index.js

const hmacsha1 = require('hmacsha1');
const uuidv4 = require('uuid/v4');
const sha1 = require('js-sha1');
const Base64 = require('js-base64').Base64;
const hex2bin = require('locutus/php/strings/hex2bin');
const crypto = require('crypto');

const masterKey = process.env.DOCX_API_KEY;
const docxpressoInstallation = 'https://cysae.a.docxpresso.com';

function returnLink(url, id, opt) {
  const uuid = uuidv4().replace(/-/g, '');
  const timestamp = Math.floor(new Date().getTime() / 1000);

  let control = ''
  control += id + '-';
  control += timestamp + '-' + uuid;
  control += '-' + opt;

  const dataKey = crypto.createHash('sha1').update(control).digest();
  const apiKey = crypto.createHmac('sha1', masterKey).update(dataKey).digest('hex');

  let addr = `${url}?uniqid=${uuid}&timestamp=${timestamp}&APIKEY=${apiKey}&options=${opt}`;

  return addr;
}


function previewDocument(id, responseURL = '', responseDataURI = '') {
  let url = `${docxpressoInstallation}/documents/preview/${id}`;

  const opt = {
    format: 'odt',
    responseURL,
    responseDataURI,
  }

  const optBase64 = Base64.encodeURI(JSON.stringify(opt));
  return returnLink(url, id, optBase64+',,');
}

module.exports.previewDocument = previewDocument