import Constants from 'expo-constants';
import * as Notifications from 'expo-notifications';
import * as Permissions from 'expo-permissions';
import React, { useState, useEffect } from 'react';
import { Text, View, Button, Platform } from 'react-native';

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

export default function App() {
  const [expoPushToken, setExpoPushToken] = useState('');
  const [notification, setNotification] = useState(false);

  useEffect(() => {
    registerForPushNotificationsAsync().then(token => setExpoPushToken(token));
    Notifications.addNotificationReceivedListener(notification => {
      setNotification(notification);
    });

    return () => {
      Notifications.removeAllNotificationListeners();
    };
  });

  return (
    <View
      style={{
        flex: 1,
        alignItems: 'center',
        justifyContent: 'space-around',
      }}>
      <Text>Your expo push token: {expoPushToken}</Text>
      <View style={{ alignItems: 'center', justifyContent: 'center' }}>
        <Text>Title: {notification && notification.request.content.title} </Text>
        <Text>Body: {notification && notification.request.content.body}</Text>
        <Text>Data: {notification && JSON.stringify(notification.request.content.data.body)}</Text>
      </View>
      <Button
        title="Press to Send Notification"
        onPress={async () => {
          await sendPushNotification(expoPushToken);
        }}
      />
    </View>
  );
}

// Can use this function below, OR use Expo's Push Notification Tool-> https://expo.io/dashboard/notifications
async function sendPushNotification(expoPushToken) {
  const message = {
    to: expoPushToken,
    sound: 'default',
    title: 'Original Title',
    body: 'And here is the body!',
    data: { data: 'goes here' },
  };

  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),
  });
}

async function registerForPushNotificationsAsync() {
  let token;
  if (Constants.isDevice) {
    const { status: existingStatus } = await Permissions.getAsync(Permissions.NOTIFICATIONS);
    let finalStatus = existingStatus;
    if (existingStatus !== 'granted') {
      const { status } = await Permissions.askAsync(Permissions.NOTIFICATIONS);
      finalStatus = status;
    }
    if (finalStatus !== 'granted') {
      alert('Failed to get push token for push notification!');
      return;
    }
    token = (await Notifications.getExpoPushTokenAsync()).data;
    console.log(token);
  } else {
    alert('Must use physical device for Push Notifications');
  }

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

  return token;
}

expo init bugTest (select blank)
cd bugTest
expo install expo-notifications
expo start