Discounts (#2510)

src/pretix/api/serializers/cart.py

@@ -37,9 +37,15 @@ from pretix.base.models import Quota, Seat
 from pretix.base.models.orders import CartPosition
 
 
+class TaxIncludedField(serializers.Field):
+    def to_representation(self, instance: CartPosition):
+        return not instance.custom_price_input_is_net
+
+
 class CartPositionSerializer(I18nAwareModelSerializer):
     answers = AnswerSerializer(many=True)
     seat = InlineSeatSerializer()
+    includes_tax = TaxIncludedField(source='*')
 
     class Meta:
         model = CartPosition
@@ -54,6 +60,7 @@ class CartPositionCreateSerializer(I18nAwareModelSerializer):
     attendee_name = serializers.CharField(required=False, allow_null=True)
     seat = serializers.CharField(required=False, allow_null=True)
     sales_channel = serializers.CharField(required=False, default='sales_channel')
+    includes_tax = serializers.BooleanField(required=False, allow_null=True)
 
     class Meta:
         model = CartPosition
@@ -127,6 +134,9 @@ class CartPositionCreateSerializer(I18nAwareModelSerializer):
             raise ValidationError('The specified product requires to choose a seat.')
 
         validated_data.pop('sales_channel')
+        validated_data['custom_price_input'] = validated_data['price']  # todo: does this make sense?
+        # todo: listed price, etc?
+        validated_data['custom_price_input_is_net'] = validated_data.pop('includes_tax')
         cp = CartPosition.objects.create(event=self.context['event'], **validated_data)
 
         for answ_data in answers_data:

src/pretix/api/serializers/discount.py

@@ -0,0 +1,49 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io 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 pretix.api.serializers.i18n import I18nAwareModelSerializer
+from pretix.base.models import Discount
+
+
+class DiscountSerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = Discount
+        fields = ('id', 'active', 'internal_name', 'position', 'sales_channels', 'available_from',
+                  'available_until', 'subevent_mode', 'condition_all_products', 'condition_limit_products',
+                  'condition_apply_to_addons', 'condition_min_count', 'condition_min_value',
+                  'benefit_discount_matching_percent', 'benefit_only_apply_to_cheapest_n_matches',
+                  'condition_ignore_voucher_discounted')
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['condition_limit_products'].queryset = self.context['event'].items.all()
+
+    def validate(self, data):
+        data = super().validate(data)
+
+        full_data = self.to_internal_value(self.to_representation(self.instance)) if self.instance else {}
+        full_data.update(data)
+
+        Discount.validate_config(full_data)
+
+        return data

src/pretix/api/serializers/order.py

@@ -56,7 +56,9 @@ from pretix.base.models.orders import (
 from pretix.base.pdf import get_images, get_variables
 from pretix.base.services.cart import error_messages
 from pretix.base.services.locking import NoLockManager
-from pretix.base.services.pricing import get_price
+from pretix.base.services.pricing import (
+    apply_discounts, get_line_price, get_listed_price, is_included_for_free,
+)
 from pretix.base.settings import COUNTRIES_WITH_STATE_IN_ADDRESS
 from pretix.base.signals import register_ticket_outputs
 from pretix.multidomain.urlreverse import build_absolute_uri
@@ -1040,29 +1042,18 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
 
                     if v.budget is not None:
                         price = pos_data.get('price')
+                        listed_price = get_listed_price(pos_data.get('item'), pos_data.get('variation'), pos_data.get('subevent'))
+
+                        if pos_data.get('voucher'):
+                            price_after_voucher = pos_data.get('voucher').calculate_price(listed_price)
+                        else:
+                            price_after_voucher = listed_price
                         if price is None:
-                            price = get_price(
-                                item=pos_data.get('item'),
-                                variation=pos_data.get('variation'),
-                                voucher=v,
-                                custom_price=None,
-                                subevent=pos_data.get('subevent'),
-                                addon_to=pos_data.get('addon_to'),
-                                invoice_address=ia,
-                            ).gross
-                        pbv = get_price(
-                            item=pos_data['item'],
-                            variation=pos_data.get('variation'),
-                            voucher=None,
-                            custom_price=None,
-                            subevent=pos_data.get('subevent'),
-                            addon_to=pos_data.get('addon_to'),
-                            invoice_address=ia,
-                        )
+                            price = price_after_voucher
 
                         if v not in v_budget:
                             v_budget[v] = v.budget - v.budget_used()
-                        disc = pbv.gross - price
+                        disc = max(listed_price - price, 0)
                         if disc > v_budget[v]:
                             new_disc = v_budget[v]
                             v_budget[v] -= new_disc
@@ -1158,52 +1149,85 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                     order.invoice_address = ia
                     ia.last_modified = now()
 
+            # Generate position objects
             pos_map = {}
             for pos_data in positions_data:
-                answers_data = pos_data.pop('answers', [])
                 addon_to = pos_data.pop('addon_to', None)
                 attendee_name = pos_data.pop('attendee_name', '')
                 if attendee_name and not pos_data.get('attendee_name_parts'):
                     pos_data['attendee_name_parts'] = {
                         '_legacy': attendee_name
                     }
-                pos = OrderPosition(**pos_data)
+                pos = OrderPosition(**{k: v for k, v in pos_data.items() if k != 'answers'})
                 if simulate:
                     pos.order = order._wrapped
                 else:
                     pos.order = order
                 if addon_to:
                     if simulate:
-                        pos.addon_to = pos_map[addon_to]._wrapped
+                        pos.addon_to = pos_map[addon_to]
                     else:
                         pos.addon_to = pos_map[addon_to]
 
-                if pos.price is None:
-                    price = get_price(
-                        item=pos.item,
-                        variation=pos.variation,
-                        voucher=pos.voucher,
-                        custom_price=None,
-                        subevent=pos.subevent,
-                        addon_to=pos.addon_to,
-                        invoice_address=ia,
-                    )
-                    pos.price = price.gross
-                    pos.tax_rate = price.rate
-                    pos.tax_value = price.tax
-                    pos.tax_rule = pos.item.tax_rule
-                else:
-                    pos._calculate_tax()
+                pos_map[pos.positionid] = pos
+                pos_data['__instance'] = pos
 
-                pos.price_before_voucher = get_price(
-                    item=pos.item,
-                    variation=pos.variation,
-                    voucher=None,
-                    custom_price=None,
-                    subevent=pos.subevent,
-                    addon_to=pos.addon_to,
-                    invoice_address=ia,
-                ).gross
+            # Calculate prices if not set
+            for pos_data in positions_data:
+                pos = pos_data['__instance']
+                if pos.addon_to_id and is_included_for_free(pos.item, pos.addon_to):
+                    listed_price = Decimal('0.00')
+                else:
+                    listed_price = get_listed_price(pos.item, pos.variation, pos.subevent)
+
+                if pos.price is None:
+                    if pos.voucher:
+                        price_after_voucher = pos.voucher.calculate_price(listed_price)
+                    else:
+                        price_after_voucher = listed_price
+
+                    line_price = get_line_price(
+                        price_after_voucher=price_after_voucher,
+                        custom_price_input=None,
+                        custom_price_input_is_net=False,
+                        tax_rule=pos.item.tax_rule,
+                        invoice_address=ia,
+                        bundled_sum=Decimal('0.00'),
+                    )
+                    pos.price = line_price.gross
+                    pos._auto_generated_price = True
+                else:
+                    if pos.voucher:
+                        if not pos.item.tax_rule or pos.item.tax_rule.price_includes_tax:
+                            price_after_voucher = max(pos.price, pos.voucher.calculate_price(listed_price))
+                        else:
+                            price_after_voucher = max(pos.price - pos.tax_value, pos.voucher.calculate_price(listed_price))
+                    else:
+                        price_after_voucher = listed_price
+                    pos._auto_generated_price = False
+                pos._voucher_discount = listed_price - price_after_voucher
+                if pos.voucher:
+                    pos.voucher_budget_use = max(listed_price - price_after_voucher, Decimal('0.00'))
+
+            order_positions = [pos_data['__instance'] for pos_data in positions_data]
+            discount_results = apply_discounts(
+                self.context['event'],
+                order.sales_channel,
+                [
+                    (cp.item_id, cp.subevent_id, cp.price, bool(cp.addon_to), cp.is_bundled, pos._voucher_discount)
+                    for cp in order_positions
+                ]
+            )
+            for cp, (new_price, discount) in zip(order_positions, discount_results):
+                if new_price != pos.price and pos._auto_generated_price:
+                    pos.price = new_price
+                pos.discount = discount
+
+            # Save instances
+            for pos_data in positions_data:
+                answers_data = pos_data.pop('answers', [])
+                pos = pos_data['__instance']
+                pos._calculate_tax()
 
                 if simulate:
                     pos = WrappedModel(pos)
@@ -1216,6 +1240,7 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                         answers.append(answ)
                     pos.answers = answers
                     pos.pseudonymization_id = "PREVIEW"
+                    pos_map[pos.positionid] = pos
                 else:
                     if pos.voucher:
                         Voucher.objects.filter(pk=pos.voucher.pk).update(redeemed=F('redeemed') + 1)
@@ -1238,7 +1263,6 @@ class OrderCreateSerializer(I18nAwareModelSerializer):
                         else:
                             answ = pos.answers.create(**answ_data)
                             answ.options.add(*options)
-                pos_map[pos.positionid] = pos
 
             if not simulate:
                 for cp in delete_cps:

src/pretix/api/urls.py

@@ -41,8 +41,8 @@ from rest_framework import routers
 from pretix.api.views import cart
 
 from .views import (
-    checkin, device, event, exporters, item, oauth, order, organizer, upload,
-    user, version, voucher, waitinglist, webhooks,
+    checkin, device, discount, event, exporters, item, oauth, order, organizer,
+    upload, user, version, voucher, waitinglist, webhooks,
 )
 
 router = routers.DefaultRouter()
@@ -72,6 +72,7 @@ event_router.register(r'clone', event.CloneEventViewSet)
 event_router.register(r'items', item.ItemViewSet)
 event_router.register(r'categories', item.ItemCategoryViewSet)
 event_router.register(r'questions', item.QuestionViewSet)
+event_router.register(r'discounts', discount.DiscountViewSet)
 event_router.register(r'quotas', item.QuotaViewSet)
 event_router.register(r'vouchers', voucher.VoucherViewSet)
 event_router.register(r'orders', order.OrderViewSet)

src/pretix/api/views/discount.py

@@ -0,0 +1,99 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io 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/>.
+#
+
+# This file is based on an earlier version of pretix which was released under the Apache License 2.0. The full text of
+# the Apache License 2.0 can be obtained at <http://www.apache.org/licenses/LICENSE-2.0>.
+#
+# This file may have since been changed and any changes are released under the terms of AGPLv3 as described above. A
+# full history of changes and contributors is available at <https://github.com/pretix/pretix>.
+#
+# This file contains Apache-licensed contributions copyrighted by: Ture Gjørup
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the Apache License 2.0 is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under the License.
+
+from django_filters.rest_framework import DjangoFilterBackend, FilterSet
+from django_scopes import scopes_disabled
+from rest_framework import viewsets
+from rest_framework.exceptions import PermissionDenied
+from rest_framework.filters import OrderingFilter
+
+from pretix.api.serializers.discount import DiscountSerializer
+from pretix.api.views import ConditionalListView
+from pretix.base.models import CartPosition, Discount
+
+with scopes_disabled():
+    class DiscountFilter(FilterSet):
+        class Meta:
+            model = Discount
+            fields = ['active']
+
+
+class DiscountViewSet(ConditionalListView, viewsets.ModelViewSet):
+    serializer_class = DiscountSerializer
+    queryset = Discount.objects.none()
+    filter_backends = (DjangoFilterBackend, OrderingFilter)
+    filterset_class = DiscountFilter
+    ordering_fields = ('id', 'position')
+    ordering = ('position', 'id')
+    permission = None
+    write_permission = 'can_change_items'
+
+    def get_queryset(self):
+        return self.request.event.discounts.all()
+
+    def perform_create(self, serializer):
+        serializer.save(event=self.request.event)
+        serializer.instance.log_action(
+            'pretix.event.discount.added',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=self.request.data
+        )
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['event'] = self.request.event
+        return ctx
+
+    def perform_update(self, serializer):
+        serializer.save(event=self.request.event)
+        serializer.instance.log_action(
+            'pretix.event.discount.changed',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=self.request.data
+        )
+
+    def perform_destroy(self, instance):
+        if not instance.allow_delete():
+            raise PermissionDenied('You cannot delete this discount because it already has '
+                                   'been used as part of an order.')
+
+        instance.log_action(
+            'pretix.event.discount.deleted',
+            user=self.request.user,
+            auth=self.request.auth,
+        )
+        CartPosition.objects.filter(discount=instance).update(discount=None)
+        super().perform_destroy(instance)

src/pretix/base/channels.py

@@ -89,6 +89,13 @@ class SalesChannel:
         """
         return True
 
+    @property
+    def discounts_supported(self) -> bool:
+        """
+        If this property is ``True``, this sales channel can be selected for automatic discounts.
+        """
+        return True
+
 
 def get_all_sales_channels():
     global _ALL_CHANNELS

src/pretix/base/migrations/0210_auto_20220303_2017.py

@@ -0,0 +1,89 @@
+# Generated by Django 3.2.2 on 2022-03-03 20:17
+
+from decimal import Decimal
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+import pretix.base.models.base
+import pretix.base.models.fields
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0209_device_info'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='cartposition',
+            name='custom_price_input',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='custom_price_input_is_net',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='line_price_gross',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='listed_price',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='price_after_voucher',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='tax_rate',
+            field=models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=7),
+        ),
+        migrations.CreateModel(
+            name='Discount',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('active', models.BooleanField(default=True)),
+                ('internal_name', models.CharField(max_length=255)),
+                ('position', models.PositiveIntegerField(default=0)),
+                ('sales_channels', pretix.base.models.fields.MultiStringField(default=['web'])),
+                ('available_from', models.DateTimeField(blank=True, null=True)),
+                ('available_until', models.DateTimeField(blank=True, null=True)),
+                ('subevent_mode', models.CharField(max_length=50, default='mixed')),
+                ('condition_all_products', models.BooleanField(default=True)),
+                ('condition_min_count', models.PositiveIntegerField(default=0)),
+                ('condition_min_value', models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=10)),
+                ('benefit_discount_matching_percent', models.DecimalField(decimal_places=2, default=Decimal('0.00'), max_digits=10)),
+                ('benefit_only_apply_to_cheapest_n_matches', models.PositiveIntegerField(null=True)),
+                ('condition_limit_products', models.ManyToManyField(to='pretixbase.Item')),
+                ('condition_apply_to_addons', models.BooleanField(default=True)),
+                        ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='discounts', to='pretixbase.event')),
+            ],
+            options={
+                'abstract': False,
+            },
+            bases=(models.Model, pretix.base.models.base.LoggingMixin),
+        ),
+        migrations.AddField(
+            model_name='cartposition',
+            name='discount',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='pretixbase.discount'),
+        ),
+        migrations.AddField(
+            model_name='orderposition',
+            name='discount',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='pretixbase.discount'),
+        ),
+        migrations.AddField(
+            model_name='orderposition',
+            name='voucher_budget_use',
+            field=models.DecimalField(decimal_places=2, max_digits=10, null=True),
+        ),
+    ]

src/pretix/base/migrations/0211_auto_20220314_2001.py

@@ -0,0 +1,28 @@
+# Generated by Django 3.2.2 on 2022-03-14 20:01
+from decimal import Decimal
+
+from django.db import migrations
+from django.db.models import F
+from django.db.models.functions import Greatest
+
+
+def migrate_voucher_budget_use(apps, schema_editor):
+    OrderPosition = apps.get_model('pretixbase', 'OrderPosition')  # noqa
+    OrderPosition.all.filter(
+        price_before_voucher__isnull=False
+    ).exclude(price=F('price_before_voucher')).update(
+        voucher_budget_use=Greatest(F('price') - F('price_before_voucher'), Decimal('0.00'))
+    )
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('pretixbase', '0210_auto_20220303_2017'),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            migrate_voucher_budget_use,
+            migrations.RunPython.noop,
+        ),
+    ]

src/pretix/base/migrations/0212_auto_20220318_1408.py

@@ -0,0 +1,29 @@
+# Generated by Django 3.2.12 on 2022-03-18 14:08
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0211_auto_20220314_2001'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='includes_tax',
+        ),
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='override_tax_rate',
+        ),
+        migrations.RemoveField(
+            model_name='cartposition',
+            name='price_before_voucher',
+        ),
+        migrations.RemoveField(
+            model_name='orderposition',
+            name='price_before_voucher',
+        ),
+    ]

src/pretix/base/migrations/0213_discount_condition_ignore_voucher_discounted.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.2 on 2022-04-13 08:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0212_auto_20220318_1408'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='discount',
+            name='condition_ignore_voucher_discounted',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/models/__init__.py

