import 'package:flutter/material.dart';
import 'package:tm_app/core/utils/result.dart';
import 'package:tm_app/data/repositories/notification_repository.dart';
import 'package:tm_app/data/services/model/notification__response/notification_response_model.dart';

class NotificationViewModel with ChangeNotifier {
  final NotificationsRepository _repository;

  NotificationViewModel({required NotificationsRepository repositoryViewModel})
    : _repository = repositoryViewModel {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      getNotifications();
    });
  }

  bool _isLoading = false;
  String? _errorMessage;
  NotificationResponseModel? _notificationResponseModel;

  int currentPage = 1;
  static const int _pageSize = 10;
  int _totalPages = 0;
  bool _hasMoreData = true;

  bool get isLoading => _isLoading;
  String? get errorMessage => _errorMessage;
  NotificationResponseModel? get notificationResponse =>
      _notificationResponseModel;
  bool get hasMoreData => _hasMoreData;
  int get totalPages => _totalPages;

  /// Fetch notifications
Future<void> getNotifications({int page = 1, bool isMobile = false}) async {
  _isLoading = true;
  notifyListeners();

  final int offset = _pageSize * page;

  final result = await _repository.getNotifications(
    limit: _pageSize,
    offset: offset,
  );

  switch (result) {
    case Ok<NotificationResponseModel>():
      if (isMobile && page > 1) {
        final oldNotifications =
            _notificationResponseModel?.data?.notifications ?? [];

        final newNotifications = result.value.data?.notifications ?? [];

        _notificationResponseModel = result.value.copyWith(
          data: result.value.data?.copyWith(
            notifications: [...oldNotifications, ...newNotifications],
          ),
        );
      } else {
        _notificationResponseModel = result.value;
      }

      currentPage = page;
      _hasMoreData =
          (result.value.data?.notifications?.length ?? 0) >= _pageSize;
      _totalPages = result.value.data?.meta?.pages ?? 1;
      break;

    case Error<NotificationResponseModel>():
      _errorMessage = result.error.toString();
      break;
  }

  _isLoading = false;
  notifyListeners();
}

  /// Jump to page
  Future<void> jumpToPage(int page) async {
    if (_totalPages == 0 || page < 1 || page > _totalPages) {
      return;
    }
    await getNotifications(page: page);
  }

  /// Mark all as read
  Future<void> markAllAsRead() async {
    _errorMessage = null;
    notifyListeners();

    final result = await _repository.markAllAsRead();

    switch (result) {
      case Ok<NotificationResponseModel>():
        if (_notificationResponseModel?.data?.notifications != null) {
          final updatedNotifications =
              _notificationResponseModel!.data!.notifications!
                  .map((n) => n.copyWith(seen: true))
                  .toList();

          _notificationResponseModel = _notificationResponseModel!.copyWith(
            data: _notificationResponseModel!.data!.copyWith(
              notifications: updatedNotifications,
            ),
          );
        }
        break;

      case Error<NotificationResponseModel>():
        _errorMessage = result.error.toString();
        break;
    }

    notifyListeners();
  }

  String timeAgo(String dateTimeString) {
    final createdAt = DateTime.parse(dateTimeString);
    final now = DateTime.now();
    final difference = now.difference(createdAt);

    if (difference.inMinutes < 1) {
      return 'Now';
    } else if (difference.inMinutes < 60) {
      return '${difference.inMinutes} Min ';
    } else if (difference.inHours < 24) {
      return '${difference.inHours} Hour ';
    } else if (difference.inDays == 1) {
      return 'Yesterday';
    } else {
      return '${difference.inDays} days ago';
    }
  }
}