/* 引入Cesium */
// import * as Cesium from 'Cesium';

/**
 * 创建随机数
 * @return {String} 唯一标识符
 */
export function setSessionid(num) {
	let len = num || 32;
	let chars = "ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678";
	let maxPos = chars.length;
	let pwd = "";
	for (let i = 0; i < len; i++) {
		pwd += chars.charAt(Math.floor(Math.random() * maxPos));
	}
	return pwd;
}

/**
 * 创建GUID
 * @return {String} 唯一标识符
 */
export function guid() {
	function S4() {
		return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
	}
	return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
}

/**
 * 创建GUID
 * @return {String} 唯一标识符
 */
export function getGuid(removeMinus) {
	let d = new Date().getTime();
	let uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
		const r = (d + Math.random() * 16) % 16 | 0;
		d = Math.floor(d / 16);
		return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16);
	});
	if (removeMinus) {
		uuid = uuid.replace(/-/g, "");
	}
	return uuid;
}

/**
 * 获取非精确的地形的高度(一个点)
 * sampleTerrain :   获取非精确的地形的高度
 * @param {Object} viewer 三维场景
 * @param {Object} options 
 * @param {Number} options.longitude 经度，以度为单位
 * @param {Number} options.latitude 纬度，以度为单位
 * @param {Number} options.level 指定地形级别
 */
export function getHeigthByLngLat(viewer, options) {

	if (!viewer) throw new Cesium.DeveloperError('no viewer object!');

	if (!Cesium.defined(options.longitude) && !Cesium.defined(options.latitude)) {
		throw new Cesium.DeveloperError("longitude and  latitude are required.");
	}

	options.level = Cesium.defaultValue(options.level, 11);

	let positions = Cesium.Cartographic.fromDegrees(options.longitude, options.latitude); //经纬度转为世界坐标
	let terrainProvider = viewer.terrainProvider;

	//异步函数
	return new Promise((resolve, reject) => {
		//获取指定地形级别的高程
		new Cesium.sampleTerrain(terrainProvider, options.level, [positions]).then(function(updatedPositions) {
			if (updatedPositions) {
				resolve(updatedPositions[0].height)
			}
		})
	})
}

/**
 * 获取非精确的地形的高度（多点）
 * sampleTerrain :   获取非精确的地形的高度
 * @param {Object} viewer 三维场景
 * @param {Object} options
 * @param {Number} options.points  [[lng,lat],[lng,lat],......]  
 * @param {Number} options.level 指定地形级别
 */
export function getHeigthByPoints(viewer, options) {

	if (!viewer) throw new Cesium.DeveloperError('no viewer object!');

	if (!Cesium.defined(options)) {
		throw new Cesium.DeveloperError("options is required.");
	}

	options.level = Cesium.defaultValue(options.level, 11);

	let positions = [];
	let points = options.points;
	for (let i = 0; i < points.length; i++) {
		let pointX = points[i][0];
		let pointY = points[i][1];
		positions.push(
			Cesium.Cartographic.fromDegrees(pointX, pointY) //经纬度转为世界坐标
		);
	}

	let terrainProvider = viewer.terrainProvider;

	//异步函数
	return new Promise((resolve, reject) => {
		//获取指定地形级别的高程
		new Cesium.sampleTerrain(terrainProvider, options.level, positions).then(function(updatedPositions) {
			if (updatedPositions) {
				resolve(updatedPositions);
			}
		});
	});
}

/**
 * 获取尽量精确的地形的高度（多点）
 * sampleTerrainMostDetailed： 获取尽量精确的地形的高度
 * @param {Object} viewer 三维场景
 * @param {Number} points  [[lng,lat],[lng,lat],......]  
 */
export function getHeigthByPointsMostDetailed(viewer, points) {

	if (!viewer) throw new Cesium.DeveloperError('no viewer object!');

	if (!Cesium.defined(points)) {
		throw new Cesium.DeveloperError("points is required.");
	}

	let positions = [];
	for (let i = 0; i < points.length; i++) {
		let pointX = points[i][0];
		let pointY = points[i][1];
		positions.push(Cesium.Cartographic.fromDegrees(pointX, pointY)); //经纬度转为世界坐标;
	}

	let terrainProvider = viewer.terrainProvider;

	//异步函数
	return new Promise((resolve, reject) => {
		let promise = new Cesium.sampleTerrainMostDetailed(terrainProvider, positions);
		promise.then(function(updatedPositions) {
			// positions[0].height and positions[1].height have been updated.
			// updatedPositions is just a reference to positions.
			resolve(updatedPositions);
		});
	})
}

/**
 * 获取尽量精确的地形的高度（单点）
 * sampleTerrainMostDetailed： 获取尽量精确的地形的高度
 * @param {Object} viewer 三维场景
 * @param {Number} points  [lng,lat]
 */
export function getHeigthByPointMostDetailed(viewer, points) {

	if (!viewer) throw new Cesium.DeveloperError('no viewer object!');

	if (!Cesium.defined(points)) {
		throw new Cesium.DeveloperError("points is required.");
	}

	let positions = Cesium.Cartographic.fromDegrees(points[0], points[1]); //经纬度转为世界坐标;

	let terrainProvider = viewer.terrainProvider;

	//异步函数
	return new Promise((resolve, reject) => {
		let promise = new Cesium.sampleTerrainMostDetailed(terrainProvider, positions);
		promise.then(function(updatedPositions) {
			resolve(updatedPositions);
		});
	})
}

import '../../Assets/styles/tooltip.css';
export function createTooltip(frameDiv) {

	var tooltip = function(frameDiv) {

		var div = document.createElement('DIV');
		div.className = "twipsy right";

		var arrow = document.createElement('DIV');
		arrow.className = "twipsy-arrow";
		div.appendChild(arrow);

		var title = document.createElement('DIV');
		title.className = "twipsy-inner";
		div.appendChild(title);

		this._div = div;
		this._title = title;

		// add to frame div and display coordinates
		frameDiv.appendChild(div);
	}

	tooltip.prototype.setVisible = function(visible) {
		this._div.style.display = visible ? 'block' : 'none';
	}

	tooltip.prototype.showAt = function(position, message) {
		if (position && message) {
			this.setVisible(true);
			this._title.innerHTML = message;
			this._div.style.left = position.x + 10 + "px";
			this._div.style.top = (position.y - this._div.clientHeight / 2) + "px";
		}
	}

	return new tooltip(frameDiv);
}