Melo/lib/player/now_playing_screen.dart

import 'package:audio_service/audio_service.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../library/database.dart';
import '../services/navidrome_service.dart';
import '../shared/cover.dart';
import '../shared/favorite_button.dart';
import '../shared/server_favorite_button.dart';
import '../shared/theme.dart';
import 'audio_handler.dart';
import 'lrc.dart';
import 'queue_screen.dart';

/// Vollbild-Wiedergabe: Cover, Titel, Fortschritt, Transport-Controls.
class NowPlayingScreen extends StatelessWidget {
  const NowPlayingScreen({super.key});

  void _showLyrics(BuildContext context, String songId) {
    if (songId.isEmpty) return;
    showModalBottomSheet(
      context: context,
      builder: (ctx) => _LyricsSheet(songId: songId),
    );
  }

  @override
  Widget build(BuildContext context) {
    final handler = context.read<MeloAudioHandler>();
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        actions: [
          StreamBuilder<MediaItem?>(
            stream: handler.mediaItem,
            builder: (context, snapshot) {
              final item = snapshot.data;
              if (item == null) return const SizedBox.shrink();
              return Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  IconButton(
                    tooltip: 'Songtext',
                    icon: const Icon(Icons.lyrics),
                    // Bei Server-Titeln die Navidrome-ID, nicht die
                    // Abspiel-Adresse: mit der fragte die App den Server nach
                    // einem Titel namens "https://…" und bekam nie einen Text.
                    onPressed: () => _showLyrics(
                        context, songIdOf(item) ?? navidromeIdOf(item) ?? ''),
                  ),
                  // Ein Titel der Bibliothek wird lokal favorisiert, einer
                  // vom Server am Server — beide bekommen dasselbe Herz,
                  // statt dass eines davon ausgegraut bleibt.
                  _Herz(item: item),
                ],
              );
            },
          ),
          _SleepTimerButton(handler: handler),
          IconButton(
            tooltip: 'Warteschlange',
            icon: const Icon(Icons.queue_music),
            onPressed: () => Navigator.push(
              context,
              MaterialPageRoute(builder: (_) => const QueueScreen()),
            ),
          ),
        ],
      ),
      body: SafeArea(
        child: StreamBuilder<MediaItem?>(
          stream: handler.mediaItem,
          builder: (context, snapshot) {
            final item = snapshot.data;
            if (item == null) {
              return const Center(child: Text('Nichts in Wiedergabe'));
            }
            return Padding(
              padding: const EdgeInsets.symmetric(horizontal: 24),
              child: Column(
                children: [
                  Expanded(child: Center(child: _Cover(item: item))),
                  const SizedBox(height: 24),
                  Text(
                    item.title,
                    style: Theme.of(context).textTheme.headlineSmall,
                    maxLines: 2,
                    overflow: TextOverflow.ellipsis,
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: 8),
                  Text(
                    item.artist ?? 'Unbekannt',
                    style: const TextStyle(color: MeloTheme.text2),
                  ),
                  const SizedBox(height: 24),
                  _ProgressBar(handler: handler),
                  const _Controls(),
                  const SizedBox(height: 16),
                ],
              ),
            );
          },
        ),
      ),
    );
  }
}

/// Das passende Herz für den laufenden Titel.
class _Herz extends StatelessWidget {
  const _Herz({required this.item});
  final MediaItem item;

  @override
  Widget build(BuildContext context) {
    final songId = songIdOf(item);
    if (songId != null && songId.isNotEmpty) {
      return FavoriteButton(songId: songId);
    }
    final navId = navidromeIdOf(item);
    if (navId == null) return const SizedBox.shrink();
    return ServerFavoriteButton(
      // Ohne Schlüssel behielte das Herz beim Titelwechsel seinen Zustand:
      // Flutter würde dasselbe Element weiterverwenden, und der nächste Titel
      // erschiene als Favorit, obwohl er nie einer war.
      key: ValueKey(navId),
      navidromeId: navId,
      navidrome: context.read<MeloAudioHandler>().navidrome,
    );
  }
}

class _Cover extends StatelessWidget {
  const _Cover({required this.item});
  final MediaItem item;

