Disable caching for first-visit unlocalized homepage

mandelstudio/middleware_language_redirect.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from django.conf import settings
 from django.http import HttpRequest, HttpResponseRedirect
+from django.utils.cache import add_never_cache_headers, patch_vary_headers
 from django.utils.translation import (
     get_language_from_request,
     get_supported_language_variant,
@@ -36,7 +37,11 @@ class FirstVisitLanguageRedirectMiddleware:
         redirect_url = self._build_redirect_url(request)
         if redirect_url:
             return HttpResponseRedirect(redirect_url)
-        return self.get_response(request)
+        response = self.get_response(request)
+        if self._should_disable_home_cache(request):
+            patch_vary_headers(response, ("Accept-Language", "Cookie"))
+            add_never_cache_headers(response)
+        return response
 
     def _build_redirect_url(self, request: HttpRequest) -> str | None:
         if request.method != "GET":
@@ -100,3 +105,13 @@ class FirstVisitLanguageRedirectMiddleware:
             if normalized in self.supported_languages:
                 return normalized
         return None
+
+    def _should_disable_home_cache(self, request: HttpRequest) -> bool:
+        if request.method != "GET":
+            return False
+        if self.language_cookie_name in request.COOKIES:
+            return False
+        path = request.path_info or "/"
+        if path != "/":
+            return False
+        return not self._is_localized_path(path)