import { Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';
import rateLimit from 'express-rate-limit';

@Injectable()
export class RateLimiterMiddleware implements NestMiddleware {
  private limiter: ReturnType<typeof rateLimit>;

  constructor() {
    this.limiter = rateLimit({
      windowMs: 1 * 60 * 1000, // 1 minutes
      max: 100, // Limit each IP to 100 requests per windowMs
      standardHeaders: true, // Return rate limit info in the `RateLimit-*` headers
      legacyHeaders: false, // Disable the `X-RateLimit-*` headers
      message: {
        statusCode: 429,
        error: 'Too Many Requests',
        message: 'Rate limit exceeded. Please try again later.',
      },
      handler: (req: Request, res: Response) => {
        res.status(429).json({
          statusCode: 429,
          timestamp: new Date().toISOString(),
          path: req.url,
          message: 'Too many requests, please try again later',
        });
      },
    });
  }

  use(req: Request, res: Response, next: NextFunction) {
    this.limiter(req, res, next);
  }
}