airbnb/caravel

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
import jwt_decode from "jwt-decode";

export const REFRESH_TIMING_BUFFER_MS = 5000 // refresh guest token early to avoid failed superset requests
export const MIN_REFRESH_WAIT_MS = 10000 // avoid blasting requests as fast as the cpu can handle
export const DEFAULT_TOKEN_EXP_MS = 300000 // (5 min) used only when parsing guest token exp fails

// when do we refresh the guest token?
export function getGuestTokenRefreshTiming(currentGuestToken: string) {
  const parsedJwt = jwt_decode<Record<string, any>>(currentGuestToken);
  // 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;
}