/**
 * 网络请求封装
 * 包含Token自动刷新机制
 */

// 从配置文件导入API_BASE
import { API_BASE } from '@/config/api.js';

let isRefreshing = false; // 是否正在刷新token
let requests = []; // 存储待重试的请求

/**
 * 统一请求方法
 */
const request = (options) => {
  return new Promise((resolve, reject) => {
    // 获取token
    const token = uni.getStorageSync('token');
    
    // 设置请求头
    const header = {
      'Content-Type': 'application/json',
      ...options.header
    };
    
    if (token) {
      header['Authorization'] = `Bearer ${token}`;
    }
    
    uni.request({
      url: API_BASE + options.url,
      method: options.method || 'GET',
      data: options.data || {},
      header: header,
      success: (res) => {
        // 请求成功
        if (res.statusCode === 200) {
          resolve(res.data);
        } 
        // Token过期
        else if (res.statusCode === 401) {
          // 如果正在刷新token，将请求加入队列
          if (isRefreshing) {
            requests.push(() => {
              request(options).then(resolve).catch(reject);
            });
          } else {
            // 开始刷新token
            isRefreshing = true;
            
            refreshToken()
              .then((newToken) => {
                // 刷新成功，重试当前请求
                isRefreshing = false;
                
                // 重试当前请求
                request(options).then(resolve).catch(reject);
                
                // 重试队列中的请求
                requests.forEach(cb => cb());
                requests = [];
              })
              .catch((err) => {
                // 刷新失败，跳转登录
                isRefreshing = false;
                requests = [];
                
                uni.showToast({
                  title: '登录已过期，请重新登录',
                  icon: 'none'
                });
                
                setTimeout(() => {
                  uni.reLaunch({
                    url: '/pages/login/login'
                  });
                }, 1500);
                
                reject(err);
              });
          }
        } 
        // 其他错误
        else {
          reject(res);
        }
      },
      fail: (err) => {
        reject(err);
      }
    });
  });
};

/**
 * 刷新Token
 */
const refreshToken = () => {
  return new Promise((resolve, reject) => {
    const refreshToken = uni.getStorageSync('refreshToken');
    
    if (!refreshToken) {
      reject(new Error('No refresh token'));
      return;
    }
    
    uni.request({
      url: API_BASE + '/api/users/refresh-token',
      method: 'POST',
      data: {
        refreshToken: refreshToken
      },
      success: (res) => {
        if (res.statusCode === 200 && res.data.success) {
          // 保存新token
          const newToken = res.data.data.token;
          const newRefreshToken = res.data.data.refreshToken;
          
          uni.setStorageSync('token', newToken);
          uni.setStorageSync('refreshToken', newRefreshToken);
          
          resolve(newToken);
        } else {
          reject(new Error('Refresh token failed'));
        }
      },
      fail: (err) => {
        reject(err);
      }
    });
  });
};

/**
 * GET请求
 */
export const get = (url, data = {}, header = {}) => {
  return request({
    url,
    method: 'GET',
    data,
    header
  });
};

/**
 * POST请求
 */
export const post = (url, data = {}, header = {}) => {
  return request({
    url,
    method: 'POST',
    data,
    header
  });
};

/**
 * PUT请求
 */
export const put = (url, data = {}, header = {}) => {
  return request({
    url,
    method: 'PUT',
    data,
    header
  });
};

/**
 * DELETE请求
 */
export const del = (url, data = {}, header = {}) => {
  return request({
    url,
    method: 'DELETE',
    data,
    header
  });
};

export default {
  get,
  post,
  put,
  del,
  request
};