import Redis, { RedisOptions } from 'ioredis'

type RedisClientType = 'cache' | 'mq'
type RedisDataSourceOption = {
  url?: string
  cert?: string
}
export type RedisDataSourceOptions = {
  [key in RedisClientType]: RedisDataSourceOption
}

export class RedisDataSource {
  options: RedisDataSourceOptions

  cacheClient: Redis
  queueRedisClient: Redis

  constructor(options: RedisDataSourceOptions) {
    this.options = options

    const cacheClient = createIORedisClient('cache', this.options)
    if (!cacheClient) throw 'Error initializing cache redis client'

    this.cacheClient = cacheClient
    this.queueRedisClient =
      createIORedisClient('mq', this.options) || this.cacheClient // if mq is not defined, use cache
  }

  async shutdown(): Promise<void> {
    try {
      await this.cacheClient?.quit()

      if (this.queueRedisClient !== this.cacheClient) {
        await this.queueRedisClient.quit()
      }

      console.log('redis shutdown complete')
    } catch (err) {
      console.error('error while shutting down redis', err)
    }
  }
}

const createIORedisClient = (
  name: RedisClientType,
  options: RedisDataSourceOptions
): Redis | undefined => {
  const option = options[name]
  const redisURL = option.url
  if (!redisURL) {
    console.log(`no redisURL supplied: ${name}`)
    return undefined
  }

  const redisCert = option.cert
  const tls =
    redisURL.startsWith('rediss://') && redisCert
      ? {
          ca: redisCert,
          rejectUnauthorized: false,
        }
      : undefined

  const redisOptions: RedisOptions = {
    tls,
    name,
    connectTimeout: 10000,
    maxRetriesPerRequest: null,
    offlineQueue: false,
  }
  return new Redis(redisURL, redisOptions)
}