import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:spotiflac_android/l10n/l10n.dart';
import 'package:spotiflac_android/providers/download_queue_provider.dart';
import 'package:spotiflac_android/providers/library_browse_provider.dart';
import 'package:spotiflac_android/screens/downloaded_album_screen.dart';
import 'package:spotiflac_android/screens/local_album_screen.dart';
import 'package:spotiflac_android/services/downloaded_embedded_cover_resolver.dart';
import 'package:spotiflac_android/services/library_database.dart';
import 'package:spotiflac_android/utils/nav_bar_inset.dart';
import 'package:spotiflac_android/widgets/app_bottom_sheet.dart';
import 'package:spotiflac_android/widgets/app_search_field.dart';
import 'package:spotiflac_android/widgets/app_sliver_header.dart';
import 'package:spotiflac_android/widgets/cached_cover_image.dart';

enum MornyeLibraryPage { overview, albums, artists }

class MornyeLibraryScreen extends ConsumerStatefulWidget {
  const MornyeLibraryScreen({
    super.key,
    required this.onOpenSection,
    this.page = MornyeLibraryPage.overview,
    this.artist,
  });

  final ValueChanged<String> onOpenSection;
  final MornyeLibraryPage page;
  final String? artist;

  @override
  ConsumerState<MornyeLibraryScreen> createState() =>
      _MornyeLibraryScreenState();
}

class _MornyeLibraryScreenState extends ConsumerState<MornyeLibraryScreen> {
  final _scroll = ScrollController();
  final _search = TextEditingController();
  Timer? _debounce;
  bool _showSearch = false;
  String _query = '';
  late String _sort;
  int _limit = 40;
  List<LibraryBrowseEntry> _rows = const [];
  bool _loading = true;

  bool get _overview => widget.page == MornyeLibraryPage.overview;
  bool get _artists => widget.page == MornyeLibraryPage.artists;
  LibraryBrowseRequest get _request => (
    artists: _artists,
    artist: widget.artist,
    search: _query,
    sort: _sort,
    limit: _limit,
  );

  @override
  void initState() {
    super.initState();
    _sort = _overview ? 'latest' : 'a-z';
    _scroll.addListener(() {
      if (_scroll.position.extentAfter < 500 &&
          !_loading &&
          _rows.length >= _limit) {
        setState(() => _limit += 40);
      }
    });
  }

  @override
  void dispose() {
    _debounce?.cancel();
    _scroll.dispose();
    _search.dispose();
    super.dispose();
  }

  void _searchChanged(String value) {
    _debounce?.cancel();
    _debounce = Timer(const Duration(milliseconds: 300), () {
      if (!mounted || _query == value.trim()) return;
      setState(() {
        _query = value.trim();
        _limit = 40;
        _rows = const [];
      });
    });
  }

  void _openPage(MornyeLibraryPage page, {String? artist}) {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (_) => Scaffold(
          body: MornyeLibraryScreen(
            page: page,
            artist: artist,
            onOpenSection: widget.onOpenSection,
          ),
        ),
      ),
    );
  }

  Future<void> _openAlbum(LibraryBrowseEntry entry) async {
    if (entry.source != 'local') {
      await Navigator.of(context).push(
        MaterialPageRoute<void>(
          builder: (_) => DownloadedAlbumScreen(
            albumName: entry.name,
            artistName: entry.artist,
            coverUrl: entry.cover,
          ),
        ),
      );
      return;
    }
    final rows = await LibraryDatabase.instance.getQueueLocalAlbumTracksByKey(
      entry.key,
    );
    if (!mounted) return;
    await Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (_) => LocalAlbumScreen(
          albumName: entry.name,
          artistName: entry.artist,
          coverPath: entry.cover,
          tracks: rows.map(LocalLibraryItem.fromJson).toList(growable: false),
        ),
      ),
    );
  }

  Future<void> _chooseSort() async {
    final selected = await showAppBottomSheet<String>(
      context: context,
      builder: (context) => Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          for (final option in [
            ('a-z', context.l10n.searchSortTitleAZ),
            ('latest', context.l10n.libraryRecentlyAdded),
          ])
            ListTile(
              title: Text(option.$2),
              trailing: _sort == option.$1 ? const Icon(Icons.check) : null,
              onTap: () => Navigator.pop(context, option.$1),
            ),
        ],
      ),
    );
    if (!mounted || selected == null || selected == _sort) return;
    setState(() {
      _sort = selected;
      _limit = 40;
      _rows = const [];
    });
    _scroll.jumpTo(0);
  }

