hrt/lib/notification.dart

// ignore_for_file: avoid_print

import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:timezone/data/latest.dart';
import 'package:timezone/timezone.dart';

const details = NotificationDetails(
  android: AndroidNotificationDetails(
    'hrt',
    'HRT',
    autoCancel: false,
    styleInformation: BigPictureStyleInformation(
      DrawableResourceAndroidBitmap('take_your_hrt'),
    ),
    importance: Importance.max,
    ongoing: true,
    actions: [AndroidNotificationAction("confirmation", "Done!")],
  ),
);

void _initializePlugin() async {
  var initialized = await FlutterLocalNotificationsPlugin().initialize(
    const InitializationSettings(
      android: AndroidInitializationSettings('estrogen'),
    ),
  );

  if (initialized != true) {
    throw "Not initialized";
  }
}

void sendNotification() async {
  _initializePlugin();
  await FlutterLocalNotificationsPlugin().show(
    1,
    null,
    null,
    details,
  );
}

void scheduleNotification() async {
  _initializePlugin();
  initializeTimeZones();

  // [Hours, Minutes]
  var times = [
    [12, 00],
    [18, 00],
  ];

  if (times.isEmpty) return;

  final SharedPreferences prefs = await SharedPreferences.getInstance();
  var currentTime = TZDateTime.now(local);

  // Map the time entries to TZDateTime objects
  var notificationTimes = times
      .map((item) => TZDateTime(
            local,
            currentTime.year,
            currentTime.month,
            currentTime.day,
            item[0],
            item[1],
          ))
      .toList();

  // For all entries in the past, add 1 day
  for (var time
      in notificationTimes.where((time) => time.compareTo(currentTime) < 0)) {
    notificationTimes.remove(time);
    notificationTimes.add(time.add(const Duration(days: 1)));
  }

  // Sort the array so we can find the closest time
  notificationTimes.sort((a, b) => a.compareTo(b));
  var notificationTime = notificationTimes[0];

  if (prefs.getString('scheduled_notification') ==
      notificationTime.toIso8601String()) {
    print("Notification already scheduled for "
        "${notificationTime.toIso8601String()}, not re-scheduling");
    return;
  }

  print("Scheduling notification for ${notificationTime.toIso8601String()}");

  await FlutterLocalNotificationsPlugin().zonedSchedule(
    1,
    null,
    null,
    notificationTime,
    details,
    uiLocalNotificationDateInterpretation:
        UILocalNotificationDateInterpretation.absoluteTime,
  );
  await prefs.setString(
      'scheduled_notification', notificationTime.toIso8601String());
}