import 'dart:io';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../services/download_service.dart';
import '../utils/farb_theme.dart';
import '../services/melo_logger.dart';

class DownloadScreen extends StatefulWidget {
  final DownloadService downloader;
  final VoidCallback onSongsChanged;

  const DownloadScreen({
    super.key,
    required this.downloader,
    required this.onSongsChanged,
  });

  @override
  State<DownloadScreen> createState() => _DownloadScreenState();
}

class _DownloadScreenState extends State<DownloadScreen> {
  final _urlController = TextEditingController();
  bool _ladt = false;
  String? _fehler;
  String? _erfolg;
  String _speicherOrt = 'Intern (Documents/music)';

  @override
  void initState() {
    super.initState();
    _ladeSpeicherPfad();
  }

  @override
  void dispose() {
    _urlController.dispose();
    super.dispose();
  }

  Future<void> _ladeSpeicherPfad() async {
    final prefs = await SharedPreferences.getInstance();
    final pfad = prefs.getString('speicher_pfad');
    if (pfad != null && pfad.isNotEmpty) {
      widget.downloader.setzeSpeicherPfad(pfad);
      setState(() => _speicherOrt = pfad.split('/').last);
    } else {
      final pf = await _standardPfad();
      widget.downloader.setzeSpeicherPfad(pf);
    }
  }

  Future<String> _standardPfad() async {
    if (Platform.isIOS) return '${(await getApplicationDocumentsDirectory()).path}/music';
    final p = await SharedPreferences.getInstance();
    if (p.getBool('manage_storage') == true) {
      final d = await getDownloadsDirectory();
      if (d != null) return '${d.path}/Melo';
    }
    final ext = await getExternalStorageDirectory();
    return ext != null ? '${ext.path}/Melo' : '${(await getApplicationDocumentsDirectory()).path}/music';
  }

  Future<void> _ordnerDialog() async {
    if (Platform.isIOS) {
      final appDir = await getApplicationDocumentsDirectory();
      final pfad = '${appDir.path}/music';
      widget.downloader.setzeSpeicherPfad(pfad);
      setState(() => _speicherOrt = '📁 App-intern');
      return;
    }

    // Android: Ordner wählen via Text-Eingabe oder vordefinierte Optionen
    final auswahl = await showDialog<String>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: MeloTheme.dunkel1,
        title: const Text('Speicherort', style: TextStyle(color: Colors.white, fontSize: 16)),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            _optionTile(ctx, '📁 Intern (App-Ordner)', 'intern', icon: Icons.phone_android),
            const Divider(color: MeloTheme.dunkel2),
            _optionTile(ctx, '⬇ Downloads/Melo', 'downloads', icon: Icons.download),
            const Divider(color: MeloTheme.dunkel2),
            _optionTile(ctx, '📂 Eigener Pfad...', 'custom', icon: Icons.folder_open),
          ],
        ),
      ),
    );
    if (auswahl == null || !mounted) return;

    String pfad;
    if (auswahl == 'custom') {
      final ctrl = TextEditingController();
      final p = await showDialog<String>(
        context: context,
        builder: (ctx) => AlertDialog(
          backgroundColor: MeloTheme.dunkel1,
          title: const Text('Pfad eingeben', style: TextStyle(color: Colors.white, fontSize: 15)),
          content: TextField(
            controller: ctrl, autofocus: true,
            style: const TextStyle(color: Colors.white),
            decoration: InputDecoration(
              hintText: '/storage/emulated/0/Music/Melo',
              hintStyle: const TextStyle(color: Colors.grey),
              border: const OutlineInputBorder(),
              prefixIcon: const Icon(Icons.folder, color: Colors.grey),
            ),
          ),
          actions: [
            TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('Abbrechen')),
            TextButton(onPressed: () => Navigator.pop(ctx, ctrl.text.trim()), child: const Text('OK', style: TextStyle(color: MeloTheme.rot))),
          ],
        ),
      );
      if (p == null || p.isEmpty) return;
      pfad = p;
    } else if (auswahl == 'intern') {
      pfad = await _standardPfad();
    } else {
      final d = await getDownloadsDirectory();
      pfad = d != null ? '${d.path}/Melo' : await _standardPfad();
    }

    await Directory(pfad).create(recursive: true);
    widget.downloader.setzeSpeicherPfad(pfad);

