index.js

var fs = require('fs');
var readline = require('readline');
var {google} = require('googleapis');
var OAuth2 = google.auth.OAuth2;
const connectDB = require('./config/db');
connectDB();
var Donator = require("./models/donations");



// If modifying these scopes, delete your previously saved credentials
// at ~/.credentials/youtube-nodejs-quickstart.json
var SCOPES = ['https://www.googleapis.com/auth/youtube.readonly', 'https://www.googleapis.com/auth/youtube.upload', 'https://www.googleapis.com/auth/youtubepartner', 'https://www.googleapis.com/auth/youtube', 'https://www.googleapis.com/auth/youtube.force-ssl'];
var TOKEN_DIR = (process.env.HOME || process.env.HOMEPATH ||
    process.env.USERPROFILE) + '/.credentials/';
var TOKEN_PATH = TOKEN_DIR + 'youtube-nodejs-quickstart.json';

// Load client secrets from a local file. 
fs.readFile('json file name containing client secret, id, redirect url', function processClientSecrets(err, content) {
  if (err) {
    console.log('Error loading client secret file: ' + err);
    return;
  }
  // Authorize a client with the loaded credentials, then call the YouTube API.
  authorize(JSON.parse(content), updateVideoTitle);
  
});

/**
 * Create an OAuth2 client with the given credentials, and then execute the
 * given callback function.
 *
 * @param {Object} credentials The authorization client credentials.
 * @param {function} callback The callback to call with the authorized client.
 */
function authorize(credentials, callback) {
  var clientSecret = credentials.web.client_secret;
  var clientId = credentials.web.client_id;
  var redirectUrl = credentials.web.redirect_uris[0];
  var oauth2Client = new OAuth2(clientId, clientSecret, redirectUrl);

  // Check if we have previously stored a token.
  fs.readFile(TOKEN_PATH, function(err, token) {
    if (err) {
      getNewToken(oauth2Client, callback);
    } else {
      oauth2Client.credentials = JSON.parse(token);
      callback(oauth2Client);
    }
  });
}

/**
 * Get and store new token after prompting for user authorization, and then
 * execute the given callback with the authorized OAuth2 client.
 *
 * @param {google.auth.OAuth2} oauth2Client The OAuth2 client to get token for.
 * @param {getEventsCallback} callback The callback to call with the authorized
 *     client.
 */
function getNewToken(oauth2Client, callback) {
  var authUrl = oauth2Client.generateAuthUrl({
    access_type: 'offline',
    scope: SCOPES
  });
  console.log('Authorize this app by visiting this url: ', authUrl);
  var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
  });
  rl.question('Enter the code from that page here: ', function(code) {
    rl.close();
    oauth2Client.getToken(code, function(err, token) {
      if (err) {
        console.log('Error while trying to retrieve access token', err);
        return;
      }
      oauth2Client.credentials = token;
      storeToken(token);
      callback(oauth2Client);
    });
  });
}

/**
 * Store token to disk be used in later program executions.
 *
 * @param {Object} token The token to store to disk.
 */
function storeToken(token) {
  try {
    fs.mkdirSync(TOKEN_DIR);
  } catch (err) {
    if (err.code != 'EEXIST') {
      throw err;
    }
  }
  fs.writeFile(TOKEN_PATH, JSON.stringify(token), (err) => {
    if (err) throw err;
    console.log('Token stored to ' + TOKEN_PATH);
  });
}

/**
 * Lists the names and IDs of up to 10 files.
 *
 * @param {google.auth.OAuth2} auth An authorized OAuth2 client.
 */

function updateVideoTitle(auth) {
  Donator.find({})
  .then((allfetched) => {
    var amount = Math.round(
      allfetched.reduce((acc, val) => acc + parseFloat(val.amount), 0)
    );
    console.log(amount);
    const service = google.youtube('v3');
    service.videos.update({
        auth: auth,
        part: 'snippet',
        resource: {
            id: process.env.VIDEO_ID,
            snippet: {
                title: `${amount}`,
                categoryId: 26 //add your own category
            }
        }
    }, function(err, response) {
      if (err) {
        console.log('The API returned an error: ' + err);
        return;
      }else{
        console.log("check the video!");
      }
    });
    })
  .catch((err) =>
    console.log(err)
  );  
  
}