Deal with cancelling memberships (#2130)

src/pretix/base/migrations/0194_membership_canceled.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.3 on 2021-06-17 10:28
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0193_auto_20210611_1355'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='membership',
+            name='canceled',
+            field=models.BooleanField(default=False),
+        ),
+    ]

src/pretix/base/models/memberships.py

@@ -118,6 +118,10 @@ class Membership(models.Model):
         verbose_name=_('Test mode'),
         default=False
     )
+    canceled = models.BooleanField(
+        verbose_name=_('Canceled'),
+        default=False
+    )
     customer = models.ForeignKey(
         Customer,
         related_name='memberships',

src/pretix/base/models/orders.py

@@ -599,6 +599,8 @@ class Order(LockModel, LoggedModel):
             for gc in op.issued_gift_cards.all():
                 if gc.value != op.price:
                     return False
+            if op.granted_memberships.with_usages().filter(usages__gt=0):
+                return False
         if self.user_cancel_deadline and now() > self.user_cancel_deadline:
             return False
         if self.status == Order.STATUS_PENDING:

src/pretix/base/services/memberships.py

@@ -141,6 +141,11 @@ def validate_memberships_in_order(customer: Customer, positions: List[AbstractPo
                 _('You selected a membership that is connected to a different customer account.')
             )
 
+        if m.canceled:
+            raise ValidationError(
+                _('You selected membership that has been canceled.')
+            )
+
         if m.testmode != testmode:
             raise ValidationError(
                 _('You can only use a test mode membership for test mode tickets.')

src/pretix/base/services/orders.py

@@ -177,6 +177,10 @@ def reactivate_order(order: Order, force: bool=False, user: User=None, auth=None
                         gc = GiftCard.objects.select_for_update().get(pk=gc.pk)
                         gc.transactions.create(value=position.price, order=order)
                         break
+
+                    for m in position.granted_memberships.all():
+                        m.canceled = False
+                        m.save()
         else:
             raise OrderError(is_available)
 
@@ -410,6 +414,10 @@ def _cancel_order(order, user=None, send_mail: bool=True, api_token=None, device
                 else:
                     gc.transactions.create(value=-position.price, order=order)
 
+            for m in position.granted_memberships.all():
+                m.canceled = True
+                m.save()
+
         if cancellation_fee:
             with order.event.lock():
                 for position in order.positions.all():
@@ -1768,7 +1776,26 @@ class OrderChangeManager:
                     else:
                         gc.transactions.create(value=-op.position.price, order=self.order)
 
+                for m in op.position.granted_memberships.with_usages().all():
+                    m.canceled = True
+                    m.save()
+
                 for opa in op.position.addons.all():
+                    for gc in opa.issued_gift_cards.all():
+                        gc = GiftCard.objects.select_for_update().get(pk=gc.pk)
+                        if gc.value < opa.position.price:
+                            raise OrderError(_(
+                                'A position can not be canceled since the gift card {card} purchased in this order has '
+                                'already been redeemed.').format(
+                                card=gc.secret
+                            ))
+                        else:
+                            gc.transactions.create(value=-opa.position.price, order=self.order)
+
+                    for m in opa.granted_memberships.with_usages().all():
+                        m.canceled = True
+                        m.save()
+
                     self.order.log_action('pretix.event.order.changed.cancel', user=self.user, auth=self.auth, data={
                         'position': opa.pk,
                         'positionid': opa.positionid,