@@ -25,6 +25,7 @@ from .base import CachedFile, LoggedModel, cachedfile_name
 from .checkin import Checkin, CheckinList
 from .customers import Customer
 from .devices import Device, Gate
+from .discount import Discount
 from .event import (
     Event, Event_SettingsStore, EventLock, EventMetaProperty, EventMetaValue,
     SubEvent, SubEventMetaValue, generate_invite_token,

src/pretix/base/models/discount.py

@@ -0,0 +1,368 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io 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 typing import Dict, Optional, Tuple
+
+from django.core.exceptions import ValidationError
+from django.core.validators import MinValueValidator
+from django.db import models
+from django.utils.translation import gettext_lazy as _, pgettext_lazy
+from django_scopes import ScopedManager
+
+from pretix.base.decimal import round_decimal
+from pretix.base.models import fields
+from pretix.base.models.base import LoggedModel
+
+
+class Discount(LoggedModel):
+    SUBEVENT_MODE_MIXED = 'mixed'
+    SUBEVENT_MODE_SAME = 'same'
+    SUBEVENT_MODE_DISTINCT = 'distinct'
+    SUBEVENT_MODE_CHOICES = (
+        (SUBEVENT_MODE_MIXED, pgettext_lazy('subevent', 'Dates can be mixed without limitation')),
+        (SUBEVENT_MODE_SAME, pgettext_lazy('subevent', 'All matching products must be for the same date')),
+        (SUBEVENT_MODE_DISTINCT, pgettext_lazy('subevent', 'Each matching product must be for a different date')),
+    )
+
+    event = models.ForeignKey(
+        'Event',
+        on_delete=models.CASCADE,
+        related_name='discounts',
+    )
+    active = models.BooleanField(
+        verbose_name=_("Active"),
+        default=True,
+    )
+    internal_name = models.CharField(
+        verbose_name=_("Internal name"),
+        max_length=255
+    )
+    position = models.PositiveIntegerField(
+        default=0,
+        verbose_name=_("Position")
+    )
+    sales_channels = fields.MultiStringField(
+        verbose_name=_('Sales channels'),
+        default=['web'],
+        blank=False,
+    )
+
+    available_from = models.DateTimeField(
+        verbose_name=_("Available from"),
+        null=True,
+        blank=True,
+    )
+    available_until = models.DateTimeField(
+        verbose_name=_("Available until"),
+        null=True,
+        blank=True,
+    )
+
+    subevent_mode = models.CharField(
+        verbose_name=_('Event series handling'),
+        max_length=50,
+        default=SUBEVENT_MODE_MIXED,
+        choices=SUBEVENT_MODE_CHOICES,
+    )
+
+    condition_all_products = models.BooleanField(
+        default=True,
+        verbose_name=_("Apply to all products (including newly created ones)")
+    )
+    condition_limit_products = models.ManyToManyField(
+        'Item',
+        verbose_name=_("Apply to specific products"),
+        blank=True
+    )
+    condition_apply_to_addons = models.BooleanField(
+        default=True,
+        verbose_name=_("Apply to add-on products"),
+        help_text=_("Discounts never apply to bundled products"),
+    )
+    condition_ignore_voucher_discounted = models.BooleanField(
+        default=False,
+        verbose_name=_("Ignore products discounted by a voucher"),
+        help_text=_("If this option is checked, products that already received a discount through a voucher will not "
+                    "be considered for this discount. However, products that use a voucher only to e.g. unlock a "
+                    "hidden product or gain access to sold-out quota will still receive the discount."),
+    )
+    condition_min_count = models.PositiveIntegerField(
+        verbose_name=_('Minimum number of matching products'),
+        default=0,
+    )
+    condition_min_value = models.DecimalField(
+        verbose_name=_('Minimum gross value of matching products'),
+        decimal_places=2,
+        max_digits=10,
+        default=Decimal('0.00'),
+    )
+
+    benefit_discount_matching_percent = models.DecimalField(
+        verbose_name=_('Percentual discount on matching products'),
+        decimal_places=2,
+        max_digits=10,
+        default=Decimal('0.00'),
+        validators=[MinValueValidator(Decimal('0.00'))],
+    )
+    benefit_only_apply_to_cheapest_n_matches = models.PositiveIntegerField(
+        verbose_name=_('Apply discount only to this number of matching products'),
+        help_text=_(
+            'This option allows you to create discounts of the type "buy X get Y reduced/for free". For example, if '
+            'you set "Minimum number of matching products" to four and this value to two, the customer\'s cart will be '
+            'split into grups of four tickets and  the cheapest two tickets within every group will be discounted. If '
+            'you want to grant the discount on all matching products, keep this field empty.'
+        ),
+        null=True,
+        blank=True,
+        validators=[MinValueValidator(1)],
+    )
+
+    # more feature ideas:
+    # - max_usages_per_order
+    # - promote_to_user_if_almost_satisfied
+    # - require_customer_account
+
+    objects = ScopedManager(organizer='event__organizer')
+
+    class Meta:
+        ordering = ('position', 'id')
+
+    def __str__(self):
+        return self.internal_name
+
+    @property
+    def sortkey(self):
+        return self.position, self.id
+
+    def __lt__(self, other) -> bool:
+        return self.sortkey < other.sortkey
+
+    @classmethod
+    def validate_config(cls, data):
+        # We forbid a few combinations of settings, because we don't think they are neccessary and at the same
+        # time they introduce edge cases, in which it becomes almost impossible to compute the discount optimally
+        # and also very hard to understand for the user what is going on.
+        if data.get('condition_min_count') and data.get('condition_min_value'):
+            raise ValidationError(
+                _('You can either set a minimum number of matching products or a minimum value, not both.')
+            )
+
+        if not data.get('condition_min_count') and not data.get('condition_min_value'):
+            raise ValidationError(
+                _('You need to either set a minimum number of matching products or a minimum value.')
+            )
+
+        if data.get('condition_min_value') and data.get('benefit_only_apply_to_cheapest_n_matches'):
+            raise ValidationError(
+                _('You cannot apply the discount only to some of the matched products if you are matching '
+                  'on a minimum value.')
+            )
+
+        if data.get('subevent_mode') == cls.SUBEVENT_MODE_DISTINCT and data.get('condition_min_value'):
+            raise ValidationError(
+                _('You cannot apply the discount only to bookings of different dates if you are matching '
+                  'on a minimum value.')
+            )
+
+    def allow_delete(self):
+        return not self.orderposition_set.exists()
+
+    def clean(self):
+        super().clean()
+        Discount.validate_config({
+            'condition_min_count': self.condition_min_count,
+            'condition_min_value': self.condition_min_value,
+            'benefit_only_apply_to_cheapest_n_matches': self.benefit_only_apply_to_cheapest_n_matches,
+            'subevent_mode': self.subevent_mode,
+        })
+
+    def _apply_min_value(self, positions, idx_group, result):
+        if self.condition_min_value and sum(positions[idx][2] for idx in idx_group) < self.condition_min_value:
+            return
+
+        if self.condition_min_count or self.benefit_only_apply_to_cheapest_n_matches:
+            raise ValueError('Validation invariant violated.')
+
+        for idx in idx_group:
+            previous_price = positions[idx][2]
+            new_price = round_decimal(
+                previous_price * (Decimal('100.00') - self.benefit_discount_matching_percent) / Decimal('100.00'),
+                self.event.currency,
+            )
+            result[idx] = new_price
+
+    def _apply_min_count(self, positions, idx_group, result):
+        if len(idx_group) < self.condition_min_count:
+            return
+
+        if not self.condition_min_count or self.condition_min_value:
+            raise ValueError('Validation invariant violated.')
+
+        if self.benefit_only_apply_to_cheapest_n_matches:
+            if not self.condition_min_count:
+                raise ValueError('Validation invariant violated.')
+
+            idx_group = sorted(idx_group, key=lambda idx: (positions[idx][2], -idx))  # sort by line_price
+
+            # Prevent over-consuming of items, i.e. if our discount is "buy 2, get 1 free", we only
+            # want to match multiples of 3
+            consume_idx = idx_group[:len(idx_group) // self.condition_min_count * self.condition_min_count]
+            benefit_idx = idx_group[:len(idx_group) // self.condition_min_count * self.benefit_only_apply_to_cheapest_n_matches]
+        else:
+            consume_idx = idx_group
+            benefit_idx = idx_group
+
+        for idx in benefit_idx:
+            previous_price = positions[idx][2]
+            new_price = round_decimal(
+                previous_price * (Decimal('100.00') - self.benefit_discount_matching_percent) / Decimal('100.00'),
+                self.event.currency,
+            )
+            result[idx] = new_price
+
+        for idx in consume_idx:
+            result.setdefault(idx, positions[idx][2])
+
+    def apply(self, positions: Dict[int, Tuple[int, Optional[int], Decimal, bool, Decimal]]) -> Dict[int, Decimal]:
+        """
+        Tries to apply this discount to a cart
+
+        :param positions: Dictionary mapping IDs to tuples of the form
+                          ``(item_id, subevent_id, line_price_gross, is_addon_to, voucher_discount)``.
+                          Bundled positions may not be included.
+
+        :return: A dictionary mapping keys from the input dictionary to new prices. All positions
+                 contained in this dictionary are considered "consumed" and should not be considered
+                 by other discounts.
+        """
+        result = {}
+
+        if not self.active:
+            return result
+
+        limit_products = set()
+        if not self.condition_all_products:
+            limit_products = {p.pk for p in self.condition_limit_products.all()}
+
+        # First, filter out everything not even covered by our product scope
+        initial_candidates = [
+            idx
+            for idx, (item_id, subevent_id, line_price_gross, is_addon_to, voucher_discount) in positions.items()
+            if (
+                (self.condition_all_products or item_id in limit_products) and
+                (self.condition_apply_to_addons or not is_addon_to) and
+                (not self.condition_ignore_voucher_discounted or voucher_discount is None or voucher_discount == Decimal('0.00'))
+            )
+        ]
+
+        if self.subevent_mode == self.SUBEVENT_MODE_MIXED:  # also applies to non-series events
+            if self.condition_min_count:
+                self._apply_min_count(positions, initial_candidates, result)
+            else:
+                self._apply_min_value(positions, initial_candidates, result)
+
+        elif self.subevent_mode == self.SUBEVENT_MODE_SAME:
+            def key(idx):
+                return positions[idx][1]  # subevent_id
+
+            # Build groups of candidates with the same subevent, then apply our regular algorithm
+            # to each group
+
+            _groups = groupby(sorted(initial_candidates, key=key), key=key)
+            candidate_groups = [list(g) for k, g in _groups]
+
+            for g in candidate_groups:
+                if self.condition_min_count:
+                    self._apply_min_count(positions, g, result)
+                else:
+                    self._apply_min_value(positions, g, result)
+
+        elif self.subevent_mode == self.SUBEVENT_MODE_DISTINCT:
+            if self.condition_min_value:
+                raise ValueError('Validation invariant violated.')
+
+            # Build optimal groups of candidates with distinct subevents, then apply our regular algorithm
+            # to each group. Optimal, in this case, means:
+            # - First try to build as many groups of size condition_min_count as possible while trying to
+            #   balance out the cheapest products so that they are not all in the same group
+            # - Then add remaining positions to existing groups if possible
+            candidate_groups = []
+
+            # Build a list of subevent IDs in descending order of frequency
+            subevent_to_idx = defaultdict(list)
+            for idx, p in positions.items():
+                subevent_to_idx[p[1]].append(idx)
+            for v in subevent_to_idx.values():
+                v.sort(key=lambda idx: positions[idx][2])
+            subevent_order = sorted(list(subevent_to_idx.keys()), key=lambda s: len(subevent_to_idx[s]), reverse=True)
+
+            # Build groups of exactly condition_min_count distinct subevents
+            current_group = []
+            while True:
+                # Build a list of candidates, which is a list of all positions belonging to a subevent of the
+                # maximum cardinality, where the cardinality of a subevent is defined as the number of tickets
+                # for that subevent that are not yet part of any group
+                candidates = []
+                cardinality = None
+                for se, l in subevent_to_idx.items():
+                    l = [ll for ll in l if ll not in current_group]
+                    if cardinality and len(l) != cardinality:
+                        continue
+                    if se not in {positions[idx][1] for idx in current_group}:
+                        candidates += l
+                        cardinality = len(l)
+
+                if not candidates:
+                    break
+
+                # Sort the list by prices, then pick one. For "buy 2 get 1 free" we apply a "pick 1 from the start
+                # and 2 from the end" scheme to optimize price distribution among groups
+                candidates = sorted(candidates, key=lambda idx: positions[idx][2])
+                if len(current_group) < (self.benefit_only_apply_to_cheapest_n_matches or 0):
+                    candidate = candidates[0]
+                else:
+                    candidate = candidates[-1]
+
+                current_group.append(candidate)
+
+                # Only add full groups to the list of groups
+                if len(current_group) >= max(self.condition_min_count, 1):
+                    candidate_groups.append(current_group)
+                    for c in current_group:
+                        subevent_to_idx[positions[c][1]].remove(c)
+                    current_group = []
+
+            # Distribute "leftovers"
+            for se in subevent_order:
+                if subevent_to_idx[se]:
+                    for group in candidate_groups:
+                        if se not in {positions[idx][1] for idx in group}:
+                            group.append(subevent_to_idx[se].pop())
+                            if not subevent_to_idx[se]:
+                                break
+
+            for g in candidate_groups:
+                self._apply_min_count(positions, g, result)
+        return result

src/pretix/base/models/log.py

@@ -138,8 +138,8 @@ class LogEntry(models.Model):
     @cached_property
     def display_object(self):
         from . import (
-            Event, Item, ItemCategory, Order, Question, Quota, SubEvent,
-            TaxRule, Voucher,
+            Discount, Event, Item, ItemCategory, Order, Question, Quota,
+            SubEvent, TaxRule, Voucher,
         )
 
         try:
@@ -202,6 +202,16 @@ class LogEntry(models.Model):
                 }),
                 'val': escape(co.name),
             }
+        elif isinstance(co, Discount):
+            a_text = _('Discount {val}')
+            a_map = {
+                'href': reverse('control:event.items.discounts.edit', kwargs={
+                    'event': self.event.slug,
+                    'organizer': self.event.organizer.slug,
+                    'discount': co.id
+                }),
+                'val': escape(co.internal_name),
+            }
         elif isinstance(co, ItemCategory):
             a_text = _('Category {val}')
             a_map = {

src/pretix/base/models/orders.py

@@ -906,10 +906,10 @@ class Order(LockModel, LoggedModel):
                 if force:
                     continue
 
