请求工具方法

import qs from "qs";
import cache from "./cache";
import { refreshTokenService, loginUserService } from "@/service/index";
import { CLIENT_SECRET, CLIENT_ID } from "@/constants/app";
import { to } from "@/utils/util";

// 默认刷新状态，确保一旦遇到token过期的状况就能更新
let isTokenRefreshing = false;
// 防止多次请求token获取接口（限制三次，三次以后直接显示账号信息错误）
let refreshTokenTimes = 0;
// 防止access_token错误情况下而refresh_token的无限请求边际情况
let wrongAuth = 0;
// 是否存在token
let firstTokenGetting = false;
// 防止获取token次数过多
let tokenFirstGetTimes = 0;
// 被拦截的请求数组
let subscribers: any[] = [];

// 处理被缓存的请求
function onAccessTokenFetched() {
  subscribers.forEach((callback) => {
    callback();
  });
  // 处理完后清空缓存请求数组
  subscribers = [];
}

const doLogin = async () => {
  const [res_code, err_code] = await to(wx.login());
  if (err_code) {
    console.log("wxlogin出错:", err_code);
  }
  if (res_code) {
    const [res, err] = await loginUserService({
      code: res_code.code,
      client_id: CLIENT_ID,
    });
    if (res) {
      cache.set(
        "access_token",
        res.data.data.access_token,
        res.data.data.expires_in
      );
      cache.set("refresh_token", res.data.data.refresh_token);
      return res;
    }
    if (err) {
      wx.showToast({
        title: "用户认证失败",
        icon: "error",
      });
    }
  }
};

// 将请求缓存到请求数组中
const addSubscriber = (callback: any) => {
  subscribers.push(callback);
};

const refreshToken = async () => {
  if (refreshTokenTimes >= 3) {
    console.error("登陆信息过期");
    return;
  }
  console.log("token开始更新");
  isTokenRefreshing = true;
  refreshTokenTimes++;
  const [res] = await refreshTokenService({
    access_token: cache.get("refresh_token"),
    client_id: CLIENT_ID,
    client_secret: CLIENT_SECRET,
  });
  isTokenRefreshing = false;
  if (res && res.statusCode === 200) {
    cache.set(
      "access_token",
      res.data.data.access_token,
      res.data.data.expires_in
    );
    cache.set("refresh_token", res.data.data.refresh_token);
    onAccessTokenFetched();
  } else {
    refreshToken();
  }
};

const getToken = async () => {
  if (tokenFirstGetTimes >= 3) {
    console.error("登录失败");
    return;
  }
  firstTokenGetting = true;
  tokenFirstGetTimes += 1;
  console.log("token开始首次获取");
  const res = await doLogin();
  if (res) {
    onAccessTokenFetched();
  } else {
    getToken();
  }
};

const checkHasToken = (url: string, method: any, data: any) => {
  // 本地没有token时获取token的函数,这需要添加一个开关，防止重复请求
  if (!firstTokenGetting) {
    getToken();
  }
  // 将当前的请求保存在观察者数组中
  const retryOriginalRequest = new Promise((resolve) => {
    addSubscriber(() => {
      resolve(requestBase(url, method, data));
    });
  });
  return retryOriginalRequest;
};

const checkTokenRefreshStatus = (url: string, method: any, data: any) => {
  // 刷新token的函数,这需要添加一个开关，防止重复请求
  if (isTokenRefreshing) {
    refreshToken();
  }
  isTokenRefreshing = false;
  // 将当前的请求保存在观察者数组中
  const retryOriginalRequest = new Promise((resolve) => {
    addSubscriber(() => {
      resolve(requestBase(url, method, data));
    });
  });
  return retryOriginalRequest;
};

const requestBase = (url: string, method: any, data: any) => {
  if (wrongAuth >= 5) {
    console.error("多个请求授权失败，重新登陆下？");
    return;
  }
  return new Promise((resolve, reject) => {
    wx.request({
      url: data ? url : url + "?" + qs.stringify(data),
      header: {
        "content-type": "application/json;charset=UTF-8;",
        authorization: `Bearer ${cache.get("access_token")}`,
      },
      method: method,
      data: data,
      success(res) {
        if (res && res.statusCode !== 200) {
          if (res.statusCode === 401) {
            wrongAuth++;
            try {
              if (!cache.directGet("access_token")) {
                resolve(checkHasToken(url, method, data));
              }
              // 注意此处如果过期了那么会直接被后端拦截，不会有code等信息，所以接口类不适用
              else if (
                res.data.detail === "身份认证信息未提供。" ||
                res.data.detail ===
                  "Authentication credentials were not provided."
              ) {
                resolve(checkTokenRefreshStatus(url, method, data));
              }
            } catch (e) {
              throw e;
            }
          }
        } else {
          if (res && res.data.code === 20000) {
            resolve(res);
            console.log("全局打印请求成功:", res);
          } else {
            reject(res);
            console.log("状态码非20000:", res);
          }
        }
      },
      fail(err) {
        reject(err);
        console.error("全局打印请求失败:", err);
      },
    });
  });
};

export const post = (url: string, data: any) => {
  return requestBase(url, "POST", data);
};

export const get = (url: string, data: any) => {
  return requestBase(url, "GET", data);
};