index.js

const Telegraf = require('telegraf')
const TelegrafI18n = require('telegraf-i18n')
const rateLimit = require('telegraf-ratelimit')
const path = require('path')
const html = require('html-escaper')

const BOT_TOKEN = process.env.BOT_TOKEN
if (BOT_TOKEN === undefined) {
  console.error('ERROR: You need to provide an environment variable called BOT_TOKEN with the telegram bot token.')
  process.exit(1)
}
if (BOT_TOKEN.split(':').length !== 2 || BOT_TOKEN.split(':')[1].length !== 35) {
  console.error('ERROR: The environment variable BOT_TOKEN seems to be malformatted.')
  process.exit(1)
}

const bot = new Telegraf(BOT_TOKEN)

const i18n = new TelegrafI18n({
  defaultLanguage: 'en',
  allowMissing: true,
  directory: path.resolve(__dirname, 'locales')
})

bot.use(i18n.middleware())

const limitConfig = {
  window: 12000,
  limit: 4,
  keyGenerator: (ctx) => {
    if (ctx.chat !== undefined) { return ctx.chat.id } else if (ctx.from !== undefined) { return ctx.from.id } else { return 0 }
  },
  onLimitExceeded: (ctx, next) => {
    // Only rate limit in group chats:
    if (ctx.chat !== undefined && ctx.chat.type === 'private') next()
  }
}

bot.use(rateLimit(limitConfig))

const getAge = require('./idage.js')

let botName = ''

const getAgeString = (ctx, key) => {
  const idAgeHelpLink = `<a href="https://t.me/${botName}?start=idhelp">(?)</a>`
  const createDate = getAge(ctx.message[key].id)
  return ctx.i18n.t(createDate[0]) + ' ' + createDate[1] + ' ' + idAgeHelpLink
}

const getDateString = (ctx) => {
  const date = new Date(ctx.message.forward_date * 1000)
  return date.toUTCString()
}

const getAdminsString = async (chatId) => {
  const admins = await bot.telegram.getChatAdministrators(chatId)
  console.log(admins)
  const resStr = admins
    .map(a =>
      (a.status === 'creator' ? '⭐️' : (a.user.is_bot ? '🤖' : '👤')) + ' ' +
      (a.user.username ? '<a href="https://t.me/' + a.user.username + '">' : '') +
      html.escape(a.user.first_name + (a.user.last_name ? ' ' + a.user.last_name : ''))
        .substring(0, 35) +
      (a.user.username ? '</a>' : '')
    )
    .join('\n')

  console.log('AdminsString:', "'" + resStr + "'")
  return resStr
}

bot.start(ctx => {
  // Filter out group chats
  if (ctx.message.chat.type !== 'private') {
    return false
  }

  if (ctx.message.text === '/start idhelp') {
    ctx.reply(ctx.i18n.t('idhelp'), { parse_mode: 'HTML' })
  } else {
    // username may be not defined, first_name may be empty
    const userIdentity = ctx.chat.username || ctx.chat.first_name

    let comma = ''
    let username
    if (userIdentity) {
      username = html.escape(userIdentity)
      comma = ','
    } else {
      username = ctx.i18n.t('human')
    }

    let msgText = ctx.i18n.t('start', { comma, username })

    msgText += '\n\n' + treeify.renderTree(ctx.from, ctx.i18n.t('you_header'))
    ctx.replyWithHTML(msgText)
  }
})

bot.help(ctx => {
  ctx.reply(ctx.i18n.t('help'), { parse_mode: 'HTML' })
})

const treeify = require('./treeify.js')

bot.command('admins', async ctx => {
  if (ctx.chat.type === 'private' || ctx.chat.type === 'channel') {
    ctx.replyWithHTML(ctx.i18n.t('admin_private_chat'))
  } else {
    const adminsStr = await getAdminsString(ctx.chat.id)
    await ctx.replyWithHTML(ctx.i18n.t('admin_list', { adminsStr }), {
      disable_web_page_preview: true
    })
  }
})

bot.command('json', ctx => {
  if (ctx.message.reply_to_message === undefined) {
    ctx.replyWithHTML(ctx.i18n.t('json_needs_reply'))
  } else {
    const rtm = ctx.message.reply_to_message
    const jsonStr = html.escape(JSON.stringify(rtm, null, 2))
    if (jsonStr.length > 4096) {
      ctx.replyWithHTML(ctx.i18n.t('json_too_long'), {
        disable_web_page_preview: true
      })
    } else {
      ctx.replyWithHTML('<code>' + jsonStr + '</code>', {
        disable_web_page_preview: true
      })
    }
  }
})

bot.command('user', ctx => {
  if (ctx.message.reply_to_message === undefined) {
    ctx.replyWithHTML(ctx.i18n.t('user_needs_reply'))
  } else {
    const rtm = ctx.message.reply_to_message

    rtm.from.created = getAgeString({ message: rtm, i18n: ctx.i18n }, 'from')
    ctx.replyWithHTML(treeify.renderTree(rtm.from, ctx.i18n.t('user_header')), {
      disable_web_page_preview: true
    })
  }
})

bot.on('message', ctx => {
  if (ctx.message.chat.type === 'private') {
    handlePrivateChat(ctx)
  } else {
    handleGroupChat(ctx)
  }
})

async function handleGroupChat (ctx) {
  if (ctx.message.new_chat_members !== undefined) {
    if (ctx.message.new_chat_members.some(m => m.username === botName)) {
      // Bot was just added to group

      const adminsStr = await getAdminsString(ctx.chat.id)
      console.log(adminsStr)

      ctx.replyWithHTML(ctx.i18n.t('group_chat_start', {
        chatInfoStr: treeify.renderTree(ctx.chat, ctx.i18n.t('this_chat_header')),
        adminsStr
      }), {
        disable_web_page_preview: true
      })
    } else {
      // Other new members
      // TODO: For now, do nothing
    }
  }
}

function handlePrivateChat (ctx) {
  const renders = []

