Add Order.cancellation_date (#1629)

* Add Order.cancellation_date

* Add tests

src/pretix/base/migrations/0149_order_cancellation_date.py

@@ -0,0 +1,46 @@
+# Generated by Django 3.0.4 on 2020-03-25 14:40
+
+from django.db import migrations, models
+from django.db.models import OuterRef, Count, Subquery, Q
+from django.utils.timezone import now
+
+
+def fill_cancellation_date(apps, schema_editor):
+    Order = apps.get_model('pretixbase', 'Order')
+    LogEntry = apps.get_model('pretixbase', 'LogEntry')
+    OrderPosition = apps.get_model('pretixbase', 'OrderPosition')
+
+    s = OrderPosition.all.filter(
+        order=OuterRef('pk'),
+        canceled=False,
+    ).order_by().values('order').annotate(k=Count('id')).values('k')
+    for o in Order.objects.annotate(
+            pcnt=Subquery(s)
+    ).filter(
+        Q(pcnt=0) | Q(pcnt__isnull=True) | Q(status="c")
+    ).values('id').iterator():
+        le = LogEntry.objects.filter(
+            content_type__model="order",
+            object_id=o['id'],
+            action_type='pretix.event.order.canceled'
+        ).order_by('-datetime').only('datetime').first()
+        if le:
+            Order.objects.filter(pk=o['id']).update(
+                cancellation_date=le.datetime,
+                last_modified=now()
+            )
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('pretixbase', '0148_cancellationrequest'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='order',
+            name='cancellation_date',
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+        migrations.RunPython(fill_cancellation_date, migrations.RunPython.noop)
+    ]

src/pretix/base/models/orders.py

@@ -152,6 +152,9 @@ class Order(LockModel, LoggedModel):
     datetime = models.DateTimeField(
         verbose_name=_("Date"), db_index=True
     )
+    cancellation_date = models.DateTimeField(
+        null=True, blank=True
+    )
     expires = models.DateTimeField(
         verbose_name=_("Expiration date")
     )

src/pretix/base/services/orders.py

@@ -109,10 +109,11 @@ def reactivate_order(order: Order, force: bool=False, user: User=None, auth=None
                 order.status = Order.STATUS_PAID
             else:
                 order.status = Order.STATUS_PENDING
+            order.cancellation_date = None
             order.set_expires(now(),
                               order.event.subevents.filter(id__in=[p.subevent_id for p in order.positions.all()]))
             with transaction.atomic():
-                order.save(update_fields=['expires', 'status'])
+                order.save(update_fields=['expires', 'status', 'cancellation_date'])
                 order.log_action(
                     'pretix.event.order.reactivated',
                     user=user,
@@ -389,14 +390,16 @@ def _cancel_order(order, user=None, send_mail: bool=True, api_token=None, device
                     raise OrderError(_('The cancellation fee cannot be higher than the payment credit of this order.'))
                 order.status = Order.STATUS_PAID
                 order.total = cancellation_fee
-                order.save(update_fields=['status', 'total'])
+                order.cancellation_date = now()
+                order.save(update_fields=['status', 'cancellation_date', 'total'])
 
             if i:
                 invoices.append(generate_invoice(order))
         else:
             with order.event.lock():
                 order.status = Order.STATUS_CANCELED
-                order.save(update_fields=['status'])
+                order.cancellation_date = now()
+                order.save(update_fields=['status', 'cancellation_date'])
 
             for position in order.positions.all():
                 if position.voucher: