import '../../../../data/network/i_api_client.dart';
import '../../../../data/cache/cache_store.dart';
import '../../../../core/notification/models/reminder_alarm.dart';
import '../../../../core/notification/services/reminder_reconcile_service.dart';
import '../models/schedule_item_model.dart';

class CalendarService {
  static const _prefix = '/api/v1/schedule-items';

  final IApiClient _apiClient;
  final CacheInvalidator _invalidator;
  final ReminderReconcileService? _reminderReconcileService;

  CalendarService({
    required IApiClient apiClient,
    required CacheInvalidator invalidator,
    ReminderReconcileService? reminderReconcileService,
  }) : _apiClient = apiClient,
       _invalidator = invalidator,
       _reminderReconcileService = reminderReconcileService;

  Future<List<ScheduleItemModel>> getEventsForDay(DateTime date) async {
    final start = DateTime(date.year, date.month, date.day);
    final end = DateTime(date.year, date.month, date.day, 23, 59, 59);
    return getEventsForRange(start, end);
  }

  Future<List<ScheduleItemModel>> getEventsForRange(
    DateTime start,
    DateTime end,
  ) async {
    final startParam = Uri.encodeQueryComponent(
      start.toUtc().toIso8601String(),
    );
    final endParam = Uri.encodeQueryComponent(end.toUtc().toIso8601String());
    final response = await _apiClient.get<List<dynamic>>(
      '$_prefix?start_at=$startParam&end_at=$endParam',
    );
    final data = response.data;
    if (data == null) {
      throw StateError('Invalid getEventsForRange response: empty payload');
    }
    final events = data
        .map((item) => item as Map<String, dynamic>)
        .map(ScheduleItemModel.fromJson)
        .toList(growable: false);
    await _reminderReconcileService?.reconcileEvents(
      events.map(_toReminderSnapshot).toList(growable: false),
    );
    return events;
  }

  Future<ScheduleItemModel> getEventById(
    String id, {
    bool reconcileReminder = true,
  }) async {
    final response = await _apiClient.get<Map<String, dynamic>>('$_prefix/$id');
    final data = response.data;
    if (data == null) {
      throw StateError('Invalid getEventById response: empty payload');
    }
    final event = ScheduleItemModel.fromJson(data);
    if (reconcileReminder) {
      await _reminderReconcileService?.reconcileEvent(
        _toReminderSnapshot(event),
      );
    }
    return event;
  }

  Future<ScheduleItemModel> addEvent(ScheduleItemModel event) async {
    final response = await _apiClient.post<Map<String, dynamic>>(
      _prefix,
      data: event.toCreateJson(),
    );
    final data = response.data;
    if (data == null) {
      throw StateError('Invalid addEvent response: empty payload');
    }
    final created = ScheduleItemModel.fromJson(data);
    _invalidateEventCache(created);
    await _reminderReconcileService?.reconcileEvent(
      _toReminderSnapshot(created),
    );
    return created;
  }

  Future<ScheduleItemModel> updateEvent(ScheduleItemModel event) async {
    final response = await _apiClient.patch<Map<String, dynamic>>(
      '$_prefix/${event.id}',
      data: event.toUpdateJson(),
    );
    final data = response.data;
    if (data == null) {
      throw StateError('Invalid updateEvent response: empty payload');
    }
    final updated = ScheduleItemModel.fromJson(data);
    _invalidateEventCache(updated);
    await _reminderReconcileService?.reconcileEvent(
      _toReminderSnapshot(updated),
    );
    return updated;
  }

  Future<ScheduleItemModel> archiveEvent(String id) async {
    final event = await getEventById(id);
    final updatedEvent = await updateEvent(
      event.copyWith(status: ScheduleStatus.archived),
    );
    _invalidateEventCache(updatedEvent);
    await _reminderReconcileService?.archiveAndCancel(id);
    return updatedEvent;
  }

  Future<void> deleteEvent(String id) async {
    final event = await getEventById(id);
    _invalidateEventCache(event);
    await _apiClient.delete<void>('$_prefix/$id');
    await _reminderReconcileService?.archiveAndCancel(id);
  }

  void _invalidateEventCache(ScheduleItemModel event) {
    var current = DateTime(
      event.startAt.year,
      event.startAt.month,
      event.startAt.day,
    );
    final end = DateTime(
      event.endAt?.year ?? event.startAt.year,
      event.endAt?.month ?? event.startAt.month,
      event.endAt?.day ?? event.startAt.day,
    );
    while (!current.isAfter(end)) {
      _invalidator.invalidateCalendarDay(current);
      current = current.add(const Duration(days: 1));
    }
  }

  ReminderEventSnapshot _toReminderSnapshot(ScheduleItemModel event) {
    return ReminderEventSnapshot(
      eventId: event.id,
      title: event.title,
      startAt: event.startAt,
      endAt: event.endAt,
      timezone: event.timezone,
      reminderMinutes: event.metadata?.reminderMinutes,
      location: event.metadata?.location,
      notes: event.metadata?.notes,
      isArchived: event.status == ScheduleStatus.archived,
    );
  }
}