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).colorScheme;
    final result = ref.watch(libraryBrowseProvider(_request));
    _loading = result.isLoading;
    if (result.hasValue) _rows = result.requireValue;
    final title =
        widget.artist ??
        (_overview
            ? context.l10n.navLibrary
            : _artists
            ? context.l10n.searchArtists
            : context.l10n.searchAlbums);
    final actions = <Widget>[
      IconButton(
        tooltip: context.l10n.librarySearchHint,
        icon: const Icon(Icons.search),
        onPressed: () => setState(() => _showSearch = !_showSearch),
      ),
      if (_overview)
        Consumer(
          builder: (context, ref, _) {
            final count = ref.watch(
              downloadQueueLookupProvider.select(
                (s) => s.notCompletedItemIds.length,
              ),
            );
            return TextButton.icon(
              onPressed: () => widget.onOpenSection('downloads'),
              icon: Badge(
                isLabelVisible: count > 0,
                label: Text('$count'),
                child: const Icon(Icons.downloading_outlined),
              ),
              label: Text(context.l10n.libraryDownloads),
            );
          },
        )
      else if (!_artists)
        IconButton(
          tooltip: context.l10n.searchSortTitle,
          icon: const Icon(Icons.sort),
          onPressed: _chooseSort,
        ),
    ];
    return RefreshIndicator(
      onRefresh: () async {
        ref.invalidate(libraryBrowseProvider(_request));
        await ref.read(libraryBrowseProvider(_request).future);
      },
      child: CustomScrollView(
        controller: _scroll,
        physics: const AlwaysScrollableScrollPhysics(),
        slivers: [
          if (_overview)
            AppSliverHeader.tabRoot(title: title, actions: actions)
          else
            AppSliverHeader.page(title: title, actions: actions),
          if (_showSearch)
            SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.fromLTRB(24, 8, 24, 16),
                child: AppSearchField(
                  controller: _search,
                  autofocus: true,
                  hintText: context.l10n.librarySearchHint,
                  clearTooltip: context.l10n.dialogClear,
                  onChanged: _searchChanged,
                  onClear: () {
                    _search.clear();
                    _searchChanged('');
                  },
                ),
              ),
            ),
          if (_overview && _query.isEmpty)
            SliverPadding(
              padding: const EdgeInsets.fromLTRB(24, 0, 24, 20),
              sliver: SliverList.list(
                children: [
                  for (final category in [
                    (
                      Icons.queue_music,
                      context.l10n.searchPlaylists,
                      () => widget.onOpenSection('playlists'),
                    ),
                    (
                      Icons.mic_none,
                      context.l10n.searchArtists,
                      () => _openPage(MornyeLibraryPage.artists),
                    ),
                    (
                      Icons.album_outlined,
                      context.l10n.searchAlbums,
                      () => _openPage(MornyeLibraryPage.albums),
                    ),
                    (
                      Icons.music_note_outlined,
                      context.l10n.searchSongs,
                      () => widget.onOpenSection('all'),
                    ),
                  ]) ...[
                    ListTile(
                      contentPadding: EdgeInsets.zero,
                      minVerticalPadding: 12,
                      leading: Icon(
                        category.$1,
                        color: colors.primary,
                        size: 28,
                      ),
                      title: Text(
                        category.$2,
                        style: const TextStyle(fontSize: 22),
                      ),
                      trailing: Icon(
                        Icons.chevron_right,
                        color: colors.onSurfaceVariant,
                      ),
                      onTap: category.$3,
                    ),
                    const Divider(height: 1, indent: 48),
                  ],
                ],
              ),
            ),
          if (_overview)
            SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.fromLTRB(24, 8, 24, 16),
                child: Text(
                  _query.isEmpty
                      ? context.l10n.libraryRecentlyAdded
                      : context.l10n.searchAlbums,
                  style: Theme.of(context).textTheme.headlineSmall?.copyWith(
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
            ),
          if (_rows.isNotEmpty)
            if (_artists)
              SliverList.builder(
                itemCount: _rows.length,
                itemBuilder: (context, index) {
                  final entry = _rows[index];
                  return Column(
                    children: [
                      ListTile(
                        contentPadding: const EdgeInsets.symmetric(
                          horizontal: 24,
                          vertical: 8,
                        ),
                        leading: ClipOval(
                          child: SizedBox.square(
                            dimension: 56,
                            child: _LibraryBrowseArtwork(entry: entry),