-                if op.voucher and op.voucher.budget is not None and op.price_before_voucher is not None:
+                if op.voucher and op.voucher.budget is not None and op.voucher_budget_use:
                     if op.voucher not in v_budget:
                         v_budget[op.voucher] = op.voucher.budget - op.voucher.budget_used()
-                    disc = op.price_before_voucher - op.price
+                    disc = op.voucher_budget_use
                     if disc > v_budget[op.voucher]:
                         raise Quota.QuotaExceededException(error_messages['voucher_budget'].format(
                             voucher=op.voucher.code
@@ -1275,9 +1275,6 @@ class AbstractPosition(models.Model):
         verbose_name=_("Variation"),
         on_delete=models.PROTECT
     )
-    price_before_voucher = models.DecimalField(
-        decimal_places=2, max_digits=10, null=True,
-    )
     price = models.DecimalField(
         decimal_places=2, max_digits=10,
         verbose_name=_("Price")
@@ -1314,6 +1311,10 @@ class AbstractPosition(models.Model):
     )
     is_bundled = models.BooleanField(default=False)
 
+    discount = models.ForeignKey(
+        'Discount', null=True, blank=True, on_delete=models.RESTRICT
+    )
+
     company = models.CharField(max_length=255, blank=True, verbose_name=_('Company name'), null=True)
     street = models.TextField(verbose_name=_('Address'), blank=True, null=True)
     zipcode = models.CharField(max_length=30, verbose_name=_('ZIP code'), blank=True, null=True)
@@ -2160,6 +2161,9 @@ class OrderPosition(AbstractPosition):
         related_name='all_positions',
         on_delete=models.PROTECT
     )
+    voucher_budget_use = models.DecimalField(
+        max_digits=10, decimal_places=2, null=True, blank=True,
+    )
     tax_rate = models.DecimalField(
         max_digits=7, decimal_places=2,
         verbose_name=_('Tax rate')
@@ -2232,6 +2236,8 @@ class OrderPosition(AbstractPosition):
                 else:
                     setattr(op, f.name, getattr(cartpos, f.name))
             op._calculate_tax()
+            if cartpos.voucher:
+                op.voucher_budget_use = cartpos.listed_price - cartpos.price_after_voucher
             op.positionid = i + 1
             op.save()
             ops.append(op)
@@ -2580,12 +2586,25 @@ class CartPosition(AbstractPosition):
         verbose_name=_("Expiration date"),
         db_index=True
     )
-    includes_tax = models.BooleanField(
-        default=True
+
+    tax_rate = models.DecimalField(
+        max_digits=7, decimal_places=2, default=Decimal('0.00'),
+        verbose_name=_('Tax rate')
     )
-    override_tax_rate = models.DecimalField(
-        max_digits=10, decimal_places=2,
-        null=True, blank=True
+    listed_price = models.DecimalField(
+        decimal_places=2, max_digits=10, null=True,
+    )
+    price_after_voucher = models.DecimalField(
+        decimal_places=2, max_digits=10, null=True,
+    )
+    custom_price_input = models.DecimalField(
+        decimal_places=2, max_digits=10, null=True,
+    )
+    custom_price_input_is_net = models.BooleanField(
+        default=False,
+    )
+    line_price_gross = models.DecimalField(
+        decimal_places=2, max_digits=10, null=True,
     )
 
     objects = ScopedManager(organizer='event__organizer')
@@ -2599,21 +2618,66 @@ class CartPosition(AbstractPosition):
             self.item.id, self.variation.id if self.variation else 0, self.cart_id
         )
 
-    @property
-    def tax_rate(self):
-        if self.includes_tax:
-            if self.override_tax_rate is not None:
-                return self.override_tax_rate
-            return self.item.tax(self.price, base_price_is='gross').rate
-        else:
-            return Decimal('0.00')
-
     @property
     def tax_value(self):
-        if self.includes_tax:
-            return self.item.tax(self.price, override_tax_rate=self.override_tax_rate, base_price_is='gross').tax
+        net = round_decimal(self.price - (self.price * (1 - 100 / (100 + self.tax_rate))),
+                            self.event.currency)
+        return self.price - net
+
+    def update_listed_price_and_voucher(self, voucher_only=False, max_discount=None):
+        from pretix.base.services.pricing import (
+            get_listed_price, is_included_for_free,
+        )
+
+        if voucher_only:
+            listed_price = self.listed_price
         else:
-            return Decimal('0.00')
+            if self.addon_to_id and is_included_for_free(self.item, self.addon_to):
+                listed_price = Decimal('0.00')
+            else:
+                listed_price = get_listed_price(self.item, self.variation, self.subevent)
+
+        if self.voucher:
+            price_after_voucher = self.voucher.calculate_price(listed_price, max_discount)
+        else:
+            price_after_voucher = listed_price
+
+        if self.is_bundled:
+            bundle = self.addon_to.item.bundles.filter(bundled_item=self.item, bundled_variation=self.variation).first()
+            if bundle:
+                listed_price = bundle.designated_price
+                price_after_voucher = bundle.designated_price
+
+        if listed_price != self.listed_price or price_after_voucher != self.price_after_voucher:
+            self.listed_price = listed_price
+            self.price_after_voucher = price_after_voucher
+            self.save(update_fields=['listed_price', 'price_after_voucher'])
+
+    def migrate_free_price_if_necessary(self):
+        # Migrate from pre-discounts position
+        if self.item.free_price and self.custom_price_input is None:
+            custom_price = self.price
+            if custom_price > 100000000:
+                raise ValueError('price_too_high')
+            self.custom_price_input = custom_price
+            self.custom_price_input_is_net = not False
+            self.save(update_fields=['custom_price_input', 'custom_price_input_is_net'])
+
+    def update_line_price(self, invoice_address, bundled_positions):
+        from pretix.base.services.pricing import get_line_price
+
+        line_price = get_line_price(
+            price_after_voucher=self.price_after_voucher,
+            custom_price_input=self.custom_price_input,
+            custom_price_input_is_net=self.custom_price_input_is_net,
+            tax_rule=self.item.tax_rule,
+            invoice_address=invoice_address,
+            bundled_sum=sum([b.price_after_voucher for b in bundled_positions]),
+        )
+        if line_price.gross != self.line_price_gross or line_price.rate != self.tax_rate:
+            self.line_price_gross = line_price.gross
+            self.tax_rate = line_price.rate
+            self.save(update_fields=['line_price_gross', 'tax_rate'])
 
 
 class InvoiceAddress(models.Model):

src/pretix/base/models/vouchers.py

@@ -39,7 +39,7 @@ from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.core.validators import MinLengthValidator
 from django.db import connection, models
-from django.db.models import F, OuterRef, Q, Subquery, Sum
+from django.db.models import OuterRef, Q, Subquery, Sum
 from django.db.models.functions import Coalesce
 from django.utils.crypto import get_random_string
 from django.utils.timezone import now
@@ -530,6 +530,8 @@ class Voucher(LoggedModel):
         original price will be returned.
         """
         if self.value is not None:
+            if not isinstance(self.value, Decimal):
+                self.value = Decimal(self.value)
             if self.price_mode == 'set':
                 p = self.value
             elif self.price_mode == 'subtract':
@@ -569,21 +571,21 @@ class Voucher(LoggedModel):
     def annotate_budget_used_orders(cls, qs):
         opq = OrderPosition.objects.filter(
             voucher_id=OuterRef('pk'),
-            price_before_voucher__isnull=False,
+            voucher_budget_use__isnull=False,
             order__status__in=[
                 Order.STATUS_PAID,
                 Order.STATUS_PENDING
             ]
-        ).order_by().values('voucher_id').annotate(s=Sum(F('price_before_voucher') - F('price'))).values('s')
+        ).order_by().values('voucher_id').annotate(s=Sum('voucher_budget_use')).values('s')
         return qs.annotate(budget_used_orders=Coalesce(Subquery(opq, output_field=models.DecimalField(max_digits=10, decimal_places=2)), Decimal('0.00')))
 
     def budget_used(self):
         ops = OrderPosition.objects.filter(
             voucher=self,
-            price_before_voucher__isnull=False,
+            voucher_budget_use__isnull=False,
             order__status__in=[
                 Order.STATUS_PAID,
                 Order.STATUS_PENDING
             ]
-        ).aggregate(s=Sum(F('price_before_voucher') - F('price')))['s'] or Decimal('0.00')
+        ).aggregate(s=Sum('voucher_budget_use'))['s'] or Decimal('0.00')
         return ops

src/pretix/base/services/cart.py

@@ -54,11 +54,14 @@ from pretix.base.models import (
 )
 from pretix.base.models.event import SubEvent
 from pretix.base.models.orders import OrderFee
-from pretix.base.models.tax import TAXED_ZERO, TaxedPrice, TaxRule
+from pretix.base.models.tax import TaxRule
 from pretix.base.reldate import RelativeDateWrapper
 from pretix.base.services.checkin import _save_answers
 from pretix.base.services.locking import LockTimeoutException, NoLockManager
-from pretix.base.services.pricing import get_price
+from pretix.base.services.pricing import (
+    apply_discounts, get_line_price, get_listed_price, get_price,
+    is_included_for_free,
+)
 from pretix.base.services.quotas import QuotaAvailability
 from pretix.base.services.tasks import ProfiledEventTask
 from pretix.base.settings import PERSON_NAME_SCHEMES, LazyI18nStringList
@@ -145,13 +148,15 @@ error_messages = {
 
 
 class CartManager:
-    AddOperation = namedtuple('AddOperation', ('count', 'item', 'variation', 'price', 'voucher', 'quotas',
-                                               'addon_to', 'subevent', 'includes_tax', 'bundled', 'seat',
-                                               'price_before_voucher'))
+    AddOperation = namedtuple('AddOperation', ('count', 'item', 'variation', 'voucher', 'quotas',
+                                               'addon_to', 'subevent', 'bundled', 'seat', 'listed_price',
+                                               'price_after_voucher', 'custom_price_input',
+                                               'custom_price_input_is_net'))
     RemoveOperation = namedtuple('RemoveOperation', ('position',))
-    VoucherOperation = namedtuple('VoucherOperation', ('position', 'voucher', 'price'))
-    ExtendOperation = namedtuple('ExtendOperation', ('position', 'count', 'item', 'variation', 'price', 'voucher',
-                                                     'quotas', 'subevent', 'seat', 'price_before_voucher'))
+    VoucherOperation = namedtuple('VoucherOperation', ('position', 'voucher', 'price_after_voucher'))
+    ExtendOperation = namedtuple('ExtendOperation', ('position', 'count', 'item', 'variation', 'voucher',
+                                                     'quotas', 'subevent', 'seat', 'listed_price',
+                                                     'price_after_voucher'))
     order = {
         RemoveOperation: 10,
         VoucherOperation: 15,
@@ -178,8 +183,8 @@ class CartManager:
 
     @property
     def positions(self):
-        return CartPosition.objects.filter(
-            Q(cart_id=self.cart_id) & Q(event=self.event)
+        return self.event.cartposition_set.filter(
+            Q(cart_id=self.cart_id)
         ).select_related('item', 'subevent')
 
     def _is_seated(self, item, subevent):
@@ -390,7 +395,6 @@ class CartManager:
             'addons'
         ).order_by('-is_bundled')
         err = None
-        changed_prices = {}
         for cp in expired:
             removed_positions = {op.position.pk for op in self._operations if isinstance(op, self.RemoveOperation)}
             if cp.pk in removed_positions or (cp.addon_to_id and cp.addon_to_id in removed_positions):
@@ -401,40 +405,16 @@ class CartManager:
             if cp.is_bundled:
                 bundle = cp.addon_to.item.bundles.filter(bundled_item=cp.item, bundled_variation=cp.variation).first()
                 if bundle:
-                    price = bundle.designated_price or 0
+                    listed_price = bundle.designated_price or 0
                 else:
-                    price = cp.price
-
-                changed_prices[cp.pk] = price
-
-                if not cp.includes_tax:
-                    price = self._get_price(cp.item, cp.variation, cp.voucher, price, cp.subevent,
-                                            force_custom_price=True, cp_is_net=False)
-                    price = TaxedPrice(net=price.net, gross=price.net, rate=0, tax=0, name='')
-                else:
-                    price = self._get_price(cp.item, cp.variation, cp.voucher, price, cp.subevent,
-                                            force_custom_price=True)
-                pbv = TAXED_ZERO
+                    listed_price = cp.price
+                price_after_voucher = listed_price
             else:
-                bundled_sum = Decimal('0.00')
-                if not cp.addon_to_id:
-                    for bundledp in cp.addons.all():
-                        if bundledp.is_bundled:
-                            bundledprice = changed_prices.get(bundledp.pk, bundledp.price)
-                            bundled_sum += bundledprice
-
-                if not cp.includes_tax:
-                    price = self._get_price(cp.item, cp.variation, cp.voucher, cp.price, cp.subevent,
-                                            cp_is_net=True, bundled_sum=bundled_sum)
-                    price = TaxedPrice(net=price.net, gross=price.net, rate=Decimal('0'), tax=Decimal('0'), name='')
-                    pbv = self._get_price(cp.item, cp.variation, None, cp.price, cp.subevent,
-                                          cp_is_net=True, bundled_sum=bundled_sum)
-                    pbv = TaxedPrice(net=pbv.net, gross=pbv.net, rate=Decimal('0'), tax=Decimal('0'), name='')
+                listed_price = get_listed_price(cp.item, cp.variation, cp.subevent)
+                if cp.voucher:
+                    price_after_voucher = cp.voucher.calculate_price(listed_price)
                 else:
-                    price = self._get_price(cp.item, cp.variation, cp.voucher, cp.price, cp.subevent,
-                                            bundled_sum=bundled_sum)
-                    pbv = self._get_price(cp.item, cp.variation, None, cp.price, cp.subevent,
-                                          bundled_sum=bundled_sum)
+                    price_after_voucher = listed_price
 
             quotas = list(cp.quotas)
             if not quotas:
@@ -450,7 +430,8 @@ class CartManager:
 
             op = self.ExtendOperation(
                 position=cp, item=cp.item, variation=cp.variation, voucher=cp.voucher, count=1,
-                price=price, quotas=quotas, subevent=cp.subevent, seat=cp.seat, price_before_voucher=pbv
+                quotas=quotas, subevent=cp.subevent, seat=cp.seat, listed_price=listed_price,
+                price_after_voucher=price_after_voucher,
             )
             self._check_item_constraints(op)
 
