/**  
* @fileoverview GeoUtils类提供若干几何算法，用来帮助用户判断点与矩形、  
* 圆形、多边形线、多边形面的关系,并提供计算折线长度和多边形的面积的公式。   
* 主入口类是<a href="symbols/BMapLib.GeoUtils.html">GeoUtils</a>，  
* 基于Baidu Map API 1.2。  
*  
* @author Baidu Map Api Group   
* @version 1.2  
*/    
    
//BMapLib.GeoUtils.degreeToRad(Number)    
//将度转化为弧度    
    
//BMapLib.GeoUtils.getDistance(Point, Point)    
//计算两点之间的距离,两点坐标必须为经纬度    
    
//BMapLib.GeoUtils.getPolygonArea(polygon)    
//计算多边形面或点数组构建图形的面积,注意：坐标类型只能是经纬度，且不适合计算自相交多边形的面积(封闭的面积)    
    
//BMapLib.GeoUtils.getPolylineDistance(polyline)    
//计算折线或者点数组的长度    
    
//BMapLib.GeoUtils.isPointInCircle(point, circle)    
//判断点是否在圆形内    
    
//BMapLib.GeoUtils.isPointInPolygon(point, polygon)    
//判断点是否多边形内    
    
//BMapLib.GeoUtils.isPointInRect(point, bounds)    
//判断点是否在矩形内    
    
//BMapLib.GeoUtils.isPointOnPolyline(point, polyline)    
//判断点是否在折线上    
    
//BMapLib.GeoUtils.radToDegree(Number)    
//将弧度转化为度    
 
function getCenterPoint(path)
{
    //var path = e.;//Array<Point> 返回多边型的点数组
    //var ret=parseFloat(num1)+parseFloat(num2);  
    var x = 0.0;
    var y = 0.0;
    for(var i=0;i<path.length;i++){
         x=x+ parseFloat(path[i].lng);
         y=y+ parseFloat(path[i].lat);
    }
    x=x/path.length;
    y=y/path.length;
    return new BMap.Point(x,y);
}


/**   
* @namespace BMap的所有library类均放在BMapLib命名空间下  
*/    
var BMapLib =  {};    
(function () {    

/**  
* 地球半径  
*/    
var EARTHRADIUS = 6370996.81;    

/**   
* @exports GeoUtils as BMapLib.GeoUtils   
*/    
var GeoUtils =    
/**  
* GeoUtils类，静态类，勿需实例化即可使用  
* @class GeoUtils类的<b>入口</b>。  
* 该类提供的都是静态方法，勿需实例化即可使用。       
*/    
 BMapLib.GeoUtils = function () {    
 }    

/**  
* 判断点是否在矩形内  
* @param {Point} point 点对象  
* @param {Bounds} bounds 矩形边界对象  
* @returns {Boolean} 点在矩形内返回true,否则返回false  
*/    
GeoUtils.isPointInRect = function (point, bounds) {    
    //检查类型是否正确    
    if (!(point instanceof BMap.Point) ||    
         !(bounds instanceof BMap.Bounds)) {    
        return false;    
    }    
    var sw = bounds.getSouthWest(); //西南脚点    
    var ne = bounds.getNorthEast(); //东北脚点    
    return (point.lng >= sw.lng && point.lng <= ne.lng && point.lat >= sw.lat && point.lat <= ne.lat);    
}    

/**  
* 判断点是否在圆形内  
* @param {Point} point 点对象  
* @param {Circle} circle 圆形对象  
* @returns {Boolean} 点在圆形内返回true,否则返回false  
*/    
GeoUtils.isPointInCircle = function (point, circle) {    
    //检查类型是否正确    
    if (!(point instanceof BMap.Point) ||    
        !(circle instanceof BMap.Circle)) {    
        return false;    
    }    

