class AbstractConditionalOffer(models.Model):
"""
A conditional offer (eg buy 1, get 10% off)
"""
name = models.CharField(
_("Name"),
max_length=128,
unique=True,
help_text=_("This is displayed within the customer's basket"))
slug = fields.AutoSlugField(_("Slug"),
max_length=128,
unique=True,
populate_from='name')
description = models.TextField(_("Description"),
blank=True,
help_text=_("This is displayed on the offer"
" browsing page"))
# Offers come in a few different types:
# (a) Offers that are available to all customers on the site. Eg a
# 3-for-2 offer.
# (b) Offers that are linked to a voucher, and only become available once
# that voucher has been applied to the basket
# (c) Offers that are linked to a user. Eg, all students get 10% off. The
# code to apply this offer needs to be coded
# (d) Session offers - these are temporarily available to a user after some
# trigger event. Eg, users coming from some affiliate site get 10%
# off.
SITE, VOUCHER, USER, SESSION = ("Site", "Voucher", "User", "Session")
TYPE_CHOICES = (
(SITE, _("Site offer - available to all users")),
(VOUCHER,
_("Voucher offer - only available after entering "
"the appropriate voucher code")),
(USER, _("User offer - available to certain types of user")),
(SESSION,
_("Session offer - temporary offer, available for "
"a user for the duration of their session")),
)
offer_type = models.CharField(_("Type"),
choices=TYPE_CHOICES,
default=SITE,
max_length=128)
# We track a status variable so it's easier to load offers that are
# 'available' in some sense.
OPEN, SUSPENDED, CONSUMED = "Open", "Suspended", "Consumed"
status = models.CharField(_("Status"), max_length=64, default=OPEN)
condition = models.ForeignKey('offer.Condition',
verbose_name=_("Condition"))
benefit = models.ForeignKey('offer.Benefit', verbose_name=_("Benefit"))
# Some complicated situations require offers to be applied in a set order.
priority = models.IntegerField(
_("Priority"),
default=0,
help_text=_("The highest priority offers are applied first"))
# AVAILABILITY
# Range of availability. Note that if this is a voucher offer, then these
# dates are ignored and only the dates from the voucher are used to
# determine availability.
start_datetime = models.DateTimeField(_("Start date"),
blank=True,
null=True)
end_datetime = models.DateTimeField(
_("End date"),
blank=True,
null=True,
help_text=_("Offers are active until the end of the 'end date'"))
# Use this field to limit the number of times this offer can be applied in
# total. Note that a single order can apply an offer multiple times so
# this is not necessarily the same as the number of orders that can use it.
# Also see max_basket_applications.
max_global_applications = models.PositiveIntegerField(
_("Max global applications"),
help_text=_("The number of times this offer can be used before it "
"is unavailable"),
blank=True,
null=True)
# Use this field to limit the number of times this offer can be used by a
# single user. This only works for signed-in users - it doesn't really
# make sense for sites that allow anonymous checkout.
max_user_applications = models.PositiveIntegerField(
_("Max user applications"),
help_text=_("The number of times a single user can use this offer"),
blank=True,
null=True)
# Use this field to limit the number of times this offer can be applied to
# a basket (and hence a single order). Often, an offer should only be
# usable once per basket/order, so this field will commonly be set to 1.
max_basket_applications = models.PositiveIntegerField(
_("Max basket applications"),
blank=True,
null=True,
help_text=_("The number of times this offer can be applied to a "
"basket (and order)"))
# Use this field to limit the amount of discount an offer can lead to.
# This can be helpful with budgeting.
max_discount = models.DecimalField(
_("Max discount"),
decimal_places=2,
max_digits=12,
null=True,
blank=True,
help_text=_("When an offer has given more discount to orders "
"than this threshold, then the offer becomes "
"unavailable"))
