Mengintegrasikan NextAuth.js

npm install next-auth

import NextAuth from "next-auth";
import CredentialsProvider from "next-auth/providers/credentials";

export const { handlers, auth, signIn, signOut } = NextAuth({
  providers: [
    CredentialsProvider({
      name: "Credentials",
      credentials: {
        username: { label: "Username", type: "text", placeholder: "jsmith" },
        password: { label: "Password", type: "password" }
      },
      async authorize(credentials, req) {
        // Logic to verify user credentials
        // Return user object if successful, null otherwise
        return null; 
      }
    })
  ],
  pages: {
    signIn: '/auth/signin',
  }
});

import NextAuth from "next-auth";
import CredentialsProvider from "next-auth/providers/credentials";

export const { handlers, auth, signIn, signOut } = NextAuth({
  providers: [
    CredentialsProvider({
      name: "Credentials",
      credentials: {
        username: { label: "Username", type: "text", placeholder: "test" },
        password: { label: "Password", type: "password" }
      },
      async authorize(credentials) {
        if (credentials?.username === "user" && credentials?.password === "pass") {
          return { id: "1", name: "Test User", email: "test@example.com" };
        }
        return null; // Authentication failed
      }
    })
  ],
  pages: {
    signIn: '/auth/signin',
  }
});

// app/auth/signin/page.tsx (Client Component)
'use client';

import { signIn } from "next-auth/react";
import { useState } from "react";

export default function SignInPage() {
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    const result = await signIn('credentials', {
      username,
      password,
      redirect: false, // Don't redirect automatically
    });

    if (result?.error) {
      alert(result.error);
    } else {
      window.location.href = '/'; // Redirect on success
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <input
        type="text"
        placeholder="Username (user)"
        value={username}
        onChange={(e) => setUsername(e.target.value)}
      />
      <input
        type="password"
        placeholder="Password (pass)"
        value={password}
        onChange={(e) => setPassword(e.target.value)}
      />
      <button type="submit">Sign In</button>
    </form>
  );
}

// app/page.tsx (Server Component)
import { auth, signOut } from "@/auth"; // Adjust path if needed

export default async function HomePage() {
  const session = await auth();

  return (
    <div>
      <h1>Welcome!</h1>
      {session?.user ? (
        <div>
          <p>Signed in as {session.user.name || session.user.email}</p>
          {/* SignOut button would be in a Client Component */}
        </div>
      ) : (
        <p>Not signed in. <a href="/auth/signin">Sign In</a></p>
      )}
    </div>
  );
}

// app/components/SignOutButton.tsx (Client Component)
'use client';

import { signOut } from "next-auth/react";

export default function SignOutButton() {
  return (
    <button onClick={() => signOut({ callbackUrl: '/' })}> 
      Sign Out
    </button>
  );
}