    //point与圆心距离小于圆形半径，则点在圆内，否则在圆外    
    var c = circle.getCenter();    
    var r = circle.getRadius();    

    var dis = GeoUtils.getDistance(point, c);    
    if (dis <= r) {    
        return true;    
    } else {    
        return false;    
    }    
}    

/**  
* 判断点是否在折线上  
* @param {Point} point 点对象  
* @param {Polyline} polyline 折线对象  
* @returns {Boolean} 点在折线上返回true,否则返回false  
*/    
GeoUtils.isPointOnPolyline = function (point, polyline) {    
    //检查类型    
    if (!(point instanceof BMap.Point) ||    
         !(polyline instanceof BMap.Polyline)) {    
        return false;    
    }    

    //首先判断点是否在线的外包矩形内，如果在，则进一步判断，否则返回false    
    var lineBounds = polyline.getBounds();    
    if (!this.isPointInRect(point, lineBounds)) {    
        return false;    
    }    

    //判断点是否在线段上，设点为Q，线段为P1P2 ，    
    //判断点Q在该线段上的依据是：( Q - P1 ) × ( P2 - P1 ) = 0，且 Q 在以 P1，P2为对角顶点的矩形内    
    var pts = polyline.getPath();    
    for (var i = 0; i < pts.length - 1; i++) {    
        var curPt = pts[i];    
        var nextPt = pts[i + 1];    
        //首先判断point是否在curPt和nextPt之间，即：此判断该点是否在该线段的外包矩形内    
        if (point.lng >= Math.min(curPt.lng, nextPt.lng) && point.lng <= Math.max(curPt.lng, nextPt.lng) &&    
             point.lat >= Math.min(curPt.lat, nextPt.lat) && point.lat <= Math.max(curPt.lat, nextPt.lat)) {    
            //判断点是否在直线上公式    
            var precision = (curPt.lng - point.lng) * (nextPt.lat - point.lat) - (nextPt.lng - point.lng) * (curPt.lat - point.lat);    
            if (precision < 2e-10 && precision > -2e-10) {//实质判断是否接近0    
                return true;    
            }    
        }    
    }    
    return false;    
}    

/**  
* 判断点是否多边形内  
* @param {Point} point 点对象  
* @param {Polyline} polygon 多边形对象  
* @returns {Boolean} 点在多边形内返回true,否则返回false  
*/    
GeoUtils.isPointInPolygon = function (point, polygon) {    
    //检查类型    
    if (!(point instanceof BMap.Point) ||    
         !(polygon instanceof BMap.Polygon)) {    
        return false;    
    }    

    //首先判断点是否在多边形的外包矩形内，如果在，则进一步判断，否则返回false    
    var polygonBounds = polygon.getBounds();    
    if (!this.isPointInRect(point, polygonBounds)) {    
        return false;    
    }    

    var pts = polygon.getPath(); //获取多边形点    

    //下述代码来源：http://paulbourke.net/geometry/insidepoly/，进行了部分修改    
    //基本思想是利用射线法，计算射线与多边形各边的交点，如果是偶数，则点在多边形外，否则    
    //在多边形内。还会考虑一些特殊情况，如点在多边形顶点上，点在多边形边上等特殊情况。    

    var N = pts.length;    
    var boundOrVertex = true; //如果点位于多边形的顶点或边上，也算做点在多边形内，直接返回true    
    var intersectCount = 0; //cross points count of x     
    var precision = 2e-10; //浮点类型计算时候与0比较时候的容差    
    var p1, p2; //neighbour bound vertices    
    var p = point; //测试点    

    p1 = pts[0]; //left vertex            
    for (var i = 1; i <= N; ++i) {//check all rays                
        if (p.equals(p1)) {    
            return boundOrVertex; //p is an vertex    
        }    