# TRACKING
# These fields are used to enforce the limits set by the
# max_* fields above.
total_discount = models.DecimalField(_("Total Discount"),
decimal_places=2,
max_digits=12,
default=D('0.00'))
num_applications = models.PositiveIntegerField(_("Number of applications"),
default=0)
num_orders = models.PositiveIntegerField(_("Number of Orders"), default=0)
redirect_url = fields.ExtendedURLField(_("URL redirect (optional)"),
blank=True)
date_created = models.DateTimeField(_("Date Created"), auto_now_add=True)
objects = models.Manager()
active = ActiveOfferManager()
# We need to track the voucher that this offer came from (if it is a
# voucher offer)
_voucher = None
class Meta:
abstract = True
app_label = 'offer'
ordering = ['-priority']
verbose_name = _("Conditional offer")
verbose_name_plural = _("Conditional offers")
def save(self, *args, **kwargs):
# Check to see if consumption thresholds have been broken
if not self.is_suspended:
if self.get_max_applications() == 0:
self.status = self.CONSUMED
else:
self.status = self.OPEN
return super(AbstractConditionalOffer, self).save(*args, **kwargs)
def get_absolute_url(self):
return reverse('offer:detail', kwargs={'slug': self.slug})
def __str__(self):
return self.name
def clean(self):
if (self.start_datetime and self.end_datetime
and self.start_datetime > self.end_datetime):
raise exceptions.ValidationError(
_('End date should be later than start date'))
@property
def is_open(self):
return self.status == self.OPEN
@property
def is_suspended(self):
return self.status == self.SUSPENDED
def suspend(self):
self.status = self.SUSPENDED
self.save()
suspend.alters_data = True
def unsuspend(self):
self.status = self.OPEN
self.save()
unsuspend.alters_data = True
def is_available(self, user=None, test_date=None):
"""
Test whether this offer is available to be used
"""
if self.is_suspended:
return False
if test_date is None:
test_date = now()
predicates = []
if self.start_datetime:
predicates.append(self.start_datetime > test_date)
if self.end_datetime:
predicates.append(test_date > self.end_datetime)
if any(predicates):
return False
return self.get_max_applications(user) > 0
def is_condition_satisfied(self, basket):
return self.condition.proxy().is_satisfied(self, basket)
def is_condition_partially_satisfied(self, basket):
return self.condition.proxy().is_partially_satisfied(self, basket)
def get_upsell_message(self, basket):
return self.condition.proxy().get_upsell_message(self, basket)
def apply_benefit(self, basket):
"""
Applies the benefit to the given basket and returns the discount.
"""
if not self.is_condition_satisfied(basket):
return results.ZERO_DISCOUNT
return self.benefit.proxy().apply(basket, self.condition.proxy(), self)
def apply_deferred_benefit(self, basket, order, application):
"""
Applies any deferred benefits. These are things like adding loyalty
points to somone's account.
"""
return self.benefit.proxy().apply_deferred(basket, order, application)
def set_voucher(self, voucher):
self._voucher = voucher
def get_voucher(self):
return self._voucher
def get_max_applications(self, user=None):
"""
Return the number of times this offer can be applied to a basket for a
given user.
"""
if self.max_discount and self.total_discount >= self.max_discount:
return 0
# Hard-code a maximum value as we need some sensible upper limit for
# when there are not other caps.
limits = [10000]
if self.max_user_applications and user:
limits.append(
max(
0, self.max_user_applications -
self.get_num_user_applications(user)))
if self.max_basket_applications:
limits.append(self.max_basket_applications)
if self.max_global_applications:
limits.append(
max(0, self.max_global_applications - self.num_applications))
return min(limits)
def get_num_user_applications(self, user):
OrderDiscount = get_model('order', 'OrderDiscount')
aggregates = OrderDiscount.objects.filter(offer_id=self.id,
order__user=user)\
