Add support for reserved seating (#1228)

* Initial work on seating

* Add seat guids

* Add product_list_top

* CartAdd: Ignore item when a seat is passed

* Cart display

* product_list_top → render_seating_plan

* Render seating plan in voucher redemption

* Fix failing tests

* Add tests for extending cart positions with seats

* Add subevent_forms to docs

* Update schema, migrations

* Dealing with expired orders

* steps to order change

* Change order positions

* Allow to add seats

* tests for ocm

* Fix things after rebase

* Seating plans API

* Add more tests for cart behaviour

* Widget support

* Adjust widget tests

* Re-enable CSP

* Update schema

* Api: position.seat

* Add guid to word list

* API: (sub)event.seating_plan

* Vali fixes

* Fix api

* Fix reference in test

* Fix test for real

src/pretix/api/views/organizer.py

@@ -1,8 +1,12 @@
 from rest_framework import filters, viewsets
+from rest_framework.exceptions import PermissionDenied
 
 from pretix.api.models import OAuthAccessToken
-from pretix.api.serializers.organizer import OrganizerSerializer
-from pretix.base.models import Organizer
+from pretix.api.serializers.organizer import (
+    OrganizerSerializer, SeatingPlanSerializer,
+)
+from pretix.base.models import Organizer, SeatingPlan
+from pretix.helpers.dicts import merge_dicts
 
 
 class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
@@ -30,3 +34,50 @@ class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
             return Organizer.objects.filter(pk=self.request.auth.organizer_id)
         else:
             return Organizer.objects.filter(pk=self.request.auth.team.organizer_id)
+
+
+class SeatingPlanViewSet(viewsets.ModelViewSet):
+    serializer_class = SeatingPlanSerializer
+    queryset = SeatingPlan.objects.none()
+    permission = 'can_change_organizer_settings'
+    write_permission = 'can_change_organizer_settings'
+
+    def get_queryset(self):
+        return self.request.organizer.seating_plans.all()
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['organizer'] = self.request.organizer
+        return ctx
+
+    def perform_create(self, serializer):
+        inst = serializer.save(organizer=self.request.organizer)
+        self.request.organizer.log_action(
+            'pretix.seatingplan.added',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=merge_dicts(self.request.data, {'id': inst.pk})
+        )
+
+    def perform_update(self, serializer):
+        if serializer.instance.events.exists() or serializer.instance.subevents.exists():
+            raise PermissionDenied('This plan can not be changed while it is in use for an event.')
+        inst = serializer.save(organizer=self.request.organizer)
+        self.request.organizer.log_action(
+            'pretix.seatingplan.changed',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=merge_dicts(self.request.data, {'id': serializer.instance.pk})
+        )
+        return inst
+
+    def perform_destroy(self, instance):
+        if instance.events.exists() or instance.subevents.exists():
+            raise PermissionDenied('This plan can not be deleted while it is in use for an event.')
+        instance.log_action(
+            'pretix.seatingplan.deleted',
+            user=self.request.user,
+            auth=self.request.auth,
+            data={'id': instance.pk}
+        )
+        instance.delete()