import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:just_audio/just_audio.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../utils/farb_theme.dart';
import '../services/cloud_service.dart';
import '../services/melo_logger.dart';
import '../models/song.dart';
import '../database/db_helper.dart';
import '../services/id3_reader.dart';

class CloudScreen extends StatefulWidget {
  final CloudService cloud;
  final VoidCallback onSongsChanged;
  const CloudScreen({super.key, required this.cloud, required this.onSongsChanged});

  @override
  State<CloudScreen> createState() => _CloudScreenState();
}

class _CloudScreenState extends State<CloudScreen> {
  int _serverCount = 0;
  bool _ladt = false;
  String? _status;
  bool _autoSync = true;
  int _syncIntervall = 6;
  String _aktuellerDownload = '';
  int _downloadFortschritt = 0;
  int _downloadGesamt = 0;

  @override
  void initState() {
    super.initState();
    _ladeStatus();
    _ladeSettings();
  }

  Future<void> _ladeStatus() async {
    final p = await SharedPreferences.getInstance();
    final nutzer = p.getString('melo_nutzer') ?? '';
    await widget.cloud.restoreLogin();
    if (nutzer.isEmpty || !widget.cloud.istAngemeldet) {
      if (mounted) setState(() { _serverCount = 0; _status = 'Nicht angemeldet'; });
      return;
    }
    final st = await widget.cloud.status();
    if (!mounted) return;
    setState(() {
      _serverCount = st?['total'] ?? 0;
      _status = st != null ? 'Verbunden ($nutzer)' : 'Keine Verbindung';
    });
  }

  Future<void> _ladeSettings() async {
    final p = await SharedPreferences.getInstance();
    if (mounted) setState(() {
      _autoSync = p.getBool('cloud_auto') ?? true;
      _syncIntervall = p.getInt('cloud_interval') ?? 6;
    });
  }

  Future<void> _upload() async {
    setState(() => _ladt = true);
    final dir = Directory('${(await getApplicationDocumentsDirectory()).path}/music');
    if (!await dir.exists()) {
      setState(() { _ladt = false; _status = 'Keine lokalen Songs'; });
      return;
    }
    final files = dir.listSync().whereType<File>().where((f) =>
        f.path.endsWith('.mp3') || f.path.endsWith('.m4a'));
    int count = 0;
    for (final f in files) {
      final sid = await widget.cloud.upload(f.path, f.path.split('/').last);
      if (sid != null) count++;
    }
    await _ladeStatus();
    if (mounted) {
      setState(() { _ladt = false; _status = '$count Songs hochgeladen'; });
      MeloLogger().aktion('cloud_upload', {'count': count});
    }
  }

  Future<void> _download() async {
    setState(() {
      _ladt = true;
      _status = null;
      _aktuellerDownload = 'Lade Liste...';
      _downloadFortschritt = 0;
      _downloadGesamt = 0;
    });

    // Auf Android: Music/Melo (getExternalStorageDirectory)
    // Auf iOS: Documents/music (Sandbox, sichtbar in Dateien-App)
    String basePath;
    if (Platform.isIOS) {
      basePath = '${(await getApplicationDocumentsDirectory()).path}/music';
    } else {
      // Wenn voller Speicherzugriff: Downloads/Melo (sichtbar)
      final p = await SharedPreferences.getInstance();
      if (p.getBool('manage_storage') == true) {
        final d = await getDownloadsDirectory();
        basePath = d != null ? '${d.path}/Melo' : '${(await getApplicationDocumentsDirectory()).path}/music';
      } else {
        final ext = await getExternalStorageDirectory();
        basePath = ext != null ? '${ext.path}/Melo' : '${(await getApplicationDocumentsDirectory()).path}/music';
      }
    }
    final dir = Directory(basePath);
    if (!await dir.exists()) await dir.create(recursive: true);

    final localFiles = dir.listSync().whereType<File>()
        .map((f) => f.path.split('/').last).toSet();
    final serverSongs = await widget.cloud.listSongs();

