import 'dart:convert';
import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:http/http.dart' as http;
import 'package:shared_preferences/shared_preferences.dart';
import 'package:awesome_notifications/awesome_notifications.dart';
import 'package:scheduled_timer/scheduled_timer.dart';

void main() {
  AwesomeNotifications().initialize(
    // set the icon to null if you want to use the default app icon
      null,
      [
        NotificationChannel(
            channelGroupKey: 'reminder_channel_group',
            channelKey: 'reminder_channel',
            channelName: 'Check-In Reminder notifications',
            channelDescription: 'Notification channel for Check-In Reminders',
            defaultColor: Colors.cyan.shade900,
            ledColor: Colors.white)
      ],
      // Channel groups are only visual and are not required
      channelGroups: [
        NotificationChannelGroup(
            channelGroupkey: 'reminder_channel_group',
            channelGroupName: 'Reminder group')
      ],
      debug: true
  );
  runApp(const TBDoctor());
}

class TBDoctor extends StatelessWidget {
  const TBDoctor({Key? key}) : super(key: key);

  get id => null;

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'TBDoctor',
      theme: ThemeData(
        primarySwatch: Colors.cyan,
      ),
      home: const TBDoctorHomePage(title: 'Telecommuting Bank Doctor'),
    );
  }
}

class SNowBuildingReservation {
  final DateTime reservationDateTime;
  final String locationLink;
  final String? reservationLink;

  const SNowBuildingReservation({
    required this.reservationDateTime,
    required this.locationLink,
    this.reservationLink,
  });
  factory SNowBuildingReservation.fromJson(Map<String, dynamic> json) {
    try {
      return SNowBuildingReservation(
        reservationDateTime: DateTime.parse(json['u_reservation_short_date']),
        locationLink: json['location']['link'],
        reservationLink: json['workplace_request']['link'],
      );
    } catch (e) {
      return SNowBuildingReservation(
        reservationDateTime: DateTime.parse(json['u_reservation_short_date']),
        locationLink: json['location']['link'],
      );
    }
  }

  static List<SNowBuildingReservation> sampleFromJson(String str) {
    final Map<String, dynamic> jsonData = json.decode(str);
    return List<SNowBuildingReservation>.from(
        jsonData['result'].map((x) => SNowBuildingReservation.fromJson(x)));
  }
}

class SNowUser {
  final String userSysId;
  final String userName;

  const SNowUser({
    required this.userName,
    required this.userSysId,
  });
  factory SNowUser.fromJson(Map<String, dynamic> json) {
    return SNowUser(
      userName: json['result']['user_name'],
      userSysId: json['result']['user_sys_id'],
    );
  }
}

class TBDoctorHomePage extends StatefulWidget {
  const TBDoctorHomePage({Key? key, required this.title}) : super(key: key);
  final String title;

  @override
  State<TBDoctorHomePage> createState() => _TBDoctorHomePageState();
}

class _TBDoctorHomePageState extends State<TBDoctorHomePage> {
  // Set by user interaction
  static String? _cookie;
  static String? _xUserToken;
  static double _tbdHoursToDate = 8.0;
  static String? _snowServer;

  static double _inOfficeHoursToDate = 4.5;

  // Set from SNow API
  static SNowUser selfUser = const SNowUser(userName: "", userSysId: "");
  static Map<String, String> locations = <String, String>{};
  List<SNowBuildingReservation> reservations = <SNowBuildingReservation>[];

  // Given by Administration
  final double _totalWorkingHours = 1860.00;
  final double _summerHoursOffsetHours = 16.00;
  final double _allHandsHours = 90.0;
  final double _focusWeekFirstHours = 37.5;
  final double _focusWeekSecondHours = 37.5;

  // Set using calculations
  double _totalTBDTimeHours = 0.0;
  double _totalInOfficeHours = 0.0;
  double _totalInOfficeDays = 0.0;
  double _tbdHoursLeftForYear = 0.0;
  double _tbdDaysLeftForYear = 0.0;
  double _inOfficeDaysLeftForYear = 0.0;

