deguapp/frontend/app/context/AuthContext.js

import { createContext, useContext, useEffect, useState } from "react";
import storageUtil from "./storage";

const TOKEN_KEY = "my-jwt";
export const API_URL = "http://10.69.1.137:6060/api/v1";
const AuthContext = createContext(null);

export function useAuth() {
  const authContext = useContext(AuthContext);
  if (authContext === undefined) {
    throw new Error("Context is outside of provider");
  }
  return authContext;
}

export function AuthProvider({ children }) {
  const [authState, setAuthState] = useState({
    token: null,
    authenticated: null,
  });

  useEffect(() => {
    // tohle se zavola jen poprve pri startu appky
    async function loadToken() {
      const token = await storageUtil.getItem(TOKEN_KEY);
      console.log(`stored: ${token}`);

      const resUser = await fetch(`${API_URL}/auth/status`, {
        credentials: "include",
      });

      const userData = await resUser.json();

      if (token && resUser.status == 200) {
        setAuthState({
          token: token,
          authenticated: true,
          user: userData.data,
        });

        return;
      }
      setAuthState({
        authenticated: false,
        token: null,
        user: null,
      });
    }
    loadToken();
  }, []);

  async function register(username, email, password) {
    try {
      const res = await fetch(`${API_URL}/auth/signup`, {
        method: 'POST',
        credentials: 'include',
        headers: {
          "Content-Type": "application/json"
        },
        body: JSON.stringify({
          username,
          email,
          password
        })
      })
      return res;
    } catch (err) {
      return { error: true, msg: err.response.data };
    }
  }

  async function login(email, password) {
    try {
      const resLogin = await fetch(`${API_URL}/auth/signin`, {
        method: "POST",
        credentials: "include",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          email,
          password,
        }),
      });

      const loginData = await resLogin.json();

      const resUser = await fetch(`${API_URL}/auth/status`, {
        credentials: "include",
      });

      if (resUser.status != 200) {
        throw Error("user does not have user data");
      }

      const userData = await resUser.json();

      setAuthState({
        token: loginData.data.jwt,
        authenticated: true,
        user: userData.data,
      });

      await storageUtil.setItem(TOKEN_KEY, loginData.data.jwt);
    } catch (err) {
      console.error("Failed to log in", err)
      return { error: true, msg: err.res };
    }
  }

  async function logout() {
    let res = await fetch(`${API_URL}/auth/logout`, {
      method: "POST",
      credentials: "include",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({}),
    });
    res = await res.json();

    await storageUtil.delItem(TOKEN_KEY);

    setAuthState({
      token: null,
      authenticated: false,
      user: null,
    });
  }

  const value = {
    onSignin: register,
    onLogin: login,
    onLogout: logout,
    authState,
  };

  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
}