src/middleware/request_context.py

from __future__ import annotations

import logging
import time
import uuid
from collections.abc import Awaitable, Callable

from fastapi import Request, Response

logger = logging.getLogger("nexus.request")


async def request_context_middleware(
    request: Request,
    call_next: Callable[[Request], Awaitable[Response]],
) -> Response:
    request_id = request.headers.get("x-request-id") or str(uuid.uuid4())
    started = time.perf_counter()
    response: Response | None = None
    try:
        response = await call_next(request)
        return response
    finally:
        duration_ms = int((time.perf_counter() - started) * 1000)
        status_code = response.status_code if response else 500
        if response:
            response.headers["x-request-id"] = request_id
        logger.info(
            "request completed",
            extra={
                "request_id": request_id,
                "method": request.method,
                "path": request.url.path,
                "status_code": status_code,
                "duration_ms": duration_ms,
            },
        )