Files
pretix_cgo/src/pretix/base/services/cross_selling.py
Raphael Michel 0259899e00 Discount: Respect addon grouping in line selection (Z#23220058) (#5782)
* Discount: Respect addon grouping in line selection (Z#23220058)

* Update src/pretix/base/models/discount.py

Co-authored-by: Richard Schreiber <schreiber@pretix.eu>

---------

Co-authored-by: Richard Schreiber <schreiber@pretix.eu>
2026-01-16 15:23:59 +01:00

236 lines
11 KiB
Python

#
# This file is part of pretix (Community Edition).
#
# Copyright (C) 2014-2020 Raphael Michel and contributors
# Copyright (C) 2020-today pretix GmbH and contributors
#
# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
# Public License as published by the Free Software Foundation in version 3 of the License.
#
# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
# this file, see <https://pretix.eu/about/en/license>.
#
# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along with this program. If not, see
# <https://www.gnu.org/licenses/>.
#
from collections import defaultdict
from decimal import Decimal
from itertools import groupby
from math import inf
from typing import List
from django.utils.functional import cached_property
from pretix.base.models import CartPosition, ItemCategory, SalesChannel
from pretix.presale.views.event import get_grouped_items
class DummyCategory:
"""
Used to create fake category objects for displaying the same cross-selling category multiple times,
once for each subevent
"""
def __init__(self, category: ItemCategory, subevent):
self.id = category.id
self.name = str(category.name)
self.subevent_name = str(subevent)
self.description = category.description
class CrossSellingService:
def __init__(self, event, sales_channel: SalesChannel, cartpositions: List[CartPosition], customer):
self.event = event
self.sales_channel = sales_channel
self.cartpositions = cartpositions
self.customer = customer
def get_data(self):
if self.event.has_subevents:
subevents = set(pos.subevent for pos in self.cartpositions)
result = (
(DummyCategory(category, subevent),
self._prepare_items(subevent, items_qs, discount_info),
f'subevent_{subevent.pk}_')
for subevent in subevents
for (category, items_qs, discount_info) in self._applicable_categories(subevent.pk)
)
else:
result = (
(category,
self._prepare_items(None, items_qs, discount_info),
'')
for (category, items_qs, discount_info) in self._applicable_categories(0)
)
result = [(category, items, form_prefix) for (category, items, form_prefix) in result if len(items) > 0]
for category, items, form_prefix in result:
category.category_has_discount = any(item.original_price or (
item.has_variations and any(var.original_price for var in item.available_variations)
) for item in items)
return result
def _applicable_categories(self, subevent_id):
return [
(c, products_qs, discount_info) for (c, products_qs, discount_info) in
(
(c, *self._get_visible_items_for_category(subevent_id, c))
for c in self.event.categories.filter(cross_selling_mode__isnull=False).prefetch_related('items')
)
if products_qs is not None
]
def _get_visible_items_for_category(self, filter_subevent_id, category: ItemCategory):
"""
If this category should be visible in the cross-selling step for a given cart and sales_channel, this method
returns a queryset of the items that should be displayed, as well as a dict giving additional information on them.
:returns: (QuerySet<Item>, dict<(subevent_id, item_pk): (max_count, discount_rule)>)
max_count is `inf` if the item should not be limited
discount_rule is None if the item will not be discounted
"""
if category.cross_selling_mode is None:
return None, {}
if category.cross_selling_condition == 'always':
return category.items.all(), {}
if category.cross_selling_condition == 'products':
match = set(match.pk for match in category.cross_selling_match_products.only('pk')) # TODO prefetch this
return (category.items.all(), {}) if any(pos.item.pk in match for pos in self.cartpositions) else (None, {})
if category.cross_selling_condition == 'discounts':
my_item_pks = [item.id for item in category.items.all()]
potential_discount_items = {
item.pk: (max_count, discount_rule)
for subevent_id, item, max_count, discount_rule in self._potential_discounts_by_subevent_and_item_for_current_cart
