++

backend/app/api/presets.py

@@ -1,9 +1,35 @@
-from fastapi import APIRouter
+from __future__ import annotations
+
+from fastapi import APIRouter, Request
+
 from app.presets import PRESETS
+from app.services.i18n import DEFAULT_LOCALE, locale_from_request
 
 router = APIRouter(prefix="/api")
 
 
+def _localize(value, locale: str):
+    """Recursively unwrap {en, zh} dicts to the requested locale.
+
+    Falls back to the default locale, then to the first available value.
+    Strings (and other scalars) are returned as-is.
+    """
+    if isinstance(value, dict):
+        # Heuristic: dicts with only "en"/"zh" keys are translation maps.
+        keys = set(value.keys())
+        if keys <= {"en", "zh"}:
+            if locale in value:
+                return value[locale]
+            if DEFAULT_LOCALE in value:
+                return value[DEFAULT_LOCALE]
+            return next(iter(value.values()))
+        return {k: _localize(v, locale) for k, v in value.items()}
+    if isinstance(value, list):
+        return [_localize(v, locale) for v in value]
+    return value
+
+
 @router.get("/presets")
-async def get_presets():
-    return {"presets": PRESETS}
+async def get_presets(request: Request):
+    locale = locale_from_request(request)
+    return {"presets": _localize(PRESETS, locale)}