@@ -489,26 +470,22 @@ class CartManager:
             if p.is_bundled:
                 continue
 
-            bundled_sum = Decimal('0.00')
-            if not p.addon_to_id:
-                for bundledp in p.addons.all():
-                    if bundledp.is_bundled:
-                        bundledprice = bundledp.price
-                        bundled_sum += bundledprice
-
-            price = self._get_price(p.item, p.variation, voucher, None, p.subevent, bundled_sum=bundled_sum)
-            """
-            if price.gross > p.price:
-                continue
-            """
+            if p.listed_price is None:
+                if p.addon_to_id and is_included_for_free(p.item, p.addon_to):
+                    listed_price = Decimal('0.00')
+                else:
+                    listed_price = get_listed_price(p.item, p.variation, p.subevent)
+            else:
+                listed_price = p.listed_price
+            price_after_voucher = voucher.calculate_price(listed_price)
 
             voucher_use_diff[voucher] += 1
-            ops.append((p.price - price.gross, self.VoucherOperation(p, voucher, price)))
+            ops.append((listed_price - price_after_voucher, self.VoucherOperation(p, voucher, price_after_voucher)))
 
         # If there are not enough voucher usages left for the full cart, let's apply them in the order that benefits
         # the user the most.
         ops.sort(key=lambda k: k[0], reverse=True)
-        self._operations += [k[1] for k in ops]\
+        self._operations += [k[1] for k in ops]
 
         if not voucher_use_diff:
             raise CartError(error_messages['voucher_no_match'])
@@ -575,7 +552,6 @@ class CartManager:
 
             # Fetch bundled items
             bundled = []
-            bundled_sum = Decimal('0.00')
             db_bundles = list(item.bundles.all())
             self._update_items_cache([b.bundled_item_id for b in db_bundles], [b.bundled_variation_id for b in db_bundles])
             for bundle in db_bundles:
@@ -595,28 +571,49 @@ class CartManager:
                 else:
                     bundle_quotas = []
 
-                if bundle.designated_price:
-                    bprice = self._get_price(bitem, bvar, None, bundle.designated_price, subevent, force_custom_price=True,
-                                             cp_is_net=False)
-                else:
-                    bprice = TAXED_ZERO
-                bundled_sum += bundle.designated_price * bundle.count
-
                 bop = self.AddOperation(
-                    count=bundle.count, item=bitem, variation=bvar, price=bprice,
-                    voucher=None, quotas=bundle_quotas, addon_to='FAKE', subevent=subevent,
-                    includes_tax=bool(bprice.rate), bundled=[], seat=None, price_before_voucher=bprice,
+                    count=bundle.count,
+                    item=bitem,
+                    variation=bvar,
+                    voucher=None,
+                    quotas=bundle_quotas,
+                    addon_to='FAKE',
+                    subevent=subevent,
+                    bundled=[],
+                    seat=None,
+                    listed_price=bundle.designated_price,
+                    price_after_voucher=bundle.designated_price,
+                    custom_price_input=None,
+                    custom_price_input_is_net=False,
                 )
                 self._check_item_constraints(bop, operations)
                 bundled.append(bop)
 
-            price = self._get_price(item, variation, voucher, i.get('price'), subevent, bundled_sum=bundled_sum)
-            pbv = self._get_price(item, variation, None, i.get('price'), subevent, bundled_sum=bundled_sum)
+            listed_price = get_listed_price(item, variation, subevent)
+            if voucher:
+                price_after_voucher = voucher.calculate_price(listed_price)
+            else:
+                price_after_voucher = listed_price
+            custom_price = None
+            if item.free_price and i.get('price'):
+                custom_price = Decimal(str(i.get('price')).replace(",", "."))
+                if custom_price > 100000000:
+                    raise ValueError('price_too_high')
 
             op = self.AddOperation(
-                count=i['count'], item=item, variation=variation, price=price, voucher=voucher, quotas=quotas,
-                addon_to=False, subevent=subevent, includes_tax=bool(price.rate), bundled=bundled, seat=seat,
-                price_before_voucher=pbv
+                count=i['count'],
+                item=item,
+                variation=variation,
+                voucher=voucher,
+                quotas=quotas,
+                addon_to=False,
+                subevent=subevent,
+                bundled=bundled,
+                seat=seat,
+                listed_price=listed_price,
+                price_after_voucher=price_after_voucher,
+                custom_price_input=custom_price,
+                custom_price_input_is_net=self.event.settings.display_net_prices,
             )
             self._check_item_constraints(op, operations)
             operations.append(op)
@@ -707,16 +704,27 @@ class CartManager:
             input_addons[cp.id][a['item'], a['variation']] = a.get('count', 1)
             selected_addons[cp.id, item.category_id][a['item'], a['variation']] = a.get('count', 1)
 
-            if price_included[cp.pk].get(item.category_id):
-                price = TAXED_ZERO
+            if is_included_for_free(item, cp):
+                listed_price = Decimal('0.00')
             else:
-                price = self._get_price(item, variation, None, a.get('price'), cp.subevent)
+                listed_price = get_listed_price(item, variation, cp.subevent)
+            custom_price = None
+            if item.free_price and a.get('price'):
+                custom_price = Decimal(str(a.get('price')).replace(",", "."))
+                if custom_price > 100000000:
+                    raise ValueError('price_too_high')
 
             # Fix positions with wrong price (TODO: happens out-of-cartmanager-transaction and therefore a little hacky)
             for ca in current_addons[cp][a['item'], a['variation']]:
-                if ca.price != price.gross:
-                    ca.price = price.gross
-                    ca.save(update_fields=['price'])
+                if ca.listed_price != listed_price:
+                    ca.listed_price = ca.listed_price
+                    ca.price_after_voucher = ca.price_after_voucher
+                    ca.save(update_fields=['listed_price', 'price_after_voucher'])
+                if ca.custom_price_input != custom_price:
+                    ca.custom_price_input = custom_price
+                    ca.custom_price_input_is_net = self.event.settings.display_net_prices
+                    ca.price_after_voucher = ca.price_after_voucher
+                    ca.save(update_fields=['custom_price_input', 'custom_price_input'])
 
             if a.get('count', 1) > len(current_addons[cp][a['item'], a['variation']]):
                 # This add-on is new, add it to the cart
@@ -725,9 +733,18 @@ class CartManager:
 
                 op = self.AddOperation(
                     count=a.get('count', 1) - len(current_addons[cp][a['item'], a['variation']]),
-                    item=item, variation=variation, price=price, voucher=None, quotas=quotas,
-                    addon_to=cp, subevent=cp.subevent, includes_tax=bool(price.rate), bundled=[], seat=None,
-                    price_before_voucher=None
+                    item=item,
+                    variation=variation,
+                    voucher=None,
+                    quotas=quotas,
+                    addon_to=cp,
+                    subevent=cp.subevent,
+                    bundled=[],
+                    seat=None,
+                    listed_price=listed_price,
+                    price_after_voucher=listed_price,
+                    custom_price_input=custom_price,
+                    custom_price_input_is_net=self.event.settings.display_net_prices,
                 )
                 self._check_item_constraints(op, operations)
                 operations.append(op)
@@ -972,13 +989,31 @@ class CartManager:
                         err = err or error_messages['seat_unavailable']
 
                     for k in range(available_count):
+                        line_price = get_line_price(
+                            price_after_voucher=op.price_after_voucher,
+                            custom_price_input=op.custom_price_input,
+                            custom_price_input_is_net=op.custom_price_input_is_net,
+                            tax_rule=op.item.tax_rule,
+                            invoice_address=self.invoice_address,
+                            bundled_sum=sum([pp.count * pp.price_after_voucher for pp in op.bundled]),
+                        )
                         cp = CartPosition(
-                            event=self.event, item=op.item, variation=op.variation,
-                            price=op.price.gross, expires=self._expiry, cart_id=self.cart_id,
-                            voucher=op.voucher, addon_to=op.addon_to if op.addon_to else None,
-                            subevent=op.subevent, includes_tax=op.includes_tax, seat=op.seat,
-                            override_tax_rate=op.price.rate,
-                            price_before_voucher=op.price_before_voucher.gross if op.price_before_voucher is not None else None
+                            event=self.event,
+                            item=op.item,
+                            variation=op.variation,
+                            expires=self._expiry,
+                            cart_id=self.cart_id,
+                            voucher=op.voucher,
+                            addon_to=op.addon_to if op.addon_to else None,
+                            subevent=op.subevent,
+                            seat=op.seat,
+                            listed_price=op.listed_price,
+                            price_after_voucher=op.price_after_voucher,
+                            custom_price_input=op.custom_price_input,
+                            custom_price_input_is_net=op.custom_price_input_is_net,
+                            line_price_gross=line_price.gross,
+                            tax_rate=line_price.tax,
+                            price=line_price.gross,
                         )
                         if self.event.settings.attendee_names_asked:
                             scheme = PERSON_NAME_SCHEMES.get(self.event.settings.name_scheme)
@@ -1007,12 +1042,26 @@ class CartManager:
                         if op.bundled:
                             cp.save()  # Needs to be in the database already so we have a PK that we can reference
                             for b in op.bundled:
+                                bline_price = (
+                                    b.item.tax_rule or TaxRule(rate=Decimal('0.00'))
+                                ).tax(b.listed_price, base_price_is='gross', invoice_address=self.invoice_address)  # todo compare with previous behaviour
                                 for j in range(b.count):
                                     new_cart_positions.append(CartPosition(
-                                        event=self.event, item=b.item, variation=b.variation,
-                                        price=b.price.gross, expires=self._expiry, cart_id=self.cart_id,
-                                        voucher=None, addon_to=cp, override_tax_rate=b.price.rate,
-                                        subevent=b.subevent, includes_tax=b.includes_tax, is_bundled=True
+                                        event=self.event,
+                                        item=b.item,
+                                        variation=b.variation,
+                                        expires=self._expiry, cart_id=self.cart_id,
+                                        voucher=None,
+                                        addon_to=cp,
+                                        subevent=b.subevent,
+                                        listed_price=b.listed_price,
+                                        price_after_voucher=b.price_after_voucher,
+                                        custom_price_input=b.custom_price_input,
+                                        custom_price_input_is_net=b.custom_price_input_is_net,
+                                        line_price_gross=bline_price.gross,
+                                        tax_rate=bline_price.tax,
+                                        price=bline_price.gross,
+                                        is_bundled=True
                                     ))
 
                         new_cart_positions.append(cp)
@@ -1024,11 +1073,11 @@ class CartManager:
                         op.position.delete()
                     elif available_count == 1:
                         op.position.expires = self._expiry
-                        op.position.price = op.price.gross
-                        if op.price_before_voucher is not None:
-                            op.position.price_before_voucher = op.price_before_voucher.gross
+                        op.position.listed_price = op.listed_price
+                        op.position.price_after_voucher = op.price_after_voucher
+                        # op.position.price will be updated by recompute_final_prices_and_taxes()
                         try:
-                            op.position.save(force_update=True)
+                            op.position.save(force_update=True, update_fields=['expires', 'listed_price', 'price_after_voucher'])
                         except DatabaseError:
                             # Best effort... The position might have been deleted in the meantime!
                             pass
@@ -1046,10 +1095,10 @@ class CartManager:
                         # be expected
                         continue
 
-                op.position.price_before_voucher = op.position.price
-                op.position.price = op.price.gross
+                op.position.price_after_voucher = op.price_after_voucher
                 op.position.voucher = op.voucher
-                op.position.save()
+                # op.posiiton.price will be set in recompute_final_prices_and_taxes
+                op.position.save(update_fields=['price_after_voucher', 'voucher'])
                 vouchers_ok[op.voucher] -= 1
 
         for p in new_cart_positions:
@@ -1074,6 +1123,35 @@ class CartManager:
 
         return False
 
+    def recompute_final_prices_and_taxes(self):
+        positions = sorted(list(self.positions), key=lambda op: -(op.addon_to_id or 0))
+        diff = Decimal('0.00')
+        for cp in positions:
+            if cp.listed_price is None:
+                # migration from old system? also used in unit tests
+                cp.update_listed_price_and_voucher()
+                cp.migrate_free_price_if_necessary()
+
+            cp.update_line_price(self.invoice_address, [b for b in positions if b.addon_to_id == cp.pk and b.is_bundled])
+
+        discount_results = apply_discounts(
+            self.event,
+            self._sales_channel,
+            [
+                (cp.item_id, cp.subevent_id, cp.line_price_gross, bool(cp.addon_to), cp.is_bundled, cp.listed_price - cp.price_after_voucher)
+                for cp in positions
+            ]
+        )
+
+        for cp, (new_price, discount) in zip(positions, discount_results):
+            if cp.price != new_price or cp.discount_id != (discount.pk if discount else None):
+                diff += new_price - cp.price
+                cp.price = new_price
+                cp.discount = discount
+                cp.save(update_fields=['price', 'discount'])
+
+        return diff
+
     def commit(self):
         self._check_presale_dates()
         self._check_max_cart_size()
@@ -1091,33 +1169,11 @@ class CartManager:
                 self.now_dt = now_dt
                 self._extend_expiry_of_valid_existing_positions()
                 err = self._perform_operations() or err
+                self.recompute_final_prices_and_taxes()
             if err:
                 raise CartError(err)
 