  @override
  Widget build(BuildContext context) {
    return AspectRatio(
      aspectRatio: 1,
      child: CoverImage(artUri: item.artUri, radius: 16),
    );
  }
}

class _ProgressBar extends StatelessWidget {
  const _ProgressBar({required this.handler});
  final MeloAudioHandler handler;

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<Duration?>(
      stream: handler.durationStream,
      builder: (context, dSnap) {
        final total = dSnap.data ?? Duration.zero;
        return StreamBuilder<Duration>(
          stream: handler.positionStream,
          builder: (context, pSnap) {
            var position = pSnap.data ?? Duration.zero;
            final hasDuration = total > Duration.zero;
            if (hasDuration && position > total) position = total;
            final maxMs = hasDuration ? total.inMilliseconds.toDouble() : 1.0;
            final valueMs =
                position.inMilliseconds.toDouble().clamp(0.0, maxMs).toDouble();
            return Column(
              children: [
                Slider(
                  value: valueMs,
                  max: maxMs,
                  semanticFormatterCallback: (v) =>
                      _fmt(Duration(milliseconds: v.round())),
                  onChanged: hasDuration
                      ? (v) => handler.seek(Duration(milliseconds: v.round()))
                      : null,
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 8),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(_fmt(position),
                          style: const TextStyle(color: MeloTheme.text2)),
                      Text(_fmt(total),
                          style: const TextStyle(color: MeloTheme.text2)),
                    ],
                  ),
                ),
              ],
            );
          },
        );
      },
    );
  }

  static String _fmt(Duration d) {
    final m = d.inMinutes.remainder(60).toString().padLeft(2, '0');
    final s = d.inSeconds.remainder(60).toString().padLeft(2, '0');
    return '$m:$s';
  }
}

class _Controls extends StatelessWidget {
  const _Controls();

  @override
  Widget build(BuildContext context) {
    final handler = context.read<MeloAudioHandler>();
    return StreamBuilder<PlaybackState>(
      stream: handler.playbackState,
      builder: (context, snapshot) {
        final state = snapshot.data;
        final playing = state?.playing ?? false;
        final shuffle = state?.shuffleMode == AudioServiceShuffleMode.all;
        final repeat = state?.repeatMode ?? AudioServiceRepeatMode.none;
        return Row(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: [
            IconButton(
              tooltip: 'Zufallswiedergabe',
              icon: Icon(Icons.shuffle,
                  color: shuffle ? MeloTheme.red : MeloTheme.text2),
              onPressed: () => handler.setShuffleMode(shuffle
                  ? AudioServiceShuffleMode.none
                  : AudioServiceShuffleMode.all),
            ),
            IconButton(
              tooltip: 'Vorheriger Titel',
              iconSize: 40,
              icon: const Icon(Icons.skip_previous),
              onPressed: handler.skipToPrevious,
            ),
            IconButton(
              tooltip: playing ? 'Pause' : 'Abspielen',
              iconSize: 64,
              icon: Icon(playing ? Icons.pause_circle : Icons.play_circle,
                  color: MeloTheme.red),
              onPressed: playing ? handler.pause : handler.play,
            ),
            IconButton(
              tooltip: 'Nächster Titel',
              iconSize: 40,
              icon: const Icon(Icons.skip_next),
              onPressed: handler.skipToNext,
            ),
            IconButton(
              tooltip: 'Wiederholen',
              icon: Icon(
                repeat == AudioServiceRepeatMode.one
                    ? Icons.repeat_one
                    : Icons.repeat,
                color: repeat == AudioServiceRepeatMode.none
                    ? MeloTheme.text2
                    : MeloTheme.red,
              ),
              onPressed: () => handler.setRepeatMode(switch (repeat) {
                AudioServiceRepeatMode.none => AudioServiceRepeatMode.all,
                AudioServiceRepeatMode.all => AudioServiceRepeatMode.one,
                _ => AudioServiceRepeatMode.none,
              }),
            ),
          ],
        );
      },
    );
  }
}

