on-message.js

////////////////////////////////////////////////////////////////////////////
// Program: monster
// Purpose: monster all-in-one demo of Wechaty hot
// Authors: Tong Sun (c) 2018, All rights reserved
//          Huan LI  (c) 2018, All rights reserved
//          xinbenlv (c) 2017, All rights reserved
////////////////////////////////////////////////////////////////////////////

/**
 *   Wechaty - https://github.com/chatie/wechaty
 *
 *   @copyright 2016-2017 Huan LI <zixia@zixia.net>
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

const fs = require('fs')
const { hotImport } = require('hot-import')

import { MediaMessage, Misc, log } from 'wechaty'

export default async function onMessage (message) {
  try {
    const room      = message.room()
    const sender    = message.from()
    const content   = message.text()
    const roomName  = room ? `[${await room.topic()}] ` : ''

    process.stdout.write(
	`${roomName}<${sender.name()}>(${message.type()}:${message.typeSub()}): `)

    if (message instanceof MediaMessage) {
      saveMediaFile(message)
      return
    }

    console.log(`${Misc.digestEmoji(message)}`)
    // add an extra CR if too long
    if (content.length > 80) console.log("")

    const config = await hotImport('config.js')
    // Hot import! Try to change the msgKW1&2 to 'ping' & 'pong'
    // after the bot has already started!
    if (content === config.msgKW1) {
      await message.say(`${config.msgKW2}, thanks for ${config.msgKW1} me`)
      log.info('Bot', `REPLY: ${config.msgKW2}`)
    } else if (content === config.msgKW2) {
      await sender.say('ok, ${config.msgKW2} me is welcome, too.')
    } else if (/^hello/i.test(content)) {
      return `How are you, ${sender.name()} from ${roomName}`
    }
  } catch (e) {
    log.error('Bot', 'on(message) exception: %s' , e)
  }
}

async function saveMediaFile(message) {
  const filename = message.filename()
  console.log('IMAGE local filename: ' + filename)

  const fileStream = fs.createWriteStream(filename)

  process.stdout.write('saving...')
  try {
    const netStream = await message.readyStream()
    netStream
      .pipe(fileStream)
      .on('close', _ => {
        const stat = fs.statSync(filename)
        console.log(', saved as ', filename, ' size: ', stat.size)
      })
  } catch (e) {
    console.error('stream error:', e)
  }
}