1 files changed, 19 insertions, 1 deletions

diff --git a/server/src/http_server.cppm b/server/src/http_server.cppm
index 12c83db..2bf3c63 100644
--- a/server/src/http_server.cppm
+++ b/server/src/http_server.cppm
@@ -200,7 +200,7 @@ auto cors_middleware(std::vector<std::string> const& allow_origins)
 }
 
 template <class Ctx>
-auto trace_id_middleware(
+auto expose_trace_id_middleware(
     Ctx ctx, bhttp::request_header<bhttp::fields>& req_hdr,
     next_handler_t<Ctx> next) -> net::awaitable<presponse>
 {
@@ -214,6 +214,24 @@ auto trace_id_middleware(
   co_return std::move(prersp);
 }
 
+template <class Ctx>
+auto expose_content_language_middleware(
+    Ctx ctx, bhttp::request_header<bhttp::fields>& req_hdr,
+    next_handler_t<Ctx> next) -> net::awaitable<presponse>
+{
+  std::ignore = req_hdr;
+  auto prersp = co_await next(std::move(ctx));
+  if (prersp.header().find(bhttp::field::content_language)
+          == prersp.header().end()
+      && std::has_facet<locale::bcp47_tag>(ctx.locale))
+  {
+    prersp.header().set(
+        bhttp::field::content_language,
+        std::use_facet<locale::bcp47_tag>(ctx.locale).tag());
+  }
+  co_return std::move(prersp);
+}
+
 struct keep_alive
 {
   bool value;