Payment event ledger (PaymentEvent) replicated to the backup server, plus CSV export script on 247

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

payment/tests_events.py

@@ -0,0 +1,27 @@
+from unittest import mock
+
+from django.test import TestCase
+
+from payment import events
+from payment.models import Order, PaymentEvent
+from payment.services import cancel_pending_order, create_order
+
+
+class PaymentEventTests(TestCase):
+    def test_create_order_records_event_once_per_order(self):
+        order, _ = create_order(user_id=7, amount=1000, idempotency_key='k-1')
+        create_order(user_id=7, amount=1000, idempotency_key='k-1')  # همان سفارش، رویدادِ دوم نه
+        rows = PaymentEvent.objects.filter(order_id=order.id, event='order_created')
+        self.assertEqual(rows.count(), 1)
+        self.assertEqual(rows.get().user_id, 7)
+
+    def test_cancel_records_event(self):
+        order, _ = create_order(user_id=7, amount=1000)
+        cancel_pending_order(order, staff='tester')
+        self.assertTrue(PaymentEvent.objects.filter(order_id=order.id, event='admin_cancel').exists())
+
+    def test_failure_to_record_does_not_raise(self):
+        with mock.patch.object(PaymentEvent.objects, 'create', side_effect=RuntimeError('db')):
+            with self.assertLogs('payment.events', level='ERROR'):
+                events.record('x', user_id=1)
+        self.assertEqual(Order.objects.count(), 0)