import IORedis from 'ioredis';
import logger from '@utils/logger';

const redisUrl = process.env.REDIS_URL || 'redis://localhost:6379';
const redisPassword = process.env.REDIS_PASSWORD || undefined;

// Throttle Redis error/close logs when Redis is down (avoid flooding terminal)
let lastRedisErrorLog = 0;
let lastRedisCloseLog = 0;
const REDIS_LOG_INTERVAL_MS = 2 * 60 * 1000; // 2 minutes

const redisOptions: any = {
  maxRetriesPerRequest: null, // Required for BullMQ
  enableReadyCheck: false,
  retryStrategy: (times: number) => {
    if (times > 5) {
      if (Date.now() - lastRedisErrorLog >= REDIS_LOG_INTERVAL_MS) {
        lastRedisErrorLog = Date.now();
        logger.error('[Redis] Connection failed after 5 attempts. TAT/Pause-Resume need Redis. Start Redis or ignore if not needed.');
      }
      return null;
    }
    return Math.min(times * 2000, 10000);
  },
  connectTimeout: 30000,
  commandTimeout: 20000,
  keepAlive: 30000,
  autoResubscribe: true,
  autoResendUnfulfilledCommands: true
};

if (redisPassword) {
  redisOptions.password = redisPassword;
  logger.info('[Redis] Using password authentication');
}

let sharedConnection: IORedis | null = null;

// Create a SINGLE shared connection for both Queue and Worker
export const getSharedRedisConnection = (): IORedis => {
  if (!sharedConnection) {
    logger.info(`[Redis] Connecting to ${redisUrl}`);
    
    sharedConnection = new IORedis(redisUrl, redisOptions);

    sharedConnection.on('connect', () => {
      logger.info(`[Redis] ✅ Connected successfully`);
    });

    sharedConnection.on('error', (err) => {
      const now = Date.now();
      if (now - lastRedisErrorLog >= REDIS_LOG_INTERVAL_MS) {
        lastRedisErrorLog = now;
        logger.error('[Redis] Connection error: ' + err.message + ' (next log in 2 min if still down)');
      }
    });

    sharedConnection.on('close', () => {
      const now = Date.now();
      if (now - lastRedisCloseLog >= REDIS_LOG_INTERVAL_MS) {
        lastRedisCloseLog = now;
        logger.warn('[Redis] Connection closed (next log in 2 min if still down)');
      }
    });
  }
  
  return sharedConnection;
};

// Export for backwards compatibility
export const sharedRedisConnection = getSharedRedisConnection();

export default sharedRedisConnection;