/**
 * 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 config from "../../config";
import features from "../../features";
import type { IMetaPlaylistPrivateInfos, ISegment } from "../../manifest";
import Manifest from "../../manifest/classes";
import type { IParserResponse as IMPLParserResponse } from "../../parsers/manifest/metaplaylist";
import parseMetaPlaylist from "../../parsers/manifest/metaplaylist";
import type { ICdnMetadata, IParsedManifest } from "../../parsers/manifest/types";
import isNullOrUndefined from "../../utils/is_null_or_undefined";
import objectAssign from "../../utils/object_assign";
import type { CancellationSignal } from "../../utils/task_canceller";
import type {
  IChunkTimeInfo,
  ILoadedAudioVideoSegmentFormat,
  ILoadedTextSegmentFormat,
  IManifestParserOptions,
  IManifestParserRequestScheduler,
  IManifestParserResult,
  IRequestedData,
  ISegmentContext,
  ISegmentLoaderCallbacks,
  ISegmentLoaderOptions,
  ISegmentLoaderResultChunkedComplete,
  ISegmentLoaderResultSegmentCreated,
  ISegmentLoaderResultSegmentLoaded,
  ISegmentParserParsedInitChunk,
  ISegmentParserParsedMediaChunk,
  ITextTrackSegmentData,
  ITransportOptions,
  ITransportPipelines,
} from "../types";
import generateManifestLoader from "./manifest_loader";

/**
 * Get base - real - content from an offseted metaplaylist content.
 * @param {Object} mplContext
 * @returns {Object}
 */
function getOriginalContext(mplContext: ISegmentContext): ISegmentContext {
  const { segment } = mplContext;
  if (segment.privateInfos?.metaplaylistInfos === undefined) {
    throw new Error("MetaPlaylist: missing private infos");
  }
  const { isLive, periodStart, periodEnd, manifestPublishTime } =
    segment.privateInfos.metaplaylistInfos;
  const { originalSegment } = segment.privateInfos.metaplaylistInfos;
  return {
    segment: originalSegment,
    type: mplContext.type,
    language: mplContext.language,
    mimeType: mplContext.mimeType,
    baseCodecs: mplContext.baseCodecs,
    chosenCodec: mplContext.chosenCodec,
    isLive,
    periodStart,
    periodEnd,
    manifestPublishTime,
  };
}

/**
 * @param {Object} transports
 * @param {string} transportName
 * @param {Object} options
 * @returns {Object}
 */
function getTransportPipelines(
  transports: Partial<Record<string, ITransportPipelines>>,
  transportName: string,
  options: ITransportOptions,
): ITransportPipelines {
  const initialTransport = transports[transportName];
  if (initialTransport !== undefined) {
    return initialTransport;
  }

  const feature = features.transports[transportName];

  if (feature === undefined) {
    throw new Error(`MetaPlaylist: Unknown transport ${transportName}.`);
  }
  const transport = feature(options);
  transports[transportName] = transport;
  return transport;
}

/**
 * @param {Object} segment
 * @returns {Object}
 */
function getMetaPlaylistPrivateInfos(segment: ISegment): IMetaPlaylistPrivateInfos {
  const { privateInfos } = segment;
  if (privateInfos?.metaplaylistInfos === undefined) {
    throw new Error("MetaPlaylist: Undefined transport for content for metaplaylist.");
  }
  return privateInfos.metaplaylistInfos;
}
export default function (options: ITransportOptions): ITransportPipelines {
  const transports: Partial<Record<string, ITransportPipelines>> = {};

  const manifestLoader = generateManifestLoader({
    customManifestLoader: options.manifestLoader,
  });

  // remove some options that we might not want to apply to the
  // other streaming protocols used here
  const otherTransportOptions = objectAssign({}, options, {
    manifestLoader: undefined,
  });

  const manifestPipeline = {
    loadManifest: manifestLoader,

    parseManifest(
      manifestData: IRequestedData<unknown>,
      parserOptions: IManifestParserOptions,
      onWarnings: (warnings: Error[]) => void,
      cancelSignal: CancellationSignal,
      scheduleRequest: IManifestParserRequestScheduler,
    ): Promise<IManifestParserResult> {
      const url = manifestData.url ?? parserOptions.originalUrl;
      const { responseData } = manifestData;

      const mplParserOptions = {
        url,
        serverSyncInfos: options.serverSyncInfos,
      };
      const parsed = parseMetaPlaylist(responseData, mplParserOptions);

      return handleParsedResult(parsed);

      function handleParsedResult(
        parsedResult: IMPLParserResponse<IParsedManifest>,
      ): Promise<IManifestParserResult> {
        if (parsedResult.type === "done") {
          const manifest = new Manifest(parsedResult.value, options);
          return Promise.resolve({ manifest });
        }

