import { useState, useEffect } from 'react';
import { isUserRegistered } from '../utils/index.ts';

/**
 * Custom hook for reactive authentication state
 * Provides current authentication status and updates when it changes
 */
export const useAuth = () => {
  const [isAuthenticated, setIsAuthenticated] = useState(isUserRegistered());

  useEffect(() => {
    // Check authentication status on mount and when storage changes
    const checkAuth = () => {
      setIsAuthenticated(isUserRegistered());
    };

    // Listen for storage changes (when user_id is set/cleared)
    const handleStorageChange = (e: StorageEvent) => {
      if (e.key === 'user_id') {
        checkAuth();
      }
    };

    // Listen for custom auth events (for immediate updates after login/logout)
    const handleAuthChange = () => {
      checkAuth();
    };

    window.addEventListener('storage', handleStorageChange);
    window.addEventListener('authChange', handleAuthChange);

    // Initial check
    checkAuth();

    return () => {
      window.removeEventListener('storage', handleStorageChange);
      window.removeEventListener('authChange', handleAuthChange);
    };
  }, []);

  return { isAuthenticated };
};