halkyon/halkyon_learn_flutter/test/feature/jellyfin/jellyfin_data_test.dart

import 'dart:convert';
import 'dart:io';

import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_learn_flutter/src/core/video/subtitles.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/bloc/watch_cubit.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/data/jellyfin_gateway.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/data/jellyfin_repository.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/data/jellyfin_store.dart';
import 'package:halkyon_learn_flutter/src/feature/jellyfin/model/jellyfin.dart';
import 'package:halkyon_learn_flutter/src/feature/tag/model/tag.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';

import '../../support/fake_jellyfin.dart';
import '../../support/sample_episode.dart';

/// A server answering as Jellyfin v12.2.0 does (its answers recorded),
/// noting each request.
MockClient jellyfin12(List<http.Request> requests) => MockClient((
  request,
) async {
  requests.add(request);
  http.Response json(Object? body, [int status = 200]) => http.Response.bytes(
    utf8.encode(jsonEncode(body)),
    status,
    headers: {
      'content-type': 'application/json; charset=utf-8',
    },
  );
  final token = request.headers['Authorization'] ?? '';
  final signedIn = token.contains('Token="t-1"');
  return switch ((request.method, request.url.path)) {
    // v12 writes this one in camelCase, the rest in PascalCase.
    ('GET', '/System/Info/Public') => json({
      'localAddress': 'http://172.17.0.2:8096',
      'serverName': 'Living room',
      'version': '12.2.0',
      'productName': 'Jellyfin Server',
      'id': 'e39b17f2',
      'startupWizardCompleted': true,
    }),
    // The people the server shows on its login screen, in either case of
    // field names; whether one has a password, which servers before v10.11
    // said, counts for nothing.
    ('GET', '/Users/Public') => json([
      {'Name': 'Demo', 'Id': 'u-2', 'HasPassword': false},
      {'name': 'mika', 'id': 'u-1', 'hasPassword': true},
    ]),
    ('POST', '/Users/AuthenticateByName') =>
      (jsonDecode(request.body) as Map<String, Object?>)['Pw'] == 'secret'
          ? json({
              'User': {'Name': 'mika', 'Id': 'u-1', 'ServerId': 'e39b17f2'},
              'AccessToken': 't-1',
              'ServerId': 'e39b17f2',
            })
          : json({'error': 'Invalid user or password'}, 401),
    _ when !signedIn => json(null, 401),
    ('GET', '/UserViews') => json({
      'Items': [
        {
          'Name': 'Anime',
          'Id': 'lib-1',
          'Type': 'CollectionFolder',
          'CollectionType': 'tvshows',
          'ImageTags': <String, String>{},
        },
        {
          'Name': 'Music',
          'Id': 'lib-2',
          'Type': 'CollectionFolder',
          'CollectionType': 'music',
        },
        {'Name': 'A book', 'Id': 'book-1', 'Type': 'Book'},
      ],
      'TotalRecordCount': 2,
    }),
    ('GET', '/Items/song-1') => json({
      'Name': '幽霊船戦',
      'Id': 'song-1',
      'Type': 'Audio',
      'AlbumArtists': [
        {'Name': '宝鐘マリン', 'Id': 'artist-1'},
      ],
      'ProviderIds': {'MusicBrainzTrack': 'mb-track-1'},
      'AlbumArtist': '宝鐘マリン',
      'Album': 'Ahoy!!',
      'HasLyrics': true,
      'IndexNumber': 3,
      'ParentIndexNumber': 1,
      'RunTimeTicks': 2000000000,
      'ImageTags': {'Primary': 'a1'},
    }),
    ('GET', '/Audio/song-1/Lyrics') => json({
      'Metadata': <String, Object?>{},
      'Lyrics': [
        {'Text': '海賊なら Yo-Ho!', 'Start': 68200000, 'Cues': <Object?>[]},