class _SleepTimerButton extends StatelessWidget {
  const _SleepTimerButton({required this.handler});
  final MeloAudioHandler handler;

  void _showSleepOptions(BuildContext context) {
    showModalBottomSheet(
      context: context,
      builder: (ctx) => Container(
        color: Theme.of(ctx).scaffoldBackgroundColor,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Padding(
              padding: const EdgeInsets.all(16),
              child: Text(
                'Sleep-Timer',
                style: Theme.of(ctx).textTheme.titleLarge,
              ),
            ),
            ...const [5, 10, 15, 30, 60].map(
              (minutes) => ListTile(
                title: Text('$minutes Minuten'),
                onTap: () {
                  handler.sleepTimer.start(Duration(minutes: minutes));
                  Navigator.pop(ctx);
                },
              ),
            ),
            ValueListenableBuilder<Duration?>(
              valueListenable: handler.sleepTimer.remaining,
              builder: (_, remaining, _) => remaining == null
                  ? const SizedBox.shrink()
                  : ListTile(
                      title: const Text('Timer beenden'),
                      leading: const Icon(Icons.close),
                      onTap: () {
                        handler.sleepTimer.cancel();
                        Navigator.pop(ctx);
                      },
                    ),
            ),
            const SizedBox(height: 16),
          ],
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<Duration?>(
      valueListenable: handler.sleepTimer.remaining,
      builder: (context, remaining, _) {
        if (remaining == null) {
          return IconButton(
            tooltip: 'Sleep-Timer',
            icon: const Icon(Icons.bedtime_outlined),
            onPressed: () => _showSleepOptions(context),
          );
        }
        final minutes = remaining.inMinutes;
        final seconds = (remaining.inSeconds % 60).toString().padLeft(2, '0');
        return IconButton(
          tooltip: 'Sleep-Timer: noch $minutes:$seconds',
          icon: Icon(Icons.bedtime, color: MeloTheme.red),
          onPressed: () => _showSleepOptions(context),
        );
      },
    );
  }
}

class _LyricsSheet extends StatefulWidget {
  const _LyricsSheet({required this.songId});
  final String songId;

  @override
  State<_LyricsSheet> createState() => _LyricsSheetState();
}

class _LyricsSheetState extends State<_LyricsSheet> {
  late final NavidromeService _nav = NavidromeService();
  String? _text;
  List<LyricZeile> _zeilen = const [];
  bool _loading = true;
  final _scroll = ScrollController();
  int? _gezeigteZeile;

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

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

  /// Zuerst der Songtext aus dem Tag der Datei — der ist sofort da und
  /// funktioniert offline. Nur wenn keiner drinsteht, wird der Server gefragt.
  Future<void> _load() async {
    final db = context.read<MeloDb>();
    final lokal = await db.lyricsOf(widget.songId);
    if (lokal != null) {
      if (mounted) setState(() => _uebernimm(lokal));
      return;
    }
    await _nav.ladeGespeicherteZugangsdaten();
    if (_nav.istVerbunden) {
      final lyrics = await _nav.getLyrics(widget.songId);
      if (mounted) {
        setState(() => _uebernimm(lyrics.isEmpty ? null : lyrics.text));
      }
      return;
    }
    if (mounted) setState(() => _loading = false);
  }

  void _uebernimm(String? text) {
    _text = text;
    // Trägt der Text Zeitmarken, läuft er mit; sonst bleibt es eine
    // Textwand — beides kommt vor, je nach Tag und Server.
    _zeilen = text == null ? const [] : parseLrc(text);
    _loading = false;
  }

