fis_lib_vid/lib/data_host/web/broswer.dart

part of 'data_host.dart';

class _VidDataHostBroswer implements VidDataHostInterface {
  _VidDataHostBroswer(this.url);

  @override
  final String url;

  VidUsImageData? _data;

  VidFileDownloadCancelToken? _downloadCancelToken;

  @override
  int get frameCount => _data == null ? -1 : _data!.imageCount;

  @override
  VidUsProbe get probe => _data!.probe;

  @override
  Future<VidUsImageData?> getData() async => _data;

  @override
  Future<VidUsImage> getFrame(int index) async {
    if (_data == null) {
      throw Exception(
          "[VidDataHost] getFrame: must call load first and data is not null.");
    }
    return _data!.getImage(index);
  }

  @override
  Future<VidDataHostLoadInfo?> load() async {
    _downloadCancelToken = VidFileDownloadCancelToken();
    final bytes = await VidFileDownloader.download(
      url,
      cancelToken: _downloadCancelToken,
    );
    if (bytes != null && bytes.isNotEmpty) {
      _data = VidUsImageData(bytes);
      final info = VidDataHostLoadInfo(_data!.probe);
      return info;
    }
    return null;
  }

  @override
  Future<void> release() async {
    try {
      _downloadCancelToken?.cancel();
    } catch (e) {}
    _data = null;
  }
}