import 'dart:convert';
import 'package:flutter_test/flutter_test.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:melo_app/services/cloud_service.dart';

/// CloudService-Tests mit http-Mocks (package:http/testing.dart — Teil von
/// http, kein neues Package). Abgedeckt: LWW-Sync-Konflikt-Pfade (updated_at
/// bleibt für den Client-Vergleich erhalten), Auth-Fehler (401) und
/// Netzwerkfehler (alle Pfade failen sauber statt zu crashen).
void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  http.Response jsonOk(Map<String, dynamic> body) =>
      http.Response(jsonEncode(body), 200,
          headers: {'content-type': 'application/json'});

  group('login (Auth)', () {
    test('200 → verbunden (true)', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 200)),
      );
      expect(await cloud.login('dustin'), isTrue);
    });

    test('401 (Auth-Fehler) → false', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.login('dustin'), isFalse);
    });

    test('Netzwerkfehler → false (kein Crash)', () async {
      final cloud = CloudService(
        client: MockClient(
            (req) async => throw http.ClientException('Verbindung weg')),
      );
      expect(await cloud.login('dustin'), isFalse);
    });
  });

  group('verbinde()', () {
    test('ohne Benutzer → Status fehler (kein Request)', () async {
      var requests = 0;
      final cloud = CloudService(
        client: MockClient((req) async {
          requests++;
          return http.Response('{}', 200);
        }),
      );
      await cloud.verbinde();
      expect(cloud.verbindungGestartet, isTrue);
      expect(cloud.status, CloudStatus.fehler);
      expect(cloud.istVerbunden, isFalse);
      expect(requests, 0);
    });
  });

  group('statusDaten (Auth-Fehler)', () {
    test('200 → JSON-Map', () async {
      final cloud = CloudService(
        client: MockClient(
            (req) async => jsonOk({'songs': 5, 'users': 2})),
      );
      final d = await cloud.statusDaten();
      expect(d, isNotNull);
      expect(d!['songs'], 5);
    });

    test('401 → null (Token abgelaufen)', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.statusDaten(), isNull);
    });

    test('Netzwerkfehler → null', () async {
      final cloud = CloudService(
        client: MockClient(
            (req) async => throw http.ClientException('offline')),
      );
      expect(await cloud.statusDaten(), isNull);
    });
  });

  group('syncChanges — LWW-Sync-Konflikt-Pfade', () {
    test('parst Changes inkl. updated_at (Grundlage für LWW-Vergleich)',
        () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({
              'changes': [
                {
                  'id': 'song-1',
                  'title': 'Neu vom Server',
                  'updated_at': '2026-08-04T10:00:00Z',
                },
                {
                  'id': 'song-2',
                  'title': 'Älterer Eintrag',
                  'updated_at': '2026-08-04T09:00:00Z',
                },
              ],
            })),
      );
      final changes = await cloud.syncChanges('2026-08-04T08:00:00Z');
      expect(changes, hasLength(2));
      // LWW-Vertrag: Timestamps bleiben unverändert erhalten, damit der
      // Client lokal neueren Stand (Upload via syncAll) von server-neuerem
      // Stand (Übernahme) unterscheiden kann.
      expect(changes[0]['updated_at'], '2026-08-04T10:00:00Z');
      expect(changes[1]['updated_at'], '2026-08-04T09:00:00Z');
      expect(changes[0]['title'], 'Neu vom Server');
    });

    test('leere Changes-Liste → []', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({'changes': []})),
      );
      expect(await cloud.syncChanges('2026-08-04T08:00:00Z'), isEmpty);
    });

    test('fehlendes changes-Feld → []', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({})),
      );
      expect(await cloud.syncChanges('2026-08-04T08:00:00Z'), isEmpty);
    });

    test('401 (Auth-Fehler) → []', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.syncChanges('2026-08-04T08:00:00Z'), isEmpty);
    });

    test('Netzwerkfehler → []', () async {
      final cloud = CloudService(
        client: MockClient(
            (req) async => throw http.ClientException('offline')),
      );
      expect(await cloud.syncChanges('2026-08-04T08:00:00Z'), isEmpty);
    });

    test('sendet since-Timestamp als Body', () async {
      late Map<String, dynamic> gesendeterBody;
      final cloud = CloudService(
        client: MockClient((req) async {
          gesendeterBody = jsonDecode(req.body) as Map<String, dynamic>;
          return jsonOk({'changes': []});
        }),
      );
      await cloud.syncChanges('2026-08-04T08:00:00Z');
      expect(gesendeterBody['since'], '2026-08-04T08:00:00Z');
    });
  });

  group('syncAll (LWW-Schreibpfad)', () {
    test('200 → Status-Map', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({'status': 'ok'})),
      );
      final d = await cloud.syncAll();
      expect(d?['status'], 'ok');
    });

    test('401 → null (Auth-Fehler)', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.syncAll(), isNull);
    });
  });

  group('Playlisten', () {
    test('getPlaylists parst Liste', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({
              'playlists': [
                {'id': 1, 'name': 'Workout'},
              ],
            })),
      );
      final list = await cloud.getPlaylists();
      expect(list, hasLength(1));
      expect(list.first['name'], 'Workout');
    });

