namespace IStation.Curve
{
    /// <summary>
    /// 抛物线 Parabola :  H=K*