import { axios } from "./libs";
let cities = [];
const cityIndexMap = { 广州市: "G", 南京市: "N" };
const init = async () => {
  const [malls] = await Promise.all([axios.get("/Api/Coupon/MallList")]);
  cities = Object.values(
    malls.reduce((acc, nxt) => {
      const mall = {
        name: nxt.name,
        code: nxt.mallCode,
      };
      if (acc[nxt.areaName]) {
        acc[nxt.areaName].malls.push(mall);
      } else
        acc[nxt.areaName] = {
          name: nxt.areaName,
          malls: [mall],
          index: cityIndexMap[nxt.areaName],
        };
      return acc;
    }, {})
  );
  cities.sort((a, b) => a.index.charCodeAt(0) - b.index.charCodeAt(0));
};
export const getCities = async () => {
  if (!cities.length) {
    await init();
    return cities;
  } else return cities;
};

const toRadians = (lonlat) => (lonlat / 180) * Math.PI;
const ToDigits = (radian) => (radian / Math.PI) * 180;
const R = 6371;
const r = 50;
const offset = Math.asin(r / 2 / R) * 2;
const getRestrict = (lon, lat) => {
  const lonR = toRadians(lon);
  const latR = toRadians(lat);
  return [lonR - offset, lonR + offset, latR - offset, latR + offset].map(
    ToDigits
  );
};
const getMall = ([minLon, maxLon, minLat, maxLat]) =>
  new Promise((resolve) => {});

export const getNearMall = async ({ longitude, latitude }) => {
  const restrict = getRestrict(longitude, latitude);
  return (await getCities())[0];
};