetime]): When the discount should stop being
offered.
limit (Optional[int]): How many times the discount is allowed to be
applied -- to all users.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("discount (time/stock limit)")
verbose_name_plural = _("discounts (time/stock limit)")
class VoucherDiscount(VoucherCondition, DiscountBase):
''' Discounts that are enabled when a voucher code is in the current
cart. These are normally configured in the Admin page at the same time as
creating a Voucher object.
Attributes:
voucher (inventory.Voucher): The voucher that enables this discount.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("discount (enabled by voucher)")
verbose_name_plural = _("discounts (enabled by voucher)")
class IncludedProductDiscount(IncludedProductCondition, DiscountBase):
''' Discounts that are enabled because another product has been purchased.
e.g. A conference ticket includes a free t-shirt.
Attributes:
enabling_products ([inventory.Product, ...]): The products that enable
the discount.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("discount (product inclusions)")
verbose_name_plural = _("discounts (product inclusions)")
class RoleDiscount(object):
''' Discounts that are enabled because the active user has a specific
role. This is for e.g. volunteers who can get a discount ticket. '''
# TODO: implement RoleDiscount
pass
@python_2_unicode_compatible
class FlagBase(models.Model):
''' This defines a condition which allows products or categories to
be made visible, or be prevented from being visible.
Attributes:
description (str): A human-readable description that is used to
identify the flag to staff in the admin interface. It's not seen
anywhere else in Registrasion.
condition (int): This determines the effect of this flag's condition
being met. There are two types of condition:
``ENABLE_IF_TRUE`` conditions switch on the products and
categories included under this flag if *any* such condition is met.
``DISABLE_IF_FALSE`` conditions *switch off* the products and
categories included under this flag is any such condition
*is not* met.
If you have both types of conditions attached to a Product, every
``DISABLE_IF_FALSE`` condition must be met, along with one
``ENABLE_IF_TRUE`` condition.
products ([inventory.Product, ...]):
The Products affected by this flag.
categories ([inventory.Category, ...]):
The Categories whose Products are affected by this flag.
'''
objects = InheritanceManager()
DISABLE_IF_FALSE = 1
ENABLE_IF_TRUE = 2
def __str__(self):
return self.description
def effects(self):
''' Returns all of the items affected by this condition. '''
return itertools.chain(self.products.all(), self.categories.all())
@property
def is_disable_if_false(self):
return self.condition == FlagBase.DISABLE_IF_FALSE
@property
def is_enable_if_true(self):
return self.condition == FlagBase.ENABLE_IF_TRUE
description = models.CharField(max_length=255)
condition = models.IntegerField(
default=ENABLE_IF_TRUE,
choices=(
(DISABLE_IF_FALSE, _("Disable if false")),
(ENABLE_IF_TRUE, _("Enable if true")),
),
help_text=_("If there is at least one 'disable if false' flag "
"defined on a product or category, all such flag "
" conditions must be met. If there is at least one "
"'enable if true' flag, at least one such condition must "
"be met. If both types of conditions exist on a product, "
"both of these rules apply."
),
)
products = models.ManyToManyField(
inventory.Product,
blank=True,
help_text=_("Products affected by this flag's condition."),
related_name="flagbase_set",
)
categories = models.ManyToManyField(
inventory.Category,
blank=True,
help_text=_("Categories whose products are affected by this flag's "
"condition."
),
related_name="flagbase_set",
)
class TimeOrStockLimitFlag(TimeOrStockLimitCondition, FlagBase):
''' Product groupings that can be used to enable a product during a
specific date range, or when fewer than a limit of products have been
sold.
Attributes:
start_time (Optional[datetime]): This condition is only met after this
time.
end_time (Optional[datetime]): This condition is only met before this
time.
limit (Optional[int]): The number of products that *all users* can
purchase under this limit, regardless of their per-user limits.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("flag (time/stock limit)")
verbose_name_plural = _("flags (time/stock limit)")
@python_2_unicode_compatible
class ProductFlag(IncludedProductCondition, FlagBase):
''' The condition is met because a specific product is purchased.
Attributes:
2016-04-25 00:15:13 +00:00
enabling_products ([inventory.Product, ...]): The products that cause
this condition to be met.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("flag (dependency on product)")
verbose_name_plural = _("flags (dependency on product)")
def __str__(self):
return "Enabled by products: " + str(self.enabling_products.all())
@python_2_unicode_compatible
class CategoryFlag(FlagBase):
''' The condition is met because a product in a particular product is
purchased.
Attributes:
enabling_category (inventory.Category): The category that causes this
condition to be met.
'''
class Meta:
app_label = "registrasion"
verbose_name = _("flag (dependency on product from category)")
verbose_name_plural = _("flags (dependency on product from category)")
def __str__(self):
return "Enabled by product in category: " + str(self.enabling_category)
enabling_category = models.ForeignKey(
inventory.Category,
help_text=_("If a product from this category is purchased, this "
"condition is met."),
)
@python_2_unicode_compatible
class VoucherFlag(VoucherCondition, FlagBase):
''' The condition is met because a Voucher is present. This is for e.g.
enabling sponsor tickets. '''
class Meta:
app_label = "registrasion"
verbose_name = _("flag (dependency on voucher)")
verbose_name_plural = _("flags (dependency on voucher)")
def __str__(self):
return "Enabled by voucher: %s" % self.voucher
# @python_2_unicode_compatible
class RoleFlag(object):
''' The condition is met because the active user has a particular Role.
This is for e.g. enabling Team tickets. '''
# TODO: implement RoleFlag
pass