feat(grants): Pretix voucher and email when grantee confirms

When a grantee confirms via sendGrantReply, enqueue create_and_send_voucher_to_grantee
after transaction.on_commit: create or reuse ConferenceVoucher in Pretix
(create_conference_voucher), then send_conference_voucher_email (voucher_code
template, same as Voucher admin).

Task mirrors schedule voucher flow: skip duplicate Pretix row for existing
GRANT/SPEAKER; queue email if voucher_email_sent_at is None (retry after partial
success); upgrade CO_SPEAKER to GRANT. Staff resend anytime via Voucher admin
Send voucher via email.

Admin Create grant vouchers uses create_conference_voucher with prefetched
existing rows; no transaction.atomic around Pretix loop. Confirm pending status
unchanged.

Remove grant_voucher_code email identifier; migration 0022 rewrites rows to
voucher_code and documents noop reverse.

Tests: GraphQL confirm + on_commit, grant admin vouchers, grant/conference tasks.

Author: estyxx

backend/api/grants/mutations.py

@@ -15,7 +15,11 @@
     create_change_admin_log_entry,
 )
 from grants.models import Grant as GrantModel
-from grants.tasks import get_name, notify_new_grant_reply_slack
+from grants.tasks import (
+    create_and_send_voucher_to_grantee,
+    get_name,
+    notify_new_grant_reply_slack,
+)
 from notifications.models import EmailTemplate, EmailTemplateIdentifier
 from participants.models import Participant
 from privacy_policy.record import record_privacy_policy_acceptance
@@ -342,9 +346,17 @@ def send_grant_reply(
         if grant.status in (GrantModel.Status.pending, GrantModel.Status.rejected):
             return SendGrantReplyError(message="You cannot reply to this grant")
 
+        old_status = grant.status
         grant.status = input.status.to_grant_status()
         grant.save()
 
+        if old_status != grant.status and grant.status == GrantModel.Status.confirmed:
+            transaction.on_commit(
+                lambda gid=grant.id: create_and_send_voucher_to_grantee.delay(
+                    grant_id=gid
+                )
+            )
+
         create_change_admin_log_entry(
             request.user, grant, f"Grantee has replied with status {grant.status}."
         )

backend/api/grants/tests/test_send_grant_reply.py

@@ -75,17 +75,25 @@ def test_user_cannot_reply_if_status_is_rejected(graphql_client, user):
     )
 
 
-def test_status_is_updated_when_reply_is_confirmed(graphql_client, user):
+def test_status_is_updated_when_reply_is_confirmed(
+    graphql_client, user, mocker, django_capture_on_commit_callbacks
+):
     graphql_client.force_login(user)
     grant = GrantFactory(user_id=user.id, status=Grant.Status.waiting_for_confirmation)
+    mock_voucher = mocker.patch(
+        "api.grants.mutations.create_and_send_voucher_to_grantee"
+    )
 
-    response = _send_grant_reply(graphql_client, grant, status="confirmed")
+    with django_capture_on_commit_callbacks(execute=True):
+        response = _send_grant_reply(graphql_client, grant, status="confirmed")
 
     assert response["data"]["sendGrantReply"]["__typename"] == "Grant"
 
     grant.refresh_from_db()
     assert grant.status == Grant.Status.confirmed
 
+    mock_voucher.delay.assert_called_once_with(grant_id=grant.id)
+
     # Verify audit log entry was created correctly
     assert LogEntry.objects.filter(
         user=user,
@@ -94,9 +102,12 @@ def test_status_is_updated_when_reply_is_confirmed(graphql_client, user):
     ).exists()
 
 
-def test_status_is_updated_when_reply_is_refused(graphql_client, user):
+def test_status_is_updated_when_reply_is_refused(graphql_client, user, mocker):
     graphql_client.force_login(user)
     grant = GrantFactory(user_id=user.id, status=Grant.Status.waiting_for_confirmation)
+    mock_voucher = mocker.patch(
+        "api.grants.mutations.create_and_send_voucher_to_grantee"
+    )
 
     response = _send_grant_reply(graphql_client, grant, status="refused")
 
@@ -105,6 +116,9 @@ def test_status_is_updated_when_reply_is_refused(graphql_client, user):
     grant.refresh_from_db()
     assert grant.status == Grant.Status.refused
 
