rate limit poc

packages/server/src/utils/rateLimit.ts

@@ -0,0 +1,56 @@
+import { NextFunction, Request, Response } from 'express'
+import { rateLimit, RateLimitRequestHandler } from 'express-rate-limit'
+
+interface RateLimit {
+    id: string
+    rateLimitObj: RateLimitRequestHandler
+}
+
+export const specificRouteLimiter: RateLimitRequestHandler = rateLimit({
+    windowMs: 1 * 60 * 1000, // 15 minutes
+    max: 1, // Limit each IP to 100 requests per windowMs
+    message: 'Too many requests, please try again later.'
+})
+
+let rateLimiters: RateLimit[] = []
+
+export function createRateLimiter(req: Request) {
+    const id = req.body.id
+    const duration = req.body.duration
+    const limit = req.body.limit
+    const message = req.body.message
+
+    const rateLimitObj: RateLimitRequestHandler = rateLimit({
+        windowMs: Number(duration),
+        max: limit,
+        handler: (req, res) => {
+            res.status(429).json({ error: message })
+        }
+    })
+
+    const existingIndex: number = rateLimiters.findIndex((rateLimit) => rateLimit.id === id)
+
+    if (existingIndex === -1) {
+        rateLimiters.push({
+            id,
+            rateLimitObj
+        })
+    } else {
+        rateLimiters[existingIndex] = {
+            id,
+            rateLimitObj
+        }
+    }
+}
+
+export function getRateLimiter(req: Request, res: Response, next: NextFunction) {
+    const id = req.params.id
+
+    const ratelimiter = rateLimiters.find((rateLimit) => rateLimit.id === id)
+
+    if (!ratelimiter) return next()
+
+    const idRateLimiter = ratelimiter.rateLimitObj
+
+    return idRateLimiter(req, res, next)
+}