import DomUtil from './common/doms.js'

import '../Assets/styles/StatusBar.css';

/**
 * 状态栏
 */
class StatusBar {
	/**
	 * 状态栏工具类
	 * @param {Viewer} viewer - 三维场景
	 */
	constructor(viewer) {
		if (!viewer) throw new Error('viewer is required!');
		this._viewer = viewer;
		this._show = false; //初始化显示状态
		this._handler;

		this._posX;
		this._posY;
		this._posZ;
		this._cameraHeight;
		this._pitch;
		this._heading;
		this._scale;

		this.initListener()
	}
	/**
	 * 状态栏参数
	 * @readonly
	 */
	get params() {
		return {
			posX: this._posX, //经度
			posY: this._posY, //维度
			posZ: this._posZ, //模型高度
			cameraHeight: this._cameraHeight, //相机视角高度
			pitch: this._pitch, //俯仰角
			heading: this._heading, //方向
			scale: this._scale //比例尺
		}
	}
	get statusDom() {
		let innerHtml = `
		<span class="status-scale">
			比例尺：
			<span class="scale-border">
				${this._scale}
			</span>
		</span>
		<span class="status-position">
			<span id="status_spaceInfo">空间信息</span>
			刷帧率：<span id="status_ms"></span>|<span id="status_fps"></span>
		</span>
		`
		return innerHtml
	}
	/**
	 * 控制显示Boolean常量
	 * @constant
	 */
	get show() {
		return this._show
	}
	set show(bool) {
		bool ? this.createStatusBar() : this.removeStatusBar()
		this._show = bool
	}
	initListener() {
		const $this = this
		const scene = this._viewer.scene
		this._scaleListener = function() {
			let width = scene.canvas.clientWidth
			let height = scene.canvas.clientHeight
			let left = scene.camera.getPickRay(
				new Cesium.Cartesian2((width / 2) | 0, height - 1)
			)
			let right = scene.camera.getPickRay(
				new Cesium.Cartesian2((1 + width / 2) | 0, height - 1)
			)
			let globe = scene.globe
			let leftPosition = globe.pick(left, scene)
			let rightPosition = globe.pick(right, scene)
			if (leftPosition && rightPosition) {
				let geodesic = new Cesium.EllipsoidGeodesic()
				let leftCartographic = globe.ellipsoid.cartesianToCartographic(leftPosition)
				let rightCartographic = globe.ellipsoid.cartesianToCartographic(rightPosition)
				geodesic.setEndPoints(leftCartographic, rightCartographic)
				let distance = geodesic.surfaceDistance
				let curScaleNum = $this.closest(distance / 10)
				if (curScaleNum < 1) {
					$this._scale = curScaleNum * 1000 + 'm'
				} else {
					$this._scale = curScaleNum + 'km'
				}
			}

			document.getElementsByClassName("scale-border")[0].innerText = $this._scale;

			if (document.getElementsByClassName("cesium-performanceDisplay-ms").length > 0) {
				document.getElementById("status_ms").innerText = document.getElementsByClassName("cesium-performanceDisplay-ms")[0].innerText;
			}
			if (document.getElementsByClassName("cesium-performanceDisplay-fps").length > 0) {
				document.getElementById("status_fps").innerText = document.getElementsByClassName("cesium-performanceDisplay-fps")[0].innerText;
			}

		}
	}
	createStatusBar() {
		const _delegate = this._viewer
		this.initHandler(_delegate)
		this.initScale(_delegate, true)
		this._domContainer = DomUtil.create(
			'div',
			'lk-status-bar',
			document.getElementById(this._viewer._container.id)
		)

		this._domContainer.innerHTML = this.statusDom;

		// var canvas = this._viewer.canvas; // 获取画布
		// this._domContainer.style.width = canvas.width + "px";
		// console.log('画布', canvas.width)

	}
	removeStatusBar() {
		this.initScale(this._viewer, false)
		if (this._handler) {
			this._handler.destroy()
		}
		if (this._domContainer) {
			DomUtil.remove(this._domContainer)
		}
	}
	initHandler(viewer) {
		const $this = this
		this._handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas)
		const mouseOverHandler = function(movement) {

			/* 识别屏幕位置 */
			let loc = $this._getScreenClickPositionAndHeight(movement.endPosition);

			if (!Cesium.defined(loc)) return;

			if (!loc.lng) return;

