Tax rules and reverse charge (#559)

Tax rules and reverse charge

src/pretix/api/views/event.py

@@ -1,8 +1,10 @@
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from rest_framework import filters, viewsets
 
-from pretix.api.serializers.event import EventSerializer, SubEventSerializer
-from pretix.base.models import Event, ItemCategory
+from pretix.api.serializers.event import (
+    EventSerializer, SubEventSerializer, TaxRuleSerializer,
+)
+from pretix.base.models import Event, ItemCategory, TaxRule
 from pretix.base.models.event import SubEvent
 
 
@@ -32,3 +34,11 @@ class SubEventViewSet(viewsets.ReadOnlyModelViewSet):
         return self.request.event.subevents.prefetch_related(
             'subeventitem_set', 'subeventitemvariation_set'
         )
+
+
+class TaxRuleViewSet(viewsets.ReadOnlyModelViewSet):
+    serializer_class = TaxRuleSerializer
+    queryset = TaxRule.objects.none()
+
+    def get_queryset(self):
+        return self.request.event.tax_rules.all()

src/pretix/api/views/item.py

@@ -1,3 +1,5 @@
+import django_filters
+from django.db.models import Q
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from rest_framework import viewsets
 from rest_framework.decorators import detail_route
@@ -12,6 +14,14 @@ from pretix.base.models import Item, ItemCategory, Question, Quota
 
 
 class ItemFilter(FilterSet):
+    tax_rate = django_filters.CharFilter(method='tax_rate_qs')
+
+    def tax_rate_qs(self, queryset, name, value):
+        if value in ("0", "None", "0.00"):
+            return queryset.filter(Q(tax_rule__isnull=True) | Q(tax_rule__rate=0))
+        else:
+            return queryset.filter(tax_rule__rate=value)
+
     class Meta:
         model = Item
         fields = ['active', 'category', 'admission', 'tax_rate', 'free_price']
@@ -26,7 +36,7 @@ class ItemViewSet(viewsets.ReadOnlyModelViewSet):
     filter_class = ItemFilter
 
     def get_queryset(self):
-        return self.request.event.items.prefetch_related('variations', 'addons').all()
+        return self.request.event.items.select_related('tax_rule').prefetch_related('variations', 'addons').all()
 
 
 class ItemCategoryFilter(FilterSet):