    test('createPlaylist 200 → Playlist-Objekt', () async {
      final cloud = CloudService(
        client: MockClient((req) async =>
            jsonOk({'playlist': {'id': 7, 'name': 'Neu'}})),
      );
      final p = await cloud.createPlaylist('Neu');
      expect(p?['id'], 7);
    });

    test('deletePlaylist 200 ohne status → false', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({'status': 'ok'})),
      );
      expect(await cloud.deletePlaylist(3), isTrue);
    });
  });

  group('Favoriten', () {
    test('getFavorites parst Liste', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({
              'favorites': [
                {'id': 's1'},
              ],
            })),
      );
      final list = await cloud.getFavorites();
      expect(list, hasLength(1));
      expect(list.first['id'], 's1');
    });

    test('syncFavorites mit status ok → true', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({'status': 'ok'})),
      );
      expect(await cloud.syncFavorites(['s1', 's2']), isTrue);
    });

    test('syncFavorites 401 → false (Auth-Fehler)', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.syncFavorites(['s1']), isFalse);
    });
  });

  group('ytUrlSetzen (F2: YT-Link → Server)', () {
    test('POST /yt-url mit song_id + yt_url, status ok → true', () async {
      http.Request? anfrage;
      final cloud = CloudService(
        client: MockClient((req) async {
          anfrage = req;
          return jsonOk({'status': 'ok'});
        }),
      );
      final ok = await cloud.ytUrlSetzen('s1', 'https://youtu.be/abc');
      expect(ok, isTrue);
      expect(anfrage!.url.path, '/api/v1/cloud/yt-url');
      final body = jsonDecode(anfrage!.body) as Map<String, dynamic>;
      expect(body['song_id'], 's1');
      expect(body['yt_url'], 'https://youtu.be/abc');
    });

    test('ytUrlSetzen ohne status ok → false', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({'status': 'error'})),
      );
      expect(await cloud.ytUrlSetzen('s1', 'https://youtu.be/abc'), isFalse);
    });

    test('ytUrlSetzen 401 → false (Auth-Fehler)', () async {
      final cloud = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud.ytUrlSetzen('s1', 'https://youtu.be/abc'), isFalse);
    });
  });

  group('History & Songs', () {
    test('getHistory parst history-Liste', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({
              'history': [
                {'song_id': 's1', 'played_at': '2026-08-04T10:00:00Z'},
              ],
            })),
      );
      final list = await cloud.getHistory();
      expect(list, hasLength(1));
      expect(list.first['song_id'], 's1');
    });

    test('listSongs parst songs-Liste', () async {
      final cloud = CloudService(
        client: MockClient((req) async => jsonOk({
              'songs': [
                {'id': 's1', 'title': 'Titel'},
              ],
            })),
      );
      final list = await cloud.listSongs();
      expect(list, hasLength(1));
      expect(list.first['title'], 'Titel');
    });
  });

  group('delete / globalList (Fehlerpfade)', () {
    test('delete 200 → true, 401 → false', () async {
      final cloudOk = CloudService(
        client: MockClient((req) async => http.Response('{}', 200)),
      );
      expect(await cloudOk.delete('s1'), isTrue);

      final cloud401 = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud401.delete('s1'), isFalse);
    });

    test('delete mit deletedAt sendet deleted_at im Body (Tombstone, Sprint E)',
        () async {
      late Map<String, dynamic> gesendeterBody;
      final cloud = CloudService(
        client: MockClient((req) async {
          gesendeterBody = jsonDecode(req.body) as Map<String, dynamic>;
          return http.Response('{}', 200);
        }),
      );
      final ok = await cloud.delete('s1', deletedAt: '2026-08-05T10:00:00');
      expect(ok, isTrue);
      expect(gesendeterBody['song_id'], 's1');
      expect(gesendeterBody['deleted_at'], '2026-08-05T10:00:00');
    });

    test('delete ohne deletedAt sendet KEIN deleted_at-Feld', () async {
      late Map<String, dynamic> gesendeterBody;
      final cloud = CloudService(
        client: MockClient((req) async {
          gesendeterBody = jsonDecode(req.body) as Map<String, dynamic>;
          return http.Response('{}', 200);
        }),
      );
      final ok = await cloud.delete('s1');
      expect(ok, isTrue);
      expect(gesendeterBody['song_id'], 's1');
      expect(gesendeterBody.containsKey('deleted_at'), isFalse);
    });

    test('delete Netzwerkfehler → false (kein Crash)', () async {
      final cloud = CloudService(
        client: MockClient(
            (req) async => throw http.ClientException('offline')),
      );
      expect(await cloud.delete('s1', deletedAt: '2026-08-05T10:00:00'),
          isFalse);
    });

    test('globalList 200 → Songs, 401 → []', () async {
      final cloudOk = CloudService(
        client: MockClient((req) async =>
            jsonOk({'songs': [{'id': 'g1'}]})),
      );
      expect(await cloudOk.globalList(), hasLength(1));

      final cloud401 = CloudService(
        client: MockClient((req) async => http.Response('{}', 401)),
      );
      expect(await cloud401.globalList(), isEmpty);
    });
  });
}