        const parsedValue = parsedResult.value;
        const loaderProms = parsedValue.ressources.map((resource) => {
          const transport = getTransportPipelines(
            transports,
            resource.transportType,
            otherTransportOptions,
          );
          return scheduleRequest(loadSubManifest).then((data) =>
            transport.manifest.parseManifest(
              data,
              { ...parserOptions, originalUrl: resource.url },
              onWarnings,
              cancelSignal,
              scheduleRequest,
            ),
          );
          function loadSubManifest() {
            /*
             * Whether a ManifestLoader's timeout should be relied on here
             * is ambiguous.
             */
            const manOpts = {
              timeout: config.getCurrent().DEFAULT_REQUEST_TIMEOUT,
              connectionTimeout: config.getCurrent().DEFAULT_CONNECTION_TIMEOUT,
              cmcdPayload: undefined,
            };
            return transport.manifest.loadManifest(resource.url, manOpts, cancelSignal);
          }
        });

        return Promise.all(loaderProms).then((parsedReqs) => {
          const loadedRessources = parsedReqs.map((e) => e.manifest);
          return handleParsedResult(parsedResult.value.continue(loadedRessources));
        });
      }
    },
  };

  /**
   * @param {Object} segment
   * @returns {Object}
   */
  function getTransportPipelinesFromSegment(segment: ISegment): ITransportPipelines {
    const { transportType } = getMetaPlaylistPrivateInfos(segment);
    return getTransportPipelines(transports, transportType, otherTransportOptions);
  }

  /**
   * @param {number} contentOffset
   * @param {number|undefined} contentEnd
   * @param {Object} segmentResponse
   * @returns {Object}
   */
  function offsetTimeInfos(
    contentOffset: number,
    contentEnd: number | undefined,
    segmentResponse: ISegmentParserParsedMediaChunk<unknown>,
  ): {
    chunkInfos: IChunkTimeInfo | null;
    chunkOffset: number;
    appendWindow: [number | undefined, number | undefined];
  } {
    const offsetedSegmentOffset = segmentResponse.chunkOffset + contentOffset;
    if (isNullOrUndefined(segmentResponse.chunkData)) {
      return {
        chunkInfos: segmentResponse.chunkInfos,
        chunkOffset: offsetedSegmentOffset,
        appendWindow: [undefined, undefined],
      };
    }

    // clone chunkInfos
    const { chunkInfos, appendWindow } = segmentResponse;
    const offsetedChunkInfos = chunkInfos === null ? null : objectAssign({}, chunkInfos);
    if (offsetedChunkInfos !== null) {
      offsetedChunkInfos.time += contentOffset;
    }

    const offsetedWindowStart =
      appendWindow[0] !== undefined
        ? Math.max(appendWindow[0] + contentOffset, contentOffset)
        : contentOffset;

    let offsetedWindowEnd: number | undefined;
    if (appendWindow[1] !== undefined) {
      offsetedWindowEnd =
        contentEnd !== undefined
          ? Math.min(appendWindow[1] + contentOffset, contentEnd)
          : appendWindow[1] + contentOffset;
    } else if (contentEnd !== undefined) {
      offsetedWindowEnd = contentEnd;
    }
    return {
      chunkInfos: offsetedChunkInfos,
      chunkOffset: offsetedSegmentOffset,
      appendWindow: [offsetedWindowStart, offsetedWindowEnd],
    };
  }

  const audioPipeline = {
    loadSegment(
      wantedCdn: ICdnMetadata | null,
      context: ISegmentContext,
      loaderOptions: ISegmentLoaderOptions,
      cancelToken: CancellationSignal,
      callbacks: ISegmentLoaderCallbacks<ILoadedAudioVideoSegmentFormat>,
    ): Promise<
      | ISegmentLoaderResultSegmentLoaded<ILoadedAudioVideoSegmentFormat>
      | ISegmentLoaderResultSegmentCreated<ILoadedAudioVideoSegmentFormat>
      | ISegmentLoaderResultChunkedComplete
    > {
      const { segment } = context;
      const { audio } = getTransportPipelinesFromSegment(segment);
      const ogContext = getOriginalContext(context);
      return audio.loadSegment(
        wantedCdn,
        ogContext,
        loaderOptions,
        cancelToken,
        callbacks,
      );
    },

    parseSegment(
      loadedSegment: {
        data: ILoadedAudioVideoSegmentFormat;
        isChunked: boolean;
      },
      context: ISegmentContext,
      initTimescale: number | undefined,
    ):
      | ISegmentParserParsedInitChunk<ArrayBuffer | Uint8Array<ArrayBuffer> | null>
      | ISegmentParserParsedMediaChunk<ArrayBuffer | Uint8Array<ArrayBuffer> | null> {
      const { segment } = context;
      const { contentStart, contentEnd } = getMetaPlaylistPrivateInfos(segment);
      const { audio } = getTransportPipelinesFromSegment(segment);

