import { Redis } from "ioredis";
import { getEnv } from "./env.js";

let cacheClient: Redis | null = null;
let queueClient: Redis | null = null;
let cacheDown = false;

/** Redis client for the API cache: fail fast (no offline queue) so a Redis outage never blocks a request. */
export function getCacheRedis(): Redis | null {
  if (cacheDown) return null;
  if (!cacheClient) {
    const c = new Redis(getEnv().redisUrl, { lazyConnect: true, enableOfflineQueue: false, maxRetriesPerRequest: 1, connectTimeout: 2_000, retryStrategy: (n: number) => (n > 20 ? null : Math.min(30_000, 500 * n)) });
    c.on("error", () => { /* handled by callers: null/undefined results */ });
    c.on("end", () => { cacheDown = true; });
    c.connect().catch(() => { /* retried by ioredis */ });
    cacheClient = c;
  }
  return cacheClient;
}

/** Redis connection for BullMQ (requires maxRetriesPerRequest: null) and worker status keys. */
export function getQueueRedis(): Redis {
  if (!queueClient) {
    const c = new Redis(getEnv().redisUrl, { lazyConnect: true, maxRetriesPerRequest: null, enableOfflineQueue: true, connectTimeout: 3_000 });
    c.on("error", () => { /* surfaced through BullMQ / ops calls */ });
    queueClient = c;
  }
  return queueClient;
}

export async function redisPing(): Promise<boolean> {
  try {
    const r = getQueueRedis();
    if (r.status === "wait") await r.connect().catch(() => {});
    const pong = await Promise.race([r.ping(), new Promise<string>((_, rej) => setTimeout(() => rej(new Error("timeout")), 1500))]);
    return pong === "PONG";
  } catch {
    return false;
  }
}

export async function closeRedis(): Promise<void> {
  await Promise.allSettled([cacheClient?.quit(), queueClient?.quit()]);
  cacheClient = null;
  queueClient = null;
}