/**
 * 获取坐标的是否在围栏内
 * @param { { lat: number, lng: number } } point 坐标
 * @param { { lat: number, lng: number }[] } APoints 围栏
 * @returns { boolean } 在围栏内返回true，否则false
 */
export function isPointInPolygon(point, APoints) {
  const { lat, lng } = point
  let iSum = 0
  let dLon1, dLon2, dLat1, dLat2, dLon
  if (APoints.length < 3) return false
  const iCount = APoints.length
  for (let i = 0; i < iCount; i++) {
    if (i == iCount - 1) {
      dLon1 = APoints[i].lng
      dLat1 = APoints[i].lat
      dLon2 = APoints[0].lng
      dLat2 = APoints[0].lat
    } else {
      dLon1 = APoints[i].lng
      dLat1 = APoints[i].lat
      dLon2 = APoints[i + 1].lng
      dLat2 = APoints[i + 1].lat
    }
    //以下语句判断A点是否在边的两端点的水平平行线之间，在则可能有交点，开始判断交点是否在左射线上
    if ((lat >= dLat1 && lat < dLat2) || (lat >= dLat2 && lat < dLat1)) {
      if (Math.abs(dLat1 - dLat2) > 0) {
        //得到 A点向左射线与边的交点的x坐标：
        dLon = dLon1 - ((dLon1 - dLon2) * (dLat1 - lat)) / (dLat1 - dLat2)
        if (dLon < lng) iSum++
      }
    }
  }
  if (iSum % 2 != 0) return true
  return false
}

/**
 * 队列执行函数
 * @param {Function} asyncFunction 异步函数
 * @param {Array} items 数据数组
 * @param {Number} maxConcurrent 最大并行
 * @returns
 */
export function executeAsyncFunctionInQueue(
  asyncFunction,
  items,
  maxConcurrent = 10
) {
  items = items.slice()
  return new Promise((resolve) => {
    const total = items.length
    const results = []
    const executing = new Set()
    const executeNext = async () => {
      if (items.length === 0) {
        return
      }
      const currentIndex = total - items.length
      const item = items.shift()
      const promise = asyncFunction(item, currentIndex)
        .then((result) => {
          results.push(result)
        })
        .catch((error) => {
          results.push(error)
        })
        .finally(() => {
          executing.delete(promise)
          if (executing.size || items.length) {
            executeNext()
          } else {
            resolve(results)
          }
        })
      executing.add(promise)
    }
    while (executing.size < maxConcurrent && items.length > 0) {
      executeNext()
    }
  })
}

/**
 * 获取多个经纬度适合的缩放等级及中心点坐标
 * @param { { lat: number, lng: number }[] } points 多个经纬度
 * @returns { { center: { lat: number, lng: number }, zoom: number } } 适合的缩放等级
 */
export function getPointsCalculateZoom(points) {
  if(!points.length) throw new Error('请传入经纬度')

  const getZoom = (minPoint, maxPoint) => {
    const zoom = [
      50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 25000, 50000, 100000,
      200000, 500000, 1000000, 2000000
    ] //级别18到3。
    const distance = getDistance(minPoint, maxPoint)
    for (let i = 0, zoomLen = zoom.length; i < zoomLen; i++) {
      if (zoom[i] - distance > 0) {
        // 不同平台可能不太准，可在此处进行调整，或在调用完成后进行调整
        return 18 - i + 1
      }
    }
  }
  let maxLng = points[0].lng
  let minLng = points[0].lng
  let maxLat = points[0].lat
  let minLat = points[0].lat
  let res
  for (let i = points.length - 1; i >= 0; i--) {
    res = points[i]
    if (res.lng > maxLng) maxLng = res.lng
    if (res.lng < minLng) minLng = res.lng
    if (res.lat > maxLat) maxLat = res.lat
    if (res.lat < minLat) minLat = res.lat
  }
  const cenLng = (maxLng + minLng) / 2
  const cenLat = (maxLat + minLat) / 2
  const zoom = getZoom(
    { lng: minLng, lat: minLat },
    { lng: maxLng, lat: maxLat }
  )
  return {
    center: {
      lng: cenLng,
      lat: cenLat
    },
    zoom
  }
}

`星期${'日一二三四五六'.charAt(new Date().getDay())}`