aretherecookies-mobile/js/apis/PositionApi.js

// @flow
import { emitter } from '../streams/LocationStream';
import { getCoordsFromZip } from './GoogleMapsApi';
import { PermissionsAndroid, Platform } from 'react-native';
import AsyncStorage from '@react-native-community/async-storage';
import Geolocation from 'react-native-geolocation-service';

const {
	PERMISSIONS: { ACCESS_FINE_LOCATION },
	RESULTS,
	request: requestPermission,
} = PermissionsAndroid;

let locationPermissionResponse = false;

const askLocationPermission = async () => {
	if (Platform.OS === 'ios') {
		locationPermissionResponse = RESULTS.GRANTED;
	} else if (locationPermissionResponse !== RESULTS.GRANTED) {
		locationPermissionResponse = await requestPermission(ACCESS_FINE_LOCATION, {
			title: "Where's the TP? Location Permission",
			message: "Where's the TP? would like to use your location to find some cookies. Is that OK?",
		});
	}
	return locationPermissionResponse === RESULTS.GRANTED;
};

export const getCurrentPosition = () => {
	return new Promise((resolve, reject) => {
		askLocationPermission().then((granted) => {
			if (!granted) {
				return reject('Permission was not given for location');
			}
			Geolocation.getCurrentPosition(
				(pos: Position) => {
					emitter(pos), resolve(pos);
					return pos;
				},
				(err) => {
					reject(err);
				},
				{
					enableHighAccuracy: true,
					timeout: 5000,
				}
			);
		});
	});
};

export const getPositionFromZip = async (zip: string) => {
	const { lat: latitude, lng: longitude } = await getCoordsFromZip(zip);

	const pos: any = {
		coords: {
			latitude,
			longitude,
		},
	};

	emitter(pos);

	return pos;
};

export const getLocation: () => Promise<Position> = async () => {
	const currentZip = await AsyncStorage.getItem('zipcode');

	if (currentZip && currentZip !== 'usegps') {
		return getPositionFromZip(currentZip);
	} else {
		AsyncStorage.setItem('zipcode', 'usegps');
		return getCurrentPosition().catch((error) => {
			AsyncStorage.removeItem('zipcode');
			throw error;
		});
	}
};