import { useState, useEffect, useCallback } from 'react';
import { apiRequest, setToken, clearToken } from '../api/client';

interface User {
  id: string;
  username: string;
}

interface AuthState {
  user: User | null;
  isLoading: boolean;
  isAuthenticated: boolean;
}

export function useAuth() {
  const [state, setState] = useState<AuthState>({
    user: null,
    isLoading: true,
    isAuthenticated: false,
  });

  const checkAuth = useCallback(async () => {
    const token = localStorage.getItem('token');
    if (!token) {
      setState({ user: null, isLoading: false, isAuthenticated: false });
      return;
    }

    try {
      const user = await apiRequest<User>('/auth/me');
      setState({ user, isLoading: false, isAuthenticated: true });
    } catch {
      clearToken();
      setState({ user: null, isLoading: false, isAuthenticated: false });
    }
  }, []);

  useEffect(() => {
    checkAuth();
  }, [checkAuth]);

  const login = async (username: string, password: string) => {
    const { token, user } = await apiRequest<{ token: string; user: User }>(
      '/auth/login',
      {
        method: 'POST',
        body: JSON.stringify({ username, password }),
      }
    );
    setToken(token);
    setState({ user, isLoading: false, isAuthenticated: true });
  };

  const register = async (username: string, password: string) => {
    const { token, user } = await apiRequest<{ token: string; user: User }>(
      '/auth/register',
      {
        method: 'POST',
        body: JSON.stringify({ username, password }),
      }
    );
    setToken(token);
    setState({ user, isLoading: false, isAuthenticated: true });
  };

  const logout = () => {
    clearToken();
    setState({ user: null, isLoading: false, isAuthenticated: false });
  };

  return {
    ...state,
    login,
    register,
    logout,
  };
}