import 'package:collection/collection.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../playlists/playlists.dart';
import '../state/providers.dart';
import '../subsonic/models.dart';
import '../theme/tokens.dart';
import '../widgets/hairline_panel.dart';
import '../widgets/toast.dart';
import 'add_to_playlist_sheet.dart';

/// Playlists list — server-backed with an offline mirror. Create from the app
/// bar; each row opens its detail. Rename/delete via the row overflow menu.
class PlaylistsScreen extends ConsumerWidget {
  const PlaylistsScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final playlists = ref.watch(realPlaylistsProvider);
    final controller = ref.read(playlistsProvider.notifier);
    final connected = ref.watch(subsonicClientProvider) != null;

    return Scaffold(
      appBar: AppBar(
        title: const Text('Playlists',
            style: TextStyle(fontWeight: FontWeight.w700)),
        actions: [
          IconButton(
            tooltip: 'New playlist',
            onPressed: connected ? () => _create(context, ref) : null,
            icon: const Icon(Icons.add),
          ),
        ],
      ),
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(TimbreSpacing.lg),
          child: HairlinePanel(
            title: 'Playlists',
            active: true,
            trailing: playlists.isEmpty ? null : '(${playlists.length})',
            padding: const EdgeInsets.symmetric(vertical: TimbreSpacing.md),
            child: playlists.isEmpty
                ? Center(
                    child: Text(
                      connected
                          ? 'No playlists yet. Tap + to create one.'
                          : 'Connect to a server to see playlists.',
                      textAlign: TextAlign.center,
                      style: const TextStyle(color: TimbreColors.dimmed),
                    ),
                  )
                : ListView.builder(
                    padding: EdgeInsets.zero,
                    itemCount: playlists.length,
                    itemBuilder: (context, i) {
                      final p = playlists[i];
                      return _PlaylistRow(
                        name: p.name,
                        subtitle: p.songCount != null
                            ? '${p.songCount} tracks'
                            : null,
                        onTap: () => Navigator.of(context).push(
                          MaterialPageRoute(
                            builder: (_) => PlaylistDetailScreen(id: p.id),
                          ),
                        ),
                        onRename: connected
                            ? () async {
                                final name = await promptPlaylistName(context,
                                    title: 'Rename playlist', initial: p.name);
                                if (name != null && name.isNotEmpty) {
                                  controller.rename(p.id, name);
                                }
                              }
                            : null,
                        onDelete: connected
                            ? () => _confirmDelete(context, controller, p)
                            : null,
                      );
                    },
                  ),
          ),
        ),
      ),
    );
  }

  Future<void> _create(BuildContext context, WidgetRef ref) async {
    final name = await promptPlaylistName(context, title: 'New playlist');
    if (name != null && name.isNotEmpty) {
      await ref.read(playlistsProvider.notifier).create(name);
    }
  }

  Future<void> _confirmDelete(
      BuildContext context, PlaylistsController controller, Playlist p) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: TimbreColors.surface,
        title: Text('Delete "${p.name}"?'),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(ctx, false),
              child: const Text('Cancel')),
          TextButton(
              onPressed: () => Navigator.pop(ctx, true),
              child: const Text('Delete')),
        ],
      ),
    );
    if (ok == true) controller.delete(p.id);
  }
}

class _PlaylistRow extends StatelessWidget {
  const _PlaylistRow({
    required this.name,
    required this.onTap,
    this.subtitle,
    this.onRename,
    this.onDelete,
  });

  final String name;
  final String? subtitle;
  final VoidCallback onTap;
  final VoidCallback? onRename;
  final VoidCallback? onDelete;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      child: Container(
        constraints:
            const BoxConstraints(minHeight: TimbreSpacing.minTouchTarget),
        padding: const EdgeInsets.only(left: TimbreSpacing.lg),
        child: Row(
          children: [
            const Icon(Icons.queue_music, size: 18, color: TimbreColors.dimmed),
            const SizedBox(width: TimbreSpacing.md),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(name,
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: const TextStyle(color: TimbreColors.foreground)),
                  if (subtitle != null)
                    Text(subtitle!,
                        style: const TextStyle(
                            color: TimbreColors.dimmed, fontSize: 12)),
                ],
              ),
            ),
            if (onRename != null || onDelete != null)
              PopupMenuButton<String>(
                icon: const Icon(Icons.more_vert,
                    size: 20, color: TimbreColors.dimmed),
                color: TimbreColors.surface,
                onSelected: (v) {
                  if (v == 'rename') onRename?.call();
                  if (v == 'delete') onDelete?.call();
                },
                itemBuilder: (_) => [
                  if (onRename != null)
                    const PopupMenuItem(value: 'rename', child: Text('Rename')),
                  if (onDelete != null)
                    const PopupMenuItem(value: 'delete', child: Text('Delete')),
                ],
              ),
          ],
        ),
      ),
    );
  }
}

