import 'dart:core';

import 'package:flutter/material.dart';
import 'package:hiddingsel_app/constants/constant.dart';
import 'package:hiddingsel_app/packages/list_view_extension/colum_extension.dart';
import 'package:table_calendar/table_calendar.dart';
import '../constants/enums.dart';
import '../appflow/controller/events.dart';
import '../appflow/model/event.dart';
import '../appflow/view/navigation_drawer.dart';
import 'calendar_list.dart';

class CalendarListPage extends StatefulWidget with NavigationDrawerItem {

  final String title = 'Termine';

  @override
  State<StatefulWidget> createState() => CalendarListPageState();
}

class CalendarListPageState extends State<CalendarListPage> {
  List _selectedDayList = [];
  Map<DateTime, List<EventModel>> _events = {};

  @override
  void dispose() {
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    init();
  }

  void init() async {
    EventController.getEventListStream().forEach((events) {
      setState(() {
        _events = _mapListToCalendarEvents(events);
      });
    });
  }

  @override
  Widget build(BuildContext context) => SafeArea(
        bottom: false,
        child: Padding(
          padding: const EdgeInsets.fromLTRB(UIShapes.paddingSimple,
              UIShapes.paddingSimple, UIShapes.paddingSimple, 0),
          child: ListView(
            primary: true,
            children: <Widget>[
              FormattedCalendar(_events, _onDaySelected),
              ColumnExtension.builder(
                itemCount: _selectedDayList.length,
                itemBuilder: (context, index) =>
                    CalendarListTile(_selectedDayList[index]),
              ),
            ],
          ),
        ),
      );

  void _onDaySelected(DateTime dateTime) {
    setState(() {
      _selectedDayList = _events[DateTime(dateTime.year, dateTime.month, dateTime.day)] ?? [];
    });
  }

  Map<DateTime, List<EventModel>> _mapListToCalendarEvents(List<EventModel> list) {
    final map = <DateTime, List<EventModel>>{};
    DateTime dateKey;
    int i;
    int j;
    for (final e in list) {
      j = 0;
      dateKey = e.schedule.startTime;
      do {
        if (e.schedule.frequency != Frequency.once && e.schedule.interval != null) {
          if (e.schedule.frequency == Frequency.days) {
            dateKey = dateKey.add(Duration(days: e.schedule.interval!));
          } else if (e.schedule.frequency == Frequency.weeks) {
            dateKey = dateKey.add(Duration(days: 7 * e.schedule.interval!));
          } else if (e.schedule.frequency == Frequency.months) {
            dateKey = dateKey =
                DateTime(dateKey.year, dateKey.month + e.schedule.interval!, dateKey.day);
          }
          if (e.schedule.until != null && e.schedule.until!.isBefore(dateKey)) {
            break;
          }
        }
        i = 0;
        do {
          var dateKey2 = dateKey.add(Duration(days: i));
          dateKey2 = DateTime(dateKey2.year, dateKey2.month, dateKey2.day);
          if (map.containsKey(dateKey2)) {
            map[dateKey2]!.add(e);
          } else {
            map[dateKey2] = [e];
          }
          i++;
        } while (i < e.schedule.endTime.difference(e.schedule.startTime).inDays);
        j++;
      } while (e.schedule.frequency != Frequency.once && e.schedule.interval != null && j < 52);
    }
    return map;
  }
}

class FormattedCalendar extends StatefulWidget {
  final Map<DateTime, List<EventModel>> _events;
  final void Function(DateTime) _onDaySelected;

  FormattedCalendar(this._events, this._onDaySelected);

  @override
  _FormattedCalendarState createState() => _FormattedCalendarState();
}

class _FormattedCalendarState extends State<FormattedCalendar> {

  DateTime _focusedDay = DateTime.now();
  DateTime? _selectedDay;

  _FormattedCalendarState();

  @override
  Widget build(BuildContext context) {
    var firstDay = DateTime.utc(2010, 10, 16);
    var lastDay = DateTime.utc(2030, 3, 14);
    final calendar = TableCalendar(
      locale: 'de_DE',
      availableCalendarFormats: const {
        CalendarFormat.month: 'Month',
      },
      headerStyle: HeaderStyle(
        titleCentered: true,
        titleTextStyle: UITheme.theme.textTheme.headlineSmall!,
      ),
      firstDay: firstDay,
      lastDay: lastDay,
      focusedDay: _focusedDay,
      startingDayOfWeek: StartingDayOfWeek.monday,
      calendarStyle: CalendarStyle(
        weekendTextStyle: UITheme.theme.textTheme.bodyLarge!,
        defaultTextStyle: UITheme.theme.textTheme.bodyLarge!,
        todayTextStyle: UITheme.theme.textTheme.bodyMedium!,
        selectedTextStyle: UITheme.theme.textTheme.bodyMedium!,
        selectedDecoration: BoxDecoration(
          color: UIColors.grey5,
          shape: BoxShape.circle,
        ),
        todayDecoration: BoxDecoration(
          color: UIColors.grey4,
          shape: BoxShape.circle,
        ),
        markerDecoration: BoxDecoration(
          color: UIColors.yellow,
          shape: BoxShape.circle,
        )
      ),
      eventLoader: (day) {
        return _getEventsForDay(day);
      },
      selectedDayPredicate: (day) {
        return isSameDay(_selectedDay, day);
      },
      onDaySelected: (selectedDay, focusedDay) {
        setState(() {
          _selectedDay = selectedDay;
          _focusedDay = focusedDay;
          widget._onDaySelected(selectedDay);
        });
      },
    );
    return calendar;
  }

  List<EventModel> _getEventsForDay(DateTime day) {
    return widget._events[DateTime(day.year, day.month, day.day)] ?? [];
  }
}