@preset-sdk/embedded/lib/guestTokenRefresh.js

Frontend SDK for embedding Preset data analytics into your own application

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.REFRESH_TIMING_BUFFER_MS = exports.MIN_REFRESH_WAIT_MS = exports.DEFAULT_TOKEN_EXP_MS = void 0;
exports.getGuestTokenRefreshTiming = getGuestTokenRefreshTiming;
const REFRESH_TIMING_BUFFER_MS = 5000; // refresh guest token early to avoid failed superset requests

exports.REFRESH_TIMING_BUFFER_MS = REFRESH_TIMING_BUFFER_MS;
const MIN_REFRESH_WAIT_MS = 10000; // avoid blasting requests as fast as the cpu can handle

exports.MIN_REFRESH_WAIT_MS = MIN_REFRESH_WAIT_MS;
const DEFAULT_TOKEN_EXP_MS = 300000; // (5 min) used only when parsing guest token exp fails
// when do we refresh the guest token?

exports.DEFAULT_TOKEN_EXP_MS = DEFAULT_TOKEN_EXP_MS;

function getGuestTokenRefreshTiming(currentGuestToken) {
  // atob converts a string from base64 https://developer.mozilla.org/en-US/docs/Web/API/atob
  const parsedJwt = JSON.parse(atob(currentGuestToken.split('.')[1]).toString()); // if exp is int, it is in seconds, but Date() takes milliseconds

  const exp = new Date(/[^0-9\.]/g.test(parsedJwt.exp) ? parsedJwt.exp : parseFloat(parsedJwt.exp) * 1000);
  const isValidDate = exp.toString() !== 'Invalid Date';
  const ttl = isValidDate ? Math.max(MIN_REFRESH_WAIT_MS, exp.getTime() - Date.now()) : DEFAULT_TOKEN_EXP_MS;
  return ttl - REFRESH_TIMING_BUFFER_MS;
}