import '../models/channel_details.dart';
import 'youtube_service.dart';

class ChannelPreviewMetadataService {
  ChannelPreviewMetadataService._();

  static final ChannelPreviewMetadataService instance =
      ChannelPreviewMetadataService._();

  final YoutubeService _youtube = YoutubeService();

  final Map<String, Future<ChannelDetails?>> _channelCache =
      <String, Future<ChannelDetails?>>{};

  Future<ChannelDetails?> getChannel(
    String? channelId,
  ) {
    final id = channelId?.trim() ?? '';

    if (id.isEmpty) {
      return Future<ChannelDetails?>.value(null);
    }

    return _channelCache.putIfAbsent(
      id,
      () => _youtube.getChannelPreviewDetails(id),
    );
  }

  void invalidate(String channelId) {
    _channelCache.remove(channelId);
  }
}