'use strict';
const { RATE_LIMIT_WINDOW_MS } = require('./config');
const rateLimitBuckets = new Map();
function rateLimit(key, max, windowMs) {
const now = Date.now();
const bucket = rateLimitBuckets.get(key) || { count: 0, resetAt: now + windowMs };
if (now > bucket.resetAt) {
bucket.count = 0;
bucket.resetAt = now + windowMs;
}
bucket.count += 1;
rateLimitBuckets.set(key, bucket);
return { allowed: bucket.count <= max, remaining: Math.max(0, max - bucket.count), resetAt: bucket.resetAt };
}
function enforceRateLimit(req, res, max) {
const key = `${req.ip || 'unknown'}:${req.path}`;
const bucket = rateLimit(key, max, RATE_LIMIT_WINDOW_MS);
res.set('X-RateLimit-Limit', String(max));
res.set('X-RateLimit-Remaining', String(bucket.remaining));
res.set('X-RateLimit-Reset', String(Math.floor(bucket.resetAt / 1000)));
if (!bucket.allowed) {
res.status(429).json({ error: 'rate_limited' });
return false;
}
return true;
}
module.exports = { enforceRateLimit };
