class VBase {
  constructor(baseURL) {
    this.baseURL = baseURL || '';
    this.tokenKey = 'vbase_access_token';
    this.refreshTokenKey = 'vbase_refresh_token';
    this.userKey = 'vbase_user_info';
    this.orgKey = 'vbase_current_org';

    this._token = localStorage.getItem(this.tokenKey) || '';
    this._refreshToken = localStorage.getItem(this.refreshTokenKey) || '';
    this._user = JSON.parse(localStorage.getItem(this.userKey) || 'null');
    this._currentOrg = JSON.parse(localStorage.getItem(this.orgKey) || 'null');
  }

  // Getters
  get token() { return this._token; }
  get refreshToken() { return this._refreshToken; }
  get user() { return this._user; }
  get currentOrg() { return this._currentOrg; }

  // Setters
  set token(val) {
    this._token = val;
    if (val) localStorage.setItem(this.tokenKey, val);
    else localStorage.removeItem(this.tokenKey);
  }

  set refreshToken(val) {
    this._refreshToken = val;
    if (val) localStorage.setItem(this.refreshTokenKey, val);
    else localStorage.removeItem(this.refreshTokenKey);
  }

  set user(val) {
    this._user = val;
    if (val) localStorage.setItem(this.userKey, JSON.stringify(val));
    else localStorage.removeItem(this.userKey);
  }

  set currentOrg(val) {
    this._currentOrg = val;
    if (val) localStorage.setItem(this.orgKey, JSON.stringify(val));
    else localStorage.removeItem(this.orgKey);
  }

  // API Helpers
  async request(method, path, data = null, headers = {}) {
    const url = `${this.baseURL}${path}`;
    const config = {
      method,
      headers: {
        'Content-Type': 'application/json',
        ...this.getAuthHeaders(),
        ...headers
      }
    };
    if (data) config.body = JSON.stringify(data);

    const response = await fetch(url, config);
    const resData = await response.json();

    if (!response.ok) {
      // Include resData in the error so caller can access the response body
      const error = new Error(resData.message || `Request failed: ${response.status}`);
      Object.assign(error, resData);
      throw error;
    }

    if (resData.code && resData.code !== 200) {
      throw new Error(resData.message || 'API Error');
    }

    return resData.data || resData;
  }

  // Auth Actions
  async login(username, password) {
    try {
      const data = await this.request('POST', '/api/auth/login', { username, password });
      if (data.access_token) {
        this.token = data.access_token;
        if (data.refresh_token) this.refreshToken = data.refresh_token;
        this.user = data.user; // Set user directly from login response
        return true;
      }
      return false;
    } catch (e) {
      throw e;
    }
  }

  async logout(redirect) {
    try {
      // Optional: Call server logout
      // await this.request('POST', '/api/auth/logout');
    } catch (e) {
      console.warn('Logout API failed', e);
    } finally {
      this.clear();
      if (redirect) {
        location.href = redirect;
      } else {
        location.reload();
      }
    }
  }

  async refresh() {
    if (!this.refreshToken) throw new Error("No refresh token");
    try {
      const data = await this.request('POST', '/api/auth/refresh', { refresh_token: this.refreshToken });
      if (data.access_token) {
        this.token = data.access_token;
        if (data.refresh_token) this.refreshToken = data.refresh_token;
        return true;
      }
      return false;
    } catch (e) {
      this.logout();
      throw e;
    }
  }

  async fetchUser() {
    const user = await this.request('GET', '/api/auth/me');
    this.user = user;
    return user;
  }

  // Auth Headers
  getAuthHeaders() {
    const headers = {};
    if (this.token) {
      headers['Authorization'] = `Bearer ${this.token}`;
    }
    if (this.currentOrg && this.currentOrg.id) {
      headers['X-Org-ID'] = this.currentOrg.id;
    }
    return headers;
  }

  // Permission Check
  hasPermission(permission) {
    if (!this.user) return false;
    if (this.user.is_admin) return true;
    if (!permission) return true;
    const userPerms = this.user.permissions || [];
    return userPerms.includes(permission);
  }

  hasRole(role) {
    if (!this.user) return false;
    if (this.user.is_admin) return true;
    const userRoles = this.user.roles || [];
    return userRoles.includes(role);
  }

  // State Management
  clear() {
    this.token = '';
    this.refreshToken = '';
    this.user = null;
    this.currentOrg = null;
  }

  isExpired(token) {
    if (!token) token = this.token;
    if (!token) return true;
    try {
      const base64Url = token.split('.')[1];
      const base64 = base64Url.replace(/-/g, '+').replace(/_/g, '/');
      const payload = JSON.parse(window.atob(base64));
      const now = Math.floor(Date.now() / 1000);
      return payload.exp && payload.exp < now;
    } catch (e) {
      return true;
    }
  }

  wrapAxios(axiosInstance) {
    // Request Interceptor
    axiosInstance.interceptors.request.use(config => {
      const headers = this.getAuthHeaders();
      for (const key in headers) {
        config.headers[key] = headers[key];
      }
      return config;
    }, error => Promise.reject(error));

    // Response Interceptor
    axiosInstance.interceptors.response.use(response => {
      const res = response.data;
      if (res && res.code === 200) {
        return res.data;
      }
      if (res && res.code && res.code !== 200) {
        return Promise.reject(new Error(res.message || 'Error'));
      }
      return res || response;
    }, async error => {
      const originalRequest = error.config;
      if (error.response?.status === 401 && !originalRequest._retry) {
        originalRequest._retry = true;
        try {
          await this.refresh();
          const headers = this.getAuthHeaders();
          originalRequest.headers['Authorization'] = headers['Authorization'];
          return axiosInstance(originalRequest);
        } catch (e) {
          this.logout('/login?redirect=' + encodeURIComponent(window.location.pathname));
          return Promise.reject(e);
        }
      }
      return Promise.reject(error?.response?.data || error);
    });
  }
}

export default VBase;