import 'package:adhd_scheduler_core/scheduler_core.dart';
import 'package:test/test.dart';

void main() {
  group('Child task ownership', () {
    final now = DateTime(2026, 6, 19, 12);

    test('child references parent through parentTaskId', () {
      final parent = task(id: 'parent', title: 'Clean kitchen', createdAt: now);
      final child = task(
        id: 'child',
        title: 'Clear sink',
        createdAt: now,
        parentTaskId: parent.id,
      );
      final view = ChildTaskView(tasks: [parent, child]);

      expect(child.parentTaskId, parent.id);
      expect(view.isChildOf(child: child, parent: parent), isTrue);
      expect(view.parentOf(child), same(parent));
    });

    test('parent can query and aggregate direct children', () {
      final parent = task(id: 'parent', title: 'Clean kitchen', createdAt: now);
      final plannedChild = task(
        id: 'planned-child',
        title: 'Clear sink',
        createdAt: now,
        parentTaskId: parent.id,
      );
      final completedChild = task(
        id: 'completed-child',
        title: 'Wipe counter',
        createdAt: now,
        status: TaskStatus.completed,
        parentTaskId: parent.id,
      );
      final unrelatedChild = task(
        id: 'unrelated-child',
        title: 'Sort drawer',
        createdAt: now,
        parentTaskId: 'other-parent',
      );
      final view = ChildTaskView(
        tasks: [parent, plannedChild, unrelatedChild, completedChild],
      );

      expect(view.childrenOf(parent).map((child) => child.id), [
        'planned-child',
        'completed-child',
      ]);

      final summary = view.summaryFor(parent);
      expect(summary.totalCount, 2);
      expect(summary.plannedCount, 1);
      expect(summary.completedCount, 1);
      expect(summary.allChildrenCompleted, isFalse);
    });

    test('parent can remain incomplete while children are planned or completed',
        () {
      final parent = task(id: 'parent', title: 'Clean kitchen', createdAt: now);
      final completedChild = task(
        id: 'completed-child',
        title: 'Clear sink',
        createdAt: now,
        status: TaskStatus.completed,
        parentTaskId: parent.id,
      );
      final view = ChildTaskView(tasks: [parent, completedChild]);

      expect(parent.status, TaskStatus.planned);
      expect(view.summaryFor(parent).allChildrenCompleted, isTrue);
      expect(view.parentShouldAutoComplete(parent), isFalse);
    });

    test('child ownership does not block normal scheduling behavior', () {
      const engine = SchedulingEngine();
      final parent = task(
        id: 'parent',
        title: 'Clean kitchen',
        createdAt: now,
        status: TaskStatus.backlog,
      );
      final child = task(
        id: 'child',
        title: 'Clear sink',
        createdAt: now,
        status: TaskStatus.backlog,
        durationMinutes: 15,
        parentTaskId: parent.id,
      );

      final result = engine.insertBacklogTaskIntoNextAvailableSlot(
        input: SchedulingInput(
          tasks: [parent, child],
          window: SchedulingWindow(
            start: DateTime(2026, 6, 19, 9),
            end: DateTime(2026, 6, 19, 10),
          ),
        ),
        taskId: child.id,
        updatedAt: now,
      );
      final scheduledChild = taskById(result.tasks, child.id);
      final unchangedParent = taskById(result.tasks, parent.id);

      expect(scheduledChild.status, TaskStatus.planned);
      expect(scheduledChild.parentTaskId, parent.id);
      expect(scheduledChild.scheduledStart, DateTime(2026, 6, 19, 9));
      expect(unchangedParent.status, TaskStatus.backlog);
      expect(unchangedParent.scheduledStart, isNull);
    });
  });
}

Task task({
  required String id,
  required String title,
  required DateTime createdAt,
  TaskStatus status = TaskStatus.planned,
  int? durationMinutes,
  String? parentTaskId,
}) {
  return Task(
    id: id,
    title: title,
    projectId: 'home',
    type: TaskType.flexible,
    status: status,
    priority: PriorityLevel.medium,
    durationMinutes: durationMinutes,
    parentTaskId: parentTaskId,
    createdAt: createdAt,
    updatedAt: createdAt,
  );
}

Task taskById(List<Task> tasks, String id) {
  return tasks.singleWhere((task) => task.id == id);
}