/*!
 * Copyright 2016 Amazon.com,
 * Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Amazon Software License (the "License").
 * You may not use this file except in compliance with the
 * License. A copy of the License is located at
 *
 *     http://aws.amazon.com/asl/
 *
 * or in the "license" file accompanying this file. This file is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, express or implied. See the License
 * for the specific language governing permissions and
 * limitations under the License.
 */

import { Buffer } from 'buffer/';

/** @class */
export default class CognitoJwtToken {
  /**
   * Constructs a new CognitoJwtToken object
   * @param {string=} token The JWT token.
   */
  constructor(token) {
    // Assign object
    this.jwtToken = token || '';
    this.payload = this.decodePayload();
  }

  /**
   * @returns {string} the record's token.
   */
  getJwtToken() {
    return this.jwtToken;
  }

  /**
   * @returns {int} the token's expiration (exp member).
   */
  getExpiration() {
    return this.payload.exp;
  }

  /**
   * @returns {int} the token's "issued at" (iat member).
   */
  getIssuedAt() {
    return this.payload.iat;
  }

  /**
   * @returns {object} the token's payload.
   */
  decodePayload() {
    const payload = this.jwtToken.split('.')[1];
    try {
      return JSON.parse(Buffer.from(payload, 'base64').toString('utf8'));
    } catch (err) {
      return {};
    }
  }
}
