From d30e1086f3767bfe29923829629e000f1f9b7812 Mon Sep 17 00:00:00 2001
From: Yusur Princeps <sakuragasaki46@gmail.com>
Date: Wed, 30 Jul 2025 13:00:41 +0200
Subject: [PATCH] add BabelTowerError

---
 CHANGELOG.md           | 2 +-
 src/suou/exceptions.py | 7 +++++++
 src/suou/i18n.py       | 6 +++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8510622..b89014a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,7 +8,7 @@
 + Add module `calendar` with `want_*` date type conversion utilities and `age_and_days()`
 + Move obsolete stuff to `obsolete` package (includes configparse 0.3 as of now)
 + Add `redact` module with `redact_url_password()`
-+ Add more exceptions: `NotFoundError()`
++ Add more exceptions: `NotFoundError()`, `BabelTowerError()`
 
 ## 0.4.0
 
diff --git a/src/suou/exceptions.py b/src/suou/exceptions.py
index c1fe496..7952bc7 100644
--- a/src/suou/exceptions.py
+++ b/src/suou/exceptions.py
@@ -45,6 +45,13 @@ class NotFoundError(LookupError):
     """
     The requested item was not found.
     """
+    # Werkzeug et al.
+    code = 404
+
+class BabelTowerError(NotFoundError):
+    """
+    The user requested a language that cannot be understood.
+    """
 
 __all__ = (
     'MissingConfigError', 'MissingConfigWarning', 'LexError', 'InconsistencyError', 'NotFoundError'
diff --git a/src/suou/i18n.py b/src/suou/i18n.py
index 7080019..254c104 100644
--- a/src/suou/i18n.py
+++ b/src/suou/i18n.py
@@ -23,6 +23,7 @@ import os
 import toml
 from typing import Mapping
 
+from .exceptions import BabelTowerError
 
 class IdentityLang:
     '''
@@ -81,7 +82,10 @@ class I18n(metaclass=ABCMeta):
     def load_lang(self, name: str, filename: str | None = None) -> I18nLang:
         if not filename:
             filename = self.filename_tmpl.format(lang=name, ext=self.EXT)
-        data = self.load_file(filename)
+        try:
+            data = self.load_file(filename)
+        except OSError as e:
+            raise BabelTowerError(f'unknown language: {name}') from e
         l = self.langs.setdefault(name, I18nLang())
         l.update(data[name] if name in data else data)
         if name != self.default_lang: