Added main functionality

apk/utils/birthday-notifications.ts

@@ -0,0 +1,129 @@
+import { Platform } from "react-native";
+import * as Notifications from "expo-notifications";
+
+import type { BirthdayEntry } from "@/context/birthdays-context";
+
+const CHANNEL_ID = "birthdays";
+const NOTIFICATION_HOUR = 9;
+const NOTIFICATION_MINUTE = 0;
+const IDENTIFIER_PREFIX = "birthday-";
+
+Notifications.setNotificationHandler({
+  handleNotification: async () => ({
+    shouldPlaySound: true,
+    shouldSetBadge: false,
+    shouldShowBanner: true,
+    shouldShowList: true,
+  }),
+});
+
+function getNotificationIdentifier(id: string) {
+  return `${IDENTIFIER_PREFIX}${id}`;
+}
+
+function parseBirthdayDate(date: string) {
+  return new Date(`${date}T00:00:00`);
+}
+
+async function configureAndroidChannel() {
+  if (Platform.OS !== "android") {
+    return;
+  }
+
+  await Notifications.setNotificationChannelAsync(CHANNEL_ID, {
+    name: "Birthdays",
+    description: "Birthday reminders",
+    importance: Notifications.AndroidImportance.DEFAULT,
+  });
+}
+
+async function hasNotificationPermissionAsync() {
+  const settings = await Notifications.getPermissionsAsync();
+
+  return (
+    settings.granted ||
+    settings.ios?.status === Notifications.IosAuthorizationStatus.PROVISIONAL
+  );
+}
+
+async function ensureNotificationPermissionAsync() {
+  await configureAndroidChannel();
+
+  if (await hasNotificationPermissionAsync()) {
+    return true;
+  }
+
+  const settings = await Notifications.requestPermissionsAsync({
+    ios: {
+      allowAlert: true,
+      allowBadge: false,
+      allowSound: true,
+    },
+  });
+
+  return (
+    settings.granted ||
+    settings.ios?.status === Notifications.IosAuthorizationStatus.PROVISIONAL
+  );
+}
+
+async function clearStaleBirthdayNotifications(birthdays: BirthdayEntry[]) {
+  const validIdentifiers = new Set(
+    birthdays.map((birthday) => getNotificationIdentifier(birthday.id))
+  );
+  const scheduledNotifications =
+    await Notifications.getAllScheduledNotificationsAsync();
+
+  await Promise.all(
+    scheduledNotifications
+      .filter(
+        (notification) =>
+          notification.identifier.startsWith(IDENTIFIER_PREFIX) &&
+          !validIdentifiers.has(notification.identifier)
+      )
+      .map((notification) =>
+        Notifications.cancelScheduledNotificationAsync(notification.identifier)
+      )
+  );
+}
+
+async function scheduleBirthdayNotification(birthday: BirthdayEntry) {
+  const parsedDate = parseBirthdayDate(birthday.date);
+  const month = parsedDate.getMonth();
+  const day = parsedDate.getDate();
+
+  await Notifications.cancelScheduledNotificationAsync(
+    getNotificationIdentifier(birthday.id)
+  );
+
+  await Notifications.scheduleNotificationAsync({
+    identifier: getNotificationIdentifier(birthday.id),
+    content: {
+      title: `Today is ${birthday.name}'s birthday`,
+      body: `Wish ${birthday.name} a happy birthday!`,
+      sound: true,
+    },
+    trigger: {
+      type: Notifications.SchedulableTriggerInputTypes.YEARLY,
+      channelId: Platform.OS === "android" ? CHANNEL_ID : undefined,
+      month,
+      day,
+      hour: NOTIFICATION_HOUR,
+      minute: NOTIFICATION_MINUTE,
+    },
+  });
+}
+
+export async function syncBirthdayNotifications(birthdays: BirthdayEntry[]) {
+  if (Platform.OS === "web") {
+    return;
+  }
+
+  const permissionGranted = await ensureNotificationPermissionAsync();
+  if (!permissionGranted) {
+    return;
+  }
+
+  await clearStaleBirthdayNotifications(birthdays);
+  await Promise.all(birthdays.map(scheduleBirthdayNotification));
+}