  // Required for program
  late SharedPreferences _prefs;
  late ScheduledTimer checkinReminder;

  void _setCalcs() async {
    if (_inOfficeHoursToDate == 0.0 && _tbdHoursToDate == 0.0 ||
        _snowServer == null || _snowServer!.isEmpty) {
      showDialog(
        context: context,
        builder: (BuildContext context) => _buildPopupDialog(context),
      );
    }
    setState(() {
      _totalTBDTimeHours = (_totalWorkingHours - (_totalWorkingHours * 0.2)) -
          _summerHoursOffsetHours;
      _totalInOfficeHours = (_totalWorkingHours - (_totalWorkingHours * 0.8));
      _totalInOfficeDays = _totalInOfficeHours / 7.5;
      _tbdHoursLeftForYear = _totalTBDTimeHours - _tbdHoursToDate;
      _tbdDaysLeftForYear = _tbdHoursLeftForYear / 7.5;
      _inOfficeDaysLeftForYear =
          _totalInOfficeDays - (_inOfficeHoursToDate / 7.5);
      double totalForcedHours =
          _allHandsHours + _focusWeekFirstHours + _focusWeekSecondHours;
      _inOfficeDaysLeftForYear -= totalForcedHours / 7.5;
    });
  }

  static Future<http.Response> _requestURI(String uri) async {
    Uri? url = Uri.tryParse(uri);
    Map<String, String> myHeaders = <String, String>{};
    String cookie = '', xUserToken = '';
    if (_cookie == null) {
      var url = Uri.parse('https://$_snowServer.service-now.com/');
      if (await canLaunchUrl(url)) {
        await launchUrl(url);
        // Obtain shared preferences.
        final prefs = await SharedPreferences.getInstance();
        //TODO: Get the actual cookie/xUserToken from auth flow

        _cookie = cookie;
        _xUserToken = xUserToken;
        await prefs.setString("cookie", cookie);
        await prefs.setString("xUserToken", xUserToken);
      } else {
        throw 'Could not launch $url';
      }
    }
    myHeaders['Cookie'] = _cookie ?? cookie;
    myHeaders['X-UserToken'] = _xUserToken ?? xUserToken;
    http.Response response = await http.get(url!, headers: myHeaders);
    return response;
  }

  void _populateSelf() async {
    if (_cookie == null || _xUserToken == null) {
      _cookie = _prefs.getString("cookie");
      _xUserToken = _prefs.getString("xUserToken");
    }
    var response = await _requestURI(
        "https://$_snowServer.service-now.com/api/now/ui/user/current_user");
    if (response.statusCode == 200 || response.statusCode == 202) {
      selfUser = SNowUser.fromJson(jsonDecode(response.body));
      _setCalcs();
      _populateReservations();
    } else {
      throw Exception('Failed to load account');
    }
  }

  void _populateReservations() async {
    var response = await _requestURI(
        'https://$_snowServer.service-now.com/api/now/table/sn_wsd_core_reservation?requested_for=${selfUser.userSysId}&state=confirmed&start%3E%3Djavascript:gs.beginningOfToday()');
    if (response.statusCode == 200 || response.statusCode == 202) {
      reservations = SNowBuildingReservation.sampleFromJson(response.body);
      reservations.sort((a, b) {
        return a.reservationDateTime.compareTo(b.reservationDateTime);
      });
      for (SNowBuildingReservation res in reservations) {
        if (!_TBDoctorHomePageState.locations.containsKey(res.locationLink)) {
          var response =
              await _TBDoctorHomePageState._requestURI(res.locationLink);
          if (response.statusCode == 200 || response.statusCode == 202) {
            _TBDoctorHomePageState.locations[res.locationLink] =
                jsonDecode(response.body)['result']['name'];
          } else {
            throw Exception('Failed to load location');
          }
        }
      }

      setState(() {});
    } else {
      throw Exception('Failed to load reservations');
    }
  }

  void _launchUrl(String uri) async {
    var url = Uri.parse(uri);
    if (await canLaunchUrl(url)) {
      await launchUrl(url);
    } else {
      throw 'Could not launch $url';
    }
  }

  void _newReservation() async {
    _launchUrl(
        'https://$_snowServer.service-now.com/serviceportal?id=sc_cat_item&sys_id=8fe9981d1bdb6c10b346cb35624bcb1d');
  }

  void _healthCheck() async {
    _launchUrl(
        'https://$_snowServer.service-now.com/serviceportal?id=sc_cat_item&sys_id=9c578864ed111010fa9b395e35885545');
  }

  void _viewAllReservation() async {
    _launchUrl(
        'https://$_snowServer.service-now.com/serviceportal?id=u_my_building_schedule&t=sn_wsd_core_reservation&filter=active%3Dtrue%5Estate%3Dconfirmed%5Estart%3E%3Djavascript:gs.beginningOfToday()%5Ereservation_subtypeINsingle,occurrence%5EORDERBYstart%5EEQ');
  }

