youtube_explode/lib/src/videos/closed_captions/closed_caption_client.dart

import '../../extensions/helpers_extension.dart';
import '../../reverse_engineering/responses/responses.dart'
    hide ClosedCaption, ClosedCaptionPart, ClosedCaptionTrack;
import '../../reverse_engineering/youtube_http_client.dart';
import '../videos.dart';
import 'closed_caption.dart';
import 'closed_caption_format.dart';
import 'closed_caption_manifest.dart';
import 'closed_caption_part.dart';
import 'closed_caption_track.dart';
import 'closed_caption_track_info.dart';
import 'language.dart';

/// Queries related to closed captions of YouTube videos.
class ClosedCaptionClient {
  final YoutubeHttpClient _httpClient;

  /// Initializes an instance of [ClosedCaptionClient]
  ClosedCaptionClient(this._httpClient);

  /// Gets the manifest that contains information
  /// about available closed caption tracks in the specified video.
  Future<ClosedCaptionManifest> getManifest(
      dynamic videoId,
      {@Deprecated('Not used anymore, use track.isAutoGenerated to see if a track is autogenerated or not.') // ignore: lines_longer_than_80_chars
          bool autoGenerated = false,
      List<ClosedCaptionFormat> formats = const [
        ClosedCaptionFormat.srv1,
        ClosedCaptionFormat.srv2,
        ClosedCaptionFormat.srv3,
        ClosedCaptionFormat.ttml,
        ClosedCaptionFormat.vtt
      ]}) async {
    videoId = VideoId.fromString(videoId);
    var tracks = <ClosedCaptionTrackInfo>{};
    var videoInfoResponse =
        await VideoInfoResponse.get(_httpClient, videoId.value);
    var playerResponse = videoInfoResponse.playerResponse;

    for (final track in playerResponse.closedCaptionTrack) {
      for (final ext in formats) {
        tracks.add(ClosedCaptionTrackInfo(
            Uri.parse(track.url)
                .replaceQueryParameters({'fmt': ext.formatCode}),
            Language(track.languageCode, track.languageName),
            isAutoGenerated: track.autoGenerated,
            format: ext));
      }
    }
    return ClosedCaptionManifest(tracks);
  }

  /// Gets the actual closed caption track which is
  /// identified by the specified metadata.
  Future<ClosedCaptionTrack> get(ClosedCaptionTrackInfo trackInfo) async {
    var response =
        await ClosedCaptionTrackResponse.get(_httpClient, trackInfo.url);

    var captions = response.closedCaptions
        .where((e) => !e.text.isNullOrWhiteSpace)
        .map((e) => ClosedCaption(e.text, e.offset, e.duration,
            e.parts.map((f) => ClosedCaptionPart(f.text, f.offset))));
    return ClosedCaptionTrack(captions);
  }

  /// Returns the subtitles as a string.
  Future<String> getSubTitles(ClosedCaptionTrackInfo trackInfo) =>
      _httpClient.getString(trackInfo.url);
}