Authentication Flow with NextAuth.js

// auth.ts
import NextAuth from 'next-auth';
import { NextAuthConfig } from 'next-auth';
import Google from 'next-auth/providers/google';
import GitHub from 'next-auth/providers/github';
import Credentials from 'next-auth/providers/credentials';
import { z } from 'zod';
import { compare } from 'bcrypt';
import { getUserByEmail } from '@/lib/user';

export const authConfig: NextAuthConfig = {
providers: [
Google({
  clientId: process.env.YOUR_GOOGLE_CLIENT_ID,
  clientSecret: process.env.YOUR_GOOGLE_CLIENT_SECRET,
}),
GitHub({
  clientId: process.env.YOUR_GITHUB_CLIENT_ID,
  clientSecret: process.env.YOUR_GITHUB_CLIENT_SECRET,
}),
Credentials({
  credentials: {
    email: { label: 'Email', type: 'email' },
    password: { label: 'Password', type: 'password' }
  },
  async authorize(credentials) {
    const parsedCredentials = z
      .object({ email: z.string().email(), password: z.string().min(6) })
      .safeParse(credentials);

    if (parsedCredentials.success) {
      const { email, password } = parsedCredentials.data;
      const user = await getUserByEmail(email);
      if (!user) return null;
      
      const passwordsMatch = await compare(password, user.password);
      if (passwordsMatch) return user;
    }
    
    return null;
  },
}),
],
pages: {
signIn: '/auth/login',
error: '/auth/error',
},
callbacks: {
authorized({ auth, request: { nextUrl } }) {
  const isLoggedIn = !!auth?.user;
  const isOnDashboard = nextUrl.pathname.startsWith('/dashboard');
  if (isOnDashboard) {
    if (isLoggedIn) return true;
    return false; // Redirect unauthenticated users to login page
  } else if (isLoggedIn) {
    return true;
  }
  return true;
},
jwt({ token, user }) {
  if (user) {
    token.role = user.role;
    token.id = user.id;
  }
  return token;
},
session({ session, token }) {
  if (token && session.user) {
    session.user.role = token.role;
    session.user.id = token.id;
  }
  return session;
},
},
};

export const { handlers, auth, signIn, signOut } = NextAuth(authConfig);