        {'Text': 'さぁ今旗のもとへ', 'Start': 95800000, 'Cues': <Object?>[]},
      ],
    }),
    ('GET', '/Items/ep-1') => json({
      'Name': 'Sample Journey S01E01',
      'Id': 'ep-1',
      'Type': 'Episode',
      'SeriesName': 'Sample Journey',
      'SeriesId': 'series-1',
      'ProviderIds': {'Tmdb': '9001', 'Tvdb': ''},
      'IndexNumber': 1,
      'ParentIndexNumber': 1,
      'RunTimeTicks': 520230000,
      'ImageTags': {'Primary': '898f'},
      'UserData': {'PlaybackPositionTicks': 260115000, 'Played': false},
    }),
    ('POST', '/Items/ep-1/PlaybackInfo') => json({
      'MediaSources': [
        {
          'Id': 'ep-1',
          'Container': 'mkv',
          'SupportsDirectPlay': true,
          'RunTimeTicks': 520230000,
          'MediaStreams': [
            {'Index': 0, 'Type': 'Video', 'Codec': 'h264'},
            {
              'Index': 1,
              'Type': 'Audio',
              'Language': 'ger',
              'Codec': 'aac',
              'IsDefault': true,
              'DisplayTitle': 'German - AAC - Stereo - Default',
            },
            {
              'index': 4,
              'type': 'Audio',
              'language': 'jpn',
              'codec': 'aac',
              'isDefault': true,
              'title': 'Japanese [Original]',
            },
            {
              'Index': 2,
              'Type': 'Subtitle',
              'Language': 'jpn',
              'Codec': 'ass',
              'IsTextSubtitleStream': true,
              'IsDefault': true,
              'DisplayTitle': '日本語 - Japanese - Default - ASS',
            },
            {
              'Index': 3,
              'Type': 'Subtitle',
              'Language': 'eng',
              'Codec': 'PGSSUB',
              'IsTextSubtitleStream': false,
              'DisplayTitle': 'English - PGSSUB',
            },
            {
              'Index': 5,
              'Type': 'Subtitle',
              'Language': 'jpn',
              'Codec': 'subrip',
              'IsTextSubtitleStream': true,
              'IsForced': true,
              'DisplayTitle': '日本語 - Japanese - Forced - SUBRIP',
            },
            {
              'Index': 6,
              'Type': 'Subtitle',
              'Language': 'jpn',
              'Codec': 'subrip',
              'IsTextSubtitleStream': true,
              'Title': 'closedcaptions',
              'DisplayTitle': 'closedcaptions - 日本語 - SUBRIP',
            },
            {
              'Index': 7,
              'Type': 'Subtitle',
              'Language': 'eng',
              'Codec': 'subrip',
              'IsTextSubtitleStream': true,
              'IsHearingImpaired': true,
              'DisplayTitle': 'English - SDH - SUBRIP',
            },
          ],
        },
      ],
      'PlaySessionId': 'ps-1',
    }),
    ('GET', '/Videos/ep-1/ep-1/Subtitles/2/0/Stream.vtt') =>
      http.Response.bytes(
        utf8.encode('WEBVTT\n\n00:00:01.000 --> 00:00:05.000\n今日は\n'),
        200,
      ),
    ('GET', '/Items/series-1') => json({
      'Name': 'Sample Journey',
      'Id': 'series-1',
      'Type': 'Series',
      'providerIds': {'Tmdb': '219109', 'Tvdb': '445566'},
    }),
    ('POST', '/Sessions/Playing/Stopped') => json(null, 204),
    _ => json(null, 404),
  };
});

void main() {
  group('HttpJellyfinGateway', () {
    late List<http.Request> requests;
    late HttpJellyfinGateway gateway;

    setUp(() {
      requests = [];
      gateway = HttpJellyfinGateway(
        jellyfin12(requests),
        device: (id: 'device-1', name: 'Linux', version: '0.13.0'),
      );
    });

