/*
 * visible line from origin to target. 
 * the visible part of line renders green, otherwise renders red.
 */

(function (window) {
	'use strict';

	function define_CesiumVisibleLine(){
		//Main object
		var CesiumVisibleLine = {};
		var vlhandler;
		var visibleLineEntityC = [];
		var hiddenLineEntityC = [];
		var originEntityC = [];
		var targetEntityC = [];
		var breakEntityC = [];
		var bodyEntityC = [];
		var visiblepolygonC = [];
		var isFirst = true;//是否为第一个点
		var vcisFirst = true;//是否为第一个点
		
		CesiumVisibleLine.drawLines = function(options) {
			var isVisible = false;
			var originPosition;//前一个点的坐标
		    var targetPosition;//当前点坐标
		    var bodyPosition;
		    var isFirst = true;//是否为第一个点
		    
			vlhandler = vlhandler && vlhandler.destroy();
			//前一个点与鼠标连线的entity
		    /*var dynamicLineEntity = options.viewer.entities.add({
		        id : 'dve'+new Date().getTime(),
		        polyline : {
		            width : 3,
		            material : options.drawColor,
		            show : true
		        }
		    });*/
		    
		    vlhandler = new Cesium.ScreenSpaceEventHandler(options.viewer.scene.canvas);
		    vlhandler.setInputAction(function(movement){
		    	if(isFirst){
		    		originPosition = options.viewer.scene.pickPosition(movement.position);
		    		var cartographic = Cesium.Cartographic.fromCartesian(originPosition);
		    		var height = cartographic.height;//观察者高度
		    		if(Number(height)<0){
		    			var ray = options.viewer.camera.getPickRay(movement.position);
		    			originPosition = options.viewer.scene.globe.pick(ray,options.viewer.scene);
		    		}
		    		cartographic = Cesium.Cartographic.fromCartesian(originPosition);
		    		height = cartographic.height;
			        var lng = Cesium.Math.toDegrees(cartographic.longitude);
			        var lat = Cesium.Math.toDegrees(cartographic.latitude);
		    		bodyPosition = Cesium.Cartesian3.fromDegrees(lng, lat, height+options.bodyHeight);
		            var originEntity = options.viewer.entities.add({
			            id: 'originEntity'+new Date().getTime(),
			            position : bodyPosition,
			            point : {
			                color : options.originColor,
			                pixelSize : 10,
			            }
			        });
		            var bodyEntity = options.viewer.entities.add({
			            id: 'bodyEntity'+new Date().getTime(),
			            polyline : {
				            width : 3,
				            material : options.bodyColor,
				            show : true
				        }
			        });
		            bodyEntity.polyline.positions = [originPosition,bodyPosition];
		            
		            isFirst = false;
		            bodyEntityC.push(bodyEntity);
		    		originEntityC.push(originEntity);
		        }else{
		        	//dynamicLineEntity.show = false;
		        	targetPosition = options.viewer.scene.pickPosition(movement.position);
		        	var cartographic = Cesium.Cartographic.fromCartesian(targetPosition);
		    		var height = cartographic.height;//观察者高度
		    		if(Number(height)<0){
		    			var ray = options.viewer.camera.getPickRay(movement.position);
		    			targetPosition = options.viewer.scene.globe.pick(ray,options.viewer.scene);
		    		}
		        	var targetEntity = options.viewer.entities.add({
			            id: 'targetEntity'+new Date().getTime(),
			            position : targetPosition,
			            point : {
			                color : options.targetColor,
			                pixelSize : 10,
			            }
			        });
		        	targetEntityC.push(targetEntity);
			        
		    		var breakpoint = computeVisible(bodyPosition,targetPosition,movement.position,options.viewer.scene,options.viewer);
		    		
		    		var visibleLineEntity = options.viewer.entities.add({
				        id : 'visibleLineEntity'+new Date().getTime(),
				        polyline : {
				            width : 3,
				            material : options.visibleColor,
				            show : true
				        }
				    });
		    		
		    		if(breakpoint){
		    			var hiddenLineEntity = options.viewer.entities.add({
					        id : 'hiddenLineEntity'+new Date().getTime(),
					        polyline : {
					            width : 3,
					            material : options.hiddenColor,
					            show : true
					        }
					    });
		    			visibleLineEntity.polyline.positions = [bodyPosition,breakpoint];
		    			hiddenLineEntity.polyline.positions = [breakpoint,targetPosition];
		    			visibleLineEntityC.push(visibleLineEntity);
			    		hiddenLineEntityC.push(hiddenLineEntity);
			    		var breakEntity = options.viewer.entities.add({
				            id: 'breakEntity'+new Date().getTime(),
				            position : breakpoint,
				            point : {
				                color : options.breakColor,
				                pixelSize : 10,
				            }
				        });
			    		breakEntityC.push(breakEntity);
			    		isVisible = false;
		    		}else{
		    			visibleLineEntity.polyline.positions = [bodyPosition,targetPosition];
		    			visibleLineEntityC.push(visibleLineEntity);
		    			isVisible = true;
		    		}
		    		//dynamicLineEntity.show = true;
		        }
		    },Cesium.ScreenSpaceEventType.LEFT_CLICK);
		    /*vlhandler.setInputAction(function(movement){
		        if(!isFirst){
		            //获取当前点的坐标
		        	targetPosition = options.viewer.scene.pickPosition(movement.endPosition);
		            if(targetPosition){
						dynamicLineEntity.polyline.positions = [originPosition,targetPosition];
		            }
		        }
		    },Cesium.ScreenSpaceEventType.MOUSE_MOVE);*/
		    vlhandler.setInputAction(function(){
		        //move事件监听
		        vlhandler = vlhandler && vlhandler.destroy();
		        isFirst = true;
		    },Cesium.ScreenSpaceEventType.RIGHT_CLICK);
		    
