Features: 1) Add forwards and backwards migration logic for language field normalization using Lower; 2) Enhance allowed choices formatting in language field for improved readability;

Fixes: None;

Extra: 1) Minor code cleanup and reorganization in migration file;

vibes_auth/migrations/0003_alter_user_language.py

@@ -1,6 +1,19 @@
-# Generated by Django 5.2 on 2025-05-20 19:06
-
 from django.db import migrations, models
+from django.db.models.functions import Lower
+
+
+def forwards(apps, schema_editor):
+    User = apps.get_model('vibes_auth', 'User')
+    User.objects.all().update(language=Lower('language'))
+
+
+def backwards(apps, schema_editor):
+    User = apps.get_model('vibes_auth', 'User')
+    for u in User.objects.all():
+        parts = u.language.split('-', 1)
+        if len(parts) == 2:
+            u.language = f"{parts[0].lower()}-{parts[1].upper()}"
+            u.save(update_fields=['language'])
 
 
 class Migration(migrations.Migration):
@@ -9,15 +22,34 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        migrations.RunPython(forwards, backwards),
+
         migrations.AlterField(
             model_name='user',
             name='language',
             field=models.CharField(
-                choices=[('en-gb', 'English (British)'), ('ar-ar', 'العربية'), ('cs-cz', 'Česky'), ('da-dk', 'Dansk'),
-                         ('de-de', 'Deutsch'), ('en-us', 'English (American)'), ('es-es', 'Español'),
-                         ('fr-fr', 'Français'), ('hi-in', 'हिंदी'), ('it-it', 'Italiano'), ('ja-jp', '日本語'),
-                         ('kk-kz', 'Қазақ'), ('nl-nl', 'Nederlands'), ('pl-pl', 'Polska'), ('pt-br', 'Português'),
-                         ('ro-ro', 'Română'), ('ru-ru', 'Русский'), ('zh-hans', '简体中文')], default='en-gb',
-                max_length=7),
+                choices=[
+                    ('en-gb', 'English (British)'),
+                    ('ar-ar', 'العربية'),
+                    ('cs-cz', 'Česky'),
+                    ('da-dk', 'Dansk'),
+                    ('de-de', 'Deutsch'),
+                    ('en-us', 'English (American)'),
+                    ('es-es', 'Español'),
+                    ('fr-fr', 'Français'),
+                    ('hi-in', 'हिंदी'),
+                    ('it-it', 'Italiano'),
+                    ('ja-jp', '日本語'),
+                    ('kk-kz', 'Қазақ'),
+                    ('nl-nl', 'Nederlands'),
+                    ('pl-pl', 'Polska'),
+                    ('pt-br', 'Português'),
+                    ('ro-ro', 'Română'),
+                    ('ru-ru', 'Русский'),
+                    ('zh-hans', '简体中文'),
+                ],
+                default='en-gb',
+                max_length=7,
+            ),
         ),
     ]