/// One playlist's tracks: play all / download all from the app bar, remove a
/// track via its trailing control.
class PlaylistDetailScreen extends ConsumerStatefulWidget {
  const PlaylistDetailScreen({super.key, required this.id});

  final String id;

  @override
  ConsumerState<PlaylistDetailScreen> createState() =>
      _PlaylistDetailScreenState();
}

class _PlaylistDetailScreenState extends ConsumerState<PlaylistDetailScreen> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ref.read(playlistsProvider.notifier).loadDetail(widget.id);
    });
  }

  @override
  Widget build(BuildContext context) {
    final detail = ref.watch(
        playlistsProvider.select((s) => s.details[widget.id]));
    final summary = ref.watch(playlistsProvider.select((s) =>
        s.playlists.where((p) => p.id == widget.id).firstOrNull));
    final connected = ref.watch(subsonicClientProvider) != null;
    final playback = ref.read(playbackProvider.notifier);
    final songs = detail?.songs ?? const <Song>[];

    return Scaffold(
      appBar: AppBar(
        title: Text(detail?.name ?? summary?.name ?? 'Playlist',
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
            style: const TextStyle(fontWeight: FontWeight.w700)),
        actions: [
          IconButton(
            tooltip: 'Play all',
            onPressed:
                songs.isEmpty ? null : () => playback.playSongs(songs),
            icon: const Icon(Icons.play_arrow),
          ),
          IconButton(
            tooltip: 'Download all',
            onPressed: songs.isEmpty
                ? null
                : () {
                    ref
                        .read(downloadManagerProvider.notifier)
                        .downloadAll(songs);
                    showToast(context, 'Downloading playlist…');
                  },
            icon: const Icon(Icons.download),
          ),
        ],
      ),
      body: SafeArea(
        child: detail == null
            ? const Center(
                child: Text('Loading…',
                    style: TextStyle(color: TimbreColors.dimmed)),
              )
            : songs.isEmpty
                ? const Center(
                    child: Text('This playlist is empty.',
                        style: TextStyle(color: TimbreColors.dimmed)),
                  )
                : ListView.builder(
                    padding: const EdgeInsets.symmetric(
                        vertical: TimbreSpacing.md),
                    itemCount: songs.length,
                    itemBuilder: (context, i) {
                      final song = songs[i];
                      return _TrackRow(
                        index: i + 1,
                        song: song,
                        onTap: () => playback.playSongs(songs, startIndex: i),
                        onPlayNext: () => playback.playNext(song),
                        onAddToQueue: () => playback.addToQueue(song),
                        onRemove: connected
                            ? () => ref
                                .read(playlistsProvider.notifier)
                                .removeAt(widget.id, i)
                            : null,
                      );
                    },
                  ),
      ),
    );
  }
}

class _TrackRow extends StatelessWidget {
  const _TrackRow({
    required this.index,
    required this.song,
    required this.onTap,
    required this.onPlayNext,
    required this.onAddToQueue,
    this.onRemove,
  });

  final int index;
  final Song song;
  final VoidCallback onTap;
  final VoidCallback onPlayNext;
  final VoidCallback onAddToQueue;
  final VoidCallback? onRemove;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      child: Container(
        constraints:
            const BoxConstraints(minHeight: TimbreSpacing.minTouchTarget),
        padding: const EdgeInsets.only(left: TimbreSpacing.lg),
        child: Row(
          children: [
            SizedBox(
              width: 28,
              child: Text('$index',
                  style: const TextStyle(color: TimbreColors.dimmed)),
            ),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(song.title ?? 'Untitled',
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: const TextStyle(color: TimbreColors.foreground)),
                  if (song.artist != null)
                    Text(song.artist!,
                        maxLines: 1,
                        overflow: TextOverflow.ellipsis,
                        style: const TextStyle(
                            color: TimbreColors.dimmed, fontSize: 12)),
                ],
              ),
            ),
            PopupMenuButton<String>(
              icon: const Icon(Icons.more_vert,
                  size: 20, color: TimbreColors.dimmed),
              color: TimbreColors.surface,
              onSelected: (v) {
                switch (v) {
                  case 'next':
                    onPlayNext();
                    showToast(context, 'Playing next', icon: Icons.check);
                  case 'queue':
                    onAddToQueue();
                    showToast(context, 'Added to queue', icon: Icons.check);
                  case 'remove':
                    onRemove?.call();
                }
              },
              itemBuilder: (_) => [
                const PopupMenuItem(value: 'next', child: Text('Play next')),
                const PopupMenuItem(
                    value: 'queue', child: Text('Add to queue')),
                if (onRemove != null)
                  const PopupMenuItem(
                      value: 'remove', child: Text('Remove from playlist')),
              ],
            ),
          ],
        ),
      ),
    );
  }
}