function test() {
	return 1 + 1
}
/**
 * 获取两个经纬度之间的距离
 * @param lat1 第一点的纬度
 * @param lng1 第一点的经度
 * @param lat2 第二点的纬度
 * @param lng2 第二点的经度
 * @returns {Number}
 */
function getRad(d) {
	var PI = Math.PI;
	return d * PI / 180.0;
}

function getDistance(lat1, lng1, lat2, lng2) {
	var f = getRad((lat1 + lat2) / 2);
	var g = getRad((lat1 - lat2) / 2);
	var l = getRad((lng1 - lng2) / 2);
	var sg = Math.sin(g);
	var sl = Math.sin(l);
	var sf = Math.sin(f);
	var s, c, w, r, d, h1, h2;
	var a = 6378137.0; //The Radius of eath in meter.   
	var fl = 1 / 298.257;
	sg = sg * sg;
	sl = sl * sl;
	sf = sf * sf;
	s = sg * (1 - sl) + (1 - sf) * sl;
	c = (1 - sg) * (1 - sl) + sf * sl;
	w = Math.atan(Math.sqrt(s / c));
	r = Math.sqrt(s * c) / w;
	d = 2 * w * a;
	h1 = (3 * r - 1) / 2 / c;
	h2 = (3 * r + 1) / 2 / s;
	s = d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg));
	// s = s/1000;   
	s = s.toFixed(2); //指定小数点后的位数。   
	return s;
}

function ab2str(buf) {
	return String.fromCharCode.apply(null, new Uint16Array(buf));
}

function str2ab(str) {
	var buf = new ArrayBuffer(str.length * 2); // 2 bytes for each char
	var bufView = new Uint16Array(buf);
	for (var i = 0, strLen = str.length; i < strLen; i++) {
		bufView[i] = str.charCodeAt(i);
	}
	return buf;
}
function distance(res){
	let ALWAYS = [];
	res.markes.forEach((item,index)=>{
		 let distance =  utils.getDistance(res.coordinate.latitude,res.coordinate.longitude,item.latitude, item.longitude);
		 if(distance<1000){
			 ALWAYS.push(index)
		 }
	});
	return ALWAYS
}

module.exports = {
	distance:distance,
	test: test,
	ab2str: ab2str,
	str2ab: str2ab,
	getDistance: getDistance
}