import {
  axios
} from './libs'
let cities = []
const init = async () => {
  const db = wx.cloud.database()
  const [{
    data: {
      value: cityIndexMap
    }
  }, malls] = await Promise.all([db.collection('config').doc('cityIndexMap').get(), 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]
}