import 'package:hydrated_bloc/hydrated_bloc.dart';

import '../../../../api/marianumconnect/queries/get_capabilities/guardian_child.dart';

/// The child a guardian is currently looking at. Shared by every module that
/// shows per-child data (timetable, absence report, later messages), so
/// switching the child in one place switches it everywhere.
class ChildSelectionCubit extends HydratedCubit<String?> {
  ChildSelectionCubit() : super(null);

  void select(String childId) => emit(childId);

  Future<void> reset() async => emit(null);

  @override
  String? fromJson(Map<String, dynamic> json) => json['childId'] as String?;

  @override
  Map<String, dynamic>? toJson(String? state) => {'childId': state};
}

/// The selected child if it is still linked, otherwise the first one. Null
/// when there are no children.
GuardianChild? effectiveChild(
  List<GuardianChild> children,
  String? selectedId,
) {
  if (children.isEmpty) return null;
  for (final child in children) {
    if (child.id == selectedId) return child;
  }
  return children.first;
}