import 'dart:async';

import 'package:audio_service/audio_service.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../app/theme.dart';
import '../../audio/player_providers.dart';
import '../../audio/sound_settings.dart';
import '../../core/models.dart';
import '../../data/catalog_repository.dart';
import '../../data/user_library.dart';
import '../../shared/widgets/artwork.dart';
import '../explore/explore_screen.dart';
import 'sound_sheet.dart';

/// Pauses playback after the chosen duration. Null when off.
class SleepTimer extends Notifier<DateTime?> {
  Timer? _timer;

  @override
  DateTime? build() {
    ref.onDispose(() => _timer?.cancel());
    return null;
  }

  void start(Duration d) {
    _timer?.cancel();
    _timer = Timer(d, () {
      ref.read(audioHandlerProvider).pause();
      state = null;
    });
    state = DateTime.now().add(d);
  }

  void cancel() {
    _timer?.cancel();
    state = null;
  }
}

final sleepTimerProvider = NotifierProvider<SleepTimer, DateTime?>(SleepTimer.new);

class NowPlayingScreen extends ConsumerWidget {
  const NowPlayingScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final item = ref.watch(mediaItemProvider).value;
    if (item == null) {
      return Scaffold(
        appBar: AppBar(backgroundColor: NkColors.ground),
        body: const Center(child: Text('Nothing playing', style: TextStyle(color: NkColors.muted))),
      );
    }

    final state = ref.watch(playbackStateProvider).value;
    final track = ref.watch(currentTrackProvider);
    final liked = ref.watch(likedSongsProvider).contains(item.id);
    final occasion = Occasion.fromId(item.extras?['occasion'] as String?);
    final handler = ref.read(audioHandlerProvider);
    final controller = ref.read(playerControllerProvider);
    final text = Theme.of(context).textTheme;
    final height = MediaQuery.sizeOf(context).height;

    return Scaffold(
      body: Stack(
        children: [
          Positioned(
            left: 0,
            right: 0,
            top: 0,
            height: height * 0.52,
            child: Hero(tag: 'now-playing-art', child: _HeroImage(item: item, occasion: occasion)),
          ),
          Positioned(
            left: 0,
            right: 0,
            top: 0,
            height: height * 0.52 + 2,
            child: const PhotoScrim(stops: [0.45, 1]),
          ),
          SafeArea(
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 22),
              child: Column(
                children: [
                  Row(
                    children: [
                      IconButton(
                        tooltip: 'Close player',
                        iconSize: 30,
                        icon: const Icon(Icons.keyboard_arrow_down_rounded),
                        onPressed: () => context.pop(),
                      ),
                      const Spacer(),
                      if (track != null)
                        IconButton(
                          tooltip: 'Go to singer',
                          icon: const Icon(Icons.person_outline),
                          onPressed: () => context.push('/artist/${track.artistIds.first}'),
                        ),
                    ],
                  ),
                  const Spacer(),
                  Row(
                    crossAxisAlignment: CrossAxisAlignment.end,
                    children: [
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(item.title, style: text.headlineSmall, maxLines: 2, overflow: TextOverflow.ellipsis),
                            const SizedBox(height: 4),
                            Text('${item.artist ?? ''} · ${occasion.label}',
                                style: const TextStyle(color: NkColors.mutedOnPhoto, fontSize: 15)),
                          ],
                        ),
                      ),
                      IconButton(
                        tooltip: liked ? 'Remove from liked songs' : 'Add to liked songs',
                        iconSize: 30,
                        icon: Icon(liked ? Icons.favorite : Icons.favorite_border, color: liked ? NkColors.like : NkColors.cream),
                        onPressed: () => ref.read(likedSongsProvider.notifier).toggle(item.id),
                      ),
                    ],
                  ),
                  const SizedBox(height: 12),
                  _SeekBar(duration: item.duration ?? Duration.zero),
                  const SizedBox(height: 4),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      IconButton(
                        tooltip: 'Shuffle',
                        icon: Icon(Icons.shuffle,
                            color: state?.shuffleMode == AudioServiceShuffleMode.none ? NkColors.cream : NkColors.sun),
                        onPressed: controller.toggleShuffle,
                      ),
                      IconButton(
                        tooltip: 'Previous',
                        iconSize: 40,
                        icon: const Icon(Icons.skip_previous_rounded),
                        onPressed: handler.skipToPrevious,
                      ),
                      IconButton.filled(
                        tooltip: (state?.playing ?? false) ? 'Pause' : 'Play',
                        style: IconButton.styleFrom(fixedSize: const Size(76, 76)),
                        iconSize: 40,
                        icon: Icon((state?.playing ?? false) ? Icons.pause_rounded : Icons.play_arrow_rounded),
                        onPressed: controller.togglePlay,
                      ),
                      IconButton(
                        tooltip: 'Next',
                        iconSize: 40,
                        icon: const Icon(Icons.skip_next_rounded),
                        onPressed: handler.skipToNext,
                      ),
                      IconButton(
                        tooltip: 'Repeat',
                        icon: Icon(
                          state?.repeatMode == AudioServiceRepeatMode.one ? Icons.repeat_one : Icons.repeat,
                          color: state?.repeatMode == AudioServiceRepeatMode.none ? NkColors.cream : NkColors.sun,
                        ),
                        onPressed: controller.cycleRepeat,
                      ),
                    ],
                  ),
                  const SizedBox(height: 16),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceAround,
                    children: [
                      _Action(icon: Icons.lyrics_outlined, label: 'Lyrics', onTap: () => _showLyrics(context, item.title)),
                      _Action(icon: Icons.queue_music, label: 'Queue', onTap: () => _showQueue(context)),
                      _SleepAction(),
                      _SoundAction(),
                      _Action(
                        icon: Icons.more_horiz,
                        label: 'More',
                        onTap: track == null ? null : () => _showMore(context, ref, track),
                      ),
                    ],
                  ),
                  const SizedBox(height: 16),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  void _showMore(BuildContext context, WidgetRef ref, Track track) {
    final catalog = ref.read(catalogProvider).requireValue;
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: NkColors.surface,
      showDragHandle: true,
      builder: (sheet) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            for (final a in catalog.artistsOf(track))
              ListTile(
                leading: const Icon(Icons.person_outline),
                title: Text('Go to ${a.name}'),
                onTap: () {
                  Navigator.of(sheet).pop();
                  context.push('/artist/${a.id}');
                },
              ),
            ListTile(
              leading: Icon(track.occasion.icon),
              title: Text('More ${track.occasion.label} songs'),
              onTap: () {
                Navigator.of(sheet).pop();
                context.push('/occasion/${track.occasion.id}');
              },
            ),
          ],
        ),
      ),
    );
  }