		    return isVisible;
		};
		
		function computeVisible(origin,target,movementpoi,scene,computeviewer){
			for (var i = 1; i < 101; i++) {
				var lon = Cesium.Math.lerp(origin.x, target.x, 0.01*i);
				var lat = Cesium.Math.lerp(origin.y, target.y, 0.01*i);
				var height = origin.z-(origin.z-target.z)*0.01*i;
				var position = new Cesium.Cartesian3(lon, lat, height);
				var clampPoi = scene.clampToHeight(position);
				if(clampPoi!=undefined){
					var cartographic = Cesium.Cartographic.fromCartesian(clampPoi);
					var heightclamp = cartographic.height;
					if(heightclamp<0){
						var ray = computeviewer.camera.getPickRay(movementpoi);
						clampPoi = computeviewer.scene.globe.pick(ray,scene);
					}
				}else{
					var ray = computeviewer.camera.getPickRay(movementpoi);
					clampPoi = computeviewer.scene.globe.pick(ray,scene);
				}
				if(clampPoi.z>=height){
					return position;
				}
			}
		}
		
		CesiumVisibleLine.removeLines = function(viewer){
			isFirst = true;
			vcisFirst = true;
			vlhandler = vlhandler && vlhandler.destroy();
			for ( var i = 0; i < visibleLineEntityC.length; i++) {
				viewer.entities.remove(visibleLineEntityC[i]);
			}
			for ( var j = 0; j < hiddenLineEntityC.length; j++) {
				viewer.entities.remove(hiddenLineEntityC[j]);
			}
			for ( var m = 0; m < originEntityC.length; m++) {
				viewer.entities.remove(originEntityC[m]);
			}
			for ( var n = 0; n < targetEntityC.length; n++) {
				viewer.entities.remove(targetEntityC[n]);
			}
			for ( var o = 0; o < breakEntityC.length; o++) {
				viewer.entities.remove(breakEntityC[o]);
			}
			for ( var p = 0; p < bodyEntityC.length; p++) {
				viewer.entities.remove(bodyEntityC[p]);
			}
			for ( var q = 0; q < visiblepolygonC.length; q++) {
				viewer.entities.remove(visiblepolygonC[q]);
			}
		};
		
		CesiumVisibleLine.drawCircles = function(options){
			var originPosition;//前一个点的坐标
		    var targetPosition;//当前点坐标
		    var bodyPosition;
		    var lng;
		    var lat;
		    var breakpointC=[];
		    var vcisFirst = true;//是否为第一个点
		    
		    vlhandler = vlhandler && vlhandler.destroy();
		    vlhandler = new Cesium.ScreenSpaceEventHandler(options.viewer.scene.canvas);
		    vlhandler.setInputAction(function(movement){
				if(vcisFirst){
					originPosition = options.viewer.scene.pickPosition(movement.position);
					var cartographic = Cesium.Cartographic.fromCartesian(originPosition);
					var height = cartographic.height;//观察者高度
					if(Number(height)<0){
						var ray = options.viewer.camera.getPickRay(movement.position);
						originPosition = options.viewer.scene.globe.pick(ray,options.viewer.scene);
					}
					cartographic = Cesium.Cartographic.fromCartesian(originPosition);
			        lng = Cesium.Math.toDegrees(cartographic.longitude);
			        lat = Cesium.Math.toDegrees(cartographic.latitude);
			        height = cartographic.height;//观察者高度
		    		bodyPosition = Cesium.Cartesian3.fromDegrees(lng, lat, height+options.bodyHeight);
		            var originEntity = options.viewer.entities.add({
			            id: 'originEntity'+new Date().getTime(),
			            position : bodyPosition,
			            point : {
			                color : options.originColor,
			                pixelSize : 10,
			            }
			        });
		            var bodyEntity = options.viewer.entities.add({
			            id: 'bodyEntity'+new Date().getTime(),
			            polyline : {
				            width : 3,
				            material : options.bodyColor,
				            show : true
				        }
			        });
		            bodyEntity.polyline.positions = [originPosition,bodyPosition];
		            
