import Redis from "ioredis";

let _redis = null;

function getRedis() {
  if (!_redis) {
    _redis = new Redis({
      host: process.env.REDIS_HOST || "127.0.0.1",
      port: parseInt(process.env.REDIS_PORT || "6379"),
      password: process.env.REDIS_PASSWORD || undefined,
      db: parseInt(process.env.REDIS_DB || "1"),
      lazyConnect: true,
      maxRetriesPerRequest: 2,
      retryStrategy: (times) => Math.min(times * 200, 3000),
    });
    _redis.on("error", (err) => {
      console.warn(`[redis-cache] Connection error: ${err.message}`);
    });
  }
  return _redis;
}

async function cacheGet(key) {
  try {
    const redis = getRedis();
    if (redis.status !== "ready") {
      await redis.connect().catch(() => {});
    }
    if (redis.status !== "ready") return null;
    const data = await redis.get(key);
    return data ? JSON.parse(data) : null;
  } catch {
    return null;
  }
}

async function cacheSet(key, value, ttlSeconds = 3600) {
  try {
    const redis = getRedis();
    if (redis.status !== "ready") {
      await redis.connect().catch(() => {});
    }
    if (redis.status !== "ready") return;
    await redis.set(key, JSON.stringify(value), "EX", ttlSeconds);
  } catch {
    // 静默失败，不影响主流程
  }
}

async function cacheDel(key) {
  try {
    const redis = getRedis();
    if (redis.status !== "ready") return;
    await redis.del(key);
  } catch {
    // 静默失败
  }
}

async function disconnectRedis() {
  if (_redis) {
    await _redis.quit().catch(() => {});
    _redis = null;
  }
}

export { getRedis, cacheGet, cacheSet, cacheDel, disconnectRedis };