app.js

require('dotenv').config();
const fs = require('fs');
const tough = require('tough-cookie');
const request = require('request-promise');
const Telegraf = require('telegraf');
const bot = new Telegraf(process.env.BOT_API);
const uuidv4 = require('uuid/v4');
const { Signale } = require('signale');
const del = require('del');

const logOptions = {
  types: {
    debug: {
      color: 'blue',
      label: 'debug'
    }
  }
};
const log = new Signale(logOptions);

bot.on('document', ctx => {
  if (
    ctx.message.document &&
    ctx.message.document.mime_type === 'application/pdf'
  ) {
    console.log(ctx.message.document);
    let document = ctx.message.document;
    bot.telegram.getFileLink(document.file_id).then(data => {
      ctx.reply('Received your file.');
      log.debug('File URL', data);

      let options = {
        method: 'GET',
        uri: data,
        resolveWithFullResponse: true
      };

      let uuid = uuidv4();

      //create temp folder for pdf and pptx
      if (!fs.existsSync('./temp/' + uuid)) {
        fs.mkdirSync('./temp/' + uuid);
      }

      let fileName = document.file_name.slice(0,document.file_name.length-4);
      
      //make request to download pdf file
      request(options)
        .pipe(fs.createWriteStream('./temp/' + uuid + '/' + fileName + '.pdf'))
        .on('finish', () => {
          //console.log('finish downloading pdf..');
          log.success('finish downloading pdf...');
          convert('./temp/' + uuid, fileName, ctx);
        })
        .on('error', error => {
          console.log('Error in creating map', error);
          //remove folder and tell user error.
        });
    });
  }
});

const convert = (path, fileName, ctx) => {
  request({
    method: 'POST',
    uri: 'https://simplypdf.com/api/convert',
    headers: {
      Accept: 'application/json',
      'Content-Type': 'multipart/form-data'
    },
    formData: {
      DynamicFile: fs.createReadStream(path + '/' + fileName + '.pdf'),
      OutputFormat: 'PowerPoint'
    },
    resolveWithFullResponse: true
  })
  .then(r => {
    console.log('response', r.body);
    ctx.reply('Converting your pdf.');

    let id = JSON.parse(r.body).id;
    let cookieValue = r.headers['set-cookie'][0]
      .split('=', 2)[1]
      .slice(0, 24);
    let cookie = new tough.Cookie({
      key: 'ASP.NET_SessionId',
      value: cookieValue,
      domain: 'simplypdf.com',
      httpOnly: true
    });
    let cookiejar = request.jar();
    cookiejar.setCookie(cookie, 'https://simplypdf.com');
    let options = {
      method: 'GET',
      uri: 'https://simplypdf.com/api/status/' + id,
      headers: {
        Accept: 'application/json'
      },
      jar: cookiejar,
      resolveWithFullResponse: true
    };

    checkStatusAndDownload(ctx, options, cookiejar, path, fileName);
  })
  .catch(err => {
    log.err('error @ converting', err);
    ctx.reply('There was an error uploading your file. Please try again.');
  });
};

const checkStatusAndDownload = (ctx, options, cookiejar, path, fileName) => {
  request(options).then(res => {
    console.log('status', res.body);
    let status = JSON.parse(res.body).status;
    setTimeout(() => {
      if (status === 'ready') {
        log.success('ppt is ready for download...');
        // console.log('ready for download...');
        let id = JSON.parse(res.body).id;
        let options = {
          method: 'GET',
          uri: 'https://simplypdf.com/api/download/' + id,
          jar: cookiejar,
          resolveWithFullResponse: true
        };

        
        request(options)
          .pipe(fs.createWriteStream(path + '/' + fileName + '.pptx'))
          .on('finish', () => {
            log.success('finish downloading pptx...');
            ctx.reply('finish downloading pptx.');
            ctx.replyWithDocument({
                source: path + '/' + fileName + '.pptx',
                filename: fileName + '.pptx'
              })
              .then(() => {
                del([path]).then(paths => {
                  log.debug('Deleted files and folders:\n', paths.join('\n'));
                });
              });
          })
          .on('error', function(error) {
            console.log('Error in creating map', error);
          });
      } else {
        log.error('ppt not ready');
        checkStatusAndDownload(ctx, options, cookiejar, path, fileName);
      }
    }, 5000);
  });
};

bot.command('start', ctx => {
  ctx.reply(
    'I convert PDF to PPTX. Simply drag and drop your PDF file 📎 and magically a PPTX will be sent to you.'
  );
});

bot.command('help', ctx => {
  ctx.reply(
    '/help'
  );
});

bot.startPolling();