        p2 = pts[i % N]; //right vertex                
        if (p.lat < Math.min(p1.lat, p2.lat) || p.lat > Math.max(p1.lat, p2.lat)) {//ray is outside of our interests                 
            p1 = p2;    
            continue; //next ray left point    
        }    
        if (p.lat > Math.min(p1.lat, p2.lat) && p.lat < Math.max(p1.lat, p2.lat)) {//ray is crossing over by the algorithm (common part of)    
            if (p.lng <= Math.max(p1.lng, p2.lng)) {//x is before of ray                        
                if (p1.lat == p2.lat && p.lng >= Math.min(p1.lng, p2.lng)) {//overlies on a horizontal ray    
                    return boundOrVertex;    
                }    

                if (p1.lng == p2.lng) {//ray is vertical             


                    if (p1.lng == p.lng) {//overlies on a vertical ray    
                        return boundOrVertex;    
                    } else {//before ray    
                        ++intersectCount;    
                    }    
                } else {//cross point on the left side               


                    var xinters = (p.lat - p1.lat) * (p2.lng - p1.lng) / (p2.lat - p1.lat) + p1.lng; //cross point of lng                  


                    if (Math.abs(p.lng - xinters) < precision) {//overlies on a ray    
                        return boundOrVertex;    
                    }    

                    if (p.lng < xinters) {//before ray    
                        ++intersectCount;    
                    }    
                }    
            }    
        } else {//special case when ray is crossing through the vertex                    
            if (p.lat == p2.lat && p.lng <= p2.lng) {//p crossing over p2                        
                var p3 = pts[(i + 1) % N]; //next vertex             


                if (p.lat >= Math.min(p1.lat, p3.lat) && p.lat <= Math.max(p1.lat, p3.lat)) {//p.lat lies between p1.lat & p3.lat    
                    ++intersectCount;    
                } else {    
                    intersectCount += 2;    
                }    
            }    
        }    
        p1 = p2; //next ray left point    
    }    

    if (intersectCount % 2 == 0) {//偶数在多边形外    
        return false;    
    } else { //奇数在多边形内    
        return true;    
    }    
}    

/**  
* 将度转化为弧度  
* @param {degree} Number 度       
* @returns {Number} 弧度  
*/    
GeoUtils.degreeToRad = function (degree) {    
    return Math.PI * degree / 180;    
}    

/**  
* 将弧度转化为度  
* @param {radian} Number 弧度       
* @returns {Number} 度  
*/    
GeoUtils.radToDegree = function (rad) {    
    return (180 * rad) / Math.PI;    
}    

/**  
* 将v值限定在a,b之间，纬度使用  
*/    
function _getRange(v, a, b) {    
    if (a != null) {    
        v = Math.max(v, a);    
    }    
    if (b != null) {    
        v = Math.min(v, b);    
    }    
    return v;    
}    

/**  
* 将v值限定在a,b之间，经度使用  
*/    
function _getLoop(v, a, b) {    
    while (v > b) {    
        v -= b - a    
    }    
    while (v < a) {    
        v += b - a    
    }    
    return v;    
}    

/**  
* 计算两点之间的距离,两点坐标必须为经纬度  
* @param {point1} Point 点对象  
* @param {point2} Point 点对象  
* @returns {Number} 两点之间距离，单位为米  
*/    
GeoUtils.getDistance = function (point1, point2) {    
    //判断类型
    // debugger;    
    // if (!(point1 instanceof BMap.Point) ||    
    //      !(point2 instanceof BMap.Point)) {    
    //     return 0;    
    // }    

    point1.lng = _getLoop(point1.lng, -180, 180);    
    point1.lat = _getRange(point1.lat, -74, 74);    
    point2.lng = _getLoop(point2.lng, -180, 180);    
    point2.lat = _getRange(point2.lat, -74, 74);    

    var x1, x2, y1, y2;    
    x1 = GeoUtils.degreeToRad(point1.lng);    
    y1 = GeoUtils.degreeToRad(point1.lat);    
    x2 = GeoUtils.degreeToRad(point2.lng);    
    y2 = GeoUtils.degreeToRad(point2.lat);    

    return EARTHRADIUS * Math.acos((Math.sin(y1) * Math.sin(y2) + Math.cos(y1) * Math.cos(y2) * Math.cos(x2 - x1)));    
}    