  // Render CURRENT USER
  if (ctx.message.from !== undefined) {
    ctx.from.created = getAgeString(ctx, 'from')
    renders.push(treeify.renderTree(ctx.from, ctx.i18n.t('you_header')))
  }

  // Render ORIGIN CHAT
  if (ctx.message.forward_from_chat !== undefined) {
    renders.push(treeify.renderTree(
      ctx.message.forward_from_chat, ctx.i18n.t('origin_chat_header')
    ))
  }

  // Render ORIGIN ACCOUNT
  if (
    ctx.message.forward_from !== undefined &&
    ctx.message.from.id !== ctx.message.forward_from.id
  ) {
    const fwfrom = ctx.message.forward_from

    if (fwfrom.first_name !== undefined) {
      fwfrom.created = getAgeString(ctx, 'forward_from')
    }
    renders.push(
      treeify.renderTree(fwfrom, ctx.i18n.t('forwarded_from_header'))
    )
  }

  if (ctx.message.forward_sender_name !== undefined) {
    const fwfrom = {
      hidden: ctx.i18n.t('user_hid_account')
    }
    renders.push(
      treeify.renderTree(fwfrom, ctx.i18n.t('forwarded_from_header'))
    )
  }

  // Render PHÒTOS
  if (ctx.message.photo !== undefined) {
    renders.push(treeify.renderTree({
      file_size: ctx.message.photo.pop().file_size
    }, ctx.i18n.t('image_header')))
  }

  // Render STICKERS
  if (ctx.message.sticker !== undefined) {
    const sticker = ctx.message.sticker

    // Remove all file_ids, as they vary between bots
    delete sticker.thumb
    renders.push(treeify.renderTree(sticker, ctx.i18n.t('sticker_header')))
  }

  // Render AUDIO
  if (ctx.message.audio !== undefined) {
    const audio = ctx.message.audio

    // Remove all file_ids, as they vary between bots
    delete audio.thumb
    delete audio.file_id

    renders.push(treeify.renderTree(audio, ctx.i18n.t('audio_header')))
  }

  // Render VIDEOS
  if (ctx.message.video !== undefined) {
    const video = ctx.message.video

    // Remove all file_ids, as they vary between bots
    delete video.thumb
    delete video.file_id

    renders.push(treeify.renderTree(video, ctx.i18n.t('video_header')))
  }

  // Render DOCUMENTS
  if (ctx.message.document !== undefined) {
    const document = ctx.message.document

    // Remove all file_ids, as they vary between bots
    delete document.file_id

    renders.push(treeify.renderTree(document, ctx.i18n.t('document_header')))
  }

  // Render native POLLS
  if (ctx.message.poll !== undefined) {
    const poll = ctx.message.poll

    // Rewrite options to plain array, since we don't get votes anyways.
    poll.options = poll.options.map(o => o.text)

    renders.push(treeify.renderTree(poll, ctx.i18n.t('poll_header')))
  }

  // Render MESSAGE INFO
  const msgInfo = {}

  // add message_id with link to original chat's message
  if (ctx.message.forward_from_message_id !== undefined) {
    const msgId = ctx.message.forward_from_message_id
    const fwdFrom = ctx.message.forward_from_chat
    msgInfo.message_id = (fwdFrom.username === undefined) ? msgId
      : `<a href="https://t.me/${fwdFrom.username}/${msgId}">${msgId}</a>`
  }

  // add original sending date of message
  if (ctx.message.forward_date !== undefined) {
    msgInfo.forward_date = getDateString(ctx)
  }

  // display hidden links
  const hiddenLinks =
    (ctx.message.entities === undefined) ? [] : ctx.message.entities
      .filter(e => e.type === 'text_link')
      .map(e => e.url)
  if (hiddenLinks.length > 0) {
    msgInfo.urls = hiddenLinks
  }

  // only add the 'Message' part if it contains elements
  if (Object.keys(msgInfo).length > 0) {
    renders.push(treeify.renderTree(msgInfo, ctx.i18n.t('message_header')))
  }

  ctx.reply(renders.join('\n\n'), {
    parse_mode: 'HTML', disable_web_page_preview: true
  })

  // console.debug(JSON.stringify(ctx.message, null, 2))
}

bot.on('inline_query', (ctx) => {
  const creationDate = getAge(ctx.from.id)
  const ageString = ctx.i18n.t(creationDate[0]) + ' ' + creationDate[1]
  ctx.from.created = ageString
  const msgText = treeify.renderTree(ctx.from, ctx.i18n.t('me_header'))
  const result = [{
    type: 'article',
    id: 'me_' + ctx.from.id,
    title: ctx.i18n.t('inline_query_your_info_header'),
    description: ctx.i18n.t('inline_query_your_info_text'),
    input_message_content: {
      message_text: msgText,
      parse_mode: 'HTML',
      disable_web_page_preview: true
    }
  }]
  ctx.answerInlineQuery(result, {
    is_personal: true,
    cache_time: 30
  })
})

const getUsername = async function () {
  const botInfo = await bot.telegram.getMe()
  botName = botInfo.username
}
getUsername()

bot.startPolling()