namespace Yw.Geometry
{
    //抛物线 Parabola :  H=K*Q^2 + S (流量扬程线)
    public class ParabolaCurveHelper
    {
        //通过点simularPoint和点(0,0)的抛物线,与曲线Curve的交点(没有,返回Point(0,0))
        //曲线公式：H=K*Q^2+S (S就是equipuipCurveZeroH装置曲线静扬程)
        //equipuipCurveZeroH是装置曲线的静扬程,当Q=0时的扬程
        public static Yw.Geometry.Point2d GetSectPoint(Yw.Geometry.CubicSpline2d curveExpress, Yw.Geometry.Point2d simularPoint, double equipuipCurveZeroH)
        {
            if (curveExpress == null)
                return null;

            //if (curveExpress.SplineType == eSpline2dType.)
            //{
            //    var points = Eventech.Common.BezierCurveHelper.GetMultiplyPoints(curveExpress.DefinePoints, 3);
            //    return GetSectPoint(points, simularPoint, equipuipCurveZeroH);
            //}
            //else
            {

                var points = curveExpress.GetPointListByXRange(curveExpress.MinX, curveExpress.MaxX * 1.2, 50);
                return GetSectPoint(points, simularPoint, equipuipCurveZeroH);
            }
        }

        //
        public static Yw.Geometry.Point2d GetSectPoint(Yw.Geometry.CubicSpline2d curveExpress, Yw.Geometry.Point2d simularPoint, double equipuipCurveZeroH,
            double ratioExtend)
        {
            if (curveExpress == null)
                return null;
            //if (curveExpress.CurveFitType == Model.eCurveFitType.ThroughPoint)
            //{
            //    if (curveExpress.DefinePoints == null || curveExpress.DefinePoints.Count() < 3)
            //        return null;

            //    var points = Eventech.Common.BezierCurveHelper.GetMultiplyPoints(curveExpress.DefinePoints, 3);
            //    return GetSectPoint(points, simularPoint, equipuipCurveZeroH);
            //}
            //else
            {
                var points = curveExpress.GetPointListByXRange(curveExpress.MinX, curveExpress.MaxX * ratioExtend, 50);

                return GetSectPoint(points, simularPoint, equipuipCurveZeroH);
            }
        }

        //通过点simularPoint和点(0,0)的抛物线,与曲线Curve的交点(没有,返回Point(0,0))
        //曲线公式：H=K*Q^2+S (S就是equipuipCurveZeroH装置曲线静扬程)
        //S是装置曲线的静扬程,当Q=0时的扬程
        public static Yw.Geometry.Point2d GetSectPoint(List<Yw.Geometry.Point2d> CurvePoints, Yw.Geometry.Point2d simularPoint, double equipuipCurveZeroH)
        {
            Yw.Geometry.Point2d sectPoint = new Yw.Geometry.Point2d(0, 0);
            if (CurvePoints == null || CurvePoints.Count < 2)
                return sectPoint;
            //if (simularPoint.X < CurvePoints.First().X)
            //    return sectPoint;

            //if (DesignPoint.X > CurvePoints.Last().X)
            //    return sectPoint;


            //计算抛物线的K (a)
            if (simularPoint.X < 0.1)
            {//X=0
                return CurvePoints.First();
            }
            if (simularPoint.Y < 0.01)
            {//Y=0
                return CurvePoints.Last();
            }
            double a = (simularPoint.Y - equipuipCurveZeroH) / (simularPoint.X * simularPoint.X);
            if (a < 0.0001)
                GetSectPointLn(CurvePoints, simularPoint);

            //2点连成直线与抛物线的交点,判断交点是否在2点之间,即可是曲线的交点
            double b, c;
            double delta = 0;
            double x_j1, x_j2;
            for (int i = 0; i < CurvePoints.Count - 1; i++)
            {
                if (Math.Abs(CurvePoints[i].Y - CurvePoints[i + 1].Y) < 0.00001)
                {//水平的
                    x_j1 = Math.Sqrt((CurvePoints[i].Y - equipuipCurveZeroH) / a);
                    if (IsMiddlePt(CurvePoints[i].X, CurvePoints[i + 1].X, x_j1))
                    {
                        sectPoint.X = x_j1;
                        sectPoint.Y = CurvePoints[i].Y;
                        return sectPoint;
                    }
                }
                else
                {
                    Yw.Geometry.Line2dHelper.GetKandB(CurvePoints[i], CurvePoints[i + 1], out b, out c, 0.0000000001);
                    c = c - equipuipCurveZeroH;