/**  
* 计算折线或者点数组的长度  
* @param {Polyline|Array<Point>} polyline 折线对象或者点数组  
* @returns {Number} 折线或点数组对应的长度  
*/    
GeoUtils.getPolylineDistance = function (polyline) {    
    //检查类型    
    if (polyline instanceof BMap.Polyline ||    
         polyline instanceof Array) {    
        //将polyline统一为数组    
        var pts;    
        if (polyline instanceof BMap.Polyline) {    
            pts = polyline.getPath();    
        } else {    
            pts = polyline;    
        }    

        if (pts.length < 2) {//小于2个点，返回0    
            return 0;    
        }    

        //遍历所有线段将其相加，计算整条线段的长度    
        var totalDis = 0;    
        for (var i = 0; i < pts.length - 1; i++) {    
            var curPt = pts[i];    
            var nextPt = pts[i + 1]    
            var dis = GeoUtils.getDistance(curPt, nextPt);    
            totalDis += dis;    
        }    

        return totalDis;    

    } else {    
        return 0;    
    }    
}    

/**  
* 计算多边形面或点数组构建图形的面积,注意：坐标类型只能是经纬  

度，且不适合计算自相交多边形的面积  
* @param {Polygon|Array<Point>} polygon 多边形面对象或者点数  

组  
* @returns {Number} 多边形面或点数组构成图形的面积  
*/    
GeoUtils.getPolygonArea = function (polygon) {    
    //检查类型    
    if (!(polygon instanceof BMap.Polygon) &&    
         !(polygon instanceof Array)) {    
        return 0;    
    }    
    var pts;    
    if (polygon instanceof BMap.Polygon) {    
        pts = polygon.getPath();    
    } else {    
        pts = polygon;    
    }    