  Widget _buildPopupDialog(BuildContext context) {
    String? tbdString = _tbdHoursToDate.toString();
    String? inOfficeString = _inOfficeHoursToDate.toString();
    return AlertDialog(
      title: const Text('Manually change hours'),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Column(
            children: [
              const Text("Don't forget to save and close"),
              TextFormField(
                decoration: const InputDecoration(labelText: "SNow Server"),
                initialValue: _snowServer,
                onChanged: (String? newVal) {
                  try {
                    _snowServer = newVal;
                  } finally {
                    _prefs.setString("_snowServer", _snowServer!);
                  }
                },
              ),
              TextFormField(
                decoration: const InputDecoration(labelText: "TBD Hours Spent"),
                inputFormatters: [
                  FilteringTextInputFormatter.allow(RegExp(r'^\d+\.?\d{0,2}')),
                ],
                keyboardType:
                    const TextInputType.numberWithOptions(decimal: true),
                initialValue: _tbdHoursToDate.toString(),
                onChanged: (String? newVal) {
                  tbdString = newVal;
                  try {
                    _tbdHoursToDate = double.parse(tbdString ?? '0.0');
                    _prefs.setDouble("_tbdHoursToDate", _tbdHoursToDate);
                  } catch (e) {
                    _tbdHoursToDate = double.parse("${tbdString!}.0");
                    _prefs.setDouble("_tbdHoursToDate", _tbdHoursToDate);
                  }
                },
              ),
              TextFormField(
                decoration:
                    const InputDecoration(labelText: "Time Spent in Office"),
                inputFormatters: [
                  FilteringTextInputFormatter.allow(RegExp(r'^\d+\.?\d{0,2}')),
                ],
                keyboardType:
                    const TextInputType.numberWithOptions(decimal: true),
                initialValue: _inOfficeHoursToDate.toString(),
                onChanged: (String? newVal) {
                  inOfficeString = newVal;
                  try {
                    _inOfficeHoursToDate =
                        double.parse(inOfficeString ?? '0.0');
                    _prefs.setDouble(
                        "_inOfficeHoursToDate", _inOfficeHoursToDate);
                  } catch (e) {
                    _inOfficeHoursToDate =
                        double.parse("${inOfficeString!}.0");
                    _prefs.setDouble(
                        "_inOfficeHoursToDate", _inOfficeHoursToDate);
                  }
                },
              ),
            ],
          ),
        ],
      ),
      actions: <Widget>[
        FloatingActionButton(
          onPressed: () {
            _setCalcs();
            Navigator.pop(context);
          },
          child: const Text('Close'),
        ),
      ],
    );
  }
  void _showReminderNotification() {
    DateTime now = DateTime.now();
    if (now.weekday == DateTime.saturday || now.weekday == DateTime.sunday) {
      return;
    }
    AwesomeNotifications().createNotification(
      content: NotificationContent(
          id: 10,
          channelKey: 'reminder_channel',
          title: 'Check-In Reminder',
          body: 'Are you remote, in office, or out today?'),
      actionButtons: <NotificationActionButton>[
        NotificationActionButton(key: 'remote', label: 'Remote'),
        NotificationActionButton(key: 'office', label: 'In Office'),
        NotificationActionButton(key: 'no', label: 'Not Today'),
      ],
    );
  }

  @override
  void initState() {
    SharedPreferences.getInstance().then((SharedPreferences p) {
      _prefs = p;
      _inOfficeHoursToDate = _prefs.getDouble("_inOfficeHoursToDate") ?? 0.0;
      _tbdHoursToDate = _prefs.getDouble("_tbdHoursToDate") ?? 0.0;
      _snowServer = _prefs.getString("_snowServer");
      _setCalcs();
      _populateSelf();
    });
    DateTime now = DateTime.now();
    checkinReminder = ScheduledTimer(
      id: "checkinReminder",
      onExecute: _showReminderNotification,
      defaultScheduledTime: DateTime(now.year, now.month, now.day + 1, 7, 0),
      onMissedSchedule: _showReminderNotification,
    );

