import { BASE_URL } from "@/api/constants";

// API配置
const API_BASE_URL = 'https://77.api.qikongjian.com';

// Token存储键
const TOKEN_KEY = 'X-EASE-ADMIN-TOKEN';
const USER_KEY = 'currentUser';

/**
 * 登录用户
 */
export const loginUser = async (email: string, password: string) => {
  try {
    const response = await fetch(`${API_BASE_URL}/admin/login/signIn`, {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        userName: email,
        password: password,
      }),
    });

    const data = await response.json();

    if (data.code === '200' && data.status === 200) {
      // 保存token到本地存储
      setToken(data.body.token);
      
      // 保存用户信息
      const user = {
        id: data.body.userId,
        name: data.body.userName,
        email: email,
        token: data.body.token,
      };
      setUser(user);
      
      return user;
    } else {
      throw new Error(data.msg || '登录失败');
    }
  } catch (error) {
    console.error('Login failed:', error);
    throw error;
  }
};

/**
 * 鉴权检查
 */
export const checkAuth = async (): Promise<boolean> => {
  const token = getToken();
  if (!token) {
    return false;
  }

  try {
    const response = await fetch(`${API_BASE_URL}/admin/login/auth`, {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
        'X-EASE-ADMIN-TOKEN': token,
      },
    });

    const data = await response.json();

    if (data.code === '401' || data.status === 401) {
      // Token无效，清除本地存储
      clearAuthData();
      return false;
    }

    return data.code === '200' && data.status === 200;
  } catch (error) {
    console.error('Auth check failed:', error);
    return false;
  }
};

/**
 * 获取token
 */
export const getToken = (): string | null => {
  if (typeof window === 'undefined') return null;
  return localStorage.getItem(TOKEN_KEY);
};

/**
 * 设置token
 */
export const setToken = (token: string) => {
  if (typeof window === 'undefined') return;
  localStorage.setItem(TOKEN_KEY, token);
};

/**
 * 获取当前用户
 */
export const getCurrentUser = () => {
  if (typeof window === 'undefined') return null;
  
  const userJson = localStorage.getItem(USER_KEY);
  if (!userJson) return null;
  
  try {
    return JSON.parse(userJson);
  } catch (error) {
    console.error('Failed to parse user data from storage', error);
    return null;
  }
};

/**
 * 设置用户信息
 */
export const setUser = (user: any) => {
  if (typeof window === 'undefined') return;
  localStorage.setItem(USER_KEY, JSON.stringify(user));
};

/**
 * 清除认证数据
 */
export const clearAuthData = () => {
  if (typeof window === 'undefined') return;
  localStorage.removeItem(TOKEN_KEY);
  localStorage.removeItem(USER_KEY);
};

/**
 * 用户登出
 */
export const logoutUser = () => {
  clearAuthData();
  window.location.href = '/login';
};

/**
 * 检查是否已登录
 */
export const isAuthenticated = (): boolean => {
  return !!getToken();
};

/**
 * 创建带有token的请求头
 */
export const getAuthHeaders = () => {
  const token = getToken();
  return {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    ...(token && { 'X-EASE-ADMIN-TOKEN': token }),
  };
};

/**
 * 带有自动token处理的fetch封装
 */
export const authFetch = async (url: string, options: RequestInit = {}) => {
  const token = getToken();
  
  if (!token) {
    throw new Error('No token available');
  }

  const headers = {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'X-EASE-ADMIN-TOKEN': token,
    ...options.headers,
  };

  const response = await fetch(url, {
    ...options,
    headers,
  });

  // 检查是否token过期
  if (response.status === 401) {
    const data = await response.json();
    if (data.code === '401') {
      // Token过期，清除本地数据并重定向到登录页
      clearAuthData();
      window.location.href = '/login';
      throw new Error('Token expired');
    }
  }

  return response;
};

// Google OAuth相关函数保持不变
const GOOGLE_CLIENT_ID = '1016208801816-qtvcvki2jobmcin1g4e7u4sotr0p8g3u.apps.googleusercontent.com';
const GOOGLE_REDIRECT_URI = typeof window !== 'undefined' 
  ? BASE_URL+'/users/oauth/callback'
  : '';

/**
 * Initiates Google OAuth authentication flow
 */
export const signInWithGoogle = () => {
  const state = generateOAuthState();
  
  const params = new URLSearchParams({
    client_id: GOOGLE_CLIENT_ID,
    redirect_uri: GOOGLE_REDIRECT_URI,
    response_type: 'code',
    scope: 'email profile',
    prompt: 'select_account',
    state: state,
  });

  // Redirect to Google's OAuth endpoint
  window.location.href = `https://accounts.google.com/o/oauth2/v2/auth?${params.toString()}`;
};

/**
 * Generates and stores a state parameter for OAuth to prevent CSRF attacks
 */
export const generateOAuthState = () => {
  if (typeof window === 'undefined') return '';
  
  // Generate a random string for state
  const state = Math.random().toString(36).substring(2, 15);
  
  // Store the state in session storage to validate later
  sessionStorage.setItem('oauthState', state);
  
  return state;
};

/**
 * Validates the state parameter returned from OAuth to prevent CSRF attacks
 */
export const validateOAuthState = (state: string): boolean => {
  if (typeof window === 'undefined') return false;
  
  const storedState = sessionStorage.getItem('oauthState');
  
  // Clean up the stored state regardless of validity
  sessionStorage.removeItem('oauthState');
  
  // Validate that the returned state matches what we stored
  return state === storedState;
};