      const ogContext = getOriginalContext(context);
      const parsed = audio.parseSegment(loadedSegment, ogContext, initTimescale);
      if (parsed.segmentType === "init") {
        return parsed;
      }
      const timeInfos = offsetTimeInfos(contentStart, contentEnd, parsed);
      return objectAssign({}, parsed, timeInfos);
    },
  };

  const videoPipeline = {
    loadSegment(
      wantedCdn: ICdnMetadata | null,
      context: ISegmentContext,
      loaderOptions: ISegmentLoaderOptions,
      cancelToken: CancellationSignal,
      callbacks: ISegmentLoaderCallbacks<ILoadedAudioVideoSegmentFormat>,
    ): Promise<
      | ISegmentLoaderResultSegmentLoaded<ILoadedAudioVideoSegmentFormat>
      | ISegmentLoaderResultSegmentCreated<ILoadedAudioVideoSegmentFormat>
      | ISegmentLoaderResultChunkedComplete
    > {
      const { segment } = context;
      const { video } = getTransportPipelinesFromSegment(segment);
      const ogContext = getOriginalContext(context);
      return video.loadSegment(
        wantedCdn,
        ogContext,
        loaderOptions,
        cancelToken,
        callbacks,
      );
    },

    parseSegment(
      loadedSegment: {
        data: ILoadedAudioVideoSegmentFormat;
        isChunked: boolean;
      },
      context: ISegmentContext,
      initTimescale: number | undefined,
    ):
      | ISegmentParserParsedInitChunk<ArrayBuffer | Uint8Array<ArrayBuffer> | null>
      | ISegmentParserParsedMediaChunk<ArrayBuffer | Uint8Array<ArrayBuffer> | null> {
      const { segment } = context;
      const { contentStart, contentEnd } = getMetaPlaylistPrivateInfos(segment);
      const { video } = getTransportPipelinesFromSegment(segment);
      const ogContext = getOriginalContext(context);
      const parsed = video.parseSegment(loadedSegment, ogContext, initTimescale);
      if (parsed.segmentType === "init") {
        return parsed;
      }
      const timeInfos = offsetTimeInfos(contentStart, contentEnd, parsed);
      return objectAssign({}, parsed, timeInfos);
    },
  };

  const textTrackPipeline = {
    loadSegment(
      wantedCdn: ICdnMetadata | null,
      context: ISegmentContext,
      loaderOptions: ISegmentLoaderOptions,
      cancelToken: CancellationSignal,
      callbacks: ISegmentLoaderCallbacks<ILoadedTextSegmentFormat>,
    ): Promise<
      | ISegmentLoaderResultSegmentLoaded<ILoadedTextSegmentFormat>
      | ISegmentLoaderResultSegmentCreated<ILoadedTextSegmentFormat>
      | ISegmentLoaderResultChunkedComplete
    > {
      const { segment } = context;
      const { text } = getTransportPipelinesFromSegment(segment);
      const ogContext = getOriginalContext(context);
      return text.loadSegment(
        wantedCdn,
        ogContext,
        loaderOptions,
        cancelToken,
        callbacks,
      );
    },

    parseSegment(
      loadedSegment: { data: ILoadedTextSegmentFormat; isChunked: boolean },
      context: ISegmentContext,
      initTimescale: number | undefined,
    ):
      | ISegmentParserParsedInitChunk<ITextTrackSegmentData | null>
      | ISegmentParserParsedMediaChunk<ITextTrackSegmentData> {
      const { segment } = context;
      const { contentStart, contentEnd } = getMetaPlaylistPrivateInfos(segment);
      const { text } = getTransportPipelinesFromSegment(segment);

      const ogContext = getOriginalContext(context);
      const parsed = text.parseSegment(loadedSegment, ogContext, initTimescale);
      if (parsed.segmentType === "init") {
        return parsed;
      }
      const timeInfos = offsetTimeInfos(contentStart, contentEnd, parsed);
      return objectAssign({}, parsed, timeInfos);
    },
  };

  return {
    transportName: "metaplaylist",
    manifest: manifestPipeline,
    audio: audioPipeline,
    video: videoPipeline,
    text: textTrackPipeline,
    thumbnails: {
      loadThumbnail: () =>
        Promise.reject(
          new Error("Thumbnail tracks aren't implemented with MetaPlaylist"),
        ),
      parseThumbnail: () => {
        throw new Error("Thumbnail tracks aren't implemented with MetaPlaylist");
      },
    },
  };
}