import 'package:flutter/material.dart';
import '../../../../core/models/sensor_defs.dart';
import '../../../../core/models/units.dart';
import '../../../theme/app_colors.dart';

/// One choosable entry in [showPickerSheet].
class PickerItem {
  final String id;
  final String title;
  final String? subtitle;
  const PickerItem(this.id, this.title, [this.subtitle]);
}

/// Bottom sheet listing [items]; resolves to the chosen id, or null.
Future<String?> showPickerSheet(
  BuildContext context, {
  required String title,
  required List<PickerItem> items,
  required String currentId,
}) {
  return showModalBottomSheet<String>(
    context: context,
    isScrollControlled: true,
    backgroundColor: Colors.transparent,
    builder: (_) => _PickerSheet(
      title: title,
      items: items,
      currentId: currentId,
    ),
  );
}

/// Picker over every analog sensor, showing the unit currently in use.
Future<String?> pickSensor(
  BuildContext context, {
  required String title,
  required String currentId,
  required UnitPrefs units,
}) {
  return showPickerSheet(
    context,
    title: title,
    currentId: currentId,
    items: [
      for (final d in sensorDefs)
        PickerItem(d.id, d.displayName, sensorView(d.id, units).unit),
    ],
  );
}

/// Picker over every flag.
Future<String?> pickFlag(BuildContext context, {required String currentId}) {
  return showPickerSheet(
    context,
    title: 'SELECT FLAG',
    currentId: currentId,
    items: [for (final f in flagDefs) PickerItem(f.id, f.displayName)],
  );
}

class _PickerSheet extends StatelessWidget {
  final String title;
  final List<PickerItem> items;
  final String currentId;

  const _PickerSheet({
    required this.title,
    required this.items,
    required this.currentId,
  });

  @override
  Widget build(BuildContext context) {
    final c = AppColors.of(context);
    return DraggableScrollableSheet(
      expand: false,
      initialChildSize: 0.6,
      minChildSize: 0.4,
      maxChildSize: 0.9,
      builder: (context, scrollController) {
        return Container(
          decoration: BoxDecoration(
            color: c.surface,
            borderRadius: const BorderRadius.vertical(top: Radius.circular(16)),
          ),
          child: Column(
            children: [
              const SizedBox(height: 8),
              Container(
                width: 40,
                height: 4,
                decoration: BoxDecoration(
                  color: c.onSurfaceMuted.withAlpha(90),
                  borderRadius: BorderRadius.circular(2),
                ),
              ),
              Padding(
                padding: const EdgeInsets.all(16),
                child: Text(
                  title,
                  style: TextStyle(
                    color: c.onSurfaceMuted,
                    fontSize: 12,
                    letterSpacing: 2,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
              Divider(height: 1, color: c.divider),
              Expanded(
                child: ListView.builder(
                  controller: scrollController,
                  itemCount: items.length,
                  itemBuilder: (context, i) {
                    final item = items[i];
                    final isSelected = item.id == currentId;
                    return ListTile(
                      title: Text(
                        item.title,
                        style: TextStyle(
                          color: c.onSurface,
                          fontWeight:
                              isSelected ? FontWeight.bold : FontWeight.normal,
                        ),
                      ),
                      subtitle: item.subtitle == null
                          ? null
                          : Text(
                              item.subtitle!,
                              style: TextStyle(
                                  color: c.onSurfaceMuted, fontSize: 12),
                            ),
                      trailing: isSelected
                          ? Icon(Icons.check, color: c.accent, size: 18)
                          : null,
                      onTap: () => Navigator.pop(context, item.id),
                    );
                  },
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}