import { promisify } from 'util'
import to from 'await-to-js'
import { readFile } from 'fs'
import { Client } from 'ssh2'
import logger from '@uci/logger'
let log = {} // declare module wide log to be set during construction

const read = promisify(readFile)
// ssh client is already an event emitter
class Ssh extends Client {
  constructor(opts={}) {
    super()
    this.opts = opts
    log = logger({ name: 'remote-code', file:'src/ssh.js', class:'Ssh', id: opts.id })
    this.ready = false
    // additional options available
    this.rpath = opts.rpath || '/opt'  // will cd to this path upon connect
  }

  async connect(copts = {}) {
    const opts = Object.assign({},this.opts,copts) // merge any changes pasted via connect
    // log.info('connection options ', opts)
    opts.readyTimeout = opts.readyTimeout | 5000  // default was 20 seconds...too long
    opts.privateKey = opts.privateKey || opts.privateKeyPath ? await read(opts.privateKeyPath) : null
    //  log.info(opts.privateKeyPath, opts.privateKey)
    super.connect(opts)
    return new Promise( (resolve,reject) => {
      this.on('ready', async () => {
        this.ready=true
        log.info(`connected to ${this.opts.host}`)
        resolve(`connected to ${this.opts.host}`)
      })
      this.on('error', (err) => {
        log.info('connection error', err)
        reject(err)
      })
    })
  }

  close() {
    this.ready=false
    this.end()
  }

  async exec(command = 'ls -la', opts={}) {
    if (!this.ready) {
      log.info('not connected, attempting connect first')
      let [err] = await to(this.connect())
      if (err) return err
    }
    // log.info('executing command ', command)
    const remote = this
    let superexec = super.exec.bind(this)
    return new Promise(function(resolve, reject) {
      let reply=[]
      let error=[]
      superexec(command, function(err, stream) {
        if (err) reject(err)
        stream.on('finish', () => {
          if (remote.opts.close || opts.close) {
            log.info('closing connection')
            remote.close
          }
          if (error.length!==0) remote.emit('client:error',error)
          resolve({command:command,reply:reply,error:error})
        })
          .on('data', function(data) {
            reply.push(data)
            log.info(`${remote.opts.host}$ ${data}`)
          }).stderr.on('data', function(data) {
            error.push(data)
            log.info(`${remote.opts.host}:ERR$ ${data}`)
          })
      }) // end super
    }) // end Promise
  }
}

export default  Ssh