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

import '../api.dart';
import '../player.dart';
import '../theme.dart';
import '../widgets.dart';
import 'song_editor.dart';

class SongsScreen extends StatefulWidget {
  const SongsScreen({
    super.key,
    this.filter = SongFilter.all,
    this.query = '',
    this.albumId,
    this.artistId,
    this.filterName,
  });

  final SongFilter filter;
  final String query;
  final String? albumId;
  final String? artistId;

  /// Album or singer name, shown when the list is limited to one of them.
  final String? filterName;

  @override
  State<SongsScreen> createState() => _SongsScreenState();
}

class _SongsScreenState extends State<SongsScreen> {
  static const _pageSize = 50;

  late SongFilter _filter = widget.filter;
  late String _query = widget.query;
  bool _newestFirst = true;
  int _page = 0;
  final _selected = <String>{};
  late Future<ResultPage<AdminTrack>> _data = _load();

  Future<ResultPage<AdminTrack>> _load() async {
    final page = await AdminApi.tracks(
      query: _query,
      filter: _filter,
      albumId: widget.albumId,
      artistId: widget.artistId,
      newestFirst: _newestFirst,
      page: _page,
      pageSize: _pageSize,
    );
    AdminPlayer.instance.refresh(page.items);
    return page;
  }

  void _reload({bool resetPage = false, bool keepSelection = true}) => setState(() {
        if (resetPage) _page = 0;
        if (!keepSelection) _selected.clear();
        _data = _load();
      });

  Future<void> _setStatus(List<String> ids, SongStatus status) async {
    try {
      await AdminApi.setStatus(ids, status);
      if (!mounted) return;
      showMessage(context, '${ids.length == 1 ? 'Song' : '${ids.length} songs'}: ${status.label.toLowerCase()}');
      _selected.removeAll(ids);
      _reload();
    } catch (e) {
      if (mounted) showError(context, e);
    }
  }

  Future<void> _edit(AdminTrack t) async {
    if (await editSong(context, t)) _reload();
  }

  Future<void> _bulkEdit() async {
    if (await bulkEditSongs(context, _selected.toList())) {
      if (!mounted) return;
      showMessage(context, 'Updated ${_selected.length} songs');
      _reload(keepSelection: false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final scoped = widget.albumId != null || widget.artistId != null;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        PageHeader(
          'Songs',
          subtitle: scoped
              ? '${widget.albumId != null ? 'Album' : 'Singer'}: ${widget.filterName ?? ''}'
              : 'Search, listen, fix details and publish',
          actions: [
            if (scoped)
              OutlinedButton.icon(
                onPressed: () => context.go('/songs'),
                icon: const Icon(Icons.close, size: 18),
                label: const Text('Show all songs'),
              ),
            SearchField(
              hint: 'Title, singer, album…',
              initial: _query,
              onChanged: (q) {
                _query = q;
                _reload(resetPage: true, keepSelection: false);
              },
            ),
          ],
        ),
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 24),
          child: Wrap(
            spacing: 8,
            runSpacing: 8,
            crossAxisAlignment: WrapCrossAlignment.center,
            children: [
              for (final f in SongFilter.values)
                ChoiceChip(
                  label: Text(f.label),
                  selected: _filter == f,
                  onSelected: (_) {
                    _filter = f;
                    _reload(resetPage: true, keepSelection: false);
                  },
                ),
              const SizedBox(width: 8),
              TextButton.icon(
                onPressed: () {
                  _newestFirst = !_newestFirst;
                  _reload(resetPage: true);
                },
                icon: const Icon(Icons.sort, size: 18),
                label: Text(_newestFirst ? 'Newest first' : 'A to Z'),
              ),
            ],
          ),
        ),
        const SizedBox(height: 8),
        if (_selected.isNotEmpty) _bulkBar(),
        Expanded(
          child: Loader(
            future: _data,
            onRetry: _reload,
            builder: (context, page) => page.items.isEmpty
                ? const EmptyState('No songs match.', icon: Icons.music_off_outlined)
                : _list(page),
          ),
        ),
      ],
    );
  }