    Future<JellyfinAccount> signIn() async => await gateway.signIn(
      await gateway.server(Uri.parse('http://jellyfin.local:8096')),
      'mika',
      'secret',
    );

    test(
      'finds a server and signs in, naming the app and the device',
      () async {
        final server = await gateway.server(
          Uri.parse('http://jellyfin.local:8096'),
        );
        expect(server.name, 'Living room');
        expect(server.version, '12.2.0');

        final account = await gateway.signIn(server, 'mika', 'secret');
        expect(account.userId, 'u-1');
        expect(account.token, 't-1');
        expect(
          requests.last.headers['Authorization'],
          'MediaBrowser Client="Halkyon Learn", Device="Linux", '
          'DeviceId="device-1", Version="0.13.0"',
        );
        await expectLater(
          gateway.signIn(server, 'mika', 'wrong'),
          throwsA(
            isA<JellyfinException>().having(
              (error) => error.problem,
              'problem',
              JellyfinProblem.wrongCredentials,
            ),
          ),
        );
      },
    );

    test('lists the people a server shows on its login screen', () async {
      final server = await gateway.server(
        Uri.parse('http://jellyfin.local:8096'),
      );

      expect(await gateway.publicUsers(server), const [
        JellyfinPublicUser(id: 'u-2', name: 'Demo'),
        JellyfinPublicUser(id: 'u-1', name: 'mika'),
      ]);
    });

    test('lists libraries of videos and of music, leaving out what is '
        'neither', () async {
      final account = await signIn();

      final libraries = await gateway.libraries(account);

      expect(libraries, [
        const JellyfinItem(
          id: 'lib-1',
          name: 'Anime',
          kind: JellyfinItemKind.library,
        ),
        const JellyfinItem(
          id: 'lib-2',
          name: 'Music',
          kind: JellyfinItemKind.library,
        ),
      ]);
      expect(requests.last.headers['Authorization'], contains('Token="t-1"'));
      expect(requests.last.url.queryParameters['userId'], 'u-1');
    });

    test('a playback has its subtitle and audio tracks, which are forced '
        'and which for the hard of hearing, and where to resume; the stream '
        'is the file as stored; subtitles come as WebVTT', () async {
      final account = await signIn();

      final playback = await gateway.playback(account, 'ep-1');

      expect(playback.playSessionId, 'ps-1');
      expect(playback.resumeAt.inSeconds, 26);
      expect(playback.subtitles, [
        const JellyfinSubtitleTrack(
          index: 2,
          title: '日本語 - Japanese - Default - ASS',
          language: 'jpn',
          isDefault: true,
        ),
        const JellyfinSubtitleTrack(
          index: 3,
          title: 'English - PGSSUB',
          language: 'eng',
          isText: false,
        ),
        const JellyfinSubtitleTrack(
          index: 5,
          title: '日本語 - Japanese - Forced - SUBRIP',
          language: 'jpn',
          isForced: true,
        ),
        // Captions for the hard of hearing are often marked by their name
        // alone.
        const JellyfinSubtitleTrack(
          index: 6,
          title: 'closedcaptions - 日本語 - SUBRIP',
          language: 'jpn',
          isHearingImpaired: true,
        ),
        const JellyfinSubtitleTrack(
          index: 7,
          title: 'English - SDH - SUBRIP',
          language: 'eng',
          isHearingImpaired: true,
        ),
      ]);
      expect(playback.audio, [
        const JellyfinAudioTrack(
          index: 1,
          title: 'German - AAC - Stereo - Default',
          language: 'ger',
          isDefault: true,
        ),
        const JellyfinAudioTrack(
          index: 4,
          title: 'Japanese [Original]',
          language: 'jpn',
          isDefault: true,
        ),
      ]);
      final stream = gateway.streamOf(account, playback);
      expect(stream.path, '/Videos/ep-1/stream');
      expect(stream.queryParameters, containsPair('static', 'true'));
      expect(
        await gateway.subtitles(account, playback, playback.subtitles.first),
        contains('今日は'),
      );
    });

