import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:mirror_ui/mirror_ui.dart';
import '../providers/ha_provider.dart';

class HaEntityPickerScreen extends ConsumerStatefulWidget {
  final List<String> selectedIds;

  const HaEntityPickerScreen({super.key, this.selectedIds = const []});

  @override
  ConsumerState<HaEntityPickerScreen> createState() => _HaEntityPickerScreenState();
}

class _HaEntityPickerScreenState extends ConsumerState<HaEntityPickerScreen> {
  late Set<String> _selected;
  String _search = '';

  @override
  void initState() {
    super.initState();
    _selected = Set.from(widget.selectedIds);
  }

  String _domainOf(String entityId) {
    final dotIndex = entityId.indexOf('.');
    return dotIndex > 0 ? entityId.substring(0, dotIndex) : 'other';
  }

  @override
  Widget build(BuildContext context) {
    final entitiesAsync = ref.watch(haEntitiesProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Select HA Entities'),
        backgroundColor: MirrorTheme.background,
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(_selected.toList()),
            child: Text('Done (${_selected.length})'),
          ),
        ],
      ),
      backgroundColor: MirrorTheme.background,
      body: entitiesAsync.when(
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (e, _) => Center(child: Text('Error: $e')),
        data: (state) {
          if (state.error != null) {
            return Center(child: Text(state.error!));
          }
          return _buildList(state.entities);
        },
      ),
    );
  }

  Widget _buildList(List entities) {
    // Filter by search
    final filtered = entities.where((e) {
      final id = e.entityId as String;
      final name =
          (e.attributes['friendly_name'] as String?) ?? id;
      final query = _search.toLowerCase();
      return id.toLowerCase().contains(query) || name.toLowerCase().contains(query);
    }).toList();

    // Group by domain
    final grouped = <String, List<dynamic>>{};
    for (final entity in filtered) {
      final domain = _domainOf(entity.entityId as String);
      grouped.putIfAbsent(domain, () => []).add(entity);
    }

    final sortedDomains = grouped.keys.toList()..sort();

    return Column(
      children: [
        Padding(
          padding: const EdgeInsets.all(12),
          child: TextField(
            decoration: InputDecoration(
              hintText: 'Search entities...',
              prefixIcon: const Icon(Icons.search),
              filled: true,
              fillColor: MirrorTheme.surface,
              border: OutlineInputBorder(
                borderRadius: BorderRadius.circular(12),
                borderSide: BorderSide.none,
              ),
            ),
            onChanged: (v) => setState(() => _search = v),
          ),
        ),
        Expanded(
          child: ListView.builder(
            itemCount: sortedDomains.length,
            itemBuilder: (context, domainIndex) {
              final domain = sortedDomains[domainIndex];
              final items = grouped[domain]!;
              return ExpansionTile(
                title: Text(
                  domain,
                  style: TextStyle(color: MirrorTheme.accent, fontWeight: FontWeight.w600),
                ),
                initiallyExpanded: items.any((e) => _selected.contains(e.entityId)),
                children: items.map((entity) {
                  final id = entity.entityId as String;
                  final name =
                      (entity.attributes['friendly_name'] as String?) ?? id;
                  return CheckboxListTile(
                    title: Text(name),
                    subtitle: Text(id, style: const TextStyle(fontSize: 12)),
                    value: _selected.contains(id),
                    activeColor: MirrorTheme.accent,
                    onChanged: (checked) {
                      setState(() {
                        if (checked == true) {
                          _selected.add(id);
                        } else {
                          _selected.remove(id);
                        }
                      });
                    },
                  );
                }).toList(),
              );
            },
          ),
        ),
      ],
    );
  }
}