wavelength_app/components/services/notifications/PushNotificationManager.tsx

import React, { useState, useEffect, useRef } from 'react';
import { Alert, Platform } from 'react-native';
import * as Device from 'expo-device';
import * as Notifications from 'expo-notifications';
import Constants from 'expo-constants';
import { NotificationMessage } from '@/constants/Types';

Notifications.setNotificationHandler({
  handleNotification: async () => ({
    shouldShowAlert: true,
    shouldPlaySound: false,
    shouldSetBadge: false,
  }),
});

export const sendPushNotification = async(expoPushToken: string | null, notification: NotificationMessage) => {
  if (!expoPushToken) {
    Alert.alert('Error', 'No push token found.');
    return;
  }
  const message = { 
    to: expoPushToken,
    sound: notification.sound ?? 'default',
    title: notification.title,
    body: notification.body,
    data: notification.data ?? {},
  };
  try {
    const response = await fetch('https://exp.host/--/api/v2/push/send', {
      method: 'POST',
      headers: {
        Accept: 'application/json',
        'Accept-encoding': 'gzip, deflate',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(message),
    });
    const result = await response.json();
  } catch (error) {
    console.error('Error sending push notification:', error);
    Alert.alert('Error', 'Failed to send push notification.');
  }
};

const handleRegistrationError = (errorMessage: string) => {
  alert(errorMessage);
  throw new Error(errorMessage);
};

async function registerForPushNotificationsAsync() {
  let token;

  if (Platform.OS === 'android') {
    await Notifications.setNotificationChannelAsync('default', {
      name: 'default',
      importance: Notifications.AndroidImportance.MAX,
      vibrationPattern: [0, 250, 250, 250],
      lightColor: '#FF231F7C',
    });
  }

  if (Device.isDevice) {
    const { status: existingStatus } = await Notifications.getPermissionsAsync();
    let finalStatus = existingStatus;
    if (existingStatus !== 'granted') {
      const { status } = await Notifications.requestPermissionsAsync();
      finalStatus = status;
    }
    if (finalStatus !== 'granted') {
      alert('Failed to get push token for push notification!');
      return;
    }
    const projectId = Constants.expoConfig?.extra?.eas?.projectId;
    if (!projectId) {
      alert('Project ID not found');
      return;
    }
    token = (await Notifications.getExpoPushTokenAsync({ projectId })).data;
  } else {
    alert('Must use physical device for Push Notifications');
  }

  return token;
}

export function PushNotificationManager({ children }: { children: React.ReactNode }) {
  const [expoPushToken, setExpoPushToken] = useState<string | undefined>('');
  const [notification, setNotification] = useState<Notifications.Notification | undefined>(undefined);
  const notificationListener = useRef<Notifications.Subscription>();
  const responseListener = useRef<Notifications.Subscription>();

  useEffect(() => {
    registerForPushNotificationsAsync().then(token => setExpoPushToken(token));

    notificationListener.current = Notifications.addNotificationReceivedListener(notification => {
      setNotification(notification);
    });

    responseListener.current = Notifications.addNotificationResponseReceivedListener(response => {
      console.log(response);
      // Handle notification response here
    });

    return () => {
      Notifications.removeNotificationSubscription(notificationListener.current!);
      Notifications.removeNotificationSubscription(responseListener.current!);
    };
  }, []);

  return <>{children}</>;
}