    test('an item says what the metadata providers call it, and an episode '
        'its show, a song its artist', () async {
      final account = await signIn();

      final episode = await gateway.item(account, 'ep-1');
      expect(episode.providerIds, {'tmdb': '9001'});
      expect(episode.seriesId, 'series-1');
      expect((await gateway.item(account, 'series-1')).providerIds, {
        'tmdb': '219109',
        'tvdb': '445566',
      });
      final song = await gateway.item(account, 'song-1');
      expect(song.artistId, 'artist-1');
      expect(song.providerIds, {'musicbrainztrack': 'mb-track-1'});
    });

    test('a song is one, with its artist and whether it has lyrics, its '
        'lyrics timed line by line, none for a song without; a song streams '
        'as sound', () async {
      final account = await signIn();

      final song = await gateway.item(account, 'song-1');
      expect(song.kind, JellyfinItemKind.audio);
      expect(song.artist, '宝鐘マリン');
      expect(song.hasLyrics, isTrue);
      expect(song.seasonNumber, isNull);
      expect(await gateway.lyrics(account, 'song-1'), [
        (text: '海賊なら Yo-Ho!', start: const Duration(milliseconds: 6820)),
        (text: 'さぁ今旗のもとへ', start: const Duration(milliseconds: 9580)),
      ]);
      expect(await gateway.lyrics(account, 'song-2'), isEmpty);
      expect(
        gateway
            .streamOf(
              account,
              const JellyfinPlayback(
                itemId: 'song-1',
                mediaSourceId: 'song-1',
                playSessionId: 'ps-2',
                subtitles: [],
                audioOnly: true,
              ),
            )
            .path,
        '/Audio/song-1/stream',
      );
    });

    test('a token the server no longer takes is signed out; nothing '
        'answering is unreachable', () async {
      final server = await gateway.server(
        Uri.parse('http://jellyfin.local:8096'),
      );
      final stale = JellyfinAccount(
        server: server,
        userId: 'u-1',
        userName: 'mika',
        token: 'revoked',
      );
      await expectLater(
        gateway.libraries(stale),
        throwsA(
          isA<JellyfinException>().having(
            (error) => error.problem,
            'problem',
            JellyfinProblem.signedOut,
          ),
        ),
      );
      final offline = HttpJellyfinGateway(
        MockClient((_) => throw const SocketException('down')),
        device: (id: 'd', name: 'n', version: 'v'),
      );
      await expectLater(
        offline.server(Uri.parse('http://jellyfin.local:8096')),
        throwsA(
          isA<JellyfinException>().having(
            (error) => error.problem,
            'problem',
            JellyfinProblem.unreachable,
          ),
        ),
      );
    });

    test('reports where a video stopped, in ticks', () async {
      final account = await signIn();
      final playback = await gateway.playback(account, 'ep-1');

      await gateway.report(
        account,
        playback,
        const Duration(seconds: 21),
        stopped: true,
      );

      final body = jsonDecode(requests.last.body) as Map<String, Object?>;
      expect(requests.last.url.path, '/Sessions/Playing/Stopped');
      expect(body['PositionTicks'], 210000000);
      expect(body['PlaySessionId'], 'ps-1');
    });
  });

  group('JellyfinRepository', () {
    test("a song's lyrics are lines, each until the next, the last until "
        'the song ends; empty ones left out; untimed lyrics are text '
        'alone', () async {
      JellyfinRepository with_(List<({String text, Duration? start})> lines) =>
          JellyfinRepository(
            (_) => FakeJellyfinGateway(lyricsOf: {'song-1': lines}),
            signedInJellyfin(),
            deviceName: 'Test',
            appVersion: '1',
          );

