import 'dart:convert';

import 'package:drift/native.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:melo/library/database.dart';
import 'package:melo/library/playlist_service.dart';
import 'package:melo/services/baka_auth.dart';
import 'package:melo/services/melo_cloud_service.dart';

class _MemorySpeicher implements TokenSpeicher {
  _MemorySpeicher(this.werte);
  final Map<String, String> werte;
  @override
  Future<String?> lesen(String key) async => werte[key];
  @override
  Future<void> schreiben(String key, String wert) async => werte[key] = wert;
  @override
  Future<void> loeschen(String key) async => werte.remove(key);
}

Future<BakaAuth> _angemeldeteAuth() async {
  final auth = BakaAuth(
    speicher: _MemorySpeicher({'baka_token': 'tok', 'baka_user': 'Baka'}),
  );
  await auth.laden();
  return auth;
}

void main() {
  late MeloDb db;
  late PlaylistService service;

  setUp(() {
    db = MeloDb(NativeDatabase.memory());
    service = PlaylistService(db);
  });

  tearDown(() async => db.close());

  test('createPlaylist delegates to db and notifies listeners', () async {
    var notified = false;
    service.addListener(() => notified = true);

    await service.createPlaylist('Road Trip');

    final playlists = await db.watchPlaylists().first;
    expect(playlists.length, 1);
    expect(playlists.first.name, 'Road Trip');
    expect(notified, true);
  });

  test('toggleFavorite delegates to db and notifies listeners', () async {
    await db.into(db.songs).insert(SongsCompanion.insert(
      id: 'song-1', path: '/a.mp3', title: 'A', dateAddedMs: 0, updatedAtMs: 0,
    ));

    var notified = false;
    service.addListener(() => notified = true);

    await service.toggleFavorite('song-1');

    expect(await db.watchIsFavorite('song-1').first, true);
    expect(notified, true);
  });

  test('reorderAll schreibt lückenlose Positionen 0..N-1 in neuer Reihenfolge', () async {
    final playlistId = await db.createPlaylist('Mix');
    for (final id in ['song-1', 'song-2', 'song-3']) {
      await db.into(db.songs).insert(SongsCompanion.insert(
        id: id, path: '/$id.mp3', title: id, dateAddedMs: 0, updatedAtMs: 0,
      ));
    }
    // Ursprüngliche (evtl. lückenhafte) Positionen.
    await db.addSongToPlaylist(playlistId, 'song-1', 0);
    await db.addSongToPlaylist(playlistId, 'song-2', 5);
    await db.addSongToPlaylist(playlistId, 'song-3', 9);

    var notified = false;
    service.addListener(() => notified = true);

    await service.reorderAll(playlistId, ['song-3', 'song-1', 'song-2']);

    final songs = await db.watchPlaylistSongs(playlistId).first;
    expect(songs.map((s) => s.id).toList(), ['song-3', 'song-1', 'song-2']);
    expect(notified, true);
  });

  group('Sofort-Push der Favoriten', () {
    Future<void> legeSongAn(MeloDb db, {String? cloudId}) async {
      await db.into(db.songs).insert(SongsCompanion.insert(
            id: 'song-1',
            path: '/a.mp3',
            title: 'A',
            dateAddedMs: 0,
            updatedAtMs: 0,
          ));
      if (cloudId != null) await db.setCloudId('song-1', cloudId);
    }

    test('setzt deterministisch true beim Favorisieren', () async {
      final db2 = MeloDb(NativeDatabase.memory());
      addTearDown(db2.close);
      await legeSongAn(db2, cloudId: 'c1');

      final gesendet = <Map<String, dynamic>>[];
      final dienst = PlaylistService(
        db2,
        cloud: MeloCloudService(
          auth: await _angemeldeteAuth(),
          client: MockClient((anfrage) async {
            gesendet.add(jsonDecode(anfrage.body) as Map<String, dynamic>);
            return http.Response(jsonEncode({'status': 'ok'}), 200);
          }),
        ),
      );

      await dienst.toggleFavorite('song-1');

      expect(gesendet, [
        {'song_id': 'c1', 'set': true}
      ]);
    });

    test('setzt deterministisch false beim Ent-Favorisieren', () async {
      final db2 = MeloDb(NativeDatabase.memory());
      addTearDown(db2.close);
      await legeSongAn(db2, cloudId: 'c1');
      await db2.setFavorite('song-1', true);

      final gesendet = <Map<String, dynamic>>[];
      final dienst = PlaylistService(
        db2,
        cloud: MeloCloudService(
          auth: await _angemeldeteAuth(),
          client: MockClient((anfrage) async {
            gesendet.add(jsonDecode(anfrage.body) as Map<String, dynamic>);
            return http.Response(jsonEncode({'status': 'ok'}), 200);
          }),
        ),
      );

      await dienst.toggleFavorite('song-1');

      expect(gesendet, [
        {'song_id': 'c1', 'set': false}
      ]);
    });

    test('ohne cloudId wird nichts gemeldet', () async {
      final db2 = MeloDb(NativeDatabase.memory());
      addTearDown(db2.close);
      await legeSongAn(db2);

      var anfragen = 0;
      final dienst = PlaylistService(
        db2,
        cloud: MeloCloudService(
          auth: await _angemeldeteAuth(),
          client: MockClient((_) async {
            anfragen++;
            return http.Response(jsonEncode({'status': 'ok'}), 200);
          }),
        ),
      );

      await dienst.toggleFavorite('song-1');

      expect(anfragen, 0);
      expect(await db2.watchIsFavorite('song-1').first, isTrue);
    });

    test('ein Fehler des Servers ändert lokal nichts und wirft nicht',
        () async {
      final db2 = MeloDb(NativeDatabase.memory());
      addTearDown(db2.close);
      await legeSongAn(db2, cloudId: 'c1');

      final dienst = PlaylistService(
        db2,
        cloud: MeloCloudService(
          auth: await _angemeldeteAuth(),
          client: MockClient(
              (_) async => http.Response(jsonEncode({'error': 'weg'}), 500)),
        ),
      );

      // Der nächste Voll-Abgleich holt den Push additiv nach.
      await dienst.toggleFavorite('song-1');

      expect(await db2.watchIsFavorite('song-1').first, isTrue);
    });
  });
}