import { ReactNode, createContext, useState } from "react";

export interface AuthContextType {
  user: any;
  signIn: (user: string, callback: VoidFunction) => void;
  signOut: (callback: VoidFunction) => void;
}

export let AuthContext = createContext<AuthContextType | null>(null);

const fakeAuthProvider = {
  isAuthenticated: false,
  signIn(callback: VoidFunction) {
    this.isAuthenticated = true;
    setTimeout(callback, 100);
  },
  signOut(callback: VoidFunction) {
    this.isAuthenticated = false;
    setTimeout(callback, 100);
  },
};

const AuthProvider = ({ children }: { children: ReactNode }) => {
  const [user, setUser] = useState<any>(null);

  let signIn = (newUser: string, callback: VoidFunction) => {
    return fakeAuthProvider.signIn(() => {
      setUser(newUser);
      callback();
    });
  };

  let signOut = (callback: VoidFunction) => {
    return fakeAuthProvider.signOut(() => {
      setUser(null);
      callback();
    });
  };

  return (
    <AuthContext.Provider value={{ user, signIn, signOut }}>
      {children}
    </AuthContext.Provider>
  );
};

export default AuthProvider;

import { useContext } from "react";
import { useNavigate, Link, Outlet } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

const useAuth = () => useContext(AuthContext);

const AuthStatus = () => {
  let auth = useAuth();
  let { user, signOut } = auth as AuthContextType;
  let navigate = useNavigate();

  if (!user) return <p>沒有登錄</p>;
  return (
    <>
      <p>你好 {user}! </p>
      <button onClick={() => signOut(() => navigate("/"))}>退出</button>
    </>
  );
};

const Layout = () => {
  return (
    <div>
      <AuthStatus />
      <ul>
        <li>
          <Link to="/">公共頁(yè)面</Link>
        </li>
        <li>
          <Link to="/protected">受保護(hù)頁(yè)面</Link>
        </li>
      </ul>
      <Outlet />
    </div>
  );
};

export default Layout;

import { useContext, FormEvent } from "react";
import { useNavigate, useLocation, Location } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

interface State extends Omit<Location, "state"> {
  state: {
    from: {
      pathname: string;
    };
  };
}

const useAuth = () => useContext(AuthContext);

const Login = () => {
  let auth = useAuth();
  let { signIn } = auth as AuthContextType;
  const { state } = useLocation() as State;
  let from = state.from.pathname || "/";
  let navigate = useNavigate();

  const handleSubmit = (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault();

    let formData = new FormData(event.currentTarget);
    let username = formData.get("username") as string;

    signIn(username, () => navigate(from, { replace: true }));
  };

  return (
    <div>
      <p>您必須登錄才能查看該頁(yè)面 {from}</p>

      <form onSubmit={handleSubmit}>
        <label>
          用戶名: <input name="username" type="text" />
        </label>
        <button type="submit">登錄</button>
      </form>
    </div>
  );
};

export default Login;

import { useContext } from "react";
import { useLocation, Navigate } from "react-router-dom";
import { AuthContext, AuthContextType } from "../AuthProvider";

const useAuth = () => useContext(AuthContext);

const RequireAuth = ({ children }: { children: JSX.Element }) => {
  let auth = useAuth();
  let { user } = auth as AuthContextType;
  let location = useLocation();

  if (!user) return <Navigate to="/login" state={{ from: location }} replace />;

  return children;
};

export default RequireAuth;

import { Routes, Route } from "react-router-dom";

import AuthProvider from "src/views/AuthProvider";
import Layout from "src/views/auth/layout";
import LoginPage from "src/views/auth/login";
import PublicPage from "src/views/auth/publicPage";
import RequireAuth from "src/views/auth/requireAuth";
import ProtectedPage from "src/views/auth/protectedPage";

const App = () => {
  return (
    <AuthProvider>
      <Routes>
        <Route element={<Layout />}>
          <Route path="/" element={<PublicPage />} />
          <Route path="/login" element={<LoginPage />} />
          <Route
            path="/protected"
            element={
              <RequireAuth>
                <ProtectedPage />
              </RequireAuth>
            }
          />
        </Route>
      </Routes>
    </AuthProvider>
  );
};

export default App;