/**
 * RequestId middleware.
 * @file 请求链路 ID 中间件
 * @module middleware/request-id.middleware
 * @author zhxiao1124
 */

import { NextFunction, Request, Response } from "express";
import { validate as validateUuid, version as uuidVersion, v4 as uuidv4 } from "uuid";

export function RequestIdMiddleware(request: Request & { requestId?: string; startTime?: bigint }, response: Response, next: NextFunction) {
    const incomingRequestId = request.get("x-request-id");
    const requestId = incomingRequestId && validateUuid(incomingRequestId) && uuidVersion(incomingRequestId) === 4 ? incomingRequestId : uuidv4();

    request.requestId = requestId;
    request.startTime = process.hrtime.bigint();
    response.setHeader("X-Request-Id", requestId);
    next();
}