		            vcisFirst = false;
		            bodyEntityC.push(bodyEntity);
		    		originEntityC.push(originEntity);
				}else{
					//document.getElementById("loading").style.display = "block";
					targetPosition = options.viewer.scene.pickPosition(movement.position);
					var origincartographic = Cesium.Cartographic.fromCartesian(originPosition);
					var targetcartographic = Cesium.Cartographic.fromCartesian(targetPosition);
					var height = targetcartographic.height;
					if(Number(height)<0){
						var ray = options.viewer.camera.getPickRay(movement.position);
						targetPosition = options.viewer.scene.globe.pick(ray,options.viewer.scene);
					}
					targetcartographic = Cesium.Cartographic.fromCartesian(targetPosition);
					var geodesic = new Cesium.EllipsoidGeodesic();
					geodesic.setEndPoints(origincartographic, targetcartographic);
					var radius = geodesic.surfaceDistance;
					var targetEntity = options.viewer.entities.add({
			            id: 'targetEntity'+new Date().getTime(),
			            position : originPosition,
					    ellipse : {
					        semiMinorAxis : radius,
					        semiMajorAxis : radius,
					        height : targetcartographic.height,
					        fill : false,
					        outline : true,
					        outlineColor : options.targetColor,
					        outlineWidth : 1.5
					    }
			        });
		        	targetEntityC.push(targetEntity);
		        	
		        	var ddegree = radius/6378137;
		        	var lngr = lng*Math.PI/180;
		        	var latr = lat*Math.PI/180;
		        	for (var i = 0; i < 360; i=i+10) {
		        		/*var x = originPosition.x + radius*Math.sin(i*2*Math.PI/360);
		        		var y = originPosition.y + radius*Math.cos(i*2*Math.PI/360);
		        		var pointonCircle = Cesium.Cartesian3.fromElements(x,y,targetPosition.z);*/
		        		var ir = i*Math.PI/180;
		        		var y = Math.asin(Math.sin(latr)*Math.cos(ddegree)+Math.cos(latr)*Math.sin(ddegree)*Math.cos(ir));
		        		var x = lngr + Math.atan2(Math.sin(ir)*Math.sin(ddegree)*Math.cos(latr),
		        				Math.cos(ddegree)-Math.sin(latr)*Math.sin(y));
		        		var lononCircle = x*180/Math.PI;
		        		var latonCircle = y*180/Math.PI;
		        		var pointonCircle = Cesium.Cartesian3.fromDegrees(lononCircle,latonCircle,targetcartographic.height);
		        		var breakpoint = computeVisible(bodyPosition,pointonCircle,movement.position,options.viewer.scene,options.viewer);
		        		
		        		var visibleLineEntity = options.viewer.entities.add({
					        id : 'visibleLineEntity'+new Date().getTime(),
					        polyline : {
					            width : 3,
					            material : options.visibleColor,
					            show : true
					        }
					    });
		        		
		        		if(breakpoint){
			    			var hiddenLineEntity = options.viewer.entities.add({
						        id : 'hiddenLineEntity'+new Date().getTime(),
						        polyline : {
						            width : 3,
						            material : options.hiddenColor,
						            show : true
						        }
						    });
			    			visibleLineEntity.polyline.positions = [bodyPosition,breakpoint];
			    			hiddenLineEntity.polyline.positions = [breakpoint,pointonCircle];
			    			visibleLineEntityC.push(visibleLineEntity);
				    		hiddenLineEntityC.push(hiddenLineEntity);
				    		var breakEntity = options.viewer.entities.add({
					            id: 'breakEntity'+new Date().getTime(),
					            position : breakpoint,
					            point : {
					                color : options.breakColor,
					                pixelSize : 10,
					            }
					        });
				    		breakEntityC.push(breakEntity);
				    		breakpointC.push(breakpoint);
			    		}else{
			    			visibleLineEntity.polyline.positions = [bodyPosition,pointonCircle];
			    			visibleLineEntityC.push(visibleLineEntity);
			    			breakpointC.push(pointonCircle);
			    		}
		        	}
		        	var visiblepolygon = options.viewer.entities.add({
		        		id: 'visiblepolygon'+new Date().getTime(),
		        		polygon: {
		        			hierarchy : breakpointC,
		        			material : options.visiblePolygonColor,
		        		}
		        	});
		        	visiblepolygonC.push(visiblepolygon);
		        	//document.getElementById("loading").style.display = "none";
		        	//取消同一起始点多次分析时使用如下代码：
		        	//vlhandler = vlhandler && vlhandler.destroy();
		        	//vcisFirst = true;
				}
			},Cesium.ScreenSpaceEventType.LEFT_CLICK);
		    vlhandler.setInputAction(function(){
		        //move事件监听
		        vlhandler = vlhandler && vlhandler.destroy();
		        vcisFirst = true;
		    },Cesium.ScreenSpaceEventType.RIGHT_CLICK);
		};
		
		return CesiumVisibleLine;
	}
	
	if (typeof(CesiumVisibleLine) === 'undefined') {
		window.CesiumVisibleLine = define_CesiumVisibleLine();
	} else {
		console.log("CesiumVisibleLine already defined.");
	}
})(window);