                    //解方程 ax2-bx-c=0
                    delta = b * b + 4 * a * c;
                    if (delta < 0)
                        continue;

                    x_j1 = (b + Math.Sqrt(delta)) / (2 * a);
                    if (x_j1 >= 0 && IsMiddlePt(CurvePoints[i].X, CurvePoints[i + 1].X, x_j1))
                    {
                        sectPoint.X = x_j1;
                        sectPoint.Y = b * x_j1 + c + equipuipCurveZeroH;
                        return sectPoint;
                    }

                    x_j2 = (b - Math.Sqrt(delta)) / (2 * a);
                    if (x_j2 >= 0 && IsMiddlePt(CurvePoints[i].X, CurvePoints[i + 1].X, x_j2))
                    {
                        sectPoint.X = x_j2;
                        sectPoint.Y = b * x_j2 + c + equipuipCurveZeroH;
                        return sectPoint;
                    }
                }
            }

            return sectPoint;
        }

   

        //判断 是否在2个数之间
        public static bool IsMiddlePt(double pt1, double pt2, double p)
        {
            if (p > pt1 && p < pt2)
                return true;

            if (p < pt1 && p > pt2)
                return true;

            return false;
        }

        //通过点simularPoint和点(0,0)的抛物线,与曲线Curve的交点(没有,返回Point(0,0)):当流量特别大，H比较小时用
        //曲线公式：H=K*Q^2,然后两边取对数
        protected static Yw.Geometry.Point2d GetSectPointLn(List<Yw.Geometry.Point2d> CurvePoints, Yw.Geometry.Point2d simularPoint)
        {
            Yw.Geometry.Point2d sectPoint = new Yw.Geometry.Point2d(0, 0);
            if (CurvePoints == null || CurvePoints.Count < 2)
                return sectPoint;

            //计算取对数后直线的K
            double a = Math.Log10(simularPoint.Y) / Math.Log10(simularPoint.X);
            if (a < 0.0001)
                return sectPoint;

            //所有的线上的点取对数
            List<Yw.Geometry.Point2d> CurvePointsLn = new List<Yw.Geometry.Point2d>();
            for (int i = 0; i < CurvePoints.Count; i++)
            {
                if (CurvePoints[i].X > 1)//防止第一个点：X=0
                    CurvePointsLn.Add(new Yw.Geometry.Point2d(Math.Log10(CurvePoints[i].X), Math.Log10(CurvePoints[i].Y)));
            }

            //与2点连成直线的交点,判断交点是否在2点之间,即可是曲线的交点
            double b, c;
            double x;
            for (int i = 0; i < CurvePointsLn.Count - 1; i++)
            {
                Yw.Geometry.Line2dHelper.GetKandB(CurvePointsLn[i], CurvePointsLn[i + 1], out b, out c);

                /*解方程 
                 * y=ax
                 * y=bx+c
                 */
                if (Math.Abs(a - b) < 0.001)
                    continue;

                x = c / (a - b);
                if (IsMiddlePt(CurvePointsLn[i].X, CurvePointsLn[i + 1].X, x))
                {
                    sectPoint.X = Math.Pow(10, x);
                    sectPoint.Y = Math.Pow(10, a * x);

                    return sectPoint;
                }
            }

            return sectPoint;
        }
    }


    ////抛物线 Parabola :  y = K * Q^2 + B * Q;
    //public class ParabolaCurveHelper_E
    //{
    //    //任意两点
    //    public static bool GetCurvePara(Yw.Geometry.Point2d pt1, Yw.Geometry.Point2d pt2, out double K, out double B)
    //    {
    //        //抛物线拟合 y=ax2+bx;
    //        double y1 = pt1.Y;
    //        double x1 = pt1.X;
    //        double y2 = pt2.Y;
    //        double x2 = pt2.X;

    //        K = (y1 * x2 - y2 * x1) / (x1 * x1 * x2 - x2 * x2 * x1);
    //        B = (y1 * x2 * x2 - y2 * x1 * x1) / (x1 * x2 * x2 - x2 * x1 * x1);

    //        return true;
    //    }


    //    //工作点和高效点
    //    public static bool GetCurveParaByBEP(Yw.Geometry.Point2d wrkPt, double bep_q, out double bep_eta, out double K, out double B)
    //    {
    //        //抛物线拟合 
    //        //思路 Y=0时, X=0或 -B/K
    //        //所以 bep_q = -B/K  * 0.5



    //        K = wrkPt.Y / (wrkPt.X * wrkPt.X - 2 * bep_q * wrkPt.X);
    //        B = -2 * K * bep_q;

