Momento/memento-note/app/actions/auth.ts

'use server';

import { signIn } from '@/auth';
import { AuthError } from 'next-auth';

export async function authenticate(
  prevState: string | undefined,
  formData: FormData,
) {
  try {
    await signIn('credentials', {
      email: formData.get('email'),
      password: formData.get('password'),
      redirectTo: '/',
    });
  } catch (error) {
    if (error instanceof AuthError) {
      console.error('AuthError details:', error.type, error.message);
      switch (error.type) {
        case 'CredentialsSignin':
          return 'Invalid credentials.';
        default:
          return `Auth error: ${error.type}`;
      }
    }
    // IMPORTANT: Next.js redirects throw a special error that must be rethrown
    throw error;
  }
}