  void _showLyrics(BuildContext context, String title) {
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: NkColors.surface,
      showDragHandle: true,
      builder: (_) => Padding(
        padding: const EdgeInsets.fromLTRB(24, 0, 24, 40),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(title, style: Theme.of(context).textTheme.titleLarge),
            const SizedBox(height: 12),
            const Text(
              'Lyrics for this song haven\'t been added yet. They will appear here in Tamil script, '
              'English letters and English meaning.',
              textAlign: TextAlign.center,
              style: TextStyle(color: NkColors.muted, height: 1.5),
            ),
          ],
        ),
      ),
    );
  }

  void _showQueue(BuildContext context) {
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: NkColors.surface,
      showDragHandle: true,
      isScrollControlled: true,
      builder: (_) => const FractionallySizedBox(heightFactor: 0.7, child: _QueueSheet()),
    );
  }
}

class _HeroImage extends StatelessWidget {
  const _HeroImage({required this.item, required this.occasion});

  final MediaItem item;
  final Occasion occasion;

  @override
  Widget build(BuildContext context) {
    // Singer photo or cover when available, otherwise a Nilgiris landscape.
    final art = item.artUri?.toString();
    if (art != null) return CachedNetworkImage(imageUrl: art, fit: BoxFit.cover);
    final asset = item.extras?['coverAsset'] as String?;
    if (asset != null) return Image.asset(asset, fit: BoxFit.cover);
    final fallback = occasionPhotos[occasion] ?? ('assets/images/nilgiris_village.jpg', Alignment.center);
    return Image.asset(fallback.$1, fit: BoxFit.cover, alignment: fallback.$2);
  }
}

class _SeekBar extends ConsumerStatefulWidget {
  const _SeekBar({required this.duration});

  final Duration duration;

  @override
  ConsumerState<_SeekBar> createState() => _SeekBarState();
}

class _SeekBarState extends ConsumerState<_SeekBar> {
  double? _dragMs;

