project-codepen/src/reducers/auth.js

import { decode as atob } from "base-64";

let signatureToken = token => JSON.parse(atob(token.split(".")[1]));

function authReducer(state, { type, token }) {
	if (state === undefined) {
		if (localStorage.authToken) {
			type = "LOGIN";
			token = localStorage.authToken;
		} else {
			return {};
		}
	}

	if (type === "LOGIN") {
		console.log("LOGIN");
		localStorage.authToken = token;
		return { token, payload: signatureToken(token) };
	}

	if (type === "LOGOUT") {
		console.log("LOGOUT");
		localStorage.removeItem("authToken");
		return {};
	}

	return state;
}

export default authReducer;