                          ),
                        ),
                        title: Text(entry.artist),
                        subtitle: Text(
                          context.l10n.queueTrackCount(entry.trackCount),
                        ),
                        trailing: const Icon(Icons.chevron_right),
                        onTap: () => _openPage(
                          MornyeLibraryPage.albums,
                          artist: entry.artist,
                        ),
                      ),
                      const Divider(height: 1, indent: 96, endIndent: 24),
                    ],
                  );
                },
              )
            else
              SliverPadding(
                padding: const EdgeInsets.symmetric(horizontal: 24),
                sliver: SliverLayoutBuilder(
                  builder: (context, constraints) {
                    final columns = (constraints.crossAxisExtent / 200)
                        .floor()
                        .clamp(2, 6);
                    final width =
                        (constraints.crossAxisExtent - 20 * (columns - 1)) /
                        columns;
                    final textHeight =
                        MediaQuery.textScalerOf(context).scale(16) * 3.2 + 24;
                    return SliverGrid.builder(
                      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                        crossAxisCount: columns,
                        crossAxisSpacing: 20,
                        mainAxisSpacing: 16,
                        mainAxisExtent: width + textHeight,
                      ),
                      itemCount: _rows.length,
                      itemBuilder: (context, index) {
                        final entry = _rows[index];
                        return Semantics(
                          button: true,
                          child: GestureDetector(
                            behavior: HitTestBehavior.opaque,
                            onTap: () => _openAlbum(entry),
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                AspectRatio(
                                  aspectRatio: 1,
                                  child: ClipRRect(
                                    borderRadius: BorderRadius.circular(8),
                                    child: _LibraryBrowseArtwork(entry: entry),
                                  ),
                                ),
                                const SizedBox(height: 8),
                                Text(
                                  entry.name,
                                  maxLines: 1,
                                  overflow: TextOverflow.ellipsis,
                                  style: const TextStyle(fontSize: 16),
                                ),
                                Text(
                                  entry.artist,
                                  maxLines: 1,
                                  overflow: TextOverflow.ellipsis,
                                  style: TextStyle(
                                    fontSize: 14,
                                    color: colors.onSurfaceVariant,
                                  ),
                                ),
                              ],
                            ),
                          ),
                        );
                      },
                    );
                  },
                ),
              ),
          if (result.hasError)
            SliverToBoxAdapter(
              child: Center(
                child: TextButton.icon(
                  onPressed: () =>
                      ref.invalidate(libraryBrowseProvider(_request)),
                  icon: const Icon(Icons.refresh),
                  label: Text(context.l10n.dialogRetry),
                ),
              ),
            )
          else if (_loading)
            const SliverToBoxAdapter(
              child: Padding(
                padding: EdgeInsets.all(24),
                child: Center(child: CircularProgressIndicator.adaptive()),
              ),
            )
          else if (_rows.isEmpty)
            SliverFillRemaining(
              hasScrollBody: false,
              child: Center(child: Text(context.l10n.libraryEmptyCollection)),
            ),
          const NavBarSliverSpacer(),
        ],
      ),
    );
  }
}

class _LibraryBrowseArtwork extends StatefulWidget {
  const _LibraryBrowseArtwork({required this.entry});
  final LibraryBrowseEntry entry;

  @override
  State<_LibraryBrowseArtwork> createState() => _LibraryBrowseArtworkState();
}

class _LibraryBrowseArtworkState extends State<_LibraryBrowseArtwork> {
  @override
  Widget build(BuildContext context) {
    final entry = widget.entry;
    final embedded = entry.cover?.isNotEmpty == true
        ? null
        : DownloadedEmbeddedCoverResolver.resolve(
            entry.samplePath,
            onChanged: () {
              if (mounted) setState(() {});
            },
          );
    Widget fallback(BuildContext context) => ColoredBox(
      color: Theme.of(context).colorScheme.surfaceContainerHighest,
      child: Center(
        child: Icon(
          Icons.album_outlined,
          size: 40,
          color: Theme.of(context).colorScheme.onSurfaceVariant,
        ),
      ),
    );
    final cover = entry.cover?.isNotEmpty == true ? entry.cover! : embedded;
    return cover == null
        ? fallback(context)
        : LocalOrNetworkCoverImage(url: cover, placeholder: fallback);
  }
}