    AwesomeNotifications().actionStream.listen((receivedNotification) {
      DateTime now = DateTime.now();
      double hours = 7.5;
      if (now.weekday == DateTime.saturday || now.weekday == DateTime.sunday) {
        debugPrint("Detected weekend, no work allowed");
        return;
      }
      if (now.isAfter(DateTime(now.year, 06, 23)) ||  now.isBefore(DateTime(now.year, 09, 14))) {
        debugPrint("Detected summer hours");
        hours = 8;
        if (now.weekday == DateTime.friday) {
          debugPrint("Detected summer hours, half day friday");
          hours = 4.5;
        }
      }
      SharedPreferences.getInstance().then((SharedPreferences p) {
        _prefs = p;
        switch(receivedNotification.buttonKeyPressed) {
          case "remote":
            debugPrint("Modifying TBD since user responded 'remote'");
            _tbdHoursToDate += hours;
            _prefs.setDouble("_tbdHoursToDate", _tbdHoursToDate);
            break;
          case "office":
            debugPrint("Modifying in-office since user responded 'office'");
            _inOfficeHoursToDate += hours;
            _prefs.setDouble("_tbdHoursToDate", _tbdHoursToDate);
            break;
          default:
            debugPrint("Didn't care.");
            break;
        }
        // Schedule the next one?
        DateTime now = DateTime.now();
        checkinReminder = ScheduledTimer(
          id: "checkinReminder",
          onExecute: _showReminderNotification,
          defaultScheduledTime: DateTime(now.year, now.month, now.day + 1, 7, 0),
          onMissedSchedule: _showReminderNotification,
        );
        _setCalcs();
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.title,
          style: const TextStyle(
            color: Colors.white,
          ),
        ),
        backgroundColor: Colors.cyan.shade900,
      ),
      body: SingleChildScrollView(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: <Widget>[
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: const [
                SizedBox(
                  height: 16,
                ),
              ],
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: [
                Container(
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    color: Colors.cyan.shade900,
                  ),
                  padding: const EdgeInsets.all(8),
                  child: Column(
                    children: [
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceAround,
                        children: const [
                          Text(
                            'TBD Days Left',
                            style: TextStyle(
                              fontSize: 20,
                              color: Colors.white,
                            ),
                          ),
                        ],
                      ),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceAround,
                        children: [
                          Text(
                            (_tbdDaysLeftForYear).toStringAsFixed(2),
                            style: const TextStyle(
                              fontSize: 20,
                              color: Colors.white,
                            ),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
                Container(
                  padding: const EdgeInsets.all(8),
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(5),
                    color: Colors.cyan.shade900,
                  ),
                  child: Column(
                    children: [
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceAround,
                        children: const [
                          Text(
                            'Unscheduled Office Days Left',
                            style: TextStyle(
                              fontSize: 20,
                              color: Colors.white,
                            ),
                          ),
                        ],
                      ),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceAround,
                        children: [
                          Text(
                            (_inOfficeDaysLeftForYear).toStringAsFixed(2),
                            style: const TextStyle(
                              fontSize: 20,
                              color: Colors.white,
                            ),
                          ),
                        ],
                      )
                    ],
                  ),
                )
              ],
            ),
            Column(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    ElevatedButton(
                        onPressed: _healthCheck,
                        child: const Text('Health Check')),
                    ElevatedButton(
                        onPressed: _newReservation,
                        child: const Text('New Reservation')),
                    ElevatedButton(
                        onPressed: _viewAllReservation,
                        child: const Text('View All')),
                  ],
                ),
                ListView.separated(
                  padding: const EdgeInsets.all(15),
                  physics: const BouncingScrollPhysics(),
                  shrinkWrap: true,
                  scrollDirection: Axis.vertical,
                  itemBuilder: (BuildContext context, int index) => InkWell(
                    onTap: () {
                      _launchUrl(reservations[index].reservationLink ?? 'https://www.youtube.com/watch?v=t3otBjVZzT0');
                    },
                    child: Container(
                      padding: const EdgeInsets.fromLTRB(12, 0, 12, 0),
                      height: 40,
                      decoration: BoxDecoration(
                        borderRadius: BorderRadius.circular(5),
                        color: Colors.cyan.shade900,
                      ),
                      child: Row(
                        crossAxisAlignment: CrossAxisAlignment.stretch,
                        children: [
                          Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              Text(
                                DateFormat('dd-MMM-yyyy').format(reservations
                                    .elementAt(index)
                                    .reservationDateTime),
                                textAlign: TextAlign.start,
                                style: const TextStyle(
                                  fontSize: 18,
                                  color: Colors.white,
                                ),
                              ),
                            ],
                          ),
                          const Spacer(),
                          Column(
                            crossAxisAlignment: CrossAxisAlignment.end,
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              Text(
                                  locations[reservations
                                          .elementAt(index)
                                          .locationLink] ??
                                      "Location hasn't been discovered yet!",
                                  textAlign: TextAlign.end,
                                  style: const TextStyle(
                                      fontSize: 18, color: Colors.white)),
                            ],
                          )
                        ],
                      ),
                    ),
                  ),
                  separatorBuilder: (context, index) => const SizedBox(
                    height: 10,
                  ),
                  itemCount: reservations.length,
                ),
              ],
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          showDialog(
            context: context,
            builder: (BuildContext context) => _buildPopupDialog(context),
          );
        },
        tooltip: 'Health Check',
        child: const Icon(Icons.settings),
      ),
    );
  }
}