export interface AuthUser {
  id: number;
  name: string;
  email: string;
  role: 'admin' | 'student';
  avatar?: string;
}

export function getToken(): string | null {
  if (typeof window === 'undefined') return null;
  return localStorage.getItem('auth_token');
}

export function getUser(): AuthUser | null {
  if (typeof window === 'undefined') return null;
  const raw = localStorage.getItem('auth_user');
  if (!raw) return null;
  try {
    return JSON.parse(raw);
  } catch {
    return null;
  }
}

export function setAuth(token: string, user: AuthUser): void {
  localStorage.setItem('auth_token', token);
  localStorage.setItem('auth_user', JSON.stringify(user));
}

export function clearAuth(): void {
  localStorage.removeItem('auth_token');
  localStorage.removeItem('auth_user');
}

export function isAuthenticated(): boolean {
  return !!getToken() && !!getUser();
}