  Widget _bulkBar() => Container(
        margin: const EdgeInsets.fromLTRB(24, 4, 24, 8),
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        decoration: BoxDecoration(color: NkColors.raised, borderRadius: BorderRadius.circular(14)),
        child: Wrap(
          spacing: 8,
          runSpacing: 8,
          crossAxisAlignment: WrapCrossAlignment.center,
          children: [
            Text('${_selected.length} selected', style: const TextStyle(fontWeight: FontWeight.w800)),
            const SizedBox(width: 8),
            FilledButton.icon(
              onPressed: () => _setStatus(_selected.toList(), SongStatus.approved),
              icon: const Icon(Icons.check, size: 18),
              label: const Text('Approve'),
            ),
            OutlinedButton.icon(
              onPressed: () => _setStatus(_selected.toList(), SongStatus.takenDown),
              icon: const Icon(Icons.visibility_off_outlined, size: 18),
              label: const Text('Hide'),
            ),
            OutlinedButton.icon(
              onPressed: _bulkEdit,
              icon: const Icon(Icons.edit_outlined, size: 18),
              label: const Text('Edit…'),
            ),
            TextButton(onPressed: () => setState(_selected.clear), child: const Text('Clear selection')),
          ],
        ),
      );

  Widget _list(ResultPage<AdminTrack> page) {
    final pageIds = page.items.map((t) => t.id).toSet();
    final allOnPage = pageIds.every(_selected.contains);
    final wide = MediaQuery.sizeOf(context).width >= 1100;
    final first = _page * _pageSize + 1;
    final last = first + page.items.length - 1;
    return ListView(
      padding: const EdgeInsets.fromLTRB(24, 0, 24, 24),
      children: [
        Card(
          clipBehavior: Clip.antiAlias,
          child: Column(
            children: [
              ListTile(
                dense: true,
                leading: Checkbox(
                  value: allOnPage,
                  onChanged: (v) => setState(() => v == true ? _selected.addAll(pageIds) : _selected.removeAll(pageIds)),
                ),
                title: Text('$first–$last of ${page.total}', style: Theme.of(context).textTheme.bodySmall),
              ),
              for (final t in page.items) ...[const Divider(), _row(t, wide)],
            ],
          ),
        ),
        const SizedBox(height: 12),
        Row(
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            OutlinedButton(
              onPressed: _page == 0
                  ? null
                  : () {
                      _page--;
                      _reload();
                    },
              child: const Text('Previous'),
            ),
            const SizedBox(width: 8),
            OutlinedButton(
              onPressed: last >= page.total
                  ? null
                  : () {
                      _page++;
                      _reload();
                    },
              child: const Text('Next'),
            ),
          ],
        ),
      ],
    );
  }

  Widget _row(AdminTrack t, bool wide) {
    final small = Theme.of(context).textTheme.bodySmall;
    final quick = t.status == SongStatus.approved
        ? IconButton(
            tooltip: 'Hide from the app',
            onPressed: () => _setStatus([t.id], SongStatus.takenDown),
            icon: const Icon(Icons.visibility_off_outlined),
          )
        : IconButton(
            tooltip: 'Approve (publish in the app)',
            onPressed: t.audioKey == null ? null : () => _setStatus([t.id], SongStatus.approved),
            icon: const Icon(Icons.check_circle_outline, color: NkColors.teaLeaf),
          );
    return InkWell(
      onTap: () => _edit(t),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
        child: Row(
          children: [
            Checkbox(
              value: _selected.contains(t.id),
              onChanged: (v) => setState(() => v == true ? _selected.add(t.id) : _selected.remove(t.id)),
            ),
            PlayButton(t),
            const SizedBox(width: 8),
            Expanded(
              flex: 4,
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(t.title, maxLines: 1, overflow: TextOverflow.ellipsis,
                      style: const TextStyle(fontWeight: FontWeight.w700)),
                  Text(
                    wide ? creditLine(t) : '${creditLine(t)} · ${t.albumTitle ?? 'No album'}',
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                    style: small?.copyWith(color: t.singerNames.isEmpty ? NkColors.info : null),
                  ),
                ],
              ),
            ),
            if (wide) ...[
              Expanded(
                flex: 3,
                child: Text(t.albumTitle ?? 'No album', maxLines: 1, overflow: TextOverflow.ellipsis,
                    style: small?.copyWith(color: t.albumId == null ? NkColors.info : null)),
              ),
              SizedBox(width: 150, child: Text(occasions[t.occasion] ?? t.occasion, style: small)),
              SizedBox(width: 50, child: Text(formatDuration(t.duration), style: small)),
            ],
            SizedBox(width: 150, child: Align(alignment: Alignment.centerLeft, child: StatusChip(t.status))),
            quick,
            IconButton(tooltip: 'Edit', onPressed: () => _edit(t), icon: const Icon(Icons.edit_outlined)),
          ],
        ),
      ),
    );
  }
}