  /// Schiebt die aktive Zeile in die Mitte. Nur beim Zeilenwechsel, nicht bei
  /// jeder Positionsmeldung — sonst ruckelt die Ansicht permanent.
  void _folge(int index) {
    if (_gezeigteZeile == index || !_scroll.hasClients) return;
    _gezeigteZeile = index;
    final ziel = (index * _zeilenHoehe) -
        (_scroll.position.viewportDimension / 2) +
        (_zeilenHoehe / 2);
    _scroll.animateTo(
      ziel.clamp(0, _scroll.position.maxScrollExtent),
      duration: MeloMotion.normal,
      curve: MeloMotion.curve,
    );
  }

  static const _zeilenHoehe = 40.0;

  @override
  Widget build(BuildContext context) {
    return Container(
      color: MeloTheme.black,
      child: Column(
        children: [
          Padding(
            padding: const EdgeInsets.all(MeloSpace.md),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  _zeilen.isEmpty ? 'Songtext' : 'Songtext · läuft mit',
                  style: const TextStyle(
                      fontSize: 18, fontWeight: FontWeight.w600),
                ),
                IconButton(
                  icon: const Icon(Icons.close),
                  onPressed: () => Navigator.pop(context),
                ),
              ],
            ),
          ),
          Expanded(child: _inhalt()),
        ],
      ),
    );
  }

  Widget _inhalt() {
    if (_loading) {
      return const Center(
        child: CircularProgressIndicator(color: MeloTheme.red),
      );
    }
    final text = _text;
    if (text == null) {
      return const Center(
        child: Text('Kein Songtext verfügbar',
            style: TextStyle(color: MeloTheme.text2)),
      );
    }
    if (_zeilen.isEmpty) {
      return SingleChildScrollView(
        padding: const EdgeInsets.all(MeloSpace.md),
        child: Text(
          text,
          style: const TextStyle(fontSize: 14, height: 1.6, color: Colors.white),
        ),
      );
    }
    return _Mitlaufend(
      zeilen: _zeilen,
      scroll: _scroll,
      zeilenHoehe: _zeilenHoehe,
      onZeile: _folge,
    );
  }
}

/// Die mitlaufende Darstellung: aktive Zeile hell und hervorgehoben, der
/// Rest gedämpft. Antippen springt an die Stelle im Titel.
class _Mitlaufend extends StatelessWidget {
  const _Mitlaufend({
    required this.zeilen,
    required this.scroll,
    required this.zeilenHoehe,
    required this.onZeile,
  });

  final List<LyricZeile> zeilen;
  final ScrollController scroll;
  final double zeilenHoehe;
  final ValueChanged<int> onZeile;

  @override
  Widget build(BuildContext context) {
    final handler = context.read<MeloAudioHandler>();
    return StreamBuilder<Duration>(
      stream: handler.positionStream,
      builder: (context, snapshot) {
        final aktiv = aktiveZeile(zeilen, snapshot.data ?? Duration.zero);
        if (aktiv != null) {
          WidgetsBinding.instance.addPostFrameCallback((_) => onZeile(aktiv));
        }
        return ListView.builder(
          controller: scroll,
          itemExtent: zeilenHoehe,
          padding: const EdgeInsets.symmetric(horizontal: MeloSpace.md),
          itemCount: zeilen.length,
          itemBuilder: (context, i) {
            final istAktiv = i == aktiv;
            return InkWell(
              onTap: () => handler.seek(zeilen[i].zeit),
              child: Align(
                alignment: Alignment.centerLeft,
                child: AnimatedDefaultTextStyle(
                  duration: MeloMotion.fast,
                  style: TextStyle(
                    fontSize: istAktiv ? 17 : 15,
                    height: 1.3,
                    fontWeight: istAktiv ? FontWeight.w700 : FontWeight.w400,
                    color: istAktiv ? Colors.white : MeloTheme.text3,
                  ),
                  child: Text(zeilen[i].text,
                      maxLines: 1, overflow: TextOverflow.ellipsis),
                ),
              ),
            );
          },
        );
      },
    );
  }
}