			$this._posX = loc.lng.toFixed(8);
			$this._posY = loc.lat.toFixed(8);
			$this._posZ = loc.height.toFixed(2);

			// const cameraH = viewer.camera.positionCartographic.height
			// $this._cameraHeight =
			// 	cameraH < 1000 ?
			// 	cameraH.toFixed(2) + 'm' :
			// 	(cameraH / 1000).toFixed(2) + 'km';

			// $this._pitch = Number(viewer.scene.camera.pitch).toFixed(2);
			// $this._heading = Number(viewer.scene.camera.heading).toFixed(2);

			document.getElementById("status_spaceInfo").innerHTML = `
				<span>经度：${$this._posX}</span>
				<span>纬度：${$this._posY}</span>
				<span>高度：${$this._posZ}</span>
				`;

		}
		this._handler.setInputAction(
			mouseOverHandler,
			Cesium.ScreenSpaceEventType.MOUSE_MOVE
		)
	}
	initScale(viewer, bool) {
		const scene = viewer.scene
		bool
			?
			scene.postRender.addEventListener(this._scaleListener) :
			scene.postRender.removeEventListener(this._scaleListener)
	}
	closest(num) {
		const scaleList = [
			0.001,
			0.002,
			0.003,
			0.005,
			0.01,
			0.015,
			0.02,
			0.025,
			0.03,
			0.035,
			0.04,
			0.045,
			0.05,
			0.06,
			0.07,
			0.08,
			0.09,
			0.1,
			0.12,
			0.15,
			0.2,
			0.25,
			0.3,
			0.5,
			1,
			2,
			3,
			5,
			10,
			15,
			20,
			25,
			30,
			35,
			40,
			45,
			50,
			60,
			70,
			80,
			90,
			100,
			120,
			150,
			200,
			250,
			300,
			500,
			1000,
			2000,
			5000,
			10000,
			100000,
			500000,
			1000000
		]
		let ret = scaleList[0]
		let distance = Math.abs(ret - num)
		for (let i = 1; i < scaleList.length; i++) {
			let newDistance = Math.abs(scaleList[i] - num)
			if (newDistance < distance) {
				distance = newDistance
				ret = scaleList[i]
			}
		}
		return ret
	}

	/**
	 * 根据地形或实景或模型检测当前屏幕位置的经纬度及高度
	 * @ignore 生成方法时不对外公开
	 * @param {JSON} screenPoint 屏幕坐标
	 * @param {Number} screenPoint.x 屏幕坐标x
	 * @param {Number} screenPoint.y 屏幕坐标y
	 * @return {JSON} 位置信息{lng,lat,height}
	 */
	_getScreenClickPositionAndHeight(screenPoint) {
		var lng = undefined,
			lat = undefined,
			height = undefined;

		/* 从相机位置到 windowPosition 处的像素创建射线在世界坐标系中 */
		var ray = this._viewer.scene.camera.getPickRay(screenPoint);
		/* 找到射线与渲染的地球表面之间的交点 */
		var position = this._viewer.scene.globe.pick(ray, this._viewer.scene);
		if (position) {
			/* 获取地理位置的制图表达 */
			var cartographic = Cesium.Ellipsoid.WGS84.cartesianToCartographic(position);
			cartographic = Cesium.Cartographic.fromCartesian(position);
			/* 查询屏幕位置的要素 */
			var feature = this._viewer.scene.pick(screenPoint);
			if (feature === undefined && Cesium.defined(cartographic)) {
				lng = this._arcToDegree(cartographic.longitude);
				lat = this._arcToDegree(cartographic.latitude);
				height = cartographic.height;
			} else {
				var cartesian = this._viewer.scene.pickPosition(screenPoint);
				if (Cesium.defined(cartesian)) {
					var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
					if (Cesium.defined(cartographic)) {
						lng = this._arcToDegree(cartographic.longitude);
						lat = this._arcToDegree(cartographic.latitude);
						height = cartographic.height;
					}
				}
			}
		}

		/* 返回结果 */
		return {
			lng: lng,
			lat: lat,
			height: height,
		}
	}

	/**
	 * 弧度转度
	 * @ignore 生成方法时不对外公开
	 * @param {Number} arc 弧度
	 * @return {Number} 角度
	 */
	_arcToDegree(arc) {
		return arc / Math.PI * 180;
	}
}

export default StatusBar