+    # Verify voucher was not sent
+    mock_voucher.delay.assert_not_called()
+
     # Verify audit log entry was created correctly
     assert LogEntry.objects.filter(
         user=user,

backend/conferences/tasks.py

@@ -1,14 +1,11 @@
 from django.utils import timezone
 from notifications.models import EmailTemplate, EmailTemplateIdentifier
 from grants.tasks import get_name
-import logging
 from pycon.celery import app
 
-logger = logging.getLogger(__name__)
-
 
 @app.task
-def send_conference_voucher_email(conference_voucher_id):
+def send_conference_voucher_email(conference_voucher_id: int) -> None:
     from conferences.models import ConferenceVoucher
 
     conference_voucher = ConferenceVoucher.objects.get(id=conference_voucher_id)
@@ -31,4 +28,4 @@ def send_conference_voucher_email(conference_voucher_id):
     )
 
     conference_voucher.voucher_email_sent_at = timezone.now()
-    conference_voucher.save()
+    conference_voucher.save(update_fields=["voucher_email_sent_at"])

backend/conferences/tests/test_tasks.py

@@ -60,3 +60,26 @@ def test_send_conference_voucher_email(voucher_type, sent_emails):
     assert conference_voucher.voucher_email_sent_at == datetime(
         2020, 10, 10, 10, 0, 0, tzinfo=timezone.utc
     )
+
+
+def test_send_conference_voucher_email_sends_again_when_already_sent(sent_emails):
+    user = UserFactory(full_name="Remind Me")
+    conference_voucher = ConferenceVoucherFactory(
+        user=user,
+        voucher_type=ConferenceVoucher.VoucherType.SPEAKER,
+        voucher_code="REM123",
+        voucher_email_sent_at=datetime(2020, 1, 1, tzinfo=timezone.utc),
+    )
+    EmailTemplateFactory(
+        conference=conference_voucher.conference,
+        identifier=EmailTemplateIdentifier.voucher_code,
+    )
+
+    with time_machine.travel("2020-06-01 12:00:00Z", tick=False):
+        send_conference_voucher_email(conference_voucher_id=conference_voucher.id)
+
+    assert sent_emails().count() == 1
+    conference_voucher.refresh_from_db()
+    assert conference_voucher.voucher_email_sent_at == datetime(
+        2020, 6, 1, 12, 0, 0, tzinfo=timezone.utc
+    )

backend/grants/admin.py

@@ -4,7 +4,6 @@
 
 from django.contrib import admin, messages
 from django.contrib.admin import SimpleListFilter
-from django.db import transaction
 from django.db.models import Exists, OuterRef
 from django.db.models.query import QuerySet
 from django.urls import reverse
@@ -15,6 +14,7 @@
 from import_export.resources import ModelResource
 
 from conferences.models.conference_voucher import ConferenceVoucher
+from conferences.vouchers import create_conference_voucher
 from countries import countries
 from countries.filters import CountryFilter
 from custom_admin.admin import (
@@ -49,6 +49,7 @@
 
 logger = logging.getLogger(__name__)
 
+
 EXPORT_GRANTS_FIELDS = (
     "name",
     "full_name",
@@ -297,20 +298,20 @@ def send_reply_email_waiting_list_update(modeladmin, request, queryset):
 
 @admin.action(description="Create grant vouchers")
 @validate_single_conference_selection
-@transaction.atomic
 def create_grant_vouchers(modeladmin, request, queryset):
-    conference = queryset.first().conference
-    existing_vouchers_by_user_id = {
-        voucher.user_id: voucher
-        for voucher in ConferenceVoucher.objects.for_conference(conference).filter(
-            user_id__in=queryset.values_list("user_id", flat=True),
-        )
-    }
+    grants_ordered = list(queryset.order_by("id").select_related("user", "conference"))
+    conference_id = grants_ordered[0].conference_id if grants_ordered else None
+    user_ids = {g.user_id for g in grants_ordered if g.user_id}
 
