middleware.ts

import { Ratelimit } from '@upstash/ratelimit'
import { Redis } from '@upstash/redis'
import { type NextFetchEvent, type NextRequest, NextResponse } from 'next/server'
import env from './lib/env'

const redis = new Redis({
	url: env.UPSTASH_REDIS_REST_URL,
	token: env.UPSTASH_REDIS_REST_TOKEN
})

// Declaring the ratelimit object outside the middleware handler enables caching
const ratelimit = new Ratelimit({
	redis: redis,
	limiter: Ratelimit.slidingWindow(20, '10 s')
})

export default async function middleware(
	request: NextRequest,
	event: NextFetchEvent
): Promise<Response | undefined> {
	const { pathname } = request.nextUrl
	const ip = request.ip ?? '127.0.0.1'
	const { success } = await ratelimit.limit(ip)

	// API rate limiting
	if (pathname.startsWith('/api'))
		return success
			? NextResponse.next()
			: NextResponse.json({ success: false, message: 'Rate limit exceeded' }, { status: 429 })

	// Pages rate limiting
	return success ? NextResponse.next() : NextResponse.redirect(new URL('/blocked', request.url))
}

export const config = {
	// Match all pages, and API routes
	matcher: ['/', '/api/:function*']
}