 
-def update_tax_rates(event: Event, cart_id: str, invoice_address: InvoiceAddress):
-    positions = CartPosition.objects.filter(
-        cart_id=cart_id, event=event
-    ).select_related('item', 'item__tax_rule')
-    totaldiff = Decimal('0.00')
-    for pos in positions:
-        if not pos.item.tax_rule:
-            continue
-        rate = pos.item.tax_rule.tax_rate_for(invoice_address)
-
-        if pos.tax_rate != rate:
-            if not pos.item.tax_rule.keep_gross_if_rate_changes:
-                current_net = pos.price - pos.tax_value
-                new_gross = pos.item.tax(current_net, base_price_is='net', invoice_address=invoice_address).gross
-                totaldiff += new_gross - pos.price
-                pos.price = new_gross
-            pos.includes_tax = rate != Decimal('0.00')
-            pos.override_tax_rate = rate
-            pos.save(update_fields=['price', 'includes_tax', 'override_tax_rate'])
-
-    return totaldiff
-
-
 def get_fees(event, request, total, invoice_address, provider, positions):
     from pretix.presale.views.cart import cart_session
 

src/pretix/base/services/orders.py

@@ -35,6 +35,7 @@
 
 import json
 import logging
+import sys
 from collections import Counter, defaultdict, namedtuple
 from datetime import datetime, time, timedelta
 from decimal import Decimal
@@ -68,7 +69,6 @@ from pretix.base.models import (
     Voucher,
 )
 from pretix.base.models.event import SubEvent
-from pretix.base.models.items import ItemBundle
 from pretix.base.models.orders import (
     InvoiceAddress, OrderFee, OrderRefund, generate_secret,
 )
@@ -86,7 +86,9 @@ from pretix.base.services.mail import SendMailException
 from pretix.base.services.memberships import (
     create_membership, validate_memberships_in_order,
 )
-from pretix.base.services.pricing import get_price
+from pretix.base.services.pricing import (
+    apply_discounts, get_listed_price, get_price,
+)
 from pretix.base.services.quotas import QuotaAvailability
 from pretix.base.services.tasks import ProfiledEventTask, ProfiledTask
 from pretix.base.signals import (
@@ -565,7 +567,8 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
     _check_date(event, now_dt)
 
     products_seen = Counter()
-    changed_prices = {}
+    q_avail = Counter()
+    v_avail = Counter()
     v_budget = {}
     deleted_positions = set()
     seats_seen = set()
@@ -582,6 +585,8 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
             cp.delete()
 
     sorted_positions = sorted(positions, key=lambda s: -int(s.is_bundled))
+
+    # Check availability
     for i, cp in enumerate(sorted_positions):
         if cp.pk in deleted_positions:
             continue
@@ -601,29 +606,17 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
             break
 
         if cp.voucher:
-            redeemed_in_carts = CartPosition.objects.filter(
-                Q(voucher=cp.voucher) & Q(event=event) & Q(expires__gte=now_dt)
-            ).exclude(pk=cp.pk)
-            v_avail = cp.voucher.max_usages - cp.voucher.redeemed - redeemed_in_carts.count()
-            if v_avail < 1:
+            if cp.voucher not in v_avail:
+                redeemed_in_carts = CartPosition.objects.filter(
+                    Q(voucher=cp.voucher) & Q(event=event) & Q(expires__gte=now_dt)
+                ).exclude(cart_id=cp.cart_id)
+                v_avail[cp.voucher] = cp.voucher.max_usages - cp.voucher.redeemed - redeemed_in_carts.count()
+            v_avail[cp.voucher] -= 1
+            if v_avail[cp.voucher] < 0:
                 err = err or error_messages['voucher_redeemed']
                 delete(cp)
                 continue
 
-            if cp.voucher.budget is not None:
-                if cp.voucher not in v_budget:
-                    v_budget[cp.voucher] = cp.voucher.budget - cp.voucher.budget_used()
-                disc = cp.price_before_voucher - cp.price
-                if disc > v_budget[cp.voucher]:
-                    new_disc = max(0, v_budget[cp.voucher])
-                    cp.price = cp.price + (disc - new_disc)
-                    cp.save()
-                    err = err or error_messages['voucher_budget_used']
-                    v_budget[cp.voucher] -= new_disc
-                    continue
-                else:
-                    v_budget[cp.voucher] -= disc
-
         if cp.subevent and cp.subevent.presale_start and now_dt < cp.subevent.presale_start:
             err = err or error_messages['some_subevent_not_started']
             delete(cp)
@@ -662,7 +655,6 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
                 cp.voucher is None or not cp.voucher.show_hidden_items or not cp.voucher.applies_to(cp.item, cp.variation)
         ) and not cp.is_bundled:
             delete(cp)
-            cp.delete()
             err = error_messages['voucher_required']
             break
 
@@ -671,56 +663,14 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
             # time, since we absolutely can not overbook a seat.
             if not cp.seat.is_available(ignore_cart=cp, ignore_voucher_id=cp.voucher_id, sales_channel=sales_channel):
                 err = err or error_messages['seat_unavailable']
-                cp.delete()
+                delete(cp)
                 continue
 
         if cp.expires >= now_dt and not cp.voucher:
             # Other checks are not necessary
             continue
 
-        max_discount = None
-        if cp.price_before_voucher is not None and cp.voucher in v_budget:
-            current_discount = cp.price_before_voucher - cp.price
-            max_discount = max(v_budget[cp.voucher] + current_discount, 0)
-
-        try:
-            if cp.is_bundled:
-                try:
-                    bundle = cp.addon_to.item.bundles.get(bundled_item=cp.item, bundled_variation=cp.variation)
-                    bprice = bundle.designated_price or 0
-                except ItemBundle.DoesNotExist:
-                    bprice = cp.price
-                except ItemBundle.MultipleObjectsReturned:
-                    raise OrderError("Invalid product configuration (duplicate bundle)")
-                price = get_price(cp.item, cp.variation, cp.voucher, bprice, cp.subevent, custom_price_is_net=False,
-                                  custom_price_is_tax_rate=cp.override_tax_rate,
-                                  invoice_address=address, force_custom_price=True, max_discount=max_discount)
-                pbv = get_price(cp.item, cp.variation, None, bprice, cp.subevent, custom_price_is_net=False,
-                                custom_price_is_tax_rate=cp.override_tax_rate,
-                                invoice_address=address, force_custom_price=True, max_discount=max_discount)
-                changed_prices[cp.pk] = bprice
-            else:
-                bundled_sum = Decimal('0.00')
-                if not cp.addon_to_id:
-                    for bundledp in cp.addons.all():
-                        if bundledp.is_bundled:
-                            bundled_sum += changed_prices.get(bundledp.pk, bundledp.price)
-
-                price = get_price(cp.item, cp.variation, cp.voucher, cp.price, cp.subevent, custom_price_is_net=False,
-                                  addon_to=cp.addon_to, invoice_address=address, bundled_sum=bundled_sum,
-                                  max_discount=max_discount, custom_price_is_tax_rate=cp.override_tax_rate)
-                pbv = get_price(cp.item, cp.variation, None, cp.price, cp.subevent, custom_price_is_net=False,
-                                addon_to=cp.addon_to, invoice_address=address, bundled_sum=bundled_sum,
-                                max_discount=max_discount, custom_price_is_tax_rate=cp.override_tax_rate)
-        except TaxRule.SaleNotAllowed:
-            err = err or error_messages['country_blocked']
-            cp.delete()
-            continue
-
-        if max_discount is not None:
-            v_budget[cp.voucher] = v_budget[cp.voucher] + current_discount - (pbv.gross - price.gross)
-
-        if price is False or len(quotas) == 0:
+        if len(quotas) == 0:
             err = err or error_messages['unavailable']
             delete(cp)
             continue
@@ -742,42 +692,88 @@ def _check_positions(event: Event, now_dt: datetime, positions: List[CartPositio
                 delete(cp)
                 continue
 
-        if pbv is not None and pbv.gross != price.gross:
-            cp.price_before_voucher = pbv.gross
-        else:
-            cp.price_before_voucher = None
-
-        if price.gross != cp.price and not (cp.item.free_price and cp.price > price.gross):
-            cp.price = price.gross
-            cp.includes_tax = bool(price.rate)
-            cp.save()
-            err = err or error_messages['price_changed']
-            continue
-
         quota_ok = True
 
         ignore_all_quotas = cp.expires >= now_dt or (
-            cp.voucher and (cp.voucher.allow_ignore_quota or (cp.voucher.block_quota and cp.voucher.quota is None)))
+            cp.voucher and (
+                cp.voucher.allow_ignore_quota or (cp.voucher.block_quota and cp.voucher.quota is None)
+            )
+        )
 
         if not ignore_all_quotas:
             for quota in quotas:
                 if cp.voucher and cp.voucher.block_quota and cp.voucher.quota_id == quota.pk:
                     continue
-                avail = quota.availability(now_dt)
-                if avail[0] != Quota.AVAILABILITY_OK:
-                    # This quota is sold out/currently unavailable, so do not sell this at all
+                if quota not in q_avail:
+                    avail = quota.availability(now_dt)
+                    q_avail[quota] = avail[1] if avail[1] is not None else sys.maxsize
+                q_avail[quota] -= 1
+                if q_avail[quota] < 0:
                     err = err or error_messages['unavailable']
                     quota_ok = False
                     break
 
-        if quota_ok:
-            cp.expires = now_dt + timedelta(
-                minutes=event.settings.get('reservation_time', as_type=int))
-            cp.save()
-        else:
+        if not quota_ok:
             # Sorry, can't let you keep that!
             delete(cp)
 
+    # Check prices
+    sorted_positions = [cp for cp in sorted_positions if cp.pk and cp.pk not in deleted_positions]
+    old_total = sum(cp.price for cp in sorted_positions)
+    for i, cp in enumerate(sorted_positions):
+        if cp.listed_price is None:
+            # migration from pre-discount cart positions
+            cp.update_listed_price_and_voucher(max_discount=None)
+            cp.migrate_free_price_if_necessary()
+
+        # deal with max discount
+        max_discount = None
+        if cp.voucher and cp.voucher.budget is not None:
+            if cp.voucher not in v_budget:
+                v_budget[cp.voucher] = cp.voucher.budget - cp.voucher.budget_used()
+            max_discount = max(v_budget[cp.voucher], 0)
+
+        if cp.expires < now_dt or cp.listed_price is None:
+            # Guarantee on listed price is expired
+            cp.update_listed_price_and_voucher(max_discount=max_discount)
+        elif cp.voucher:
+            cp.update_listed_price_and_voucher(max_discount=max_discount, voucher_only=True)
+
+        if max_discount is not None:
+            v_budget[cp.voucher] = v_budget[cp.voucher] - (cp.listed_price - cp.price_after_voucher)
+
+        try:
+            cp.update_line_price(address, [b for b in sorted_positions if b.addon_to_id == cp.pk and b.is_bundled and b.pk and b.pk not in deleted_positions])
+        except TaxRule.SaleNotAllowed:
+            err = err or error_messages['country_blocked']
+            delete(cp)
+            continue
+
+    sorted_positions = [cp for cp in sorted_positions if cp.pk and cp.pk not in deleted_positions]
+    discount_results = apply_discounts(
+        event,
+        sales_channel,
+        [
+            (cp.item_id, cp.subevent_id, cp.line_price_gross, bool(cp.addon_to), cp.is_bundled, cp.listed_price - cp.price_after_voucher)
+            for cp in sorted_positions
+        ]
+    )
+    for cp, (new_price, discount) in zip(sorted_positions, discount_results):
+        if cp.price != new_price or cp.discount_id != (discount.pk if discount else None):
+            cp.price = new_price
+            cp.discount = discount
+            cp.save(update_fields=['price', 'discount'])
+
+    new_total = sum(cp.price for cp in sorted_positions)
+    if old_total != new_total:
+        err = err or error_messages['price_changed']
+
+    # Store updated positions
+    for cp in sorted_positions:
+        cp.expires = now_dt + timedelta(
+            minutes=event.settings.get('reservation_time', as_type=int))
+        cp.save()
+
     if err:
         raise OrderError(err, errargs)
 
@@ -1858,16 +1854,14 @@ class OrderChangeManager:
                 op.position.item = op.item
                 op.position.variation = op.variation
                 op.position._calculate_tax()
-                if op.position.price_before_voucher is not None and op.position.voucher and not op.position.addon_to_id:
-                    op.position.price_before_voucher = max(
-                        op.position.price,
-                        get_price(
-                            op.position.item, op.position.variation,
-                            subevent=op.position.subevent,
-                            custom_price=op.position.price,
-                            invoice_address=self._invoice_address
-                        ).gross
-                    )
+
+                if op.position.voucher_budget_use is not None and op.position.voucher and not op.position.addon_to_id:
+                    listed_price = get_listed_price(op.position.item, op.position.variation, op.position.subevent)
+                    if not op.position.item.tax_rule or op.position.item.tax_rule.price_includes_tax:
+                        price_after_voucher = max(op.position.price, op.position.voucher.calculate_price(listed_price))
+                    else:
+                        price_after_voucher = max(op.position.price - op.position.tax_value, op.position.voucher.calculate_price(listed_price))
+                    op.position.voucher_budget_use = max(listed_price - price_after_voucher, Decimal('0.00'))
                 assign_ticket_secret(
                     event=self.event, position=op.position, force_invalidate=False, save=False
                 )
@@ -1908,16 +1902,13 @@ class OrderChangeManager:
                 assign_ticket_secret(
                     event=self.event, position=op.position, force_invalidate=False, save=False
                 )
-                if op.position.price_before_voucher is not None and op.position.voucher and not op.position.addon_to_id:
-                    op.position.price_before_voucher = max(
-                        op.position.price,
-                        get_price(
-                            op.position.item, op.position.variation,
-                            subevent=op.position.subevent,
-                            custom_price=op.position.price,
-                            invoice_address=self._invoice_address
-                        ).gross
-                    )
+                if op.position.voucher_budget_use is not None and op.position.voucher and not op.position.addon_to_id:
+                    listed_price = get_listed_price(op.position.item, op.position.variation, op.position.subevent)
+                    if not op.position.item.tax_rule or op.position.item.tax_rule.price_includes_tax:
+                        price_after_voucher = max(op.position.price, op.position.voucher.calculate_price(listed_price))
+                    else:
+                        price_after_voucher = max(op.position.price - op.position.tax_value, op.position.voucher.calculate_price(listed_price))
+                    op.position.voucher_budget_use = max(listed_price - price_after_voucher, Decimal('0.00'))
                 op.position.save()
             elif isinstance(op, self.AddFeeOperation):
                 self.order.log_action('pretix.event.order.changed.addfee', user=self.user, auth=self.auth, data={

src/pretix/base/services/pricing.py

@@ -20,39 +20,30 @@
 # <https://www.gnu.org/licenses/>.
 #
 from decimal import Decimal
+from typing import List, Optional, Tuple
+
+from django.db.models import Q
+from django.utils.timezone import now
 
 from pretix.base.decimal import round_decimal
 from pretix.base.models import (
     AbstractPosition, InvoiceAddress, Item, ItemAddOn, ItemVariation, Voucher,
 )
-from pretix.base.models.event import SubEvent
+from pretix.base.models.event import Event, SubEvent
 from pretix.base.models.tax import TAXED_ZERO, TaxedPrice, TaxRule
 
 
 def get_price(item: Item, variation: ItemVariation = None,
               voucher: Voucher = None, custom_price: Decimal = None,
               subevent: SubEvent = None, custom_price_is_net: bool = False,
-              custom_price_is_tax_rate: Decimal=None,
+              custom_price_is_tax_rate: Decimal = None,
               addon_to: AbstractPosition = None, invoice_address: InvoiceAddress = None,
               force_custom_price: bool = False, bundled_sum: Decimal = Decimal('0.00'),
               max_discount: Decimal = None, tax_rule=None) -> TaxedPrice:
-    if addon_to:
-        try:
-            iao = addon_to.item.addons.get(addon_category_id=item.category_id)
-            if iao.price_included:
-                return TAXED_ZERO
-        except ItemAddOn.DoesNotExist:
-            pass
+    if is_included_for_free(item, addon_to):
+        return TAXED_ZERO
 
