From e17d868acb6bbaa31166fc7c2e8724d70e56c1f2 Mon Sep 17 00:00:00 2001
From: Benjamin Dauvergne <bdauvergne@entrouvert.com>
Date: Fri, 7 Oct 2022 09:13:51 +0200
Subject: [PATCH 3/6] api: refactor user synchronization API endpoint (#67901)

---
 src/authentic2/api_views.py | 65 +++++++++++++++++++------------------
 1 file changed, 33 insertions(+), 32 deletions(-)

diff --git a/src/authentic2/api_views.py b/src/authentic2/api_views.py
index b466f2db..fc23fff9 100644
--- a/src/authentic2/api_views.py
+++ b/src/authentic2/api_views.py
@@ -52,6 +52,7 @@ from rest_framework.validators import UniqueTogetherValidator
 from rest_framework.views import APIView
 from rest_framework.viewsets import ModelViewSet, ViewSet
 
+from authentic2.apps.journal.models import reference_integer
 from authentic2.compat.drf import action
 
 from . import api_mixins, app_settings, decorators, hooks
@@ -796,31 +797,27 @@ class UsersAPI(api_mixins.GetOrCreateMixinView, HookMixin, ExceptionHandlerMixin
         full_known_users = serializers.BooleanField(required=False)
         timestamp = serializers.DateTimeField(required=False)
 
-    def check_uuids(self, uuids, timestamp=None):
-        User = get_user_model()
-        known_uuids = User.objects.filter(uuid__in=uuids).values_list('uuid', flat=True)
-        unknown_uuids = set(uuids) - set(known_uuids)
-        modified_users_uuids = []
-        if timestamp:
-            user_ct = ContentType.objects.get_for_model(get_user_model())
-            user_events = Event.objects.filter(
-                reference_ct_ids__contains=[user_ct.id], timestamp__gt=timestamp
-            )
-            for user_event in user_events:
-                for reference in user_event.references:
-                    if (
-                        reference is not None  # xxx None references in journal?!
-                        and ContentType.objects.get_for_model(reference) == user_ct
-                        and reference.uuid not in modified_users_uuids
-                        and reference.uuid not in unknown_uuids
-                    ):
-                        modified_users_uuids.append(reference.uuid)
-        return (known_uuids, unknown_uuids, modified_users_uuids)
-
-    def get_users_from_uuids(self, known_uuids):
-        User = get_user_model()
-        known_users = User.objects.filter(uuid__in=known_uuids)
-        return [BaseUserSerializer(user).data for user in known_users]
+    def check_unknown_uuids(self, remote_uuids, users):
+        return set(remote_uuids) - {user.uuid for user in users}
+
+    def check_modified_uuids(self, timestamp, users, unknown_uuids):
+        modified_users_uuids = set()
+        user_ct = ContentType.objects.get_for_model(get_user_model())
+        reference_ids = [reference_integer(user) for user in users]
+        user_events = Event.objects.filter(
+            models.Q(reference_ids__overlap=reference_ids) | models.Q(user__in=users),
+            timestamp__gt=timestamp,
+        )
+        users_pks = {user.pk: user for user in users}
+        for user_event in user_events:
+            for ct_id, instance_pk in user_event.get_reference_ids():
+                if (
+                    ct_id == user_ct.pk
+                    and instance_pk in users_pks
+                    and users_pks[instance_pk].uuid not in modified_users_uuids
+                ):
+                    modified_users_uuids.add(users_pks[instance_pk].uuid)
+        return modified_users_uuids
 
     @action(detail=False, methods=['post'], permission_classes=(DjangoPermission('custom_user.search_user'),))
     def synchronization(self, request):
@@ -829,19 +826,23 @@ class UsersAPI(api_mixins.GetOrCreateMixinView, HookMixin, ExceptionHandlerMixin
             response = {'result': 0, 'errors': serializer.errors}
             return Response(response, status.HTTP_400_BAD_REQUEST)
         hooks.call_hooks('api_modify_serializer_after_validation', self, serializer)
-        known_uuids = serializer.validated_data.get('known_uuids', [])
-        timestamp = serializer.validated_data.get('timestamp', None)
-        known_uuids, unknown_uuids, modified_users_uuids = self.check_uuids(known_uuids, timestamp)
+        remote_uuids = serializer.validated_data.get('known_uuids', [])
+        users = User.objects.filter(uuid__in=remote_uuids).only('id', 'uuid')
+        unknown_uuids = self.check_unknown_uuids(remote_uuids, users)
         data = {
             'result': 1,
             'unknown_uuids': unknown_uuids,
-            'modified_users_uuids': modified_users_uuids,
         }
+
+        timestamp = serializer.validated_data.get('timestamp', None)
+        if timestamp:
+            data['modified_users_uuids'] = self.check_modified_uuids(timestamp, users, unknown_uuids)
+
         full_known_users = serializer.validated_data.get('full_known_users', None)
         if full_known_users:
-            if len(known_uuids) > 1000:
-                known_uuids = known_uuids[:1000]
-            data['known_users'] = self.get_users_from_uuids(known_uuids)
+            # reload users to get all fields
+            known_users = User.objects.filter(pk__in=[user.pk for user in users[:1000]])
+            data['known_users'] = [BaseUserSerializer(user).data for user in known_users]
         hooks.call_hooks('api_modify_response', self, 'synchronization', data)
         return Response(data)
 
-- 
2.37.2