-    vouchers_to_create = []
-    vouchers_to_update = []
+    existing_by_user: Dict[int, ConferenceVoucher] = {}
+    if conference_id is not None and user_ids:
+        for voucher in ConferenceVoucher.objects.filter(
+            conference_id=conference_id,
+            user_id__in=user_ids,
+        ):
+            existing_by_user[voucher.user_id] = voucher
 
-    for grant in queryset.order_by("id"):
+    for grant in grants_ordered:
         if grant.status != Grant.Status.confirmed:
             messages.error(
                 request,
@@ -319,45 +320,54 @@ def create_grant_vouchers(modeladmin, request, queryset):
             )
             continue
 
-        existing_voucher = existing_vouchers_by_user_id.get(grant.user_id)
+        if not grant.user_id:
+            messages.error(
+                request,
+                f"Grant for {grant.name} has no user linked; can't create a voucher.",
+            )
+            continue
 
-        if not existing_voucher:
+        existing = existing_by_user.get(grant.user_id)
+
+        if not existing:
+            new_voucher = create_conference_voucher(
+                conference=grant.conference,
+                user=grant.user,
+                voucher_type=ConferenceVoucher.VoucherType.GRANT,
+            )
+            existing_by_user[grant.user_id] = new_voucher
             create_addition_admin_log_entry(
                 request.user,
                 grant,
                 change_message="Created voucher for this grant.",
             )
+            continue
 
-            vouchers_to_create.append(
-                ConferenceVoucher(
-                    conference_id=grant.conference_id,
-                    user_id=grant.user_id,
-                    voucher_code=ConferenceVoucher.generate_code(),
-                    voucher_type=ConferenceVoucher.VoucherType.GRANT,
-                )
-            )
+        if existing.voucher_type in (
+            ConferenceVoucher.VoucherType.GRANT,
+            ConferenceVoucher.VoucherType.SPEAKER,
+        ):
             continue
 
-        if existing_voucher.voucher_type == ConferenceVoucher.VoucherType.CO_SPEAKER:
+        if existing.voucher_type == ConferenceVoucher.VoucherType.CO_SPEAKER:
             messages.warning(
                 request,
-                f"Grant for {grant.name} already has a Co-Speaker voucher. Upgrading to a Grant voucher.",
+                f"Grant for {grant.name} already has a Co-Speaker voucher. "
+                "Upgrading to a Grant voucher.",
             )
             create_change_admin_log_entry(
                 request.user,
-                existing_voucher,
+                existing,
                 change_message="Upgraded Co-Speaker voucher to Grant voucher.",
             )
             create_change_admin_log_entry(
                 request.user,
                 grant,
                 change_message="Updated existing Co-Speaker voucher to grant.",
             )
-            existing_voucher.voucher_type = ConferenceVoucher.VoucherType.GRANT
-            vouchers_to_update.append(existing_voucher)
-
-    ConferenceVoucher.objects.bulk_create(vouchers_to_create, ignore_conflicts=True)
-    ConferenceVoucher.objects.bulk_update(vouchers_to_update, ["voucher_type"])
+            existing.voucher_type = ConferenceVoucher.VoucherType.GRANT
+            existing.voucher_email_sent_at = None
+            existing.save(update_fields=["voucher_type", "voucher_email_sent_at"])
 
     messages.success(request, "Vouchers created!")
 

backend/grants/tasks.py

@@ -5,6 +5,8 @@
 from django.conf import settings
 from django.utils import timezone
 
+from conferences.models.conference_voucher import ConferenceVoucher
+from conferences.vouchers import create_conference_voucher
 from grants.models import Grant
 from integrations import slack
 from notifications.models import EmailTemplate, EmailTemplateIdentifier
@@ -21,6 +23,58 @@ def get_name(user: User | None, fallback: str = "<no name specified>") -> str:
     return user.full_name or user.name or user.username or fallback
 
