import { REDIS_URL, REDIS_PASSWORD, QUEUE_PREFIX } from "@mcpedia/config";
import IORedis, { type RedisOptions } from "ioredis";

/**
 * Shared ioredis connection for BullMQ. BullMQ requires an ioredis instance and
 * internally duplicates it for blocking commands, so we keep the option objects
 * explicit (maxRetriesPerRequest: null is REQUIRED for the blocking
 * connection — a finite retry count causes "Connection in key mode" errors).
 */
function buildOptions(): RedisOptions {
  const opts: RedisOptions = {
    maxRetriesPerRequest: null,
    lazyConnect: true,
    enableOfflineQueue: true,
  };
  if (REDIS_PASSWORD) opts.password = REDIS_PASSWORD;
  return opts;
}

let _connection: IORedis | null = null;

/** Lazily-created singleton ioredis connection. */
export function getConnection(): IORedis {
  if (!_connection) {
    _connection = new IORedis(REDIS_URL, buildOptions());
    _connection.on("error", (err) => {
      // Log but don't crash the process on transient Redis errors.
      console.error("[queue] redis error:", err.message);
    });
  }
  return _connection;
}

export const BULLMQ_PREFIX = QUEUE_PREFIX;