export type RateLimiter = { check: (key: string) => boolean };

export function createRateLimiter(opts: {
  windowMs: number;
  max: number;
}): RateLimiter {
  const store = new Map<string, { count: number; resetAt: number }>();
  return {
    check(key: string): boolean {
      const now = Date.now();
      const entry = store.get(key);
      if (!entry || entry.resetAt <= now) {
        store.set(key, { count: 1, resetAt: now + opts.windowMs });
        return true;
      }
      if (entry.count >= opts.max) return false;
      entry.count += 1;
      return true;
    }
  };
}