Files
routstr-core/routstr/core/not_found.py
T
2026-05-14 15:40:49 +02:00

56 lines
1.6 KiB
Python

"""Shared 404 handler used by the proxy catch-all and tests."""
from __future__ import annotations
from pathlib import Path
from fastapi import Request
from fastapi.responses import HTMLResponse, JSONResponse, Response
_NOT_FOUND_HTML_FILE = Path(__file__).parent.parent.parent / "ui_out" / "404.html"
def _read_not_found_html() -> str | None:
try:
return _NOT_FOUND_HTML_FILE.read_text(encoding="utf-8")
except OSError:
return None
_NOT_FOUND_HTML: str | None = _read_not_found_html()
def build_not_found_response(request: Request, path: str) -> Response:
"""Return a 404 response.
HTML 404 page only for GET requests from browsers (Accept: text/html).
All POST requests and API clients receive a JSON 404.
"""
accept = request.headers.get("accept", "").lower()
prefers_html = (
request.method == "GET"
and "text/html" in accept
and "application/json" not in accept
)
request_id = getattr(request.state, "request_id", "unknown")
if prefers_html and _NOT_FOUND_HTML is not None:
return HTMLResponse(content=_NOT_FOUND_HTML, status_code=404)
return JSONResponse(
status_code=404,
content={
"error": {
"message": f"Path '/{path}' not found",
"type": "not_found",
"code": 404,
},
"request_id": request_id,
},
)
async def not_found_catch_all(request: Request, path: str) -> Response:
"""ASGI handler form of :func:`build_not_found_response`."""
return build_not_found_response(request, path)