.aggregate(total=models.Sum('frequency'))
return aggregates['total'] if aggregates['total'] is not None else 0
def shipping_discount(self, charge):
return self.benefit.proxy().shipping_discount(charge)
def record_usage(self, discount):
self.num_applications += discount['freq']
self.total_discount += discount['discount']
self.num_orders += 1
self.save()
record_usage.alters_data = True
def availability_description(self):
"""
Return a description of when this offer is available
"""
restrictions = self.availability_restrictions()
descriptions = [r['description'] for r in restrictions]
return "<br/>".join(descriptions)
def availability_restrictions(self): # noqa (too complex (15))
restrictions = []
if self.is_suspended:
restrictions.append({
'description': _("Offer is suspended"),
'is_satisfied': False
})
if self.max_global_applications:
remaining = self.max_global_applications - self.num_applications
desc = _("Limited to %(total)d uses (%(remainder)d remaining)") \
% {'total': self.max_global_applications,
'remainder': remaining}
restrictions.append({
'description': desc,
'is_satisfied': remaining > 0
})
if self.max_user_applications:
if self.max_user_applications == 1:
desc = _("Limited to 1 use per user")
else:
desc = _("Limited to %(total)d uses per user") \
% {'total': self.max_user_applications}
restrictions.append({'description': desc, 'is_satisfied': True})
if self.max_basket_applications:
if self.max_user_applications == 1:
desc = _("Limited to 1 use per basket")
else:
desc = _("Limited to %(total)d uses per basket") \
% {'total': self.max_basket_applications}
restrictions.append({'description': desc, 'is_satisfied': True})
def hide_time_if_zero(dt):
# Only show hours/minutes if they have been specified
if dt.tzinfo:
localtime = dt.astimezone(get_current_timezone())
else:
localtime = dt
if localtime.hour == 0 and localtime.minute == 0:
return date_filter(localtime, settings.DATE_FORMAT)
return date_filter(localtime, settings.DATETIME_FORMAT)
if self.start_datetime or self.end_datetime:
today = now()
if self.start_datetime and self.end_datetime:
desc = _("Available between %(start)s and %(end)s") \
% {'start': hide_time_if_zero(self.start_datetime),
'end': hide_time_if_zero(self.end_datetime)}
is_satisfied \
= self.start_datetime <= today <= self.end_datetime
elif self.start_datetime:
desc = _("Available from %(start)s") % {
'start': hide_time_if_zero(self.start_datetime)
}
is_satisfied = today >= self.start_datetime
elif self.end_datetime:
desc = _("Available until %(end)s") % {
'end': hide_time_if_zero(self.end_datetime)
}
is_satisfied = today <= self.end_datetime
restrictions.append({
'description': desc,
'is_satisfied': is_satisfied
})
if self.max_discount:
desc = _("Limited to a cost of %(max)s") % {
'max': currency(self.max_discount)
}
restrictions.append({
'description':
desc,
'is_satisfied':
self.total_discount < self.max_discount
})
return restrictions
@property
def has_products(self):
return self.condition.range is not None
def products(self):
"""
Return a queryset of products in this offer
"""
Product = get_model('catalogue', 'Product')
if not self.has_products:
return Product.objects.none()
cond_range = self.condition.range
if cond_range.includes_all_products:
# Return ALL the products
queryset = Product.browsable
else:
queryset = cond_range.all_products()
return queryset.filter(is_discountable=True).exclude(
structure=Product.CHILD)
class AbstractConditionalOffer(models.Model):
"""
A conditional offer (eg buy 1, get 10% off)
有条件的报价（例如买1，获得10％的折扣）
"""
name = models.CharField(
_("Name"), max_length=128, unique=True,
help_text=_("This is displayed within the customer's basket"))
# 这陈列在顾客的购物篮里。
slug = fields.AutoSlugField(
_("Slug"), max_length=128, unique=True, populate_from='name')
description = models.TextField(_("Description"), blank=True,
help_text=_("This is displayed on the offer"
" browsing page"))