    if (pts.length < 3) {//小于3个顶点，不能构建面    
        return 0;    
    }    

    var totalArea = 0; //初始化总面积    
    var LowX = 0.0;    
    var LowY = 0.0;    
    var MiddleX = 0.0;    
    var MiddleY = 0.0;    
    var HighX = 0.0;    
    var HighY = 0.0;    
    var AM = 0.0;    
    var BM = 0.0;    
    var CM = 0.0;    
    var AL = 0.0;    
    var BL = 0.0;    
    var CL = 0.0;    
    var AH = 0.0;    
    var BH = 0.0;    
    var CH = 0.0;    
    var CoefficientL = 0.0;    
    var CoefficientH = 0.0;    
    var ALtangent = 0.0;    
    var BLtangent = 0.0;    
    var CLtangent = 0.0;    
    var AHtangent = 0.0;    
    var BHtangent = 0.0;    
    var CHtangent = 0.0;    
    var ANormalLine = 0.0;    
    var BNormalLine = 0.0;    
    var CNormalLine = 0.0;    
    var OrientationValue = 0.0;    
    var AngleCos = 0.0;    
    var Sum1 = 0.0;    
    var Sum2 = 0.0;    
    var Count2 = 0;    
    var Count1 = 0;    
    var Sum = 0.0;    
    var Radius = EARTHRADIUS; //6378137.0,WGS84椭球半径     
    var Count = pts.length;    
    for (var i = 0; i < Count; i++) {    
        if (i == 0) {    
            LowX = pts[Count - 1].lng * Math.PI / 180;    
            LowY = pts[Count - 1].lat * Math.PI / 180;    
            MiddleX = pts[0].lng * Math.PI / 180;    
            MiddleY = pts[0].lat * Math.PI / 180;    
            HighX = pts[1].lng * Math.PI / 180;    
            HighY = pts[1].lat * Math.PI / 180;    
        }    
        else if (i == Count - 1) {    
            LowX = pts[Count - 2].lng * Math.PI / 180;    
            LowY = pts[Count - 2].lat * Math.PI / 180;    
            MiddleX = pts[Count - 1].lng * Math.PI / 180;    
            MiddleY = pts[Count - 1].lat * Math.PI / 180;    
            HighX = pts[0].lng * Math.PI / 180;    
            HighY = pts[0].lat * Math.PI / 180;    
        }    
        else {    
            LowX = pts[i - 1].lng * Math.PI / 180;    
            LowY = pts[i - 1].lat * Math.PI / 180;    
            MiddleX = pts[i].lng * Math.PI / 180;    
            MiddleY = pts[i].lat * Math.PI / 180;    
            HighX = pts[i + 1].lng * Math.PI / 180;    
            HighY = pts[i + 1].lat * Math.PI / 180;    
        }    
        AM = Math.cos(MiddleY) * Math.cos(MiddleX);    
        BM = Math.cos(MiddleY) * Math.sin(MiddleX);    
        CM = Math.sin(MiddleY);    
        AL = Math.cos(LowY) * Math.cos(LowX);    
        BL = Math.cos(LowY) * Math.sin(LowX);    
        CL = Math.sin(LowY);    
        AH = Math.cos(HighY) * Math.cos(HighX);    
        BH = Math.cos(HighY) * Math.sin(HighX);    
        CH = Math.sin(HighY);    
        CoefficientL = (AM * AM + BM * BM + CM * CM) / (AM * AL + BM * BL + CM * CL);    
        CoefficientH = (AM * AM + BM * BM + CM * CM) / (AM * AH + BM * BH + CM * CH);    
        ALtangent = CoefficientL * AL - AM;    
        BLtangent = CoefficientL * BL - BM;    
        CLtangent = CoefficientL * CL - CM;    
        AHtangent = CoefficientH * AH - AM;    
        BHtangent = CoefficientH * BH - BM;    
        CHtangent = CoefficientH * CH - CM;    
        AngleCos = (AHtangent * ALtangent + BHtangent * BLtangent + CHtangent * CLtangent) / (Math.sqrt(AHtangent * AHtangent + BHtangent * BHtangent + CHtangent * CHtangent) * Math.sqrt(ALtangent * ALtangent + BLtangent * BLtangent + CLtangent * CLtangent));    
        AngleCos = Math.acos(AngleCos);    
        ANormalLine = BHtangent * CLtangent - CHtangent * BLtangent;    
        BNormalLine = 0 - (AHtangent * CLtangent - CHtangent * ALtangent);    
        CNormalLine = AHtangent * BLtangent - BHtangent * ALtangent;    
        if (AM != 0)    
            OrientationValue = ANormalLine / AM;    
        else if (BM != 0)    
            OrientationValue = BNormalLine / BM;    
        else    
            OrientationValue = CNormalLine / CM;    
        if (OrientationValue > 0) {    
            Sum1 += AngleCos;    
            Count1++;    
        }    
        else {    
            Sum2 += AngleCos;    
            Count2++;    
        }    
    }    
    var tempSum1, tempSum2;    
    tempSum1 = Sum1 + (2 * Math.PI * Count2 - Sum2);    
    tempSum2 = (2 * Math.PI * Count1 - Sum1) + Sum2;    
    if (Sum1 > Sum2) {    
        if ((tempSum1 - (Count - 2) * Math.PI) < 1)    
            Sum = tempSum1;    
        else    
            Sum = tempSum2;    
    }    
    else {    
        if ((tempSum2 - (Count - 2) * Math.PI) < 1)    
            Sum = tempSum2;    
        else    
            Sum = tempSum1;    
    }    
    totalArea = (Sum - (Count - 2) * Math.PI) * Radius * Radius;    
    return totalArea; //返回总面积    
}    

})(); //闭包结束    

export default BMapLib