import 'package:flutter_riverpod/flutter_riverpod.dart';

import 'package:household_keeper/core/providers/database_provider.dart';
import 'package:household_keeper/features/home/domain/daily_plan_models.dart';

/// Reactive daily plan data: tasks categorized into overdue/today/tomorrow
/// with progress tracking.
///
/// Defined manually (not @riverpod) because riverpod_generator has trouble
/// with drift's generated [Task] type. Same pattern as [tasksInRoomProvider].
final dailyPlanProvider =
    StreamProvider.autoDispose<DailyPlanState>((ref) {
  final db = ref.watch(appDatabaseProvider);
  final taskStream = db.dailyPlanDao.watchAllTasksWithRoomName();

  return taskStream.asyncMap((allTasks) async {
    // Get today's completion count (latest value from stream)
    final completedToday =
        await db.dailyPlanDao.watchCompletionsToday().first;

    final now = DateTime.now();
    final today = DateTime(now.year, now.month, now.day);
    final tomorrow = today.add(const Duration(days: 1));
    final dayAfterTomorrow = tomorrow.add(const Duration(days: 1));

    final overdue = <TaskWithRoom>[];
    final todayList = <TaskWithRoom>[];
    final tomorrowList = <TaskWithRoom>[];

    for (final tw in allTasks) {
      final dueDate = DateTime(
        tw.task.nextDueDate.year,
        tw.task.nextDueDate.month,
        tw.task.nextDueDate.day,
      );
      if (dueDate.isBefore(today)) {
        overdue.add(tw);
      } else if (dueDate.isBefore(tomorrow)) {
        todayList.add(tw);
      } else if (dueDate.isBefore(dayAfterTomorrow)) {
        tomorrowList.add(tw);
      }
    }

    // totalTodayCount includes completedTodayCount so the denominator
    // stays stable as tasks are completed (their nextDueDate moves to
    // the future, shrinking overdue+today, but completedToday grows).
    return DailyPlanState(
      overdueTasks: overdue,
      todayTasks: todayList,
      tomorrowTasks: tomorrowList,
      completedTodayCount: completedToday,
      totalTodayCount: overdue.length + todayList.length + completedToday,
    );
  });
});