if max_count > 0 and item.pk in my_item_pks and item.is_available() and (subevent_id == filter_subevent_id or subevent_id is None)
}
return category.items.filter(pk__in=potential_discount_items), potential_discount_items
@cached_property
def _potential_discounts_by_subevent_and_item_for_current_cart(self):
potential_discounts_by_cartpos = defaultdict(list)
from ..services.pricing import apply_discounts
self._discounted_prices = apply_discounts(
self.event,
self.sales_channel,
[
(cp.item_id, cp.subevent_id, cp.subevent.date_from if cp.subevent_id else None, cp.line_price_gross,
cp.addon_to, cp.is_bundled,
cp.listed_price - cp.price_after_voucher)
for cp in self.cartpositions
],
collect_potential_discounts=potential_discounts_by_cartpos
)
# flatten potential_discounts_by_cartpos (a dict of lists of potential discounts) into a set of potential discounts
# (which is technically stored as a dict, but we use it as an OrderedSet here)
potential_discount_set = dict.fromkeys(
info for lst in potential_discounts_by_cartpos.values() for info in lst)
# sum up the max_counts and pass them on (also pass on the discount_rules so we can calculate actual discounted prices later):
# group by benefit product
# - max_count for product: sum up max_counts
# - discount_rule for product: take first discount_rule
def discount_info(subevent_id, item, infos_for_item):
infos_for_item = list(infos_for_item)
return (
subevent_id,
item,
sum(max_count for (subevent_id, item, discount_rule, max_count, i) in infos_for_item),
next(discount_rule for (subevent_id, item, discount_rule, max_count, i) in infos_for_item),
)
return [
discount_info(subevent_id, item, infos_for_item) for (subevent_id, item), infos_for_item in
groupby(
sorted(
(
(subevent_id, item, discount_rule, max_count, i)
for (discount_rule, max_count, i, subevent_id) in potential_discount_set.keys()
for item in discount_rule.benefit_limit_products.all()
),
key=lambda tup: (tup[0], tup[1].pk)
),
lambda tup: (tup[0], tup[1]))
]
def _prepare_items(self, subevent, items_qs, discount_info):
items, _btn = get_grouped_items(
self.event,
subevent=subevent,
voucher=None,
channel=self.sales_channel,
base_qs=items_qs,
allow_addons=False,
allow_cross_sell=True,
memberships=(
self.customer.usable_memberships(
for_event=subevent or self.event,
testmode=self.event.testmode
)
if self.customer else None
),
)
new_items = list()
for item in items:
max_count = inf
if item.pk in discount_info:
(max_count, discount_rule) = discount_info[item.pk]
# only benefit_only_apply_to_cheapest_n_matches discounted items have a max_count, all others get 'inf'
if not max_count:
max_count = inf
# calculate discounted price
if discount_rule and discount_rule.benefit_discount_matching_percent > 0:
if not item.has_variations:
item.original_price = item.original_price or item.display_price
previous_price = item.display_price
new_price = (
previous_price * (
(Decimal('100.00') - discount_rule.benefit_discount_matching_percent) / Decimal('100.00'))
)
item.display_price = new_price
else:
# discounts always match "whole" items, not specific variations -> we apply the discount to all
# available variations of the item
for var in item.available_variations:
var.original_price = var.original_price or var.display_price
previous_price = var.display_price
new_price = (
previous_price * (
(Decimal('100.00') - discount_rule.benefit_discount_matching_percent) / Decimal('100.00'))
)
var.display_price = new_price
if not item.has_variations:
# reduce order_max by number of items already in cart (prevent recommending a product the user can't add anyway)
item.order_max = min(
item.order_max - sum(1 for pos in self.cartpositions if pos.item_id == item.pk),
max_count
)
if item.order_max > 0:
new_items.append(item)
else:
new_vars = list()
for var in item.available_variations:
# reduce order_max by number of items already in cart (prevent recommending a product the user can't add anyway)
var.order_max = min(
var.order_max - sum(1 for pos in self.cartpositions if pos.item_id == item.pk and pos.variation_id == var.pk),
max_count
)
if var.order_max > 0:
new_vars.append(var)
if len(new_vars):
item.available_variations = new_vars
new_items.append(item)
return new_items