  @override
  Widget build(BuildContext context) {
    final position = ref.watch(positionProvider).value ?? Duration.zero;
    final maxMs = widget.duration.inMilliseconds.toDouble();
    final valueMs = (_dragMs ?? position.inMilliseconds.toDouble()).clamp(0.0, maxMs <= 0 ? 1.0 : maxMs);
    final shown = Duration(milliseconds: valueMs.round());

    return Column(
      children: [
        Slider(
          value: maxMs <= 0 ? 0 : valueMs,
          max: maxMs <= 0 ? 1 : maxMs,
          semanticFormatterCallback: (_) => formatDuration(shown),
          onChanged: maxMs <= 0 ? null : (v) => setState(() => _dragMs = v),
          onChangeEnd: (v) {
            ref.read(audioHandlerProvider).seek(Duration(milliseconds: v.round()));
            setState(() => _dragMs = null);
          },
        ),
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 8),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text(formatDuration(shown), style: const TextStyle(fontSize: 12, color: Color(0xFFC9D6CE))),
              Text(formatDuration(widget.duration), style: const TextStyle(fontSize: 12, color: Color(0xFFC9D6CE))),
            ],
          ),
        ),
      ],
    );
  }
}

class _Action extends StatelessWidget {
  const _Action({required this.icon, required this.label, required this.onTap, this.active = false});

  final IconData icon;
  final String label;
  final VoidCallback? onTap;
  final bool active;

  @override
  Widget build(BuildContext context) {
    final color = active ? NkColors.sun : NkColors.mutedOnPhoto;
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(12),
      child: SizedBox(
        width: 72,
        height: 56,
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(icon, color: color),
            const SizedBox(height: 4),
            Text(label, style: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: color)),
          ],
        ),
      ),
    );
  }
}

class _SoundAction extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final s = ref.watch(soundSettingsProvider);
    return _Action(
      icon: Icons.equalizer_rounded,
      label: 'Sound',
      active: s.eqEnabled || s.boostDb > 0,
      onTap: () => showSoundSettings(context),
    );
  }
}

class _SleepAction extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final endsAt = ref.watch(sleepTimerProvider);
    return _Action(
      icon: Icons.bedtime_outlined,
      label: endsAt == null ? 'Sleep' : 'Until ${TimeOfDay.fromDateTime(endsAt).format(context)}',
      active: endsAt != null,
      onTap: () => showModalBottomSheet<void>(
        context: context,
        backgroundColor: NkColors.surface,
        showDragHandle: true,
        builder: (sheet) => SafeArea(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              for (final m in const [15, 30, 45, 60])
                ListTile(
                  title: Text('$m minutes'),
                  onTap: () {
                    ref.read(sleepTimerProvider.notifier).start(Duration(minutes: m));
                    Navigator.of(sheet).pop();
                  },
                ),
              if (endsAt != null)
                ListTile(
                  title: const Text('Turn off sleep timer'),
                  onTap: () {
                    ref.read(sleepTimerProvider.notifier).cancel();
                    Navigator.of(sheet).pop();
                  },
                ),
            ],
          ),
        ),
      ),
    );
  }
}

class _QueueSheet extends ConsumerWidget {
  const _QueueSheet();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final queue = ref.watch(queueProvider).value ?? const [];
    final current = ref.watch(mediaItemProvider).value?.id;
    final handler = ref.read(audioHandlerProvider);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(20, 0, 20, 8),
          child: Text('Queue', style: Theme.of(context).textTheme.titleLarge),
        ),
        Expanded(
          child: ListView.builder(
            itemCount: queue.length,
            itemBuilder: (_, i) {
              final m = queue[i];
              final isCurrent = m.id == current;
              return ListTile(
                leading: Icon(isCurrent ? Icons.graphic_eq : Icons.music_note_outlined,
                    color: isCurrent ? NkColors.sun : NkColors.muted),
                title: Text(m.title,
                    style: TextStyle(fontWeight: FontWeight.w700, color: isCurrent ? NkColors.sun : NkColors.cream)),
                subtitle: Text(m.artist ?? '', style: const TextStyle(color: NkColors.muted)),
                onTap: () => handler.skipToQueueItem(i),
              );
            },
          ),
        ),
      ],
    );
  }
}