import 'dart:async';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:finlytic_app/features/calendar/repositories/calendar_repository.dart';
import 'calendar_event.dart';
import 'calendar_state.dart';

export 'calendar_event.dart';
export 'calendar_state.dart';

class CalendarBloc extends Bloc<CalendarEvent, CalendarState> {
  final CalendarRepository repository;

  CalendarBloc({required this.repository}) : super(CalendarInitial()) {
    on<FetchCalendarEvents>(_onFetchEvents);
    on<FilterCategoryChanged>(_onFilterCategoryChanged);
    on<FilterDateSelected>(_onFilterDateSelected);
    on<MonthChanged>(_onMonthChanged);
  }

  Future<void> _onFetchEvents(FetchCalendarEvents event, Emitter<CalendarState> emit) async {
    emit(CalendarLoading());
    try {
      final events = await repository.fetchEvents(event.year, event.month);
      emit(CalendarLoaded(
        allEvents: events,
        currentMonth: DateTime(event.year, event.month),
      ));
    } catch (e) {
      emit(const CalendarError("Fehler beim Laden des Kalenders."));
    }
  }

  void _onFilterCategoryChanged(FilterCategoryChanged event, Emitter<CalendarState> emit) {
    if (state is CalendarLoaded) {
      final current = state as CalendarLoaded;
      emit(current.copyWith(selectedCategory: event.category));
    }
  }

  void _onFilterDateSelected(FilterDateSelected event, Emitter<CalendarState> emit) {
    if (state is CalendarLoaded) {
      final current = state as CalendarLoaded;
      if (event.date == null) {
        emit(current.copyWith(clearSelectedDate: true));
      } else if (current.selectedDate != null &&
          current.selectedDate!.year == event.date!.year &&
          current.selectedDate!.month == event.date!.month &&
          current.selectedDate!.day == event.date!.day) {
        emit(current.copyWith(clearSelectedDate: true));
      } else {
        emit(current.copyWith(selectedDate: event.date));
      }
    }
  }

  void _onMonthChanged(MonthChanged event, Emitter<CalendarState> emit) {
    if (state is CalendarLoaded) {
      final current = state as CalendarLoaded;
      emit(current.copyWith(
        currentMonth: event.newMonth,
        clearSelectedDate: true,
      ));
      
      // Trigger new fetch for the selected month
      add(FetchCalendarEvents(year: event.newMonth.year, month: event.newMonth.month));
    }
  }
}