      final timed = await with_(const [
        (text: '一', start: Duration(seconds: 1)),
        (text: ' ', start: Duration(seconds: 4)),
        (text: '二', start: Duration(seconds: 6)),
      ]).lyrics('song-1', runTime: const Duration(minutes: 3));
      expect(timed.synced, isTrue);
      expect(timed.lines, const [
        SubtitleCue(
          start: Duration(seconds: 1),
          end: Duration(seconds: 6),
          text: '一',
        ),
        SubtitleCue(
          start: Duration(seconds: 6),
          end: Duration(minutes: 3),
          text: '二',
        ),
      ]);

      final untimed = await with_(const [
        (text: '一', start: null),
        (text: '二', start: null),
      ]).lyrics('song-1');
      expect(untimed.synced, isFalse);
      expect([for (final line in untimed.lines) line.text], ['一', '二']);
    });

    test('an address is reached over HTTPS only, plain HTTP refused '
        'before anything is sent', () async {
      final asked = <Uri>[];
      final repository = JellyfinRepository(
        (_) => _Asking(asked),
        MemoryJellyfinStore(),
        deviceName: 'Test',
        appVersion: '1',
      );

      final server = await repository.find('jellyfin.example:8920');
      expect(server.address, Uri.parse('https://jellyfin.example:8920'));
      expect(asked, [Uri.parse('https://jellyfin.example:8920')]);

      asked.clear();
      await expectLater(
        repository.find('http://jellyfin.local:8096'),
        throwsA(
          isA<JellyfinException>().having(
            (error) => error.problem,
            'problem',
            JellyfinProblem.notEncrypted,
          ),
        ),
      );
      await expectLater(
        repository.find('httpsonly.local:8096'),
        throwsA(
          isA<JellyfinException>().having(
            (error) => error.problem,
            'problem',
            JellyfinProblem.unreachable,
          ),
        ),
      );
      expect(asked, [Uri.parse('https://httpsonly.local:8096')]);
    });

    test('a server on this machine may answer over plain HTTP: nothing '
        'leaves it', () async {
      final asked = <Uri>[];
      final repository = JellyfinRepository(
        (_) => _Asking(asked),
        MemoryJellyfinStore(),
        deviceName: 'Test',
        appVersion: '1',
      );

      expect(
        (await repository.find('localhost:8096')).address,
        Uri.parse('http://localhost:8096'),
      );
      expect(asked, [
        Uri.parse('https://localhost:8096'),
        Uri.parse('http://localhost:8096'),
      ]);
      expect(
        (await repository.find('http://127.0.0.1:8096')).address,
        Uri.parse('http://127.0.0.1:8096'),
      );
      expect(
        (await repository.find('http://[::1]:8096')).address.host,
        '::1',
      );
    });

    test('signing in is kept on the device; signing out forgets it and '
        'ends the session on the server', () async {
      final store = MemoryJellyfinStore();
      final gateway = FakeJellyfinGateway();
      final repository = JellyfinRepository(
        (_) => gateway,
        store,
        deviceName: 'Test',
        appVersion: '1',
      );

      await repository.signIn(fakeJellyfinServer, 'mika', 'secret');
      expect(store.kept?.account?.token, 'token-1');

      await repository.signOut();
      expect(store.kept?.account, isNull);
      expect(gateway.signedOut, ['token-1']);
    });

    test('Quick Connect signs in once the code is approved', () async {
      final gateway = FakeJellyfinGateway();
      final repository = JellyfinRepository(
        (_) => gateway,
        MemoryJellyfinStore(),
        deviceName: 'Test',
        appVersion: '1',
      );
      final code = await repository.startQuickConnect(fakeJellyfinServer);

      expect(
        await repository.finishQuickConnect(fakeJellyfinServer, code.secret),
        isFalse,
      );
      gateway.approved = true;
      expect(
        await repository.finishQuickConnect(fakeJellyfinServer, code.secret),
        isTrue,
      );
      expect(repository.account?.token, 'token-2');
    });