    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('speicher_pfad', pfad);

    setState(() => _speicherOrt = pfad.split('/').last);
  }

  Widget _optionTile(BuildContext ctx, String label, String wert, {IconData? icon}) {
    return ListTile(
      leading: Icon(icon ?? Icons.folder, color: MeloTheme.rot, size: 20),
      title: Text(label, style: const TextStyle(color: Colors.white, fontSize: 13)),
      onTap: () => Navigator.pop(ctx, wert),
    );
  }

  Future<void> _startDownload() async {
    final url = _urlController.text.trim();
    if (url.isEmpty) return;

    setState(() { _ladt = true; _fehler = null; _erfolg = null; });

    try {
      final song = await widget.downloader.downloadVonUrl(url);
      if (!mounted) return;
      if (song != null) {
        setState(() { _ladt = false; _erfolg = '✅ "${song.titel}" heruntergeladen!'; });
        widget.onSongsChanged();
      } else {
        setState(() { _ladt = false; _fehler = widget.downloader.fehler ?? '❌ Download fehlgeschlagen'; });
      }
    } catch (e) {
      MeloLogger().fehler('download', e);
      if (mounted) setState(() { _ladt = false; _fehler = 'Fehler: $e'; });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: MeloTheme.schwarz,
      appBar: AppBar(
        backgroundColor: MeloTheme.dunkel1,
        title: const Row(children: [
          Icon(Icons.add_circle, color: MeloTheme.rot, size: 20),
          SizedBox(width: 8),
          Text('Lied +', style: TextStyle(color: Colors.white, fontSize: 18)),
        ]),
      ),
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(children: [
          GestureDetector(
            onTap: _ladt ? null : _ordnerDialog,
            child: Container(
              width: double.infinity, padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(color: MeloTheme.dunkel1, borderRadius: BorderRadius.circular(12), border: Border.all(color: MeloTheme.dunkel2)),
              child: Row(children: [
                const Icon(Icons.folder, color: MeloTheme.rot, size: 18), const SizedBox(width: 8),
                Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
                  const Text('Speicherort', style: TextStyle(color: Colors.grey, fontSize: 11)),
                  Text(_speicherOrt, style: const TextStyle(color: Colors.white, fontSize: 13)),
                ])),
                const Icon(Icons.chevron_right, color: Colors.grey, size: 18),
              ]),
            ),
          ),
          const SizedBox(height: 16),
          TextField(
            controller: _urlController, style: const TextStyle(color: Colors.white),
            decoration: InputDecoration(
              hintText: 'YouTube / SoundCloud URL...', hintStyle: const TextStyle(color: Colors.grey),
              filled: true, fillColor: MeloTheme.dunkel1,
              border: OutlineInputBorder(borderRadius: BorderRadius.circular(12), borderSide: const BorderSide(color: MeloTheme.dunkel2)),
              prefixIcon: const Icon(Icons.link, color: Colors.grey),
            ),
          ),
          const SizedBox(height: 12),
          SizedBox(
            width: double.infinity,
            child: ElevatedButton.icon(
              style: ElevatedButton.styleFrom(backgroundColor: MeloTheme.rot, padding: const EdgeInsets.symmetric(vertical: 14), shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12))),
              onPressed: _ladt ? null : _startDownload,
              icon: _ladt ? const SizedBox(width: 20, height: 20, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white)) : const Icon(Icons.download, color: Colors.white),
              label: Text(_ladt ? 'Lädt...' : 'Download', style: const TextStyle(color: Colors.white, fontSize: 15)),
            ),
          ),
          const SizedBox(height: 12),
          if (_fehler != null) Padding(padding: const EdgeInsets.only(top: 8), child: Text(_fehler!, style: const TextStyle(color: Colors.red, fontSize: 13))),
          if (_erfolg != null) Padding(padding: const EdgeInsets.only(top: 8), child: Text(_erfolg!, style: const TextStyle(color: Colors.green, fontSize: 13))),
        ]),
      ),
    );
  }
}