    // Filter: nur neue Songs
    final neue = serverSongs.where((s) {
      final title = s['title'].toString();
      return !localFiles.contains(title);
    }).toList();

    if (neue.isEmpty) {
      if (mounted) setState(() { _ladt = false; _status = 'Alle Songs bereits lokal'; });
      return;
    }

    setState(() => _downloadGesamt = neue.length);
    final db = DbHelper();

    for (int i = 0; i < neue.length; i++) {
      final song = neue[i];
      final title = song['title'].toString();
      final sid = song['id'].toString();

      // Dateinamen säubern (p.basename verhindert Pfad-Traversal via Titel)
      final safeTitle = p.basename(title).replaceAll(RegExp(r'[^\w\s\.-]'), '_').trim();
      final dateiName = safeTitle.endsWith('.mp3') || safeTitle.endsWith('.m4a')
          ? safeTitle : '$safeTitle.mp3';
      final dest = '${dir.path}/$dateiName';

      if (mounted) setState(() {
        _aktuellerDownload = title;
        _downloadFortschritt = i + 1;
      });

      final ok = await widget.cloud.download(sid, dest);
      if (ok) {
        // Dauer auslesen
        int dauer = 0;
        try {
          final ap = AudioPlayer();
          await ap.setFilePath(dest).timeout(const Duration(milliseconds: 2000));
          dauer = ap.duration?.inSeconds ?? 0;
          await ap.dispose();
        } catch (_) {}

        // ID3-Metadaten & Cover aus der heruntergeladenen Datei extrahieren
        final id3 = Id3Reader.lesen(dest);
        String? coverPfad;
        if (id3['cover'] != null && id3['cover'] is List<int>) {
          try {
            final coversDir = Directory('${(await getApplicationDocumentsDirectory()).path}/covers');
            if (!await coversDir.exists()) await coversDir.create(recursive: true);
            final coverFile = File('${coversDir.path}/cloud_$sid.jpg');
            await coverFile.writeAsBytes(id3['cover'] as List<int>);
            coverPfad = coverFile.path;
          } catch (_) {}
        }

        try {
          await db.songEinfuegen(Song(
            titel: (id3['titel'] as String).isNotEmpty
                ? id3['titel']
                : title.replaceAll('.mp3', '').replaceAll('.m4a', ''),
            kuenstler: (id3['kuenstler'] as String).isNotEmpty
                ? id3['kuenstler']
                : 'Melo Cloud',
            album: id3['album'] ?? '',
            dauerSekunden: dauer,
            dateiPfad: dest,
            coverPfad: coverPfad,
            downloadQuelle: 'cloud',
            istHeruntergeladen: true,
          ));
        } catch (_) {}
      }
    }