    test('a token the server refuses signs the device out', () async {
      final gateway = sampleJellyfin()..fail = JellyfinProblem.signedOut;
      final repository = JellyfinRepository(
        (_) => gateway,
        signedInJellyfin(),
        deviceName: 'Test',
        appVersion: '1',
      );

      await expectLater(
        repository.libraries(),
        throwsA(isA<JellyfinException>()),
      );

      expect(repository.account, isNull);
    });
  });

  test('what the device keeps comes back as it was kept', () {
    final state = JellyfinState(
      deviceId: 'device-1',
      account: JellyfinAccount(
        server: fakeJellyfinServer,
        userId: 'user-1',
        userName: 'mika',
        token: 'token-1',
      ),
    );

    expect(
      jellyfinStateFromJson(jsonDecode(jsonEncode(jellyfinStateToJson(state)))),
      state,
    );
    expect(jellyfinStateFromJson('not a state').deviceId, hasLength(32));
  });

  test('a line of two is one: Japanese joined as it is, others with a '
      'space', () {
    expect(oneLine('昨日、駅で\n友達に会いました。'), '昨日、駅で友達に会いました。');
    expect(oneLine('Yesterday I met\na friend.'), 'Yesterday I met a friend.');
  });

  group('the tracks in a language', () {
    const forced = JellyfinSubtitleTrack(
      index: 1,
      title: 'Japanese (forced)',
      language: 'jpn',
      isDefault: true,
      isForced: true,
    );
    const captions = JellyfinSubtitleTrack(
      index: 2,
      title: 'Japanese (SDH)',
      language: 'jpn',
      isHearingImpaired: true,
    );
    const full = JellyfinSubtitleTrack(
      index: 3,
      title: 'Japanese',
      language: 'jpn',
    );
    const english = JellyfinSubtitleTrack(
      index: 4,
      title: 'English',
      language: 'eng',
      isDefault: true,
    );

    test('the subtitles read are whole: never a forced track, which only '
        "covers what the sound doesn't say; captions for the hard of "
        'hearing only without plain ones', () {
      expect(subtitleTrackIn([forced, captions, full, english], 'ja'), full);
      expect(subtitleTrackIn([forced, captions, english], 'ja'), captions);
      expect(subtitleTrackIn([forced, english], 'ja'), isNull);
      expect(subtitleTrackIn([forced, captions, full, english], 'en'), english);
      expect(subtitleTrackIn([full], null), isNull);
    });

    test('the sound is in the language, whichever track the file marks '
        'default; a commentary or a description only without another', () {
      const german = JellyfinAudioTrack(
        index: 1,
        title: 'German',
        language: 'ger',
        isDefault: true,
      );
      const commentary = JellyfinAudioTrack(
        index: 2,
        title: "Director's commentary",
        language: 'jpn',
        isDefault: true,
      );
      const japanese = JellyfinAudioTrack(
        index: 3,
        title: 'Japanese [Original]',
        language: 'jpn',
      );
      expect(audioTrackIn([german, commentary, japanese], 'ja'), japanese);
      expect(audioTrackIn([german, commentary], 'ja'), commentary);
      expect(audioTrackIn([german], 'ja'), isNull);
      expect(audioTrackIn([german, japanese], null), isNull);
    });
  });

  group('the tags a word met on Jellyfin gets', () {
    const series = JellyfinItem(
      id: 'series-1',
      name: 'あかね噺',
      kind: JellyfinItemKind.series,
      providerIds: {'tmdb': '219109'},
    );
    const episode = JellyfinItem(
      id: 'ep-1',
      name: '第1話',
      kind: JellyfinItemKind.episode,
      seriesName: 'あかね噺',
      seriesId: 'series-1',
      seasonNumber: 1,
      episodeNumber: 1,
      providerIds: {'tmdb': '9001'},
    );
    const show = JellyfinTagId(
      ids: {'tmdb': '219109', 'jellyfin:server-1': 'series-1'},
    );