-    price = item.default_price
-    if subevent and item.pk in subevent.item_price_overrides:
-        price = subevent.item_price_overrides[item.pk]
-
-    if variation is not None:
-        if variation.default_price is not None:
-            price = variation.default_price
-        if subevent and variation.pk in subevent.var_price_overrides:
-            price = subevent.var_price_overrides[variation.pk]
+    price = get_listed_price(item, variation, subevent)
 
     if voucher:
         price = voucher.calculate_price(price, max_discount=max_discount)
@@ -85,10 +76,10 @@ def get_price(item: Item, variation: ItemVariation = None,
         price = tax_rule.tax(price, invoice_address=invoice_address)
 
         if custom_price_is_net:
-            price = tax_rule.tax(max(custom_price, price.net), base_price_is='net',
+            price = tax_rule.tax(max(custom_price, price.net), base_price_is='net', override_tax_rate=price.rate,
                                  invoice_address=invoice_address, subtract_from_gross=bundled_sum)
         else:
-            price = tax_rule.tax(max(custom_price, price.gross), base_price_is='gross', gross_price_is_tax_rate=custom_price_is_tax_rate,
+            price = tax_rule.tax(max(custom_price, price.gross), base_price_is='gross', override_tax_rate=price.rate,
                                  invoice_address=invoice_address, subtract_from_gross=bundled_sum)
     else:
         price = tax_rule.tax(price, invoice_address=invoice_address, subtract_from_gross=bundled_sum)
@@ -98,3 +89,83 @@ def get_price(item: Item, variation: ItemVariation = None,
     price.tax = price.gross - price.net
 
     return price
+
+
+def is_included_for_free(item: Item, addon_to: AbstractPosition):
+    if addon_to:
+        try:
+            iao = addon_to.item.addons.get(addon_category_id=item.category_id)
+            if iao.price_included:
+                return True
+        except ItemAddOn.DoesNotExist:
+            pass
+    return False
+
+
+def get_listed_price(item: Item, variation: ItemVariation = None, subevent: SubEvent = None) -> Decimal:
+    price = item.default_price
+    if subevent and item.pk in subevent.item_price_overrides:
+        price = subevent.item_price_overrides[item.pk]
+
+    if variation is not None:
+        if variation.default_price is not None:
+            price = variation.default_price
+        if subevent and variation.pk in subevent.var_price_overrides:
+            price = subevent.var_price_overrides[variation.pk]
+
+    return price
+
+
+def get_line_price(price_after_voucher: Decimal, custom_price_input: Decimal, custom_price_input_is_net: bool,
+                   tax_rule: TaxRule, invoice_address: InvoiceAddress, bundled_sum: Decimal) -> TaxedPrice:
+    if not tax_rule:
+        tax_rule = TaxRule(
+            name='',
+            rate=Decimal('0.00'),
+            price_includes_tax=True,
+            eu_reverse_charge=False,
+        )
+    if custom_price_input:
+        price = tax_rule.tax(price_after_voucher, invoice_address=invoice_address)
+
+        if custom_price_input_is_net:
+            price = tax_rule.tax(max(custom_price_input, price.net), base_price_is='net', override_tax_rate=price.rate,
+                                 invoice_address=invoice_address, subtract_from_gross=bundled_sum)
+        else:
+            price = tax_rule.tax(max(custom_price_input, price.gross), base_price_is='gross', override_tax_rate=price.rate,
+                                 invoice_address=invoice_address, subtract_from_gross=bundled_sum)
+    else:
+        price = tax_rule.tax(price_after_voucher, invoice_address=invoice_address, subtract_from_gross=bundled_sum)
+
+    return price
+
+
+def apply_discounts(event: Event, sales_channel: str,
+                    positions: List[Tuple[int, Optional[int], Decimal, bool, bool]]) -> List[Decimal]:
+    """
+    Applies any dynamic discounts to a cart
+
+    :param event: Event the cart belongs to
+    :param sales_channel: Sales channel the cart was created with
+    :param positions: Tuple of the form ``(item_id, subevent_id, line_price_gross, is_addon_to, is_bundled, voucher_discount)``
+    :return: A list of ``(new_gross_price, discount)`` tuples in the same order as the input
+    """
+    new_prices = {}
+
+    discount_qs = event.discounts.filter(
+        Q(available_from__isnull=True) | Q(available_from__lte=now()),
+        Q(available_until__isnull=True) | Q(available_until__gte=now()),
+        sales_channels__contains=sales_channel,
+        active=True,
+    ).prefetch_related('condition_limit_products').order_by('position', 'pk')
+    for discount in discount_qs:
+        result = discount.apply({
+            idx: (item_id, subevent_id, line_price_gross, is_addon_to, voucher_discount)
+            for idx, (item_id, subevent_id, line_price_gross, is_addon_to, is_bundled, voucher_discount) in enumerate(positions)
+            if not is_bundled and idx not in new_prices
+        })
+        for k in result.keys():
+            result[k] = (result[k], discount)
+        new_prices.update(result)
+
+    return [new_prices.get(idx, (p[2], None)) for idx, p in enumerate(positions)]

src/pretix/base/timeline.py

@@ -217,6 +217,30 @@ def timeline_for_event(event, subevent=None):
                     })
                 ))
 
+    for d in event.discounts.filter(Q(available_from__isnull=False) | Q(available_until__isnull=False)):
+        if d.available_from:
+            tl.append(TimelineEvent(
+                event=event, subevent=subevent,
+                datetime=d.available_from,
+                description=pgettext_lazy('timeline', 'Discount "{name}" becomes active').format(name=str(d)),
+                edit_url=reverse('control:event.items.discounts.edit', kwargs={
+                    'event': event.slug,
+                    'organizer': event.organizer.slug,
+                    'discount': d.pk,
+                })
+            ))
+        if d.available_until:
+            tl.append(TimelineEvent(
+                event=event, subevent=subevent,
+                datetime=d.available_until,
+                description=pgettext_lazy('timeline', 'Discount "{name}" becomes inactive').format(name=str(d)),
+                edit_url=reverse('control:event.items.discounts.edit', kwargs={
+                    'event': event.slug,
+                    'organizer': event.organizer.slug,
+                    'discount': d.pk,
+                })
+            ))
+
     for p in event.items.filter(Q(available_from__isnull=False) | Q(available_until__isnull=False)):
         if p.available_from:
             tl.append(TimelineEvent(

src/pretix/control/forms/discounts.py

@@ -0,0 +1,109 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io 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 decimal import Decimal
+
+from django import forms
+from django.utils.translation import gettext_lazy as _
+
+from pretix.base.channels import get_all_sales_channels
+from pretix.base.forms import I18nModelForm
+from pretix.base.forms.widgets import SplitDateTimePickerWidget
+from pretix.base.models import Discount
+from pretix.control.forms import ItemMultipleChoiceField, SplitDateTimeField
+
+
+class DiscountForm(I18nModelForm):
+    class Meta:
+        model = Discount
+        localized_fields = '__all__'
+        fields = [
+            'active',
+            'internal_name',
+            'sales_channels',
+            'available_from',
+            'available_until',
+            'subevent_mode',
+            'condition_all_products',
+            'condition_limit_products',
+            'condition_min_count',
+            'condition_min_value',
+            'condition_apply_to_addons',
+            'condition_ignore_voucher_discounted',
+            'benefit_discount_matching_percent',
+            'benefit_only_apply_to_cheapest_n_matches',
+        ]
+        field_classes = {
+            'available_from': SplitDateTimeField,
+            'available_until': SplitDateTimeField,
+            'condition_limit_products': ItemMultipleChoiceField,
+        }
+        widgets = {
+            'subevent_mode': forms.RadioSelect,
+            'available_from': SplitDateTimePickerWidget(),
+            'available_until': SplitDateTimePickerWidget(attrs={'data-date-after': '#id_available_from_0'}),
+            'condition_limit_products': forms.CheckboxSelectMultiple(attrs={
+                'data-inverse-dependency': '<[name$=all_products]',
+                'class': 'scrolling-multiple-choice',
+            }),
+            'benefit_only_apply_to_cheapest_n_matches': forms.NumberInput(
+                attrs={
+                    'data-display-dependency': '#id_condition_min_count',
+                }
+            )
+        }
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs['event']
+        super().__init__(*args, **kwargs)
+
+        self.fields['sales_channels'] = forms.MultipleChoiceField(
+            label=_('Sales channels'),
+            required=True,
+            choices=(
+                (c.identifier, c.verbose_name) for c in get_all_sales_channels().values()
+                if c.discounts_supported
+            ),
+            widget=forms.CheckboxSelectMultiple,
+        )
+        self.fields['condition_limit_products'].queryset = self.event.items.all()
+        self.fields['condition_min_count'].required = False
+        self.fields['condition_min_count'].widget.is_required = False
+        self.fields['condition_min_value'].required = False
+        self.fields['condition_min_value'].widget.is_required = False
+
+        if not self.event.has_subevents:
+            del self.fields['subevent_mode']
+
+    def clean(self):
+        d = super().clean()
+        if d.get('condition_min_value') and d.get('benefit_only_apply_to_cheapest_n_matches'):
+            # field is hidden by JS
+            d['benefit_only_apply_to_cheapest_n_matches'] = None
+        if d.get('subevent_mode') == Discount.SUBEVENT_MODE_DISTINCT and d.get('condition_min_value'):
+            # field is hidden by JS
+            d['condition_min_value'] = Decimal('0.00')
+
+        if d.get('condition_min_count') is None:
+            d['condition_min_count'] = 0
+        if d.get('condition_min_value') is None:
+            d['condition_min_value'] = Decimal('0.00')
+        return d

src/pretix/control/logdisplay.py

@@ -449,6 +449,9 @@ def pretixcontrol_logentry_display(sender: Event, logentry: LogEntry, **kwargs):
         'pretix.event.question.added': _('The question has been added.'),
         'pretix.event.question.deleted': _('The question has been deleted.'),
         'pretix.event.question.changed': _('The question has been changed.'),
+        'pretix.event.discount.added': _('The discount has been added.'),
+        'pretix.event.discount.deleted': _('The discount has been deleted.'),
+        'pretix.event.discount.changed': _('The discount has been changed.'),
         'pretix.event.taxrule.added': _('The tax rule has been added.'),
         'pretix.event.taxrule.deleted': _('The tax rule has been deleted.'),
         'pretix.event.taxrule.changed': _('The tax rule has been changed.'),

src/pretix/control/navigation.py

@@ -186,6 +186,14 @@ def get_event_navigation(request: HttpRequest):
                     }),
                     'active': 'event.items.questions' in url.url_name,
                 },
+                {
+                    'label': _('Discounts'),
+                    'url': reverse('control:event.items.discounts', kwargs={
+                        'event': request.event.slug,
+                        'organizer': request.event.organizer.slug,
+                    }),
+                    'active': 'event.items.discounts' in url.url_name,
+                },
             ]
         })
 

src/pretix/control/templates/pretixcontrol/items/discount.html

@@ -0,0 +1,74 @@
+{% extends "pretixcontrol/items/base.html" %}
+{% load i18n %}
+{% load bootstrap3 %}
+{% block title %}{% trans "Automatic discount" %}{% endblock %}
+{% block inside %}
+    <h1>{% trans "Automatic discount" %}</h1>
+    <form action="" method="post" class="form-horizontal">
+        {% csrf_token %}
+        {% bootstrap_form_errors form %}
+        <div class="row">
+            <div class="col-xs-12{% if discount %} col-lg-10{% endif %}">
+                <fieldset>
+                    <legend>{% trans "General information" %}</legend>
+                    {% bootstrap_field form.active layout="control" %}
+                    {% bootstrap_field form.internal_name layout="control" %}
+                    {% bootstrap_field form.available_from layout="control" %}
+                    {% bootstrap_field form.available_until layout="control" %}
+                    {% bootstrap_field form.sales_channels layout="control" %}
+                </fieldset>
+                <fieldset>
+                    <legend>{% trans "Condition" context "discount" %}</legend>
+                    {% bootstrap_field form.condition_all_products layout="control" %}
+                    {% bootstrap_field form.condition_limit_products layout="control" %}
+                    {% bootstrap_field form.condition_apply_to_addons layout="control" %}
+                    {% bootstrap_field form.condition_ignore_voucher_discounted layout="control" %}
+                    {% if form.subevent_mode %}
+                        {% bootstrap_field form.subevent_mode layout="control" %}
+                    {% endif %}
+                    <div class="form-group form-alternatives">
+                        <label class="col-md-3 control-label">
+                            {% trans "Minimum cart content" %}<br>
+                            <span class="optional">{% trans "Optional" %}</span>
+                        </label>
+                        <div class="col-md-4">
+                            {% bootstrap_field form.condition_min_count form_group_class="" %}
+                        </div>
+                        <div class="col-md-1 text-center condition-or" data-display-dependency="#id_subevent_mode_2" data-inverse>
+                            <div class="hr">
+                                <div class="sep">
+                                    <div class="sepText">{% trans "OR" %}</div>
+                                </div>
+                            </div>
+                        </div>
+                        <div class="col-md-4" data-display-dependency="#id_subevent_mode_2" data-inverse>
+                            {% bootstrap_field form.condition_min_value form_group_class="" %}
+                        </div>
+                    </div>
+                </fieldset>
+                <fieldset>
+                    <legend>{% trans "Benefit" context "discount" %}</legend>
+                    {% bootstrap_field form.benefit_discount_matching_percent layout="control" addon_after="%" %}
+                    {% bootstrap_field form.benefit_only_apply_to_cheapest_n_matches layout="control" %}
+                </fieldset>
+            </div>
+            {% if discount %}
+                <div class="col-xs-12 col-lg-2">
+                    <div class="panel panel-default">
+                        <div class="panel-heading">
+                            <h3 class="panel-title">
+                                {% trans "Discount history" %}
+                            </h3>
+                        </div>
+                        {% include "pretixcontrol/includes/logs.html" with obj=discount %}
+                    </div>
+                </div>
+            {% endif %}
+        </div>
+        <div class="form-group submit-group">
+            <button type="submit" class="btn btn-primary btn-save">
+                {% trans "Save" %}
+            </button>
+        </div>
+    </form>
+{% endblock %}

