middleware.ts

import { Ratelimit } from '@upstash/ratelimit'
import { Redis } from '@upstash/redis'
import { NextRequest, NextResponse } from 'next/server'

const ratelimit = new Ratelimit({
  redis: new Redis({
    url: process.env.UPSTASH_REDIS_REST_URL!,
    token: process.env.UPSTASH_REDIS_REST_TOKEN!,
  }),
  limiter: Ratelimit.slidingWindow(100, '1 m'),
  analytics: false,
})

export async function middleware(request: NextRequest) {
  const ip = request.headers.get('x-forwarded-for')?.split(',')[0]?.trim() ?? '127.0.0.1'

  const { success, limit, remaining, reset } = await ratelimit.limit(ip)

  if (!success) {
    return NextResponse.json(
      { error: 'Too many requests. Please try again later.' },
      {
        status: 429,
        headers: {
          'X-RateLimit-Limit': String(limit),
          'X-RateLimit-Remaining': String(remaining),
          'X-RateLimit-Reset': String(reset),
          'Retry-After': String(Math.ceil((reset - Date.now()) / 1000)),
        },
      }
    )
  }

  const response = NextResponse.next()
  response.headers.set('X-RateLimit-Limit', String(limit))
  response.headers.set('X-RateLimit-Remaining', String(remaining))
  response.headers.set('X-RateLimit-Reset', String(reset))
  return response
}

export const config = {
  matcher: '/api/:path*',
}