Loading Google API and auth service

google-auth

const API_URL = 'https://apis.google.com/js/api.js';

const GOOGLE_CLIENT_ID = '';

const GOOGLE_CLIENT_SCOPE = '';

function loadScript(src) {
    return new Promise((resolve, reject) => {
        try {
            if (!document.querySelector(`script[src="${src}"]`)) {
                const js = document.createElement('script');

                document.body.appendChild(js);

                js.src = src;
                js.onload = () => resolve(true);
            } else {
                resolve(false);
            }
        } catch (err) {
            reject(err);
        }
    });
}

export const loadAPI = async () => {
    const initServices = await loadScript(API_URL);

    const { gapi } = window;

    if (initServices) {
        await new Promise((callback) =>
            gapi.load('client:auth2', { callback })
        );
    }

    return gapi;
};

export const getAuthInstance = () => {
    const { auth2 } = window.gapi;

    const params = {
        clientId: GOOGLE_CLIENT_ID,
        scope: GOOGLE_CLIENT_SCOPE
    };

    return auth2.init(params);
};

export const loadAuth = () => {
    const GoogleAuth = getAuthInstance();

    return GoogleAuth;
};

export const getSignedInUser = () => {
    const GoogleAuth = getAuthInstance();

    const isSignedIn = GoogleAuth.isSignedIn.get();

    const currentUser = GoogleAuth.currentUser.get();

    const {
        w3: { Eea: id, Paa: picture = '', ig = '', ofa = '' } = {}
    } = currentUser;

    const name = ig || ofa;

    const {
        id_token: idToken,
        access_token: accessToken
    } = currentUser.getAuthResponse(true);

    console.log('user', { idToken, accessToken });

    return {
        isSignedIn,
        idToken,
        accessToken,
        user: {
            id,
            picture,
            name
        }
    };
};

export const signIn = async () => {
    await getAuthInstance().signIn();

    return getSignedInUser();
};

export const signOut = () => getAuthInstance().signOut();

export const listenAuth = (callback) =>
    getAuthInstance().isSignedIn.listen(
        (isSignedIn) => isSignedIn && callback(getSignedInUser())
    );