const formatTime = date => {
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()

  return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':')
}

const formatNumber = n => {
  n = n.toString()
  return n[1] ? n : '0' + n
}

//  获取当前页url
const getCurrentPageUrl = () => {
  let pages = getCurrentPages();
  let currentPage = pages[pages.length - 1];
  let url = '/' + currentPage.route;
  let options = currentPage.options;
  for (let key in options) {
    url += (url.indexOf('?') >= 0 ? '&' : '?') + `${key}=${options[key]}`;
  }
  return url;
}

const setTimeOutStorage = (key,value,timeout) => {
  let timestamp = Date.parse(new Date());
  wx.setStorageSync(key,
      {
        'value': value,
        'timeout': timestamp + timeout
      })
}

const getTimeoutStorage = (key) => {
  // 当前时间
  let timestamp = Date.parse(new Date());
  // 缓存中的过期时间
  let data = wx.getStorageSync(key);
  let data_expiration = data.timeout;
  let value = data.value;
  if (data_expiration) {
    // 如果超时了，清除缓存，重新登录
    if (timestamp > data_expiration) {
      wx.removeStorageSync(key);
      return null;
    }
  }
  return value;
}

// 计算两点之间的距离（返回米）
const getDistance = (lat1, lng1, lat2, lng2) => {
  const radLat1 = lat1 * Math.PI / 180.0;
  const radLat2 = lat2 * Math.PI / 180.0;
  const a = radLat1 - radLat2;
  const b = lng1 * Math.PI / 180.0 - lng2 * Math.PI / 180.0;
  let s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
  s = s * 6378.137; // 地球半径，千米
  s = Math.round(s * 10000) / 10; // 换算成米
  return s;
}

module.exports = {
  formatTime: formatTime,
  getCurrentPageUrl: getCurrentPageUrl,
  setTimeOutStorage: setTimeOutStorage,
  getTimeoutStorage: getTimeoutStorage,
  getDistance: getDistance
}