/**
 * Copyright 2015 CANAL+ Group
 *
 * Licensed 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 { base64ToBytes, bytesToBase64 } from "../../../utils/base64";

/** Wrap byte-based data and allow serialization of it into base64. */
export default class SerializableBytes {
  /**
   * The data itself. Named `initData` for legacy reasons (cannot be changed
   * because it has an impact on saved persistent session information.
   */
  public initData: Uint8Array;

  /**
   * Create a new `SerializableBytes`, wrapping the initialization data
   * given and allowing serialization into base64.
   * @param {Uint8Array} initData
   */
  constructor(initData: Uint8Array) {
    this.initData = initData;
  }

  /**
   * Convert it to base64.
   * `toJSON` is specially interpreted by JavaScript engines to be able to rely
   * on it when calling `JSON.stringify` on it or any of its parent objects:
   * https://tc39.es/ecma262/#sec-serializejsonproperty
   * @returns {string}
   */
  toJSON(): string {
    return bytesToBase64(this.initData);
  }

  /**
   * Decode a base64 sequence representing an initialization data back to an
   * Uint8Array.
   * @param {string}
   * @returns {Uint8Array}
   */
  static decode(base64: string): Uint8Array {
    return base64ToBytes(base64);
  }
}