 
+@app.task
+def create_and_send_voucher_to_grantee(*, grant_id: int) -> None:
+    from conferences.tasks import send_conference_voucher_email
+
+    grant = Grant.objects.select_related("user", "conference").get(pk=grant_id)
+    if grant.status != Grant.Status.confirmed:
+        return
+    if not grant.user_id:
+        return
+
+    user = grant.user
+    conference = grant.conference
+    conference_voucher = (
+        ConferenceVoucher.objects.for_conference(conference).for_user(user).first()
+    )
+
+    if conference_voucher:
+        if conference_voucher.voucher_type in (
+            ConferenceVoucher.VoucherType.GRANT,
+            ConferenceVoucher.VoucherType.SPEAKER,
+        ):
+            logger.info(
+                "User %s already has a voucher for conference %s, not creating a new one",
+                user.id,
+                conference.id,
+            )
+            # Skip duplicate mail once sent_at is set; staff resends use Voucher admin
+            # "Send voucher via email" (calls send_conference_voucher_email directly).
+            if conference_voucher.voucher_email_sent_at is None:
+                send_conference_voucher_email.delay(
+                    conference_voucher_id=conference_voucher.id
+                )
+            return
+        if conference_voucher.voucher_type == ConferenceVoucher.VoucherType.CO_SPEAKER:
+            conference_voucher.voucher_type = ConferenceVoucher.VoucherType.GRANT
+            conference_voucher.voucher_email_sent_at = None
+            conference_voucher.save(
+                update_fields=["voucher_type", "voucher_email_sent_at"]
+            )
+            send_conference_voucher_email.delay(
+                conference_voucher_id=conference_voucher.id
+            )
+            return
+
+    new_voucher = create_conference_voucher(
+        conference=conference,
+        user=user,
+        voucher_type=ConferenceVoucher.VoucherType.GRANT,
+    )
+    send_conference_voucher_email.delay(conference_voucher_id=new_voucher.id)
+
+
 @app.task
 def send_grant_reply_approved_email(*, grant_id: int, is_reminder: bool) -> None:
     logger.info("Sending Reply APPROVED email for Grant %s", grant_id)

backend/grants/tests/test_admin.py

@@ -10,9 +10,9 @@
 from conferences.models.conference_voucher import ConferenceVoucher
 from conferences.tests.factories import ConferenceFactory, ConferenceVoucherFactory
 from grants.admin import (
-    confirm_pending_status,
     GrantAdmin,
     GrantReimbursementAdmin,
+    confirm_pending_status,
     create_grant_vouchers,
     mark_rejected_and_send_email,
     reset_pending_status_back_to_status,
@@ -305,6 +305,7 @@ def test_send_reply_email_waiting_list_update(rf, mocker, admin_user):
 
 def test_create_grant_vouchers(rf, mocker, admin_user):
     mock_messages = mocker.patch("grants.admin.messages")
+    mocker.patch("conferences.vouchers.create_voucher", return_value={"id": 999})
 
     conference = ConferenceFactory()
 
@@ -357,6 +358,7 @@ def test_create_grant_vouchers_with_existing_voucher_is_reused(
     rf, mocker, admin_user, type
 ):
     mock_messages = mocker.patch("grants.admin.messages")
+    mocker.patch("conferences.vouchers.create_voucher", return_value={"id": 999})
 
     conference = ConferenceFactory()
 
@@ -407,6 +409,7 @@ def test_create_grant_vouchers_with_voucher_from_other_conf_is_ignored(
     rf, mocker, type, admin_user
 ):
     mock_messages = mocker.patch("grants.admin.messages")
+    mocker.patch("conferences.vouchers.create_voucher", return_value={"id": 999})
 
     conference = ConferenceFactory()
     other_conference = ConferenceFactory()
@@ -461,6 +464,7 @@ def test_create_grant_vouchers_with_voucher_from_other_conf_is_ignored(
 
 def test_create_grant_vouchers_co_speaker_voucher_is_upgraded(rf, mocker, admin_user):
     mock_messages = mocker.patch("grants.admin.messages")
+    mocker.patch("conferences.vouchers.create_voucher", return_value={"id": 999})
 
     conference = ConferenceFactory()
 
@@ -506,6 +510,7 @@ def test_create_grant_vouchers_co_speaker_voucher_is_upgraded(rf, mocker, admin_
 
 def test_create_grant_vouchers_only_for_confirmed_grants(rf, mocker, admin_user):
     mock_messages = mocker.patch("grants.admin.messages")
+    mocker.patch("conferences.vouchers.create_voucher", return_value={"id": 999})
     conference = ConferenceFactory()
     grant_1 = GrantFactory(
         status=Grant.Status.refused,