wip

src/pretix/base/models/items.py

@@ -34,6 +34,7 @@
 # License for the specific language governing permissions and limitations under the License.
 
 import calendar
+import functools
 import os
 import sys
 import uuid
@@ -41,6 +42,7 @@ import warnings
 from collections import Counter, OrderedDict, defaultdict
 from datetime import date, datetime, time, timedelta
 from decimal import Decimal, DecimalException
+from itertools import groupby
 from typing import Optional, Tuple
 from zoneinfo import ZoneInfo
 
@@ -142,14 +144,22 @@ class ItemCategory(LoggedModel):
         verbose_name_plural = _("Product categories")
         ordering = ('position', 'id')
 
-    def cross_sell_visible(self, cart, event, sales_channel):
+    def cross_sell_visible(self, cart, sales_channel):
+        """
+        If this category should be visible in the cross-selling step for a given cart and sales_channel, this method
+        returns a dict describing the items that should be displayed.
+
+        :returns: dict {item: (max_count, discount_rule)}
+            max_count is None if the item should not be limited
+            discount_rule is None if the item will not be discounted
+        """
         if self.cross_selling_mode is None:
             return []
         if self.cross_selling_condition == 'always':
-            return self.items.all()
+            return {item: (None, None) for item in self.items.all()}
         if self.cross_selling_condition == 'products':
             match = set(match.pk for match in self.cross_selling_match_products.only('pk')) # TODO prefetch this
-            return self.items.all() if any(pos.item.pk in match for pos in cart) else []
+            return {item: (None, None) for item in self.items.all()} if any(pos.item.pk in match for pos in cart) else []
         if self.cross_selling_condition == 'discounts':
             # aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrgggghhhhhh
 
@@ -157,7 +167,7 @@ class ItemCategory(LoggedModel):
 
             potential_discounts_dict = defaultdict(list)
             discount_results = apply_discounts(
-                event,
+                self.event,
                 sales_channel,
                 [
                     (cp.item_id, cp.subevent_id, cp.line_price_gross, bool(cp.addon_to), cp.is_bundled,
@@ -167,10 +177,38 @@ class ItemCategory(LoggedModel):
                 collect_potential_discounts=potential_discounts_dict
             )
             print("potential_discounts_dict", potential_discounts_dict)
-            potential_discounts = {info for lst in potential_discounts_dict.values() for info in lst}
-            # TODO sum up the max_counts and pass them on (also pass on the discount_rules so we can calculate actual discounted prices later)
-            potential_discount_items = {item.pk for (discount_rule, max_count, i) in potential_discounts for item in discount_rule.benefit_limit_products.all()}
-            return self.items.filter(pk__in=potential_discount_items)
+            potential_discount_infos = dict.fromkeys(info for lst in potential_discounts_dict.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
+
+            grouped_by_item = [
+                (item, list(infos_for_item)) for item, infos_for_item in
+                groupby(
+                    sorted(
+                        (
+                            (item, discount_rule, max_count, i)
+                            for (discount_rule, max_count, i) in potential_discount_infos.keys()
+                            for item in discount_rule.benefit_limit_products.all()
+                        ),
+                        key=lambda tup: tup[0].pk
+                    ),
+                    lambda tup: tup[0])
+            ]
+
+            def sum_or_none(iter):
+                return functools.reduce(lambda x,y: None if x is None or y is None else x + y, iter, 0)
+
+            my_item_pks = self.items.values_list('pk', flat=True)
+            print("grouped:",grouped_by_item)
+            potential_discount_items = {item: (sum_or_none(max_count for (item, discount_rule, max_count, i) in infos_for_item), next(discount_rule for (item, discount_rule, max_count, i) in infos_for_item))
+                                        for item, infos_for_item in grouped_by_item
+                                        if item.pk in my_item_pks}
+
+            #potential_discount_items = {item.pk for (discount_rule, max_count, i) in potential_discount_infos.keys() for item in discount_rule.benefit_limit_products.all()}
+            return potential_discount_items
 
     def __str__(self):
         name = self.internal_name or self.name

src/pretix/base/services/pricing.py

@@ -186,6 +186,8 @@ def apply_discounts(event: Event, sales_channel: str,
         }, collect_potential_discounts)
         for k in result.keys():
             result[k] = (result[k], discount)
+        if collect_potential_discounts is not None:
+            print("   ->",collect_potential_discounts)
         new_prices.update(result)
 
     return [new_prices.get(idx, (p[2], None)) for idx, p in enumerate(positions)]

src/pretix/presale/checkoutflow.py

@@ -55,6 +55,7 @@ from django.utils.translation import (
 from django.views.generic.base import TemplateResponseMixin
 from django_scopes import scopes_disabled
 
+from pretix.base.decimal import round_decimal
 from pretix.base.models import Customer, Membership, Order
 from pretix.base.models.items import Question
 from pretix.base.models.orders import (
@@ -500,7 +501,7 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
         return [
             (c, products) for (c, products) in
             (
-                (c, c.cross_sell_visible(cart, self.request.event, self.request.sales_channel.identifier))
+                (c, c.cross_sell_visible(cart, self.request.sales_channel.identifier))
                 for c in self.request.event.categories.filter(cross_selling_mode__isnull=False)
             )
             if len(products) > 0
@@ -639,13 +640,13 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
                 for (category, items) in self.cross_selling_applicable_categories
             ]
 
-    def _items_for_cross_selling(self, subevent, items):
+    def _items_for_cross_selling(self, subevent, cross_sell_item_info):
         items, _btn = get_grouped_items(
             self.request.event,
             subevent=subevent,
             voucher=None,
             channel=self.request.sales_channel.identifier,
-            base_qs=items,
+            base_qs=cross_sell_item_info.keys(),
             allow_addons=True,
             allow_cross_sell=True,
             memberships=(
@@ -656,8 +657,24 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
                 if self.request.customer else None
             ),
         )
-        # TODO calculate discounted price
-        # TODO set item.order_max for benefit_only_apply_to_cheapest_n_matches discounted items
+
+        for item in items:
+            (max_count, discount_rule) = cross_sell_item_info[item]
+
+            # set item.order_max for benefit_only_apply_to_cheapest_n_matches discounted items
+            if max_count:
+                item.order_max = min(item.order_max, max_count)
+
+            # calculate discounted price
+            if discount_rule:
+                item.original_price = item.original_price or item.display_price
+                previous_price = item.display_price
+                new_price = round_decimal(
+                    previous_price * (Decimal('100.00') - discount_rule.benefit_discount_matching_percent) / Decimal('100.00'),
+                    self.event.currency,
+                )
+                item.display_price = new_price
+
         return items
 
     def get_context_data(self, **kwargs):