import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:table_calendar/table_calendar.dart';
import 'package:fast_med_flutter/ui/pages/add_event.dart';
import 'model/event.dart';

// Dias de Citas No Disponibles

final Map<DateTime, List> _holidays = {
DateTime(2020, 11, 6): ['No Hay Citas'],
DateTime(2020, 11, 3): ['Dia Elecciones'],
DateTime(2020,12,25): ['Chrismas'],
DateTime(2020,12,31): ['Despedida del anyo nuevo'],
  DateTime(2021,1,1): ['Anyo nuevo'],
};

//Iniciar la Seccion de las Citas

void main() => runApp(Calendario());

//Inicio del Area de las Citas Disponibles

class Calendario extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Citas Disponibles',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
      routes:{
        "add_event": (_) => AddEventPage(),
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

//Definimos los controladores del Calendario

class _HomePageState extends State<MyHomePage> {
  CalendarController _controller;
  Map<DateTime, List<dynamic>> _events;
  List<dynamic> _selectedEvents;
  TextEditingController _eventController;
  SharedPreferences prefs;



  @override
  void initState() {
    super.initState();
    _controller = CalendarController();
    _eventController = TextEditingController();
    _events = {};
    _selectedEvents = [];
    final _selectedDay = DateTime.now();
    initPrefs();
  }

  initPrefs() async {
    prefs = await SharedPreferences.getInstance();
    setState(() {
      _events = Map<DateTime, List<dynamic>>.from(
          decodeMap(json.decode(prefs.getString("events") ?? "{}")));
    });
  }
  // Definimos las fechas en la area de citas

  Map<DateTime, List<dynamic>> _groupEvents(List<EventModel> events) {
    Map<DateTime,List<dynamic>> data = {};
    events.forEach((event) {
      DateTime date = DateTime(event.eventDate.year, event.eventDate.month,
          event.eventDate.day, 12);
      if(data[date] == null) data[date] = [];
      data[date].add(event);
    });
    return data;
  }

  Map<String, dynamic> encodeMap(Map<DateTime, dynamic> map) {
    Map<String, dynamic> newMap = {};
    map.forEach((key, value) {
      newMap[key.toString()] = map[key];
    });
    return newMap;
  }

  Map<DateTime, dynamic> decodeMap(Map<String, dynamic> map) {
    Map<DateTime, dynamic> newMap = {};
    map.forEach((key, value) {
      newMap[DateTime.parse(key)] = map[key];
    });
    return newMap;
  }


//Definimos el estilo del area de las Citas Disponibles.
  //En este ejemplo, el calendario comenzara mostrandose por meses.
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Citas Disponibles'),
      ),
      body: SingleChildScrollView(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            TableCalendar(
              events: _events,
              holidays: _holidays,
              initialCalendarFormat: CalendarFormat.month,
              calendarStyle: CalendarStyle(
                  canEventMarkersOverflow: true,
                  todayColor: Colors.orange,
                  selectedColor: Theme.of(context).primaryColor,
                  todayStyle: TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 18.0,
                      color: Colors.white)),
              headerStyle: HeaderStyle(
                centerHeaderTitle: true,
                formatButtonDecoration: BoxDecoration(
                  color: Colors.orange,
                  borderRadius: BorderRadius.circular(20.0),
                ),
                formatButtonTextStyle: TextStyle(color: Colors.white),
                formatButtonShowsNext: false,
              ),
              startingDayOfWeek: StartingDayOfWeek.monday,

              builders: CalendarBuilders(
                selectedDayBuilder: (context, date, events) => Container(
                    margin: const EdgeInsets.all(4.0),
                    alignment: Alignment.center,
                    decoration: BoxDecoration(
                        color: Theme.of(context).primaryColor,
                        borderRadius: BorderRadius.circular(10.0)),
                    child: Text(
                      date.day.toString(),
                      style: TextStyle(color: Colors.white),
                    )),
                todayDayBuilder: (context, date, events) => Container(
                    margin: const EdgeInsets.all(4.0),
                    alignment: Alignment.center,
                    decoration: BoxDecoration(
                        color: Colors.orange,
                        borderRadius: BorderRadius.circular(10.0)),
                    child: Text(
                      date.day.toString(),
                      style: TextStyle(color: Colors.white),
                    )),
              ),
              calendarController: _controller,
            ),
            ..._selectedEvents.map((event) => ListTile(
              title: Text(event),
            )),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: _showAddDialog,
      ),
    );
  }

  //Definimos el boton para crear Citas.

  _showAddDialog() async {
    await showDialog(
        context: context,
        builder: (context) => AlertDialog(
          content: TextField(
            controller: _eventController,
            decoration: InputDecoration(
                labelText: "Razon para crear su cita",
                filled: true,
                fillColor: Colors.white,
                border: OutlineInputBorder(borderRadius: BorderRadius.circular(10))),
          ),
          actions: <Widget>[
            FlatButton(
              child: Text("Crear Su Cita Ahora"),
              onPressed: () {
                if (_eventController.text.isEmpty) return;
                if (_events[_controller.selectedDay] != null) {
                  _events[_controller.selectedDay]
                      .add(_eventController.text);
                } else {
                  _events[_controller.selectedDay] = [
                    _eventController.text
                  ];
                }
                prefs.setString("events", json.encode(encodeMap(_events)));
                _eventController.clear();
                Navigator.pop(context);
              },
            )
          ],
        ));
    setState(() {
      _selectedEvents = _events[_controller.selectedDay];
    });
  }
}