src/pretix/control/templates/pretixcontrol/items/discount_delete.html

@@ -0,0 +1,41 @@
+{% extends "pretixcontrol/items/base.html" %}
+{% load i18n %}
+{% load bootstrap3 %}
+{% block title %}{% trans "Delete discount" %}{% endblock %}
+{% block inside %}
+    <h1>{% trans "Delete discount" %}</h1>
+    <form action="" method="post" class="form-horizontal">
+        {% csrf_token %}
+        {% if not possible and not item.active %}
+            <p>{% blocktrans %}You cannot delete the discount <strong>{{ discount }}</strong> because it already has
+                been used as part of an order.{% endblocktrans %}</p>
+            <div class="form-group submit-group">
+                <a href="{% url "control:event.discounts" organizer=request.event.organizer.slug event=request.event.slug %}"
+                   class="btn btn-default btn-cancel">
+                    {% trans "Cancel" %}
+                </a>
+                <div class="clearfix"></div>
+            </div>
+        {% else %}
+            {% if possible %}
+                <p>{% blocktrans trimmed with name=discount.internal_name %}
+                    Are you sure you want to delete the discount <strong>{{ name }}</strong>?
+                {% endblocktrans %}</p>
+            {% else %}
+                <p>{% blocktrans trimmed with name=discount.internal_name %}
+                    You cannot delete the discount <strong>{{ name }}</strong> because it already has been used as part
+                    of an order, but you can deactivate it.
+                {% endblocktrans %}</p>
+            {% endif %}
+            <div class="form-group submit-group">
+                <a href="{% url "control:event.items.discounts" organizer=request.event.organizer.slug event=request.event.slug %}"
+                   class="btn btn-default btn-cancel">
+                    {% trans "Cancel" %}
+                </a>
+                <button type="submit" class="btn btn-danger btn-save">
+                    {% if possible %}{% trans "Delete" %}{% else %}{% trans "Deactivate" %}{% endif %}
+                </button>
+            </div>
+        {% endif %}
+    </form>
+{% endblock %}

src/pretix/control/templates/pretixcontrol/items/discounts.html

@@ -0,0 +1,147 @@
+{% extends "pretixcontrol/items/base.html" %}
+{% load i18n %}
+{% block title %}{% trans "Automatic discounts" %}{% endblock %}
+{% block inside %}
+    <h1>{% trans "Automatic discounts" %}</h1>
+    <p>
+        {% blocktrans trimmed %}
+            With automatic discounts, you can automatically apply a discount to purchases from your customers based
+            on certain conditions. For example, you can create group discounts like "get 20% off if you buy 3 or more
+            tickets" or "buy 2 tickets, get 1 free".
+        {% endblocktrans %}
+    </p>
+    <p>
+        {% blocktrans trimmed %}
+            Automatic discounts are available to all customers as long as they are active. If you want to offer special
+            prices only to specific customers, you can use vouchers instead. If you want to offer discounts across
+            multiple purchases ("buy a package of 10 you can turn into individual tickest later"), you can use
+            customer accounts and memberships instead.
+        {% endblocktrans %}
+    </p>
+    <p>
+        {% blocktrans trimmed %}
+            Discounts are only automatically applied during an initial purchase. They are not applied if an existing
+            order is changed through any of the available options.
+        {% endblocktrans %}
+    </p>
+    <p>
+        {% blocktrans trimmed %}
+            Every product in the cart can only be affected by one discount. If you have overlapping discounts, the
+            first one in the order of the list below will apply.
+        {% endblocktrans %}
+    </p>
+    {% if discounts|length == 0 %}
+        <div class="empty-collection">
+            <p>
+                {% blocktrans trimmed %}
+                    You haven't created any discounts yet.
+                {% endblocktrans %}
+            </p>
+
+            <a href="{% url "control:event.items.discounts.add" organizer=request.event.organizer.slug event=request.event.slug %}"
+               class="btn btn-primary btn-lg"><i class="fa fa-plus"></i> {% trans "Create a new discount" %}</a>
+        </div>
+    {% else %}
+        <p>
+            <a href="{% url "control:event.items.discounts.add" organizer=request.event.organizer.slug event=request.event.slug %}"
+               class="btn btn-default"><i class="fa fa-plus"></i> {% trans "Create a new discount" %}
+            </a>
+        </p>
+        <form method="post">
+            {% csrf_token %}
+            <div class="table-responsive">
+                <table class="table table-hover table-quotas">
+                    <thead>
+                    <tr>
+                        <th>{% trans "Internal name" %}</th>
+                        <th></th>
+                        <th></th>
+                        <th>{% trans "Products" %}</th>
+                        <th class="action-col-2"></th>
+                        <th class="action-col-2"></th>
+                    </tr>
+                    </thead>
+                    <tbody data-dnd-url="{% url "control:event.items.discounts.reorder" organizer=request.event.organizer.slug event=request.event.slug %}">
+                    {% for d in discounts %}
+                        <tr data-dnd-id="{{ d.id }}">
+                            <td>
+                                {% if d.active %}
+                                   <strong>
+                                {% else %}
+                                    <del>
+                                {% endif %}
+                                    <a  href="{% url "control:event.items.discounts.edit" organizer=request.event.organizer.slug event=request.event.slug discount=d.id %}">
+                                    {{ d.internal_name }}</a>
+                                {% if d.active %}
+                                    </strong>
+                                {% else %}
+                                    </del>
+                                {% endif %}
+                            </td>
+                            <td>
+                                {% for k, c in sales_channels.items %}
+                                    {% if k in d.sales_channels %}
+                                        <span class="fa fa-fw fa-{{ c.icon }} text-muted"
+                                              data-toggle="tooltip" title="{% trans c.verbose_name %}"></span>
+                                    {% else %}
+                                    {% endif %}
+                                {% endfor %}
+                            </td>
+                            <td>
+                                {% if d.available_from or d.available_until %}
+                                    {% if not d.is_available_by_time %}
+                                        <span class="label label-danger" data-toggle="tooltip"
+                                              title="{% trans "Currently unavailable since a limited timeframe for this product has been set" %}">
+                                            <span class="fa fa-clock-o fa-fw" data-toggle="tooltip">
+                                            </span>
+                                        </span>
+                                    {% else %}
+                                        <span class="fa fa-clock-o fa-fw text-muted" data-toggle="tooltip"
+                                              title="{% trans "Only available in a limited timeframe" %}">
+                                        </span>
+                                    {% endif %}
+                                {% endif %}
+                            </td>
+                            <td>
+                                {% if d.condition_all_products %}
+                                    <em>{% trans "All" %}</em>
+                                {% else %}
+                                    <ul>
+                                        {% for item in d.condition_limit_products.all %}
+                                            <li>
+                                                <a href="{% url "control:event.item" organizer=request.event.organizer.slug event=request.event.slug item=item.id %}">{{ item }}</a>
+                                            </li>
+                                        {% endfor %}
+                                    </ul>
+                                {% endif %}
+                            </td>
+                            <td>
+                                <button formaction="{% url "control:event.items.discounts.up" organizer=request.event.organizer.slug event=request.event.slug discount=d.id %}"
+                                        class="btn btn-default btn-sm sortable-up"
+                                        {% if forloop.counter0 == 0 and not page_obj.has_previous %}
+                                        disabled{% endif %}><i class="fa fa-arrow-up"></i></button>
+                                <button formaction="{% url "control:event.items.discounts.down" organizer=request.event.organizer.slug event=request.event.slug discount=d.id %}"
+                                        class="btn btn-default btn-sm sortable-down"
+                                        {% if forloop.revcounter0 == 0 and not page_obj.has_next %} disabled{% endif %}>
+                                    <i class="fa fa-arrow-down"></i></button>
+                                <span class="dnd-container"></span>
+                            </td>
+                            <td class="text-right flip">
+                                <a href="{% url "control:event.items.discounts.edit" organizer=request.event.organizer.slug event=request.event.slug discount=d.id %}"
+                                   class="btn btn-default btn-sm"><i class="fa fa-edit"></i></a>
+                                <a href="{% url "control:event.items.discounts.add" organizer=request.event.organizer.slug event=request.event.slug %}?copy_from={{ d.id }}"
+                                   class="btn btn-sm btn-default" title="{% trans "Clone" %}" data-toggle="tooltip">
+                                    <span class="fa fa-copy"></span>
+                                </a>
+                                <a href="{% url "control:event.items.discounts.delete" organizer=request.event.organizer.slug event=request.event.slug discount=d.id %}"
+                                   class="btn btn-danger btn-sm"><i class="fa fa-trash"></i></a>
+                            </td>
+                        </tr>
+                    {% endfor %}
+                    </tbody>
+                </table>
+            </div>
+        </form>
+        {% include "pretixcontrol/pagination.html" %}
+    {% endif %}
+{% endblock %}

src/pretix/control/templates/pretixcontrol/order/index.html

@@ -387,7 +387,7 @@
                                 {% if line.voucher %}
                                     <br/><span class="fa fa-tags fa-fw"></span> {% trans "Voucher code used:" %}
                                     <a
-                                            {% if line.price_before_voucher|default_if_none:"NONE" != "NONE" %}data-toggle="tooltip" title="{% blocktrans trimmed with price=line.price_before_voucher|money:request.event.currency %}Original price: {{ price }}{% endblocktrans %}"{% endif %}
+                                            {% if line.voucher.budget and line.voucher_budget_use|default_if_none:"NONE" != "NONE" %}data-toggle="tooltip" title="{% blocktrans trimmed with amount=line.voucher_budget_use|money:request.event.currency %}Used {{ amount }} discount from budget{% endblocktrans %}"{% endif %}
                                             href="{% url "control:event.voucher" event=request.event.slug organizer=request.event.organizer.slug voucher=line.voucher.pk %}">
                                         {{ line.voucher.code }}
                                     </a>
@@ -406,6 +406,15 @@
                                         {{ line.used_membership }}
                                     </a>
                                 {% endif %}
+                                {% if line.discount %}
+                                    <br />
+                                    <span class="text-success discounted" data-toggle="tooltip" title="{% trans "The price of this product was reduced because of an automatic discount or this product was part of the discount calculation for a different product in this order." %}">
+                                        <span class="fa fa-percent fa-fw" aria-hidden="true"></span>
+                                        <a href="{% url "control:event.items.discounts.edit" organizer=request.event.organizer.slug event=request.event.slug discount=line.discount.id %}">
+                                            {{ line.discount.internal_name }}
+                                        </a>
+                                    </span>
+                                {% endif %}
                                 {% if not line.canceled %}
                                     <div class="position-buttons">
                                         {% if line.generate_ticket %}

src/pretix/control/urls.py

@@ -37,9 +37,9 @@ from django.conf.urls import include, re_path
 from django.views.generic.base import RedirectView
 
 from pretix.control.views import (
-    auth, checkin, dashboards, event, geo, global_settings, item, main, oauth,
-    orderimport, orders, organizer, pdf, search, shredder, subevents,
-    typeahead, user, users, vouchers, waitinglist,
+    auth, checkin, dashboards, discounts, event, geo, global_settings, item,
+    main, oauth, orderimport, orders, organizer, pdf, search, shredder,
+    subevents, typeahead, user, users, vouchers, waitinglist,
 )
 
 urlpatterns = [
@@ -279,6 +279,16 @@ urlpatterns = [
         re_path(r'^quotas/(?P<quota>\d+)/delete$', item.QuotaDelete.as_view(),
                 name='event.items.quotas.delete'),
         re_path(r'^quotas/add$', item.QuotaCreate.as_view(), name='event.items.quotas.add'),
+        re_path(r'^discounts/$', discounts.DiscountList.as_view(), name='event.items.discounts'),
+        re_path(r'^discounts/(?P<discount>\d+)/delete$', discounts.DiscountDelete.as_view(),
+                name='event.items.discounts.delete'),
+        re_path(r'^discounts/(?P<discount>\d+)/up$', discounts.discount_move_up, name='event.items.discounts.up'),
+        re_path(r'^discounts/(?P<discount>\d+)/down$', discounts.discount_move_down,
+                name='event.items.discounts.down'),
+        re_path(r'^discounts/reorder$', discounts.reorder_discounts, name='event.items.discounts.reorder'),
+        re_path(r'^discounts/(?P<discount>\d+)/$', discounts.DiscountUpdate.as_view(),
+                name='event.items.discounts.edit'),
+        re_path(r'^discounts/add$', discounts.DiscountCreate.as_view(), name='event.items.discounts.add'),
         re_path(r'^vouchers/$', vouchers.VoucherList.as_view(), name='event.vouchers'),
         re_path(r'^vouchers/tags/$', vouchers.VoucherTags.as_view(), name='event.vouchers.tags'),
         re_path(r'^vouchers/rng$', vouchers.VoucherRNG.as_view(), name='event.vouchers.rng'),

