Extract HTML5 response helpers

services/api-server/src/api_server/html5_responses.py

@@ -0,0 +1,41 @@
+from __future__ import annotations
+
+from typing import Any
+
+from fastapi.responses import Response, StreamingResponse
+from fastapi.staticfiles import StaticFiles
+
+HTML5_SECURITY_HEADERS = {"X-Content-Type-Options": "nosniff"}
+
+
+class Html5StaticFiles(StaticFiles):
+    def file_response(self, *args, **kwargs):
+        response = super().file_response(*args, **kwargs)
+        response.headers.setdefault("Cache-Control", "public, max-age=86400")
+        response.headers.setdefault("X-Content-Type-Options", "nosniff")
+        return response
+
+
+def html5_sse_headers() -> dict[str, str]:
+    return {
+        "Cache-Control": "no-cache, no-transform",
+        "Connection": "keep-alive",
+        "X-Accel-Buffering": "no",
+        **HTML5_SECURITY_HEADERS,
+    }
+
+
+def html5_response(fragment: str) -> Response:
+    return Response(
+        fragment,
+        media_type="text/html; charset=utf-8",
+        headers={"Cache-Control": "no-cache, no-transform", **HTML5_SECURITY_HEADERS},
+    )
+
+
+def html5_sse_response(content: Any) -> StreamingResponse:
+    return StreamingResponse(
+        content,
+        media_type="text/event-stream",
+        headers=html5_sse_headers(),
+    )