    test("an episode: its show, by the show's ids, and itself, by them and "
        'its number', () {
      expect(jellyfinTagsOf(episode, serverId: 'server-1', whole: series), (
        whole: (name: 'あかね噺', id: show),
        part: (
          name: 'あかね噺 S1 E1',
          id: JellyfinTagId(ids: show.ids, part: 'S1E1'),
        ),
      ));
    });

    test('without its show read, the show is known by its id on the '
        'server', () {
      expect(
        jellyfinTagsOf(episode, serverId: 'server-1').whole.id,
        const JellyfinTagId(ids: {'jellyfin:server-1': 'series-1'}),
      );
    });

    test('a film is one tag, by its own ids', () {
      expect(
        jellyfinTagsOf(
          const JellyfinItem(
            id: 'film-1',
            name: 'CODA',
            kind: JellyfinItemKind.movie,
            providerIds: {'tmdb': '776503', 'imdb': 'tt10366460'},
          ),
          serverId: 'server-1',
        ),
        (
          whole: (
            name: 'CODA',
            id: const JellyfinTagId(
              ids: {
                'tmdb': '776503',
                'imdb': 'tt10366460',
                'jellyfin:server-1': 'film-1',
              },
            ),
          ),
          part: null,
        ),
      );
    });

    test("a song: its artist, by the artist's ids, and itself, by its "
        'own', () {
      const song = JellyfinItem(
        id: 'song-1',
        name: 'Ahoy!!',
        kind: JellyfinItemKind.audio,
        artist: '宝鐘マリン',
        artistId: 'artist-1',
        providerIds: {'musicbrainztrack': 'mb-track-1'},
      );
      const marine = JellyfinItem(
        id: 'artist-1',
        name: '宝鐘マリン',
        kind: JellyfinItemKind.artist,
        providerIds: {'musicbrainzartist': 'mb-artist-1'},
      );
      const artist = JellyfinTagId(
        ids: {
          'musicbrainzartist': 'mb-artist-1',
          'jellyfin:server-1': 'artist-1',
        },
      );

      expect(jellyfinTagsOf(song, serverId: 'server-1', whole: marine), (
        whole: (name: '宝鐘マリン', id: artist),
        part: (
          name: '宝鐘マリン · Ahoy!!',
          id: JellyfinTagId(
            ids: artist.ids,
            part: 'musicbrainztrack:mb-track-1',
          ),
        ),
      ));
    });
  });

  test("a studyset's language finds Jellyfin's", () {
    expect(jellyfinLanguagesOf('ja'), {'jpn'});
    expect(jellyfinLanguagesOf('de-AT'), {'ger', 'deu'});
    expect(jellyfinLanguagesOf('tlh'), {'tlh'});
  });

  test("Jellyfin's language finds every name a player may give it", () {
    expect(languageNamesOf('jpn'), {'jpn', 'ja'});
    expect(languageNamesOf('ger'), {'ger', 'deu', 'de'});
    expect(languageNamesOf('tlh'), {'tlh'});
    expect(languageNamesOf(null), isEmpty);
  });
}

/// A gateway noting the addresses tried, finding a server at
/// `jellyfin.example` over HTTPS and on this machine over plain HTTP.
class _Asking(final List<Uri> _asked) extends FakeJellyfinGateway {
  @override
  Future<JellyfinServer> server(Uri address) async {
    _asked.add(address);
    final found = address.scheme == 'https'
        ? address.host == 'jellyfin.example'
        : const {'localhost', '127.0.0.1', '::1'}.contains(address.host);
    if (!found) {
      throw JellyfinException(problem: JellyfinProblem.unreachable);
    }
    return JellyfinServer(
      address: address,
      id: fakeJellyfinServer.id,
      name: fakeJellyfinServer.name,
      version: fakeJellyfinServer.version,
    );
  }
}