# 这将陈列在报价浏览页面上。
# Offers come in a few different types:
# (a) Offers that are available to all customers on the site. Eg a
# 3-for-2 offer.
# (b) Offers that are linked to a voucher, and only become available once
# that voucher has been applied to the basket
# (c) Offers that are linked to a user. Eg, all students get 10% off. The
# code to apply this offer needs to be coded
# (d) Session offers - these are temporarily available to a user after some
# trigger event. Eg, users coming from some affiliate site get 10%
# off.
# 报价有几种不同的类型：
# （a）提供给网站上所有客户的报价。3比2报价。
# （b）与优惠券相关联的报价，只有在优惠券适用于购物篮后才可使用
# （c）与用户相关的报价。 例如，所有学生都可享受10％的折扣。 需要对应用此报价
# 的代码进行编码
# （d）会话提供 - 在某些触发事件之后，这些提供暂时可供用户使用。 例如，来自某
# 个联盟网站的用户可获得10％的折扣。
SITE, VOUCHER, USER, SESSION = ("Site", "Voucher", "User", "Session")
TYPE_CHOICES = (
(SITE, _("Site offer - available to all users")),
(VOUCHER, _("Voucher offer - only available after entering "
"the appropriate voucher code")),
(USER, _("User offer - available to certain types of user")),
(SESSION, _("Session offer - temporary offer, available for "
"a user for the duration of their session")),
)
offer_type = models.CharField(
_("Type"), choices=TYPE_CHOICES, default=SITE, max_length=128)
exclusive = models.BooleanField(
_("Exclusive offer"),
help_text=_("Exclusive offers cannot be combined on the same items"),
# 独家报价不能组合在同一项目上
default=True
)
# We track a status variable so it's easier to load offers that are
# 'available' in some sense.
# 我们跟踪状态变量，因此在某种意义上加载“可用”的商品更容易。
OPEN, SUSPENDED, CONSUMED = "Open", "Suspended", "Consumed"
status = models.CharField(_("Status"), max_length=64, default=OPEN)
condition = models.ForeignKey(
'offer.Condition',
on_delete=models.CASCADE,
related_name='offers',
verbose_name=_("Condition"))
benefit = models.ForeignKey(
'offer.Benefit',
on_delete=models.CASCADE,
related_name='offers',
verbose_name=_("Benefit"))
# Some complicated situations require offers to be applied in a set order.
# 某些复杂情况需要按订单顺序应用商品。
priority = models.IntegerField(
_("Priority"), default=0,
help_text=_("The highest priority offers are applied first"))
# 首先应用优先级最高的报价
# AVAILABILITY 可用性
# Range of availability. Note that if this is a voucher offer, then these
# dates are ignored and only the dates from the voucher are used to
# determine availability.
# 可用范围。 请注意，如果这是优惠券报价，则会忽略这些日期，并且仅使用优惠
# 券中的日期来确定可用性。
start_datetime = models.DateTimeField(
_("Start date"), blank=True, null=True,
help_text=_("Offers are active from the start date. "
"Leave this empty if the offer has no start date."))
# 报价从开始日期起生效，如果报价没有开始日期，则空。
end_datetime = models.DateTimeField(
_("End date"), blank=True, null=True,
help_text=_("Offers are active until the end date. "
"Leave this empty if the offer has no expiry date."))
# 报价一直有效到截止日期为止。如果报价没有到期日，请保留此空白。
# Use this field to limit the number of times this offer can be applied in
# total. Note that a single order can apply an offer multiple times so
# this is not necessarily the same as the number of orders that can use it.
# Also see max_basket_applications.
# 使用此字段可限制此要约的总计应用次数。 请注意，单个订单可以多次应用要约，
# 因此这不一定与可以使用它的订单数量相同。 另请参见max_basket_applications。
max_global_applications = models.PositiveIntegerField(
_("Max global applications"),
help_text=_("The number of times this offer can be used before it "
"is unavailable"), blank=True, null=True)
# 在不可用之前，可以使用该报价的次数。
# Use this field to limit the number of times this offer can be used by a
# single user. This only works for signed-in users - it doesn't really
# make sense for sites that allow anonymous checkout.
# 使用此字段可限制单个用户可以使用此优惠的次数。 这仅适用于已登录的用户 - 对于允许
# 匿名结帐的网站而言，它实际上没有意义。
max_user_applications = models.PositiveIntegerField(
_("Max user applications"),
help_text=_("The number of times a single user can use this offer"),
# 单个用户可以使用此优惠的次数
blank=True, null=True)
# Use this field to limit the number of times this offer can be applied to
# a basket (and hence a single order). Often, an offer should only be
# usable once per basket/order, so this field will commonly be set to 1.
# 使用此字段可限制此优惠可应用于购物篮的次数（因此也可以是单个订单）。 通常，
# 报价每个购物篮/订单只能使用一次，因此该字段通常设置为1。
max_basket_applications = models.PositiveIntegerField(
_("Max basket applications"),
blank=True, null=True,
help_text=_("The number of times this offer can be applied to a "
"basket (and order)"))