    //        bep_eta = K * bep_q * bep_q + B * bep_q;

    //        //if (bep_eta > 0.95)
    //        //{

    //        //}

    //        return true;
    //    }


    //}


    ////抛物线 Parabola :  H = K * Q^2   (装置曲线)
    //public class ParabolaCurveHelper_Z
    //{
    //    private double _k = 0;
    //    public double GetK()
    //    {
    //        return _k;
    //    }
    //    public ParabolaCurveHelper_Z(Yw.Geometry.Point2d pt)
    //    {
    //        this._k = pt.Y / pt.X / pt.X;
    //    }
    //    public ParabolaCurveHelper_Z(double x, double y)
    //    {
    //        this._k = y / x / x;
    //    }
    //    public double GetY(double x)
    //    {
    //        return x * x * this._k;
    //    }
    //    public double GetX(double y)
    //    {
    //        return Math.Sqrt(y * this._k);
    //    }

    //    //计算从x1到x2的弧长
    //    public double CalcCurveLengthByX(double pt1_x, double pt2_x)
    //    {
    //        //思路是从按直线叠加
    //        double x1 = pt1_x;
    //        double x2 = pt2_x;
    //        if (pt1_x > pt2_x)
    //        {
    //            x1 = pt2_x;
    //            x2 = pt1_x;
    //        }

    //        double space = (x2 - x1) / 1200;
    //        double x_last = x1;
    //        double y_last = GetY(x1);
    //        double total_length = 0;
    //        for (int i = 1; i <= 1200; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY(x);
    //            double sub_length = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            total_length += sub_length;
    //        }

    //        return total_length;
    //    }

    //    //计算点的位置, x1到x2弧长的摆放路
    //    public Yw.Geometry.Point2d CalcPointPosiByX(double x1, double x2, double length_ratio)
    //    {
    //        if (length_ratio < 0.001)
    //        {
    //            return new Yw.Geometry.Point2d(x1, GetY(x1));
    //        }

    //        //思路是从按直线叠加
    //        int point_number = 1800;
    //        double space = (x2 - x1) / point_number;
    //        double x_last = x1;
    //        double y_last = GetY(x1);
    //        double total_length = 0;

    //        for (int i = 1; i <= point_number; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY(x);
    //            double len = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            total_length += len;
    //        }

    //        double calc_length = total_length * length_ratio;
    //        double len2 = 0;
    //        x_last = x1;
    //        y_last = GetY(x1);
    //        for (int i = 1; i <= point_number; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY(x);
    //            double len = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            len2 += len;
    //            if (len2 > calc_length)
    //            {
    //                return new Yw.Geometry.Point2d(x, y);
    //            }
    //        }

    //        return new Yw.Geometry.Point2d(x2, GetY(x2));
    //    }
    //    public Yw.Geometry.Point2d CalcPointPosi(Yw.Geometry.Point2d pt1, Yw.Geometry.Point2d pt2, double length_ratio)
    //    {
    //        return CalcPointPosiByX(pt1.X, pt2.X, length_ratio);
    //    }


    //    //计算点x在弧长(x1->x2)中的百分率
    //    public double CalcPointRatioByX(double x1, double x2, double x_center)
    //    {
    //        double length1 = CalcCurveLengthByX(x1, x2);
    //        double length2 = CalcCurveLengthByX(x1, x_center);

    //        return length2 / length1;
    //    }
    //    public double CalcPointRatio(Yw.Geometry.Point2d pt1, Yw.Geometry.Point2d pt2, double x_center)
    //    {
    //        double length1 = CalcCurveLengthByX(pt1.X, pt2.X);
    //        double length2 = CalcCurveLengthByX(pt1.X, x_center);

    //        return length2 / length1;
    //    }

    //}



    ////抛物线 Parabola :  H = K * Q^2   (装置曲线) :图表法: 有时用QH差别比较大时, 用距离计算会有些问题
    //public class ParabolaCurveHelper_Z_4Chart
    //{
    //    private double _k = 1;

    //    private double _chartWidth = 1000;
    //    private double _chartHeight = 600;

    //    private double _ratio_scale_x = 1;
    //    private double _ratio_scale_y = 1;
    //    private double GetK()
    //    {//不对外 , 外部知道K 没有意义
    //        return _k;
    //    }
    //    public ParabolaCurveHelper_Z_4Chart(Yw.Geometry.Point2d pt)
    //    {
    //        if (pt == null)
    //            return;

    //        this._ratio_scale_x = _chartWidth / pt.X;
    //        this._ratio_scale_y = _chartHeight / pt.Y;