src/pretix/control/views/discounts.py

@@ -0,0 +1,269 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io 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/>.
+#
+
+import json
+from json.decoder import JSONDecodeError
+
+from django.contrib import messages
+from django.db import transaction
+from django.db.models import Max
+from django.http import (
+    Http404, HttpResponse, HttpResponseBadRequest, HttpResponseRedirect,
+)
+from django.shortcuts import redirect
+from django.urls import resolve, reverse
+from django.utils.functional import cached_property
+from django.utils.translation import gettext_lazy as _
+from django.views.decorators.http import require_http_methods
+from django.views.generic import ListView
+from django.views.generic.edit import DeleteView
+
+from pretix.base.models import CartPosition, Discount
+from pretix.control.forms.discounts import DiscountForm
+from pretix.control.permissions import (
+    EventPermissionRequiredMixin, event_permission_required,
+)
+from pretix.helpers.models import modelcopy
+
+from ...base.channels import get_all_sales_channels
+from . import CreateView, PaginationMixin, UpdateView
+
+
+class DiscountDelete(EventPermissionRequiredMixin, DeleteView):
+    model = Discount
+    template_name = 'pretixcontrol/items/discount_delete.html'
+    permission = 'can_change_items'
+    context_object_name = 'discount'
+
+    def get_context_data(self, *args, **kwargs) -> dict:
+        context = super().get_context_data(*args, **kwargs)
+        context['possible'] = self.object.allow_delete()
+        return context
+
+    def get_object(self, queryset=None) -> Discount:
+        try:
+            return self.request.event.discounts.get(
+                id=self.kwargs['discount']
+            )
+        except Discount.DoesNotExist:
+            raise Http404(_("The requested discount does not exist."))
+
+    @transaction.atomic
+    def delete(self, request, *args, **kwargs):
+        self.object = self.get_object()
+        success_url = self.get_success_url()
+        if self.object.allow_delete():
+            CartPosition.objects.filter(discount=self.object).update(discount=None)
+            self.object.log_action('pretix.event.discount.deleted', user=self.request.user)
+            self.object.delete()
+            messages.success(request, _('The selected discount has been deleted.'))
+        else:
+            o = self.get_object()
+            o.active = False
+            o.save()
+            o.log_action('pretix.event.discount.changed', user=self.request.user, data={
+                'active': False
+            })
+            messages.success(request, _('The selected discount has been deactivated.'))
+        return HttpResponseRedirect(success_url)
+
+    def get_success_url(self) -> str:
+        return reverse('control:event.items.discounts', kwargs={
+            'organizer': self.request.event.organizer.slug,
+            'event': self.request.event.slug,
+        })
+
+
+class DiscountUpdate(EventPermissionRequiredMixin, UpdateView):
+    model = Discount
+    form_class = DiscountForm
+    template_name = 'pretixcontrol/items/discount.html'
+    permission = 'can_change_items'
+    context_object_name = 'discount'
+
+    def get_object(self, queryset=None) -> Discount:
+        url = resolve(self.request.path_info)
+        try:
+            return self.request.event.discounts.get(
+                id=url.kwargs['discount']
+            )
+        except Discount.DoesNotExist:
+            raise Http404(_("The requested discount does not exist."))
+
+    @transaction.atomic
+    def form_valid(self, form):
+        messages.success(self.request, _('Your changes have been saved.'))
+        if form.has_changed():
+            self.object.log_action(
+                'pretix.event.discount.changed', user=self.request.user, data={
+                    k: form.cleaned_data.get(k) for k in form.changed_data
+                }
+            )
+        return super().form_valid(form)
+
+    def get_success_url(self) -> str:
+        return reverse('control:event.items.discounts', kwargs={
+            'organizer': self.request.event.organizer.slug,
+            'event': self.request.event.slug,
+        })
+
+    def get_form_kwargs(self):
+        kwargs = super().get_form_kwargs()
+        kwargs['event'] = self.request.event
+        return kwargs
+
+    def form_invalid(self, form):
+        messages.error(self.request, _('We could not save your changes. See below for details.'))
+        return super().form_invalid(form)
+
+
+class DiscountCreate(EventPermissionRequiredMixin, CreateView):
+    model = Discount
+    form_class = DiscountForm
+    template_name = 'pretixcontrol/items/discount.html'
+    permission = 'can_change_items'
+    context_object_name = 'discount'
+
+    def get_success_url(self) -> str:
+        return reverse('control:event.items.discounts', kwargs={
+            'organizer': self.request.event.organizer.slug,
+            'event': self.request.event.slug,
+        })
+
+    @cached_property
+    def copy_from(self):
+        if self.request.GET.get("copy_from") and not getattr(self, 'object', None):
+            try:
+                return self.request.event.discounts.get(pk=self.request.GET.get("copy_from"))
+            except Discount.DoesNotExist:
+                pass
+
+    def get_form_kwargs(self):
+        kwargs = super().get_form_kwargs()
+
+        if self.copy_from:
+            i = modelcopy(self.copy_from)
+            i.pk = None
+            kwargs['instance'] = i
+        else:
+            kwargs['instance'] = Discount(event=self.request.event)
+
+        kwargs['event'] = self.request.event
+        return kwargs
+
+    @transaction.atomic
+    def form_valid(self, form):
+        form.instance.event = self.request.event
+        form.instance.position = (self.request.event.discounts.aggregate(m=Max('position'))['m'] or 0) + 1
+        messages.success(self.request, _('The new discount has been created.'))
+        ret = super().form_valid(form)
+        form.instance.log_action('pretix.event.discount.added', data=dict(form.cleaned_data), user=self.request.user)
+        return ret
+
+    def form_invalid(self, form):
+        messages.error(self.request, _('We could not save your changes. See below for details.'))
+        return super().form_invalid(form)
+
+
+class DiscountList(PaginationMixin, ListView):
+    model = Discount
+    context_object_name = 'discounts'
+    template_name = 'pretixcontrol/items/discounts.html'
+
+    def get_queryset(self):
+        return self.request.event.discounts.prefetch_related('condition_limit_products')
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        ctx['sales_channels'] = get_all_sales_channels()
+        return ctx
+
+
+def discount_move(request, discount, up=True):
+    """
+    This is a helper function to avoid duplicating code in discount_move_up and
+    discount_move_down. It takes a discount and a direction and then tries to bring
+    all discounts for this event in a new order.
+    """
+    try:
+        discount = request.event.discounts.get(
+            id=discount
+        )
+    except Discount.DoesNotExist:
+        raise Http404(_("The requested discount does not exist."))
+    discounts = list(request.event.discounts.order_by("position"))
+
+    index = discounts.index(discount)
+    if index != 0 and up:
+        discounts[index - 1], discounts[index] = discounts[index], discounts[index - 1]
+    elif index != len(discounts) - 1 and not up:
+        discounts[index + 1], discounts[index] = discounts[index], discounts[index + 1]
+
+    for i, d in enumerate(discounts):
+        if d.position != i:
+            d.position = i
+            d.save()
+    messages.success(request, _('The order of discounts has been updated.'))
+
+
+@event_permission_required("can_change_items")
+@require_http_methods(["POST"])
+def discount_move_up(request, organizer, event, discount):
+    discount_move(request, discount, up=True)
+    return redirect('control:event.items.discounts',
+                    organizer=request.event.organizer.slug,
+                    event=request.event.slug)
+
+
+@event_permission_required("can_change_items")
+@require_http_methods(["POST"])
+def discount_move_down(request, organizer, event, discount):
+    discount_move(request, discount, up=False)
+    return redirect('control:event.items.discounts',
+                    organizer=request.event.organizer.slug,
+                    event=request.event.slug)
+
+
+@transaction.atomic
+@event_permission_required("can_change_items")
+@require_http_methods(["POST"])
+def reorder_discounts(request, organizer, event):
+    try:
+        ids = json.loads(request.body.decode('utf-8'))['ids']
+    except (JSONDecodeError, KeyError, ValueError):
+        return HttpResponseBadRequest("expected JSON: {ids:[]}")
+
+    input_discounts = list(request.event.discounts.filter(id__in=[i for i in ids if i.isdigit()]))
+
+    if len(input_discounts) != len(ids):
+        raise Http404(_("Some of the provided object ids are invalid."))
+
+    if len(input_discounts) != request.event.discounts.count():
+        raise Http404(_("Not all discounts have been selected."))
+
+    for c in input_discounts:
+        pos = ids.index(str(c.pk))
+        if pos != c.position:  # Save unneccessary UPDATE queries
+            c.position = pos
+            c.save(update_fields=['position'])
+
+    return HttpResponse()

src/pretix/control/views/item.py

@@ -169,7 +169,7 @@ def reorder_items(request, organizer, event):
     input_items = list(request.event.items.filter(id__in=[i for i in ids if i.isdigit()]))
 
     if len(input_items) != len(ids):
-        raise Http404(_("Some of the provided item ids are invalid."))
+        raise Http404(_("Some of the provided object ids are invalid."))
 
     item_categories = {i.category_id for i in input_items}
     if len(item_categories) > 1:
@@ -178,7 +178,7 @@ def reorder_items(request, organizer, event):
     # get first and only category
     item_category = next(iter(item_categories))
     if len(input_items) != request.event.items.filter(category=item_category).count():
-        raise Http404(_("Not all items have been selected."))
+        raise Http404(_("Not all objects have been selected."))
 
     for i in input_items:
         pos = ids.index(str(i.pk))
@@ -372,10 +372,10 @@ def reorder_categories(request, organizer, event):
     input_categories = list(request.event.categories.filter(id__in=[i for i in ids if i.isdigit()]))
 
     if len(input_categories) != len(ids):
-        raise Http404(_("Some of the provided category ids are invalid."))
+        raise Http404(_("Some of the provided object ids are invalid."))
 
     if len(input_categories) != request.event.categories.count():
-        raise Http404(_("Not all categories have been selected."))
+        raise Http404(_("Not all objects have been selected."))
 
     for c in input_categories:
         pos = ids.index(str(c.pk))
@@ -501,10 +501,10 @@ def reorder_questions(request, organizer, event):
     input_questions = list(request.event.questions.filter(id__in=custom_question_ids))
 
     if len(input_questions) != len(custom_question_ids):
-        raise Http404(_("Some of the provided question ids are invalid."))
+        raise Http404(_("Some of the provided object ids are invalid."))
 
     if len(input_questions) != request.event.questions.count():
-        raise Http404(_("Not all questions have been selected."))
+        raise Http404(_("Not all objects have been selected."))
 
     for q in input_questions:
         pos = ids.index(str(q.pk))

src/pretix/control/views/orders.py

@@ -360,7 +360,8 @@ class OrderDetail(OrderView):
         cartpos = queryset.order_by(
             'item', 'variation'
         ).select_related(
-            'item', 'variation', 'addon_to', 'tax_rule', 'used_membership', 'used_membership__membership_type'
+            'item', 'variation', 'addon_to', 'tax_rule', 'used_membership', 'used_membership__membership_type',
+            'discount',
         ).prefetch_related(
             'item__questions', 'issued_gift_cards',
             Prefetch('answers', queryset=QuestionAnswer.objects.prefetch_related('options').select_related('question')),

src/pretix/presale/checkoutflow.py

@@ -55,7 +55,7 @@ from pretix.base.models import Customer, Order
 from pretix.base.models.orders import InvoiceAddress, OrderPayment
 from pretix.base.models.tax import TaxedPrice, TaxRule
 from pretix.base.services.cart import (
-    CartError, error_messages, get_fees, set_cart_addons, update_tax_rates,
+    CartError, CartManager, error_messages, get_fees, set_cart_addons,
 )
 from pretix.base.services.memberships import validate_memberships_in_order
 from pretix.base.services.orders import perform_order
@@ -873,11 +873,13 @@ class QuestionsStep(QuestionsViewMixin, CartMixin, TemplateFlowStep):
                 self.cart_session['saved_invoice_address'] = saved.pk
 
             try:
-                diff = update_tax_rates(
-                    event=request.event,
+                cm = CartManager(
+                    event=self.request.event,
                     cart_id=get_or_create_cart_id(request),
-                    invoice_address=addr
+                    invoice_address=addr,
+                    sales_channel=request.sales_channel.identifier,
                 )
+                diff = cm.recompute_final_prices_and_taxes()
             except TaxRule.SaleNotAllowed:
                 messages.error(request,
                                _("Unfortunately, based on the invoice address you entered, we're not able to sell you "

src/pretix/presale/templates/pretixpresale/event/fragment_cart.html

@@ -231,6 +231,13 @@
                     {% else %}
                         {{ line.price|money:event.currency }}
                     {% endif %}
+                    {% if line.discount and line.line_price_gross != line.price %}
+                        <span class="text-success discounted" data-toggle="tooltip" title="{% trans "The price of this product was reduced because of an automatic discount." %}">
+                            <br>
+                            <span class="fa fa-percent fa-fw" aria-hidden="true"></span>
+                            {% trans "Discounted" %}
+                        </span>
+                    {% endif %}
                 </div>
             {% else %}
                 <div role="cell" class="count">
@@ -285,6 +292,13 @@
                     {% else %}
                         {{ line.price|money:event.currency }}
                     {% endif %}
+                    {% if line.discount and line.line_price_gross != line.price %}
+                        <span class="text-success discounted" data-toggle="tooltip" title="{% trans "The price of this product was reduced because of an automatic discount." %}">
+                            <br>
+                            <span class="fa fa-percent fa-fw" aria-hidden="true"></span>
+                            {% trans "Discounted" %}
+                        </span>
+                    {% endif %}
                 </div>
             {% endif %}
             <div role="cell" class="totalprice price">

src/pretix/static/pretixcontrol/js/ui/main.js

@@ -355,7 +355,7 @@ var form_handlers = function (el) {
         var dependent = $(this),
             dependency = $($(this).attr("data-display-dependency")),
             update = function (ev) {
-                var enabled = dependency.toArray().some(function(d) {return (d.type === 'checkbox' || d.type === 'radio') ? d.checked : !!d.value;});
+                var enabled = dependency.toArray().some(function(d) {return (d.type === 'checkbox' || d.type === 'radio') ? d.checked : (!!d.value && !d.value.match(/^0\.?0*$/g))});
                 if (dependent.is("[data-inverse]")) {
                     enabled = !enabled;
                 }

src/pretix/static/pretixcontrol/scss/_forms.scss

@@ -849,6 +849,7 @@ details {
     text-decoration: line-through;
   }
 }
+
 .select2-container [aria-multiselectable] .select2-results__option span span::before {
   content: "";
   font-family: FontAwesome;
@@ -860,3 +861,46 @@ details {
 .select2-container [aria-multiselectable] .select2-results__option[aria-selected=true] span span::before {
   content: ""
 }
+
+.form-alternatives {
+  div .control-label {
+    text-align: left;
+  }
+}
+.condition-or {
+  .sepText {
+    width: 75px;
+    background: #FFFFFF;
+    margin: -15px 0 0 -38px;
+    padding: 5px 0;
+    position: absolute;
+    top: 50%;
+    text-align: center;
+  }
+
+  .hr {
+    width:2px;
+    height:64px;
+    background-color: #DDDDDD;
+    position:inherit;
+    top:12px;
+    left:50%;
+    z-index:10;
+  }
+}
+
+@media (max-width: $screen-sm-max) {
+  .condition-or {
+    .hr {
+      width: 100%;
+      height: 2px;
+      left: 0px;
+      top: 4px;
+      margin: 15px 0 15px 0;
+    }
+
+    .sepText {
+      left: 50%;
+    }
+  }
+}

src/pretix/static/pretixpresale/scss/_cart.scss

@@ -20,6 +20,10 @@
         display: block;
         line-height: 1;
     }
+    .price .discounted {
+        font-size: 85%;
+        line-height: 1;
+    }
 
     .dl-indented {
         padding-left: 20px;