import { useState, useEffect, useRef } from 'react';
import { auth, setAuthErrorHandler } from '../utils/api';

export function useAuth() {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);
  const userRef = useRef(user);

  // Keep userRef in sync with user state
  useEffect(() => {
    userRef.current = user;
  }, [user]);

  const checkAuth = async () => {
    try {
      const userData = await auth.getMe();
      setUser(userData);
      setLoading(false);
      return userData; // Return user data for verification
    } catch (error) {
      // If 401/403, user is not authenticated
      // Check if it's an auth error
      if (error.message && (error.message.includes('Unauthorized') || error.message.includes('401') || error.message.includes('403'))) {
        setUser(null);
        setLoading(false);
        throw error; // Re-throw to allow caller to handle
      } else {
        // Other errors (network, etc.) - don't log out, just re-throw
        // This prevents network issues from logging users out
        setLoading(false);
        throw error; // Re-throw to allow caller to handle
      }
    }
  };

  const logout = async () => {
    try {
      await auth.logout();
    } catch (error) {
      console.error('Logout error:', error);
    } finally {
      // Refresh the page to show login
      window.location.reload();
    }
  };

  useEffect(() => {
    // Set up global auth error handler
    setAuthErrorHandler(() => {
      setUser(null);
      setLoading(false);
    });

    // Listen for auth errors from API calls
    const handleAuthErrorEvent = () => {
      setUser(null);
      setLoading(false);
    };
    window.addEventListener('auth-error', handleAuthErrorEvent);

    // Initial auth check
    checkAuth();

    // Periodic auth check every 10 seconds
    const authInterval = setInterval(() => {
      // Use ref to check current user state without dependency
      if (userRef.current) {
        // Only check if we have a user (don't spam when logged out)
        checkAuth().catch((error) => {
          // Only log out if it's actually an auth error, not a network error
          // Network errors shouldn't log the user out
          if (error.message && (error.message.includes('Unauthorized') || error.message.includes('401') || error.message.includes('403'))) {
            // This is a real auth error - user will be set to null by checkAuth
          }
          // For other errors (network, etc.), don't log out - just silently fail
        });
      }
    }, 10000); // 10 seconds

    return () => {
      window.removeEventListener('auth-error', handleAuthErrorEvent);
      clearInterval(authInterval);
    };
  }, []); // Empty deps - only run on mount/unmount

  return { user, loading, logout, refresh: checkAuth };
}