Files
pretix_cgo/src/pretix/base/models/vouchers.py
2017-02-21 17:15:43 +01:00

245 lines
9.2 KiB
Python

from decimal import Decimal
from django.conf import settings
from django.core.exceptions import ValidationError
from django.db import models
from django.utils.crypto import get_random_string
from django.utils.timezone import now
from django.utils.translation import ugettext_lazy as _
from ..decimal import round_decimal
from .base import LoggedModel
from .event import Event
from .items import Item, ItemVariation, Quota
def _generate_random_code():
charset = list('ABCDEFGHKLMNPQRSTUVWXYZ23456789')
return get_random_string(length=settings.ENTROPY['voucher_code'], allowed_chars=charset)
def generate_code():
while True:
code = _generate_random_code()
if not Voucher.objects.filter(code=code).exists():
return code
class Voucher(LoggedModel):
"""
A Voucher can reserve ticket quota or allow special prices.
:param event: The event this voucher is valid for
:type event: Event
:param code: The secret voucher code
:type code: str
:param max_usages: The number of times this voucher can be redeemed
:type max_usages: int
:param redeemed: The number of times this voucher already has been redeemed
:type redeemed: bool
:param valid_until: The expiration date of this voucher (optional)
:type valid_until: datetime
:param block_quota: If set to true, this voucher will reserve quota for its holder
:type block_quota: bool
:param allow_ignore_quota: If set to true, this voucher can be redeemed even if the event is sold out
:type allow_ignore_quota: bool
:param price_mode: Sets how this voucher affects a product's price. Can be ``none``, ``set``, ``subtract``
or ``percent``.
:type price_mode: str
:param value: The value by which the price should be modified in the way specified by ``price_mode``.
:type value: decimal.Decimal
:param item: If set, the item to sell
:type item: Item
:param variation: If set, the variation to sell
:type variation: ItemVariation
:param quota: If set, the quota to choose an item from
:type quota: Quota
:param comment: An internal comment that will only be visible to staff, and never displayed to the user
:type comment: str
:param tag: Use this field to group multiple vouchers together. If you enter the same value for multiple
vouchers, you can get statistics on how many of them have been redeemed etc.
:type tag: str
Various constraints apply:
* You need to either select a quota or an item
* If you select an item that has variations but do not select a variation, you cannot set block_quota
"""
PRICE_MODES = (
('none', _('No effect')),
('set', _('Set product price to')),
('subtract', _('Subtract from product price')),
('percent', _('Reduce product price by (%)')),
)
event = models.ForeignKey(
Event,
on_delete=models.CASCADE,
related_name="vouchers",
verbose_name=_("Event"),
)
code = models.CharField(
verbose_name=_("Voucher code"),
max_length=255, default=generate_code,
db_index=True,
)
max_usages = models.PositiveIntegerField(
verbose_name=_("Maximum usages"),
help_text=_("Number of times this voucher can be redeemed."),
default=1
)
redeemed = models.PositiveIntegerField(
verbose_name=_("Redeemed"),
default=0
)
valid_until = models.DateTimeField(
blank=True, null=True, db_index=True,
verbose_name=_("Valid until")
)
block_quota = models.BooleanField(
default=False,
verbose_name=_("Reserve ticket from quota"),
help_text=_(
"If activated, this voucher will be substracted from the affected product\'s quotas, such that it is "
"guaranteed that anyone with this voucher code does receive a ticket."
)
)
allow_ignore_quota = models.BooleanField(
default=False,
verbose_name=_("Allow to bypass quota"),
help_text=_(
"If activated, a holder of this voucher code can buy tickets, even if there are none left."
)
)
price_mode = models.CharField(
verbose_name=_("Price mode"),
max_length=100,
choices=PRICE_MODES,
default='none'
)
value = models.DecimalField(
verbose_name=_("Voucher value"),
decimal_places=2, max_digits=10, null=True, blank=True,
)
item = models.ForeignKey(
Item, related_name='vouchers',
verbose_name=_("Product"),
null=True, blank=True,
help_text=_(
"This product is added to the user's cart if the voucher is redeemed."
)
)
variation = models.ForeignKey(
ItemVariation, related_name='vouchers',
null=True, blank=True,
verbose_name=_("Product variation"),
help_text=_(
"This variation of the product select above is being used."
)
)
quota = models.ForeignKey(
Quota, related_name='quota',
null=True, blank=True,
verbose_name=_("Quota"),
help_text=_(
"If enabled, the voucher is valid for any product affected by this quota."
)
)
tag = models.CharField(
max_length=255,
verbose_name=_("Tag"),
blank=True,
db_index=True,
help_text=_("You can use this field to group multiple vouchers together. If you enter the same value for "
"multiple vouchers, you can get statistics on how many of them have been redeemed etc.")
)
comment = models.TextField(
blank=True, verbose_name=_("Comment"),
help_text=_("The text entered in this field will not be visible to the user and is available for your "
"convenience.")
)
class Meta:
verbose_name = _("Voucher")
verbose_name_plural = _("Vouchers")
unique_together = (("event", "code"),)
def __str__(self):
return self.code
def clean(self):
super().clean()
if self.quota:
if self.item:
raise ValidationError(_('You cannot select a quota and a specific product at the same time.'))
elif self.item:
if self.variation and (not self.item or not self.item.has_variations):
raise ValidationError(_('You cannot select a variation without having selected a product that provides '
'variations.'))
if self.variation and not self.item.variations.filter(pk=self.variation.pk).exists():
raise ValidationError(_('This variation does not belong to this product.'))
if self.item.has_variations and not self.variation and self.block_quota:
raise ValidationError(_('You can only block quota if you specify a specific product variation. '
'Otherwise it might be unclear which quotas to block.'))
else:
raise ValidationError(_('You need to specify either a quota or a product.'))
def save(self, *args, **kwargs):
self.code = self.code.upper()
super().save(*args, **kwargs)
self.event.get_cache().set('vouchers_exist', True)
def delete(self, using=None, keep_parents=False):
super().delete(using, keep_parents)
self.event.get_cache().delete('vouchers_exist')
def is_in_cart(self) -> bool:
"""
Returns whether a cart position exists that uses this voucher.
"""
return self.cartposition_set.exists()
def is_ordered(self) -> bool:
"""
Returns whether an order position exists that uses this voucher.
"""
return self.orderposition_set.exists()
def applies_to(self, item: Item, variation: ItemVariation=None) -> bool:
"""
Returns whether this voucher applies to a given item (and optionally
a variation).
"""
if self.quota_id:
return item.quotas.filter(pk=self.quota_id).exists()
if self.item_id and not self.variation_id:
return self.item_id == item.pk
return (self.item_id == item.pk) and (variation and self.variation_id == variation.pk)
def is_active(self):
"""
Returns True if a voucher has not yet been redeemed, but is still
within its validity (if valid_until is set).
"""
if self.redeemed >= self.max_usages:
return False
if self.valid_until and self.valid_until < now():
return False
return True
def calculate_price(self, original_price: Decimal) -> Decimal:
"""
Returns how the price given in original_price would be modified if this
voucher is applied, i.e. replaced by a different price or reduced by a
certain percentage. If the voucher does not modify the price, the
original price will be returned.
"""
if self.value is not None:
if self.price_mode == 'set':
return self.value
elif self.price_mode == 'subtract':
return original_price - self.value
elif self.price_mode == 'percent':
return round_decimal(original_price * (Decimal('100.00') - self.value) / Decimal('100.00'))
return original_price