YouTube Plays Smart Home - Script

index.js

'use strict';

const fetch = require('isomorphic-fetch')
const delay = require('delay')

// Get Google Assistant code from https://github.com/googlesamples/assistant-sdk-nodejs
const {GoogleAssistant} = require('./google-assistant')
// Follow instructions in README to generate a credentials file and refer to it here
const assistant = new GoogleAssistant(require('./prod-credentials.json'))

// Get YouTube API key and place it in this file
const {apiKey} = require('./api-key.json')

const youtubeVideoDetails = 'https://www.googleapis.com/youtube/v3/videos'
const youtubeLiveChat = 'https://www.googleapis.com/youtube/v3/liveChat/messages'
let readChats = new Set()
let totalMessages = 0
let totalAuthors = new Set()

const getChatData = async (videoId) => {
    const videoDetailsPart = 'liveStreamingDetails'

    const detailsRaw = await fetch(`${youtubeVideoDetails}?part=liveStreamingDetails&id=${videoId}&key=${apiKey}`)
    const details = await detailsRaw.json()
    const liveChatId = details.items[0].liveStreamingDetails.activeLiveChatId

    const chatsRaw = await fetch(`${youtubeLiveChat}?liveChatId=${liveChatId}&part=snippet&key=${apiKey}`)
    const chats = await chatsRaw.json()
    const chatArray = []
    const newChatsArray = []
    chats.items.forEach(chatItem => {
      const message = chatItem.snippet.displayMessage
      const author = chatItem.snippet.authorChannelId

      chatArray.push(message)

      if (readChats.has(chatItem.id)) {
        return // We already processed this one
      }
      readChats.add(chatItem.id)

      totalMessages++
      totalAuthors.add(author)

      newChatsArray.push({message, author})
    });

    return {
        liveChatId: liveChatId,
        allChats: chatArray,
        newChats: newChatsArray
    }
}

async function asyncForEach(array, callback) {
  for (let index = 0; index < array.length; index++) {
    await callback(array[index], index, array)
  }
}

// Run indefinitely
(async function() {
  const videoId = 'ExTljyJWzGY' // Or whatever livestream ID that you have
  // Repeat indefinitely
  while (true) {
    const {newChats} = await getChatData(videoId)
    if (newChats && newChats.length > 0) {
      await asyncForEach(newChats, async ({message, author}) => {
        try {
          console.log(`    ${message}`)
          const response = await assistant.assist(message)
        } catch (e) {
          console.error(`Error: ${e}`)
        }
      })
      console.log(`Got ${newChats.length} new message(s) of a total ${totalMessages} from ${totalAuthors.size} unique users`)
    }
    // Add a delay so we don't accidentally exceed quota
    await delay(50); // Delay of 0.05s for polling YouTube
  }
})()

package.json

{
  "name": "youtube-plays-smart-home",
  "private": true,
  "version": "0.1.0",
  "description": "One-stopshop!",
  "engines": {
    "node": "^8.0.0"
  },
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "dependencies": {
    "dateformat": "^3.0.3",
    "delay": "^4.1.0",
    "firebase": "^3.1.0",
    "ip": "^1.1.3",
    "isomorphic-fetch": "^2.2.1",
    "pg": "4.x",
    "google-auth-library": "0.12.0",
    "google-proto-files": "^0.15.0",
    "google-protobuf": "^3.3.0",
    "grpc": "^1.0.0"
  },
  "repository": {
    "type": "git"
  }
}