feat(accounts): Add a mechanism to automatically change the local username when creating or deleting translations

src/dgsi/models.py

@@ -2,9 +2,12 @@ from dataclasses import dataclass
 from functools import cached_property
 from typing import Optional, Self
 
+from allauth.socialaccount.models import SocialAccount
 from asgiref.sync import async_to_sync
 from django.contrib.auth.models import AbstractUser
 from django.db import models
+from django.db.models.signals import pre_delete
+from django.dispatch import receiver
 from django.http import HttpRequest
 from django.utils.translation import gettext_lazy as _
 from kanidm.exceptions import NoMatchingEntries
@@ -84,17 +87,47 @@ class Translation(models.Model):
     def __str__(self) -> str:
         return f"{self.cas_login} → {self.username}"
 
-    def save(self, **kwargs) -> None:  # pyright: ignore
+    def save(self, *args, **kwargs) -> None:
         # INFO: Only update the model if it does not already exist
         #       This will prevent a lot of pain
         if self.pk is None:
-            return super().save(**kwargs)
+            try:
+                # Find out if a user exists with the cas_login to update
+                account = SocialAccount.objects.get(
+                    provider="ens_cas", uid=self.cas_login
+                )
+                account.user.username = self.username
+                account.user.save()
+
+                # TODO: Update the distant kanidm data
+            except SocialAccount.DoesNotExist:
+                # No user has registered with this cas_login yet
+                pass
+            return super().save(*args, **kwargs)
 
     class Meta:  # pyright: ignore
         verbose_name = _("Correspondance de login")
         verbose_name_plural = _("Correspondances de login")
 
 
+# INFO: We need to use a signal receiver here, as the delete method is not called
+#       when deleteing objects from the admin interface
+@receiver(pre_delete, sender=Translation)
+def restore_username(**kwargs):
+    """
+    Restore the username to the cas_login
+    """
+
+    cas_login = kwargs["instance"].cas_login
+    try:
+        account = SocialAccount.objects.get(provider="ens_cas", uid=cas_login)
+        account.user.username = cas_login
+        account.user.save()
+    except SocialAccount.DoesNotExist:
+        # No user has registered with this cas_login yet
+        pass
+
+
 @dataclass
 class KanidmProfile:
     person: Person