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

import 'package:go_router/go_router.dart';

import '../../app/router.dart';
import '../../app/theme.dart';
import '../../audio/player_providers.dart';
import '../../core/models.dart';
import '../../offline/download_store.dart';
import '../../shared/widgets/artwork.dart';
import '../../shared/widgets/catalog_builder.dart';
import '../../shared/widgets/mini_player.dart';
import '../../shared/widgets/section_header.dart';
import '../../shared/widgets/track_tile.dart';

class AlbumScreen extends ConsumerWidget {
  const AlbumScreen({super.key, required this.albumId});

  final String albumId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Scaffold(
      bottomNavigationBar: const SafeArea(child: MiniPlayer()),
      body: CatalogBuilder(builder: (catalog) {
        final album = catalog.albumsById[albumId];
        if (album == null) {
          return const Center(
            child: EmptyState(
              icon: Icons.album_outlined,
              title: 'Album not found',
              message: 'It may have been removed.',
            ),
          );
        }
        final tracks = catalog.byAlbum(albumId);
        final total = tracks.fold(Duration.zero, (sum, t) => sum + t.duration);
        final controller = ref.read(playerControllerProvider);
        return CustomScrollView(
          slivers: [
            const SliverAppBar(pinned: true),
            SliverToBoxAdapter(
              child: Column(
                children: [
                  ClipRRect(
                    borderRadius: BorderRadius.circular(12),
                    child: SizedBox.square(dimension: 200, child: AlbumCover(album: album, size: 200)),
                  ),
                  const SizedBox(height: 16),
                  Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 24),
                    child: Text(album.title,
                        textAlign: TextAlign.center, style: Theme.of(context).textTheme.headlineSmall),
                  ),
                  const SizedBox(height: 4),
                  Text(
                    [
                      if (album.year != null) '${album.year}',
                      '${tracks.length} songs',
                      '${total.inMinutes} min',
                    ].join(' · '),
                    style: const TextStyle(color: NkColors.muted),
                  ),
                ],
              ),
            ),
            SliverPadding(
              padding: const EdgeInsets.fromLTRB(18, 12, 18, 8),
              sliver: SliverToBoxAdapter(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    _DownloadAlbumButton(tracks: tracks),
                    const SizedBox(width: 8),
                    IconButton(
                      tooltip: 'Shuffle',
                      icon: const Icon(Icons.shuffle, color: NkColors.sun),
                      onPressed: tracks.isEmpty ? null : () => controller.playTracks(tracks, shuffle: true),
                    ),
                    const SizedBox(width: 16),
                    IconButton.filled(
                      tooltip: 'Play all',
                      style: IconButton.styleFrom(fixedSize: const Size(56, 56)),
                      onPressed: tracks.isEmpty ? null : () => controller.playTracks(tracks),
                      icon: const Icon(Icons.play_arrow_rounded, size: 30),
                    ),
                  ],
                ),
              ),
            ),
            SliverPadding(
              padding: const EdgeInsets.symmetric(horizontal: 18),
              sliver: SliverList.builder(
                itemCount: tracks.length,
                itemBuilder: (_, i) => TrackTile(track: tracks[i], onTap: () => controller.playTracks(tracks, index: i)),
              ),
            ),
            const SliverToBoxAdapter(child: SizedBox(height: 24)),
          ],
        );
      }),
    );
  }
}

class _DownloadAlbumButton extends ConsumerWidget {
  const _DownloadAlbumButton({required this.tracks});

  final List<Track> tracks;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final d = ref.watch(downloadsProvider);
    final done = tracks.where((t) => d.isDownloaded(t.id)).length;
    final busy = tracks.any((t) => d.progress.containsKey(t.id));
    final all = tracks.isNotEmpty && done == tracks.length;
    return IconButton(
      tooltip: all ? 'Downloaded' : 'Download album',
      icon: busy
          ? const SizedBox.square(dimension: 22, child: CircularProgressIndicator(strokeWidth: 2.5))
          : Icon(all ? Icons.download_done_rounded : Icons.download_rounded,
              color: all ? NkColors.teaLeaf : NkColors.cream),
      onPressed: all || busy || tracks.isEmpty
          ? null
          : () {
              if (!isSignedIn) {
                context.push('/login?mode=signup');
                return;
              }
              final messenger = ScaffoldMessenger.of(context);
              ref.read(playerControllerProvider).download(tracks).then((problem) => messenger.showSnackBar(
                    SnackBar(
                      content: Text(problem ?? 'Downloading ${tracks.length - done} songs. Find them in Downloads.'),
                    ),
                  ));
            },
    );
  }
}

/// Square album card for horizontal rows and grids.
class AlbumCard extends StatelessWidget {
  const AlbumCard({super.key, required this.album, required this.songCount, required this.onTap, this.size = 140});

  final Album album;
  final int songCount;
  final VoidCallback onTap;
  final double size;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      borderRadius: BorderRadius.circular(10),
      onTap: onTap,
      child: SizedBox(
        width: size,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            ClipRRect(
              borderRadius: BorderRadius.circular(10),
              child: SizedBox.square(dimension: size, child: AlbumCover(album: album, size: size)),
            ),
            const SizedBox(height: 6),
            Text(album.title, maxLines: 1, overflow: TextOverflow.ellipsis,
                style: const TextStyle(fontWeight: FontWeight.w600)),
            Text('$songCount songs', style: const TextStyle(color: NkColors.muted, fontSize: 12)),
          ],
        ),
      ),
    );
  }
}