# 此优惠可应用于购物篮（和订单）的次数
# Use this field to limit the amount of discount an offer can lead to.
# This can be helpful with budgeting.
# 使用此字段可限制要约可能带来的折扣金额。 这对预算编制很有帮助。
max_discount = models.DecimalField(
_("Max discount"), decimal_places=2, max_digits=12, null=True,
blank=True,
help_text=_("When an offer has given more discount to orders "
"than this threshold, then the offer becomes "
"unavailable"))
# 当报价给订单的折扣超过此阈值时，报价就会变得不可用
# TRACKING 跟踪
# These fields are used to enforce the limits set by the
# max_* fields above.
# 这些字段用于强制执行上述max_ *字段设置的限制。
total_discount = models.DecimalField(
_("Total Discount"), decimal_places=2, max_digits=12,
default=D('0.00'))
num_applications = models.PositiveIntegerField(
_("Number of applications"), default=0)
num_orders = models.PositiveIntegerField(
_("Number of Orders"), default=0)
redirect_url = fields.ExtendedURLField(
_("URL redirect (optional)"), blank=True)
date_created = models.DateTimeField(_("Date Created"), auto_now_add=True)
objects = models.Manager()
active = ActiveOfferManager()
# We need to track the voucher that this offer came from (if it is a
# voucher offer)
# 我们需要跟踪此优惠来自的优惠券（如果是优惠券优惠）
_voucher = None
class Meta:
abstract = True
app_label = 'offer'
ordering = ['-priority', 'pk']
verbose_name = _("Conditional offer")
verbose_name_plural = _("Conditional offers")
def save(self, *args, **kwargs):
# Check to see if consumption thresholds have been broken
# 检查消耗阈值是否已被破坏
if not self.is_suspended:
if self.get_max_applications() == 0:
self.status = self.CONSUMED
else:
self.status = self.OPEN
return super().save(*args, **kwargs)
def get_absolute_url(self):
return reverse('offer:detail', kwargs={'slug': self.slug})
def __str__(self):
return self.name
def clean(self):
if (self.start_datetime and self.end_datetime and
self.start_datetime > self.end_datetime):
raise exceptions.ValidationError(
_('End date should be later than start date'))
@property
def is_open(self):
return self.status == self.OPEN
@property
def is_suspended(self):
return self.status == self.SUSPENDED
def suspend(self):
self.status = self.SUSPENDED
self.save()
suspend.alters_data = True
def unsuspend(self):
self.status = self.OPEN
self.save()
unsuspend.alters_data = True
def is_available(self, user=None, test_date=None):
"""
Test whether this offer is available to be used
测试是否可以使用此优惠
"""
if self.is_suspended:
return False
if test_date is None:
test_date = now()
predicates = []
if self.start_datetime:
predicates.append(self.start_datetime > test_date)
if self.end_datetime:
predicates.append(test_date > self.end_datetime)
if any(predicates):
return False
return self.get_max_applications(user) > 0
def is_condition_satisfied(self, basket):
return self.condition.proxy().is_satisfied(self, basket)
def is_condition_partially_satisfied(self, basket):
return self.condition.proxy().is_partially_satisfied(self, basket)
def get_upsell_message(self, basket):
return self.condition.proxy().get_upsell_message(self, basket)
def apply_benefit(self, basket):
"""
Applies the benefit to the given basket and returns the discount.
将收益应用于给定的购物篮并返回折扣。
"""
if not self.is_condition_satisfied(basket):
return ZERO_DISCOUNT
return self.benefit.proxy().apply(
basket, self.condition.proxy(), self)
def apply_deferred_benefit(self, basket, order, application):
"""
Applies any deferred benefits. These are things like adding loyalty
points to someone's account.
适用任何递延利益。 这些是将忠诚度积分添加到某人的帐户。
"""
return self.benefit.proxy().apply_deferred(basket, order, application)
def set_voucher(self, voucher):
self._voucher = voucher
def get_voucher(self):
return self._voucher
def get_max_applications(self, user=None):
"""
Return the number of times this offer can be applied to a basket for a
given user.
