/**
 * 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 type { IPrivateInfos, ISegment } from "../../../../../manifest";
import isNullOrUndefined from "../../../../../utils/is_null_or_undefined";
import type { IEMSG } from "../../../../containers/isobmff";

/**
 * Construct init segment for the given index.
 * @param {Object} index
 * @param {function} isEMSGWhitelisted
 * @returns {Object}
 */
export default function getInitSegment(
  index: {
    timescale: number;
    initialization?:
      | { url: string | null; range?: [number, number] | undefined }
      | undefined;
    indexRange?: [number, number] | undefined;
    indexTimeOffset: number;
  },
  isEMSGWhitelisted?: (inbandEvent: IEMSG) => boolean,
): ISegment {
  const { initialization } = index;
  const privateInfos: IPrivateInfos = {};
  if (isEMSGWhitelisted !== undefined) {
    privateInfos.isEMSGWhitelisted = isEMSGWhitelisted;
  }

  return {
    id: "init",
    isInit: true,
    time: 0,
    end: 0,
    duration: 0,
    timescale: 1,
    range: !isNullOrUndefined(initialization) ? initialization.range : undefined,
    indexRange: index.indexRange,
    url: initialization?.url ?? null,
    complete: true,
    privateInfos,
    timestampOffset: -(index.indexTimeOffset / index.timescale),
  };
}