/**
 *
 * wechaty: Wechat for Bot. and for human who talk to bot/robot
 *
 * Licenst: ISC
 * https://github.com/zixia/wechaty
 *
 */
import { createServer, Socket } from 'net'

import {
  log,
}                   from './config'

export class Doctor {
  constructor() {
    log.verbose('Doctor', 'constructor()')
  }

  /**
   * https://gist.github.com/tedmiston/5935757
   */
  testTcp(): Promise<boolean> {
    log.verbose('Doctor', 'testTcp()')

    return new Promise<boolean>(async (resolve, reject) => {
      /**
       * Server
       */
      const server = createServer(socket => socket.pipe(socket))
      /**
       * Promise Reject
       */
      server.on('error', reject)
      server.on('close', () => log.silly('Doctor', 'testTcp() server closed'))

      server.listen(8788, 'localhost', () => {
        /**
         * Client
         */
        const client = new Socket()
        client.connect(8788, 'localhost', () => {
          log.silly('Doctor', 'testTcp() client connected')
          client.write('ding')
        })

        client.on('data', function(data) {
          /**
           * Promise Resolve
           */
          resolve(true)

          client.destroy() // kill client after server's response
        })
        /**
         * Promise Reject
         */
        client.on('error', reject)

        client.on('close', err => server.close())
      })
    })
  }
}