返回此优惠可应用于给定用户的购物篮的次数。
"""
if self.max_discount and self.total_discount >= self.max_discount:
return 0
# Hard-code a maximum value as we need some sensible upper limit for
# when there are not other caps.
# 硬编码最大值，因为当没有其他上限时我们需要一些合理的上限。
limits = [10000]
if self.max_user_applications and user:
limits.append(max(0, self.max_user_applications -
self.get_num_user_applications(user)))
if self.max_basket_applications:
limits.append(self.max_basket_applications)
if self.max_global_applications:
limits.append(
max(0, self.max_global_applications - self.num_applications))
return min(limits)
def get_num_user_applications(self, user):
OrderDiscount = get_model('order', 'OrderDiscount')
aggregates = OrderDiscount.objects.filter(offer_id=self.id,
order__user=user)\
.aggregate(total=models.Sum('frequency'))
return aggregates['total'] if aggregates['total'] is not None else 0
def shipping_discount(self, charge):
return self.benefit.proxy().shipping_discount(charge)
def record_usage(self, discount):
self.num_applications += discount['freq']
self.total_discount += discount['discount']
self.num_orders += 1
self.save()
record_usage.alters_data = True
def availability_description(self):
"""
Return a description of when this offer is available
返回此优惠何时可用的说明
"""
restrictions = self.availability_restrictions()
descriptions = [r['description'] for r in restrictions]
return "<br/>".join(descriptions)
# 可用性限制
def availability_restrictions(self): # noqa (too complex (15))
restrictions = []
if self.is_suspended:
restrictions.append({
'description': _("Offer is suspended"),
'is_satisfied': False})
if self.max_global_applications:
remaining = self.max_global_applications - self.num_applications
desc = _("Limited to %(total)d uses (%(remainder)d remaining)") \
% {'total': self.max_global_applications,
'remainder': remaining}
restrictions.append({'description': desc,
'is_satisfied': remaining > 0})
if self.max_user_applications:
if self.max_user_applications == 1:
desc = _("Limited to 1 use per user")
else:
desc = _("Limited to %(total)d uses per user") \
% {'total': self.max_user_applications}
restrictions.append({'description': desc,
'is_satisfied': True})
if self.max_basket_applications:
if self.max_user_applications == 1:
desc = _("Limited to 1 use per basket")
else:
desc = _("Limited to %(total)d uses per basket") \
% {'total': self.max_basket_applications}
restrictions.append({
'description': desc,
'is_satisfied': True})
def hide_time_if_zero(dt):
# Only show hours/minutes if they have been specified
# 仅显示小时/分钟（如果已指定）
if dt.tzinfo:
localtime = dt.astimezone(get_current_timezone())
else:
localtime = dt
if localtime.hour == 0 and localtime.minute == 0:
return date_filter(localtime, settings.DATE_FORMAT)
return date_filter(localtime, settings.DATETIME_FORMAT)
if self.start_datetime or self.end_datetime:
today = now()
if self.start_datetime and self.end_datetime:
desc = _("Available between %(start)s and %(end)s") \
% {'start': hide_time_if_zero(self.start_datetime),
'end': hide_time_if_zero(self.end_datetime)}
is_satisfied \
= self.start_datetime <= today <= self.end_datetime
elif self.start_datetime:
desc = _("Available from %(start)s") % {
'start': hide_time_if_zero(self.start_datetime)}
is_satisfied = today >= self.start_datetime
elif self.end_datetime:
desc = _("Available until %(end)s") % {
'end': hide_time_if_zero(self.end_datetime)}
is_satisfied = today <= self.end_datetime
restrictions.append({
'description': desc,
'is_satisfied': is_satisfied})
if self.max_discount:
desc = _("Limited to a cost of %(max)s") % {
'max': currency(self.max_discount)}
restrictions.append({
'description': desc,
'is_satisfied': self.total_discount < self.max_discount})
return restrictions
@property
def has_products(self):
return self.condition.range is not None
def products(self):
"""
Return a queryset of products in this offer
返回此优惠中的产品查询集
"""
Product = get_model('catalogue', 'Product')
if not self.has_products:
return Product.objects.none()
cond_range = self.condition.range
if cond_range.includes_all_products:
# Return ALL the products
# 退回所有产品
queryset = Product.browsable
else:
queryset = cond_range.all_products()
return queryset.filter(is_discountable=True).exclude(
structure=Product.CHILD)
