import { Injectable, type NestMiddleware } from '@nestjs/common';
import { randomUUID } from 'node:crypto';
import type { NextFunction, Response } from 'express';

import type { RequestContext } from './request-context';

const REQUEST_ID_PATTERN = /^[a-zA-Z0-9_-]{8,64}$/;

@Injectable()
export class RequestIdMiddleware implements NestMiddleware {
  use(request: RequestContext, response: Response, next: NextFunction): void {
    const supplied = request.header('x-request-id');
    request.requestId = supplied && REQUEST_ID_PATTERN.test(supplied) ? supplied : randomUUID();
    response.setHeader('x-request-id', request.requestId);
    next();
  }
}