import { LogFn } from 'pino'
import defaultLogger from './logger'

export default function registerGracefulShutdown(
  this: any,
  closeHandlers: Array<() => Promise<any>> = [],
  {
    logger = {
      info: defaultLogger.info.bind(defaultLogger) as LogFn,
      error: defaultLogger.error.bind(defaultLogger) as LogFn,
    },
    timeout = 30,
  } = {}
) {
  // gracefully shutdown on SIGTERM or SIGINT signal
  process.once('SIGTERM', gracefulShutDown.bind(this, 'SIGTERM'))
  process.once('SIGINT', gracefulShutDown.bind(this, 'SIGINT'))

  async function gracefulShutDown(signal = 'SIGTERM') {
    logger.info(`got kill signal (${signal}), starting graceful shut down`)

    // shut down anyway after `timeout` seconds
    if (timeout) {
      setTimeout(() => {
        logger.error('could not finish in time, forcefully exiting')
        process.exit(1)
      }, timeout * 1000).unref()
    }

    // release resources
    let isError = false
    for (const handler of closeHandlers) {
      try {
        await Promise.resolve(handler())
      } catch (err) {
        logger.error(err, 'error happened during graceful shut down')
        isError = true
      }
    }

    if (isError) {
      process.exit(1)
    }

    logger.info('graceful shut down finished')
    process.kill(process.pid, signal)
  }
}