import log4js from "logger";

const logger = log4js.getLogger("APP");

type Window = { count: number; resetAt: number };

const windows = new Map<string, Window>();

export function assertUnderRateLimit(key: string, max: number, windowMs: number) {
  const now = Date.now();
  let w = windows.get(key);
  if (!w || now > w.resetAt) {
    w = { count: 0, resetAt: now + windowMs };
    windows.set(key, w);
  }
  w.count += 1;
  if (w.count > max) {
    logger.warn("[RATE-LIMIT] key=%s count=%d max=%d — 请求被限流", key, w.count, max);
    throw createError({
      statusCode: 429,
      statusMessage: "请求过于频繁，请稍后再试",
    });
  }
}