import 'package:flutter/material.dart';

import 'api.dart';
import 'theme.dart';
import 'widgets.dart';

/// Chooses singers in order: type to search, pick a match, or add a new singer by name.
class SingerPicker extends StatefulWidget {
  const SingerPicker({super.key, required this.artists, required this.selected, required this.onChanged});

  final List<AdminArtist> artists;
  final List<String> selected;
  final ValueChanged<List<String>> onChanged;

  @override
  State<SingerPicker> createState() => _SingerPickerState();
}

class _SingerPickerState extends State<SingerPicker> {
  late final _names = {for (final a in widget.artists) a.id: a.name};
  bool _adding = false;

  void _add(String id) {
    if (widget.selected.contains(id)) return;
    widget.onChanged([...widget.selected, id]);
  }

  Future<void> _createSinger(String name) async {
    setState(() => _adding = true);
    try {
      final id = await AdminApi.createArtist(name: name);
      _names[id] = name;
      _add(id);
      if (mounted) showMessage(context, 'Added singer "$name"');
    } catch (e) {
      if (mounted) showError(context, e);
    } finally {
      if (mounted) setState(() => _adding = false);
    }
  }

  @override
  Widget build(BuildContext context) => Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          if (widget.selected.isNotEmpty) ...[
            ReorderableListView(
              shrinkWrap: true,
              buildDefaultDragHandles: false,
              onReorderItem: (from, to) {
                final list = [...widget.selected];
                list.insert(to, list.removeAt(from));
                widget.onChanged(list);
              },
              children: [
                for (final (i, id) in widget.selected.indexed)
                  ListTile(
                    key: ValueKey(id),
                    dense: true,
                    contentPadding: EdgeInsets.zero,
                    leading: ReorderableDragStartListener(
                      index: i,
                      child: const Icon(Icons.drag_indicator, color: NkColors.muted),
                    ),
                    title: Text(_names[id] ?? 'Unknown singer'),
                    trailing: IconButton(
                      tooltip: 'Remove',
                      icon: const Icon(Icons.close, size: 18),
                      onPressed: () => widget.onChanged([...widget.selected]..remove(id)),
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 6),
          ],
          _SearchAdd(
            label: _adding ? 'Adding…' : 'Add a singer',
            options: [
              for (final a in widget.artists)
                if (!widget.selected.contains(a.id)) (a.id, a.name, a.hattiName),
            ],
            onPick: _add,
            createLabel: (q) => 'New singer "$q"',
            onCreate: _createSinger,
          ),
        ],
      );
}

/// Chooses one album, or none; can create a new album.
class AlbumPicker extends StatefulWidget {
  const AlbumPicker({super.key, required this.albums, required this.albumId, required this.onChanged});

  final List<AdminAlbum> albums;
  final String? albumId;
  final ValueChanged<String?> onChanged;

  @override
  State<AlbumPicker> createState() => _AlbumPickerState();
}

class _AlbumPickerState extends State<AlbumPicker> {
  late final _titles = {for (final a in widget.albums) a.id: a.title};

  Future<void> _create(String title) async {
    try {
      final id = await AdminApi.createAlbum(title: title);
      _titles[id] = title;
      widget.onChanged(id);
      if (mounted) showMessage(context, 'Added album "$title"');
    } catch (e) {
      if (mounted) showError(context, e);
    }
  }

  @override
  Widget build(BuildContext context) {
    final current = widget.albumId;
    if (current != null) {
      return InputDecorator(
        decoration: const InputDecoration(labelText: 'Album'),
        child: Row(
          children: [
            Expanded(child: Text(_titles[current] ?? 'Unknown album')),
            TextButton(onPressed: () => widget.onChanged(null), child: const Text('Change')),
          ],
        ),
      );
    }
    return _SearchAdd(
      label: 'Album (type to search)',
      options: [for (final a in widget.albums) (a.id, a.title, a.year?.toString())],
      onPick: widget.onChanged,
      createLabel: (q) => 'New album "$q"',
      onCreate: _create,
    );
  }
}

typedef _Option = (String id, String name, String? detail);

class _SearchAdd extends StatelessWidget {
  const _SearchAdd({
    required this.label,
    required this.options,
    required this.onPick,
    required this.createLabel,
    required this.onCreate,
  });

  final String label;
  final List<_Option> options;
  final ValueChanged<String> onPick;
  final String Function(String query) createLabel;
  final ValueChanged<String> onCreate;

  static const _createId = '\u0000create';

  @override
  Widget build(BuildContext context) => LayoutBuilder(
        builder: (context, box) => Autocomplete<_Option>(
          displayStringForOption: (o) => '',
          optionsBuilder: (value) {
            final q = value.text.trim().toLowerCase();
            if (q.isEmpty) return const [];
            final matches = options.where((o) => o.$2.toLowerCase().contains(q)).take(12).toList()
              ..sort((a, b) => (a.$2.toLowerCase().startsWith(q) ? 0 : 1)
                  .compareTo(b.$2.toLowerCase().startsWith(q) ? 0 : 1));
            final exact = options.any((o) => o.$2.toLowerCase() == q);
            return [...matches, if (!exact) (_createId, value.text.trim(), null)];
          },
          onSelected: (o) => o.$1 == _createId ? onCreate(o.$2) : onPick(o.$1),
          fieldViewBuilder: (context, text, focus, submit) => TextField(
            controller: text,
            focusNode: focus,
            decoration: InputDecoration(labelText: label, prefixIcon: const Icon(Icons.search, color: NkColors.muted)),
          ),
          optionsViewBuilder: (context, select, items) => Align(
            alignment: Alignment.topLeft,
            child: Material(
              color: NkColors.raised,
              elevation: 6,
              borderRadius: BorderRadius.circular(12),
              child: ConstrainedBox(
                constraints: BoxConstraints(maxHeight: 280, maxWidth: box.maxWidth),
                child: ListView(
                  shrinkWrap: true,
                  padding: const EdgeInsets.symmetric(vertical: 6),
                  children: [
                    for (final o in items)
                      ListTile(
                        dense: true,
                        leading: Icon(o.$1 == _createId ? Icons.add : Icons.check_circle_outline,
                            color: o.$1 == _createId ? NkColors.sun : NkColors.muted, size: 20),
                        title: Text(o.$1 == _createId ? createLabel(o.$2) : o.$2),
                        subtitle: o.$3 == null ? null : Text(o.$3!),
                        onTap: () => select(o),
                      ),
                  ],
                ),
              ),
            ),
          ),
        ),
      );
}