import Redis from "ioredis";

declare global {
  // eslint-disable-next-line no-var
  var __redisClient: Redis | undefined;
}

export function getRedis(): Redis {
  if (!globalThis.__redisClient) {
    globalThis.__redisClient = new Redis({
      host: process.env.REDIS_HOST ?? "localhost",
      port: parseInt(process.env.REDIS_PORT ?? "6379", 10),
      password: process.env.REDIS_PASSWORD,
      retryStrategy: (times) => Math.min(times * 200, 30_000),
      lazyConnect: false,
      enableOfflineQueue: true,
      maxRetriesPerRequest: 3,
    });

    globalThis.__redisClient.on("error", (err) => {
      console.error("[redis] connection error:", err.message);
    });
  }

  return globalThis.__redisClient;
}

/**
 * BullMQ requires a dedicated connection with maxRetriesPerRequest: null.
 * Returns plain ConnectionOptions (not an ioredis instance) to avoid the
 * dual-ioredis type conflict between the top-level ioredis and BullMQ's
 * bundled copy.
 */
export function createBullMQConnection() {
  return {
    host: process.env.REDIS_HOST ?? "localhost",
    port: parseInt(process.env.REDIS_PORT ?? "6379", 10),
    password: process.env.REDIS_PASSWORD,
    maxRetriesPerRequest: null as null,
    enableOfflineQueue: true,
  };
}