    await _ladeStatus();
    widget.onSongsChanged(); // Musik-Tab aktualisieren

    if (mounted) {
      setState(() {
        _ladt = false;
        _aktuellerDownload = '';
        _status = '${_downloadGesamt} Songs heruntergeladen';
      });
      MeloLogger().aktion('cloud_download', {'count': _downloadGesamt});
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: MeloTheme.schwarz,
      appBar: AppBar(
        backgroundColor: MeloTheme.dunkel1,
        title: const Row(children: [
          Text('☁️', style: TextStyle(fontSize: 20)),
          SizedBox(width: 8),
          Text('Cloud Sync', style: TextStyle(color: Colors.white, fontSize: 18)),
        ]),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh, color: Colors.grey, size: 20),
            onPressed: _ladeStatus,
          ),
        ],
      ),
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          children: [
            // Status-Karte
            Container(
              width: double.infinity,
              padding: const EdgeInsets.all(16),
              decoration: BoxDecoration(
                color: MeloTheme.dunkel1,
                borderRadius: BorderRadius.circular(12),
                border: Border.all(color: MeloTheme.dunkel2),
              ),
              child: Row(
                children: [
                  const Icon(Icons.storage, color: MeloTheme.rot, size: 28),
                  const SizedBox(width: 12),
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text('$_serverCount Songs auf Server',
                          style: const TextStyle(color: Colors.white, fontSize: 16, fontWeight: FontWeight.w600)),
                      Text(_status ?? 'Lädt...',
                          style: const TextStyle(color: Colors.grey, fontSize: 12)),
                    ],
                  ),
                ],
              ),
            ),
            const SizedBox(height: 16),
            // Upload / Download
            Row(
              children: [
                Expanded(child: _btn(Icons.upload, 'Upload', _upload)),
                const SizedBox(width: 12),
                Expanded(child: _btn(Icons.download, 'Download', _download)),
              ],
            ),
            // Download-Fortschritt
            if (_ladt && _aktuellerDownload.isNotEmpty) ...[
              const SizedBox(height: 12),
              LinearProgressIndicator(
                value: _downloadGesamt > 0 ? _downloadFortschritt / _downloadGesamt : null,
                backgroundColor: MeloTheme.dunkel2,
                valueColor: const AlwaysStoppedAnimation(MeloTheme.rot),
              ),
              const SizedBox(height: 6),
              Text(
                '$_downloadFortschritt/$_downloadGesamt: $_aktuellerDownload',
                style: const TextStyle(color: Colors.grey, fontSize: 12),
                maxLines: 2, overflow: TextOverflow.ellipsis,
              ),
            ],
            if (_status != null && !_ladt)
              Padding(
                padding: const EdgeInsets.only(top: 8),
                child: Text(_status!, style: const TextStyle(color: Colors.grey, fontSize: 13)),
              ),
            const SizedBox(height: 12),
            // Sync-Einstellungen
            const Divider(color: MeloTheme.dunkel2),
            const Align(
              alignment: Alignment.centerLeft,
              child: Text('⚙ Sync-Einstellungen', style: TextStyle(color: Colors.grey, fontSize: 11)),
            ),
            SwitchListTile(
              dense: true,
              title: const Text('Auto-Sync', style: TextStyle(color: Colors.white, fontSize: 13)),
              value: _autoSync,
              activeColor: MeloTheme.rot,
              onChanged: (v) async {
                setState(() => _autoSync = v);
                (await SharedPreferences.getInstance()).setBool('cloud_auto', v);
              },
            ),
            Row(
              children: ['Manuell', 'Alle 3h', 'Alle 6h', 'Alle 12h'].asMap().entries.map((e) {
                final vals = [0, 3, 6, 12];
                return Expanded(
                  child: ChoiceChip(
                    label: Text(e.value, style: TextStyle(fontSize: 10, color: _syncIntervall == vals[e.key] ? Colors.white : Colors.grey)),
                    selected: _syncIntervall == vals[e.key],
                    selectedColor: MeloTheme.rot,
                    backgroundColor: MeloTheme.dunkel2,
                    onSelected: (v) async {
                      setState(() => _syncIntervall = vals[e.key]);
                      (await SharedPreferences.getInstance()).setInt('cloud_interval', vals[e.key]);
                    },
                  ),
                );
              }).toList(),
            ),
          ],
        ),
      ),
    );
  }

  Widget _btn(IconData icon, String label, VoidCallback onTap) {
    return ElevatedButton.icon(
      style: ElevatedButton.styleFrom(
        backgroundColor: MeloTheme.dunkel1,
        padding: const EdgeInsets.symmetric(vertical: 14),
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(12),
          side: const BorderSide(color: MeloTheme.dunkel2),
        ),
      ),
      onPressed: _ladt ? null : onTap,
      icon: Icon(icon, size: 18, color: MeloTheme.rot),
      label: Text(label, style: const TextStyle(color: Colors.white, fontSize: 14)),
    );
  }
}