    //        this._k = _chartHeight / _chartWidth / _chartWidth;
    //    }
    //    public ParabolaCurveHelper_Z_4Chart(double x, double y)
    //    {
    //        this._ratio_scale_x = _chartWidth / x;
    //        this._ratio_scale_y = _chartHeight / y;
    //        this._k = _chartHeight / _chartWidth / _chartWidth;
    //    }
    //    private double GetY_chart(double x)
    //    {
    //        return x * x * this._k;
    //    }
    //    private double GetX_chart(double y)
    //    {
    //        return Math.Sqrt(y * this._k);
    //    }
    //    public double GetY(double x)
    //    {
    //        double chart_x = x * this._ratio_scale_x;
    //        var chart_y = chart_x * chart_x * this._k;
    //        return chart_y / this._ratio_scale_y;
    //    }

    //    //计算从x1到x2的弧长(注意时图表上的距离)
    //    public double CalcCurveLengthByX(double real_x_1, double real_x_2)
    //    {
    //        double pt1_x = real_x_1 * this._ratio_scale_x;
    //        double pt2_x = real_x_2 * this._ratio_scale_x;

    //        //思路是从按直线叠加
    //        double x1 = pt1_x;
    //        double x2 = pt2_x;
    //        if (pt1_x > pt2_x)
    //        {
    //            x1 = pt2_x;
    //            x2 = pt1_x;
    //        }

    //        double space = (x2 - x1) / 1200;
    //        double x_last = x1;
    //        double y_last = GetY_chart(x1);
    //        double total_length = 0;
    //        for (int i = 1; i <= 1200; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY_chart(x);
    //            double sub_length = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            total_length += sub_length;
    //        }

    //        return total_length;
    //    }

    //    private Yw.Geometry.Point2d FromChartToReal(double chart_pt_x, double chart_pt_y)
    //    {
    //        return new Yw.Geometry.Point2d(chart_pt_x / this._ratio_scale_x, chart_pt_y / this._ratio_scale_y);
    //    }
    //    //计算点的位置, x1到x2弧长的摆放路
    //    public Yw.Geometry.Point2d CalcPointPosiByX(double real_x_1, double real_x_2, double length_ratio)
    //    {
    //        double x1 = real_x_1 * this._ratio_scale_x;
    //        double x2 = real_x_2 * this._ratio_scale_x;

    //        if (length_ratio < 0.001)
    //        {
    //            return FromChartToReal(x1, GetY_chart(x1));
    //        }

    //        //思路是从按直线叠加
    //        int point_number = 1800;
    //        double space = (x2 - x1) / point_number;
    //        double x_last = x1;
    //        double y_last = GetY_chart(x1);
    //        double total_length = 0;

    //        for (int i = 1; i <= point_number; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY_chart(x);
    //            double len = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            total_length += len;
    //        }

    //        double calc_length = total_length * length_ratio;
    //        double len2 = 0;
    //        x_last = x1;
    //        y_last = GetY_chart(x1);
    //        for (int i = 1; i <= point_number; i++)
    //        {
    //            double x = x1 + space * i;
    //            double y = GetY_chart(x);
    //            double len = Math.Sqrt((x - x_last) * (x - x_last) + (y - y_last) * (y - y_last));
    //            x_last = x;
    //            y_last = y;

    //            len2 += len;
    //            if (len2 > calc_length)
    //            {
    //                return FromChartToReal(x, y);
    //            }
    //        }

    //        return FromChartToReal(x2, GetY_chart(x2));
    //    }
    //    public Yw.Geometry.Point2d CalcPointPosi(Yw.Geometry.Point2d pt1, Yw.Geometry.Point2d pt2, double length_ratio)
    //    {
    //        return CalcPointPosiByX(pt1.X, pt2.X, length_ratio);
    //    }


    //    //计算点x在弧长(x1->x2)中的百分率
    //    public double CalcPointRatioByX(double x1, double x2, double x_center)
    //    {
    //        double length1 = CalcCurveLengthByX(x1, x2);
    //        double length2 = CalcCurveLengthByX(x1, x_center);

    //        return length2 / length1;
    //    }
    //    public double CalcPointRatio(Yw.Geometry.Point2d pt1, Yw.Geometry.Point2d pt2, double x_center)
    //    {
    //        double length1 = CalcCurveLengthByX(pt1.X, pt2.X);
    //        double length2 = CalcCurveLengthByX(pt1.X, x_center);

    //        return length2 / length1;
    //    }

    //}


}