fix(payments): make checkout attempts idempotent and reconcilable

apps/payments/tests/integration/test_payment_reconciliation.py

@@ -0,0 +1,139 @@
+import pytest
+
+from apps.events.models import Registration
+from apps.payments.models import Payment
+from apps.payments.tasks import reconcile_payment
+
+pytestmark = [pytest.mark.integration, pytest.mark.django_db]
+
+
+def _pending_payment(user_factory, event_factory):
+    user = user_factory()
+    event = event_factory(price=25000)
+    registration = Registration.objects.create(
+        event=event,
+        user=user,
+        status=Registration.StatusChoices.PENDING,
+    )
+    payment = Payment.objects.create(
+        user=user,
+        event=event,
+        registration=registration,
+        base_amount=25000,
+        amount=25000,
+        authority=f"AUTH-{user.pk}",
+        status=Payment.OrderStatusChoices.PENDING,
+    )
+    return payment, registration
+
+
+def test_reconciliation_retry_confirms_payment_after_transient_timeout(
+    user_factory, event_factory, mocker, settings
+):
+    payment, registration = _pending_payment(user_factory, event_factory)
+    settings.ZARINPAL_MERCHANT_ID = "test"
+    settings.ZARINPAL_VERIFY_URL = "https://gateway.example/verify"
+    gateway = mocker.patch("apps.payments.services.requests.post")
+    gateway.side_effect = [
+        RuntimeError("temporary timeout"),
+        mocker.Mock(**{"json.return_value": {"data": {"code": 100, "ref_id": "REF-RETRY"}}}),
+    ]
+    notify = mocker.patch("apps.payments.api.views._notify_payment_status")
+
+    retry = mocker.patch.object(reconcile_payment, "retry", side_effect=RuntimeError("retry scheduled"))
+    with pytest.raises(RuntimeError, match="retry scheduled"):
+        reconcile_payment.run(payment.id)
+
+    retry.assert_called_once()
+    assert retry.call_args.kwargs["countdown"] == 60
+    gateway.side_effect = [
+        mocker.Mock(**{"json.return_value": {"data": {"code": 100, "ref_id": "REF-RETRY"}}})
+    ]
+    result = reconcile_payment.run(payment.id)
+
+    payment.refresh_from_db()
+    registration.refresh_from_db()
+    assert result == "paid"
+    assert gateway.call_count == 2
+    assert payment.status == Payment.OrderStatusChoices.PAID
+    assert payment.ref_id == "REF-RETRY"
+    assert registration.status == Registration.StatusChoices.CONFIRMED
+    notify.assert_called_once()
+
+
+def test_reconciliation_exhaustion_leaves_payment_pending_for_review(
+    user_factory, event_factory, mocker, settings
+):
+    payment, registration = _pending_payment(user_factory, event_factory)
+    settings.ZARINPAL_MERCHANT_ID = "test"
+    settings.ZARINPAL_VERIFY_URL = "https://gateway.example/verify"
+    gateway = mocker.patch("apps.payments.services.requests.post", side_effect=RuntimeError("gateway offline"))
+    notify = mocker.patch("apps.payments.api.views._notify_payment_status")
+    retry = mocker.patch.object(reconcile_payment, "retry", side_effect=RuntimeError("retry scheduled"))
+
+    for retry_number in range(reconcile_payment.max_retries + 1):
+        reconcile_payment.push_request(retries=retry_number)
+        try:
+            if retry_number < reconcile_payment.max_retries:
+                with pytest.raises(RuntimeError, match="retry scheduled"):
+                    reconcile_payment.run(payment.id)
+            else:
+                result = reconcile_payment.run(payment.id)
+        finally:
+            reconcile_payment.pop_request()
+
+    payment.refresh_from_db()
+    registration.refresh_from_db()
+    assert result == "pending_manual_review"
+    assert gateway.call_count == reconcile_payment.max_retries + 1
+    assert [call.kwargs["countdown"] for call in retry.call_args_list] == [60, 120, 240, 480, 900]
+    assert payment.status == Payment.OrderStatusChoices.PENDING
+    assert registration.status == Registration.StatusChoices.PENDING
+    notify.assert_not_called()
+
+
+def test_reconciliation_marks_only_explicit_gateway_failure_as_failed(
+    user_factory, event_factory, mocker, settings
+):
+    payment, registration = _pending_payment(user_factory, event_factory)
+    settings.ZARINPAL_MERCHANT_ID = "test"
+    settings.ZARINPAL_VERIFY_URL = "https://gateway.example/verify"
+    gateway = mocker.patch("apps.payments.services.requests.post")
+    gateway.return_value.json.return_value = {"data": {"code": -51}}
+    notify = mocker.patch("apps.payments.api.views._notify_payment_status")
+
+    result = reconcile_payment.run(payment.id)
+
+    payment.refresh_from_db()
+    registration.refresh_from_db()
+    assert result == "failed"
+    assert gateway.call_count == 1
+    assert payment.status == Payment.OrderStatusChoices.FAILED
+    assert registration.status == Registration.StatusChoices.CANCELLED
+    notify.assert_called_once()
+
+
+def test_failed_attempt_does_not_cancel_registration_used_by_another_active_payment(
+    user_factory, event_factory, mocker, settings
+):
+    payment, registration = _pending_payment(user_factory, event_factory)
+    Payment.objects.create(
+        user=payment.user,
+        event=payment.event,
+        registration=registration,
+        base_amount=payment.base_amount,
+        amount=payment.amount,
+        authority=f"AUTH-OTHER-{payment.user_id}",
+        status=Payment.OrderStatusChoices.PENDING,
+    )
+    settings.ZARINPAL_MERCHANT_ID = "test"
+    settings.ZARINPAL_VERIFY_URL = "https://gateway.example/verify"
+    gateway = mocker.patch("apps.payments.services.requests.post")
+    gateway.return_value.json.return_value = {"data": {"code": -51}}
+
+    reconcile_payment.run(payment.id)
+
+    payment.refresh_from_db()
+    registration.refresh_from_db()
+    assert payment.status == Payment.OrderStatusChoices.FAILED
+    assert registration.status == Registration.StatusChoices.PENDING