✨(backend) process reconciliation requests as transactions

Process each reconciliation requests individually as a transaction,
with the bulk updates/deletes made for each requests, to avoid
interference between requests and unwanted states

src/backend/core/admin.py

@@ -2,6 +2,7 @@
 
 from django.contrib import admin, messages
 from django.contrib.auth import admin as auth_admin
+from django.db import transaction
 from django.shortcuts import redirect
 from django.utils.translation import gettext_lazy as _
 
@@ -119,39 +120,13 @@ def process_reconciliation(_modeladmin, _request, queryset):
     Admin action to process selected user reconciliations.
     The action will process only entries that are ready and have both emails checked.
 
-    Its action is threefold:
-    - Transfer document accesses from inactive to active user, updating roles as needed.
-    - Activate the active user and deactivate the inactive user.
     """
     processable_entries = queryset.filter(
         status="ready", active_email_checked=True, inactive_email_checked=True
     )
 
-    # Prepare the bulk operations
-    updated_documentaccess = []
-    removed_documentaccess = []
-    update_users_active_status = []
-
     for entry in processable_entries:
-        new_updated_documentaccess, new_removed_documentaccess = (
-            entry.process_documentaccess_reconciliation()
-        )
-        updated_documentaccess += new_updated_documentaccess
-        removed_documentaccess += new_removed_documentaccess
-
-        entry.active_user.is_active = True
-        entry.inactive_user.is_active = False
-        update_users_active_status.append(entry.active_user)
-        update_users_active_status.append(entry.inactive_user)
-
-    # Actually perform the bulk operations
-    models.DocumentAccess.objects.bulk_update(updated_documentaccess, ["user", "role"])
-
-    if removed_documentaccess:
-        ids_to_delete = [rd.id for rd in removed_documentaccess]
-        models.DocumentAccess.objects.filter(id__in=ids_to_delete).delete()
-
-    models.User.objects.bulk_update(update_users_active_status, ["is_active"])
+        entry.process_reconciliation_request()
 
 
 @admin.register(models.UserReconciliation)

src/backend/core/models.py

@@ -378,9 +378,44 @@ class UserReconciliation(BaseModel):
 
         super().save(*args, **kwargs)
 
-    def process_documentaccess_reconciliation(self):
+    @transaction.atomic
+    def process_reconciliation_request(self):
         """
-        Process the reconciliation by transferring document accesses from the inactive user
+        Process the reconciliation request as a transaction.
+
+        Its action is threefold:
+        - Transfer document accesses from inactive to active user, updating roles as needed.
+        - Activate the active user and deactivate the inactive user.
+        - Update the reconciliation entry itself.
+        """
+
+        # Prepare the data to perform the reconciliation on
+        updated_accesses, removed_accesses = (
+            self.prepare_documentaccess_reconciliation()
+        )
+        self.active_user.is_active = True
+        self.inactive_user.is_active = False
+
+        # Actually perform the bulk operations
+        DocumentAccess.objects.bulk_update(updated_accesses, ["user", "role"])
+
+        if removed_accesses:
+            ids_to_delete = [rd.id for rd in removed_accesses]
+            DocumentAccess.objects.filter(id__in=ids_to_delete).delete()
+
+        User.objects.bulk_update([self.active_user, self.inactive_user], ["is_active"])
+
+        # Wrap up the reconciliation entry
+        self.logs += f"""Requested update for {len(updated_accesses)} DocumentAccess items
+            and deletion for {len(removed_accesses)} DocumentAccess items.\n"""
+        self.status = "done"
+        self.save()
+
+        self.send_reconciliation_done_email()
+
+    def prepare_documentaccess_reconciliation(self):
+        """
+        Prepare the reconciliation by transferring document accesses from the inactive user
         to the active user.
         """
         updated_accesses = []
@@ -408,13 +443,6 @@ class UserReconciliation(BaseModel):
                 entry.user = self.active_user
                 updated_accesses.append(entry)
 
-        self.logs += f"""Requested update for {len(updated_accesses)} DocumentAccess items
-            and deletion for {len(removed_accesses)} DocumentAccess items.\n"""
-        self.status = "done"
-        self.send_reconciliation_done_email()
-
-        self.save()
-
         return updated_accesses, removed_accesses
 
     def send_reconciliation_confirm_email(