Add an API

src/pretix/api/serializers/organizer.py

@@ -1,6 +1,11 @@
+from django.db.models import Q
+from django.utils.translation import ugettext_lazy as _
+from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
+
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.order import CompatibleJSONField
-from pretix.base.models import Organizer, SeatingPlan
+from pretix.base.models import GiftCard, Organizer, SeatingPlan
 from pretix.base.models.seating import SeatingPlanLayoutValidator
 
 
@@ -18,3 +23,27 @@ class SeatingPlanSerializer(I18nAwareModelSerializer):
     class Meta:
         model = SeatingPlan
         fields = ('id', 'name', 'layout')
+
+
+class GiftCardSerializer(I18nAwareModelSerializer):
+    value = serializers.DecimalField(max_digits=10, decimal_places=2)
+
+    def validate(self, data):
+        data = super().validate(data)
+        s = data['secret']
+        qs = GiftCard.objects.filter(
+            secret=s
+        ).filter(
+            Q(issuer=self.context["organizer"]) | Q(issuer__gift_card_collector_acceptance__collector=self.context["organizer"])
+        )
+        if self.instance:
+            qs = qs.exclude(pk=self.instance.pk)
+        if qs.exists():
+            raise ValidationError(
+                {'secret': _('A gift card with the same secret already exists in your or an affiliated organizer account.')}
+            )
+        return data
+
+    class Meta:
+        model = GiftCard
+        fields = ('id', 'secret', 'issuance', 'value', 'currency')

src/pretix/api/urls.py

@@ -19,6 +19,7 @@ orga_router.register(r'events', event.EventViewSet)
 orga_router.register(r'subevents', event.SubEventViewSet)
 orga_router.register(r'webhooks', webhooks.WebHookViewSet)
 orga_router.register(r'seatingplans', organizer.SeatingPlanViewSet)
+orga_router.register(r'giftcards', organizer.GiftCardViewSet)
 
 event_router = routers.DefaultRouter()
 event_router.register(r'subevents', event.SubEventViewSet)

src/pretix/api/views/organizer.py

@@ -1,11 +1,12 @@
+from django.db import transaction
 from rest_framework import filters, viewsets
-from rest_framework.exceptions import PermissionDenied
+from rest_framework.exceptions import MethodNotAllowed, PermissionDenied
 
 from pretix.api.models import OAuthAccessToken
 from pretix.api.serializers.organizer import (
-    OrganizerSerializer, SeatingPlanSerializer,
+    GiftCardSerializer, OrganizerSerializer, SeatingPlanSerializer,
 )
-from pretix.base.models import Organizer, SeatingPlan
+from pretix.base.models import GiftCard, Organizer, SeatingPlan
 from pretix.helpers.dicts import merge_dicts
 
 
@@ -81,3 +82,48 @@ class SeatingPlanViewSet(viewsets.ModelViewSet):
             data={'id': instance.pk}
         )
         instance.delete()
+
+
+class GiftCardViewSet(viewsets.ModelViewSet):
+    serializer_class = GiftCardSerializer
+    queryset = GiftCard.objects.none()
+    permission = 'can_manage_gift_cards'
+    write_permission = 'can_manage_gift_cards'
+
+    def get_queryset(self):
+        return self.request.organizer.issued_gift_cards.all()
+
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx['organizer'] = self.request.organizer
+        return ctx
+
+    @transaction.atomic()
+    def perform_create(self, serializer):
+        value = serializer.validated_data.pop('value')
+        inst = serializer.save(issuer=self.request.organizer)
+        inst.transactions.create(value=value)
+        self.request.organizer.log_action(
+            'pretix.giftcards.transaction.manual',
+            user=self.request.user,
+            auth=self.request.auth,
+            data=merge_dicts(self.request.data, {'id': inst.pk})
+        )
+
+    @transaction.atomic()
+    def perform_update(self, serializer):
+        old_value = serializer.instance.value
+        value = serializer.validated_data.pop('value')
+        inst = serializer.save(secret=serializer.instance.secret, currency=serializer.instance.currency)
+        diff = value - old_value
+        inst.transactions.create(value=diff)
+        self.request.organizer.log_action(
+            'pretix.giftcards.transaction.manual',
+            user=self.request.user,
+            auth=self.request.auth,
+            data={'value': diff}
+        )
+        return inst
+
+    def perform_destroy(self, instance):
+        raise MethodNotAllowed("Gift cards cannot be deleted.")

src/pretix/base/migrations/0137_auto_20190918_1820.py

@@ -0,0 +1,26 @@
+# Generated by Django 2.2.1 on 2019-09-18 18:20
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+import pretix.base.models.fields
+import pretix.base.models.giftcards
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0136_auto_20190918_1537'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='giftcard',
+            name='secret',
+            field=models.CharField(db_index=True, default=pretix.base.models.giftcards.gen_giftcard_secret, max_length=190),
+        ),
+        migrations.AlterUniqueTogether(
+            name='giftcard',
+            unique_together={('secret', 'issuer')},
+        ),
+    ]

src/pretix/base/models/giftcards.py

@@ -48,7 +48,6 @@ class GiftCard(LoggedModel):
     secret = models.CharField(
         max_length=190,
         default=gen_giftcard_secret,
-        unique=True,
         db_index=True,
         verbose_name=_('Gift card code'),
     )
@@ -62,6 +61,9 @@ class GiftCard(LoggedModel):
     def value(self):
         return self.transactions.aggregate(s=Sum('value'))['s'] or Decimal('0.00')
 
+    class Meta:
+        unique_together = (('secret', 'issuer'),)
+
 
 class GiftCardTransaction(models.Model):
     card = models.ForeignKey(

src/pretix/control/forms/organizer.py

@@ -341,7 +341,7 @@ class GiftCardCreateForm(forms.ModelForm):
         self.organizer = kwargs.pop('organizer')
         super().__init__(*args, **kwargs)
 
-    def clean_secret(self):
+    def validate_secret(self):
         s = self.cleaned_data['secret']
         if GiftCard.objects.filter(
             secret=s