auth.ts

import CredentialsProvider from 'next-auth/providers/credentials';
import NextAuth from 'next-auth';
import { loginSchema } from './lib/validators';
import { sql } from '@vercel/postgres';
import type { User } from '@/lib/definitions';
import bcrypt from 'bcryptjs';

async function getUser(email: string): Promise<User | undefined> {
  try {
    const user = await sql<User>`SELECT * FROM users WHERE email=${email}`;
    return user.rows[0];
  } catch (error) {
    console.error('Failed to fetch user:', error);
    throw new Error('Failed to fetch user.');
  }
}

export const { auth, handlers, signIn, signOut } = NextAuth({
  pages: {
    signIn: '/login',
  },
  session: {
    strategy: 'jwt',
  },
  providers: [
    CredentialsProvider({
      async authorize(credentials, req) {
        const parsedCredentials = loginSchema.safeParse(credentials);
        if (parsedCredentials.success) {
          const { email, password } = parsedCredentials.data;
          const user = await getUser(email);
          if (!user) return null;
          const passwordsMatch = await bcrypt.compare(password, user.password);

          if (passwordsMatch) return user;
        }

        return null;
      },
    }),
  ],
  callbacks: {
    authorized({ auth, request: { nextUrl } }) {
      const isLoggedIn = !!auth?.user;
      const isOnDashboard = nextUrl.pathname.startsWith('/dashboard');

      if (isOnDashboard) return isLoggedIn;

      if (isLoggedIn) {
        return Response.redirect(new URL('/dashboard', nextUrl));
      }
      return true;
    },
  },
});