From 6838cc0efcb43cca86d256cde787cccd5483299e Mon Sep 17 00:00:00 2001
From: Asger Geel Weirsoee <asger@weircon.dk>
Date: Mon, 2 Mar 2026 01:30:23 +0000
Subject: [PATCH] feat(#248): bootstrap django i18n from shared locale contract

---
 lobby/i18n.py                    | 22 ++++++----------------
 partyhub/i18n_bootstrap.py       | 30 ++++++++++++++++++++++++++++++
 partyhub/settings.py             |  9 ++++-----
 partyhub/tests_i18n_bootstrap.py | 28 ++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 21 deletions(-)
 create mode 100644 partyhub/i18n_bootstrap.py
 create mode 100644 partyhub/tests_i18n_bootstrap.py

diff --git a/lobby/i18n.py b/lobby/i18n.py
index 82fdc0d..bb449a8 100644
--- a/lobby/i18n.py
+++ b/lobby/i18n.py
@@ -1,37 +1,27 @@
-import json
 import logging
-from functools import lru_cache
-from pathlib import Path
 
 from django.http import HttpRequest, JsonResponse
 from django.utils.translation import get_language_from_request
 
+from partyhub.i18n_bootstrap import locale_config, shared_i18n_catalog
+
 LOGGER = logging.getLogger(__name__)
 
 
-@lru_cache(maxsize=1)
 def lobby_i18n_catalog() -> dict:
-    catalog_path = Path(__file__).resolve().parents[1] / "shared" / "i18n" / "lobby.json"
-    with catalog_path.open(encoding="utf-8") as handle:
-        return json.load(handle)
+    return shared_i18n_catalog()
 
 
-@lru_cache(maxsize=1)
 def i18n_locale_config() -> tuple[str, tuple[str, ...]]:
-    locales = lobby_i18n_catalog().get("locales", {})
-    default_locale = str(locales.get("default", "en")).strip().lower() or "en"
-    supported_locales = tuple(
-        locale.strip().lower() for locale in locales.get("supported", ["en", "da"]) if str(locale).strip()
-    ) or ("en", "da")
-    return default_locale, supported_locales
+    return locale_config()
 
 
 def lobby_i18n_errors() -> dict:
-    return lobby_i18n_catalog().get("backend", {}).get("error_codes", {})
+    return shared_i18n_catalog().get("backend", {}).get("error_codes", {})
 
 
 def lobby_i18n_error_messages() -> dict:
-    return lobby_i18n_catalog().get("backend", {}).get("errors", {})
+    return shared_i18n_catalog().get("backend", {}).get("errors", {})
 
 
 def _quality_value(language_candidate: str) -> float | None:
diff --git a/partyhub/i18n_bootstrap.py b/partyhub/i18n_bootstrap.py
new file mode 100644
index 0000000..fcbeee8
--- /dev/null
+++ b/partyhub/i18n_bootstrap.py
@@ -0,0 +1,30 @@
+import json
+from functools import lru_cache
+from pathlib import Path
+
+_LOCALE_LABELS = {
+    "en": "English",
+    "da": "Danish",
+}
+
+
+@lru_cache(maxsize=1)
+def shared_i18n_catalog() -> dict:
+    catalog_path = Path(__file__).resolve().parents[1] / "shared" / "i18n" / "lobby.json"
+    with catalog_path.open(encoding="utf-8") as handle:
+        return json.load(handle)
+
+
+@lru_cache(maxsize=1)
+def locale_config() -> tuple[str, tuple[str, ...]]:
+    locales = shared_i18n_catalog().get("locales", {})
+    default_locale = str(locales.get("default", "en")).strip().lower() or "en"
+    supported_locales = tuple(
+        locale.strip().lower() for locale in locales.get("supported", ["en", "da"]) if str(locale).strip()
+    ) or ("en", "da")
+    return default_locale, supported_locales
+
+
+def django_languages() -> list[tuple[str, str]]:
+    _default_locale, supported_locales = locale_config()
+    return [(locale, _LOCALE_LABELS.get(locale, locale.upper())) for locale in supported_locales]
diff --git a/partyhub/settings.py b/partyhub/settings.py
index 7ba1b97..70ae90c 100644
--- a/partyhub/settings.py
+++ b/partyhub/settings.py
@@ -1,6 +1,8 @@
 from pathlib import Path
 import os
 
+from partyhub.i18n_bootstrap import django_languages, locale_config
+
 BASE_DIR = Path(__file__).resolve().parent.parent
 
 
@@ -90,11 +92,8 @@ AUTH_PASSWORD_VALIDATORS = [
     {'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator'},
 ]
 
-LANGUAGE_CODE = 'en'
-LANGUAGES = [
-    ('en', 'English'),
-    ('da', 'Danish'),
-]
+LANGUAGE_CODE, _SUPPORTED_LOCALES = locale_config()
+LANGUAGES = django_languages()
 LOCALE_PATHS = [BASE_DIR / 'locale']
 TIME_ZONE = 'Europe/Copenhagen'
 USE_I18N = True
diff --git a/partyhub/tests_i18n_bootstrap.py b/partyhub/tests_i18n_bootstrap.py
new file mode 100644
index 0000000..73b2fa8
--- /dev/null
+++ b/partyhub/tests_i18n_bootstrap.py
@@ -0,0 +1,28 @@
+from django.conf import settings
+from django.test import TestCase
+
+from partyhub.i18n_bootstrap import django_languages, locale_config, shared_i18n_catalog
+
+
+class I18nBootstrapTests(TestCase):
+    def test_shared_catalog_bootstraps_default_and_supported_locales(self):
+        default_locale, supported_locales = locale_config()
+
+        self.assertEqual(default_locale, "en")
+        self.assertEqual(supported_locales, ("en", "da"))
+
+    def test_django_language_settings_bootstrap_from_shared_i18n_catalog(self):
+        default_locale, supported_locales = locale_config()
+
+        self.assertEqual(settings.LANGUAGE_CODE, default_locale)
+        self.assertEqual(tuple(code for code, _ in settings.LANGUAGES), supported_locales)
+        self.assertEqual(settings.LANGUAGES, django_languages())
+
+    def test_locale_contract_in_catalog_matches_django_language_codes(self):
+        catalog_locales = shared_i18n_catalog()["locales"]
+
+        self.assertEqual(settings.LANGUAGE_CODE, catalog_locales["default"])
+        self.assertEqual(
+            [code for code, _ in settings.LANGUAGES],
+            catalog_locales["supported"],
+        )