Gift cards: Improved support for cross-organizer acceptance (#3311)

Co-authored-by: Martin Gross <martin@pc-coholic.de>

src/pretix/base/models/giftcards.py

@@ -46,14 +46,19 @@ def gen_giftcard_secret(length=8):
 class GiftCardAcceptance(models.Model):
     issuer = models.ForeignKey(
         'Organizer',
-        related_name='gift_card_collector_acceptance',
+        related_name='gift_card_acceptor_acceptance',
         on_delete=models.CASCADE
     )
-    collector = models.ForeignKey(
+    acceptor = models.ForeignKey(
         'Organizer',
         related_name='gift_card_issuer_acceptance',
         on_delete=models.CASCADE
     )
+    active = models.BooleanField(default=True)
+    reusable_media = models.BooleanField(default=False)
+
+    class Meta:
+        unique_together = (('issuer', 'acceptor'),)
 
 
 class GiftCard(LoggedModel):
@@ -114,7 +119,7 @@ class GiftCard(LoggedModel):
         return self.transactions.aggregate(s=Sum('value'))['s'] or Decimal('0.00')
 
     def accepted_by(self, organizer):
-        return self.issuer == organizer or GiftCardAcceptance.objects.filter(issuer=self.issuer, collector=organizer).exists()
+        return self.issuer == organizer or GiftCardAcceptance.objects.filter(issuer=self.issuer, acceptor=organizer, active=True).exists()
 
     def save(self, *args, **kwargs):
         if not self.secret:

src/pretix/base/models/organizer.py

@@ -40,7 +40,7 @@ from django.conf import settings
 from django.core.mail import get_connection
 from django.core.validators import MinLengthValidator, RegexValidator
 from django.db import models
-from django.db.models import Exists, OuterRef, Q
+from django.db.models import Q
 from django.urls import reverse
 from django.utils.crypto import get_random_string
 from django.utils.functional import cached_property
@@ -157,17 +157,19 @@ class Organizer(LoggedModel):
         return self.cache.get_or_set(
             key='has_gift_cards',
             timeout=15,
-            default=lambda: self.issued_gift_cards.exists() or self.gift_card_issuer_acceptance.exists()
+            default=lambda: self.issued_gift_cards.exists() or self.gift_card_issuer_acceptance.filter(active=True).exists()
         )
 
     @property
     def accepted_gift_cards(self):
         from .giftcards import GiftCard, GiftCardAcceptance
 
-        return GiftCard.objects.annotate(
-            accepted=Exists(GiftCardAcceptance.objects.filter(issuer=OuterRef('issuer'), collector=self))
-        ).filter(
-            Q(issuer=self) | Q(accepted=True)
+        return GiftCard.objects.filter(
+            Q(issuer=self) |
+            Q(issuer__in=GiftCardAcceptance.objects.filter(
+                acceptor=self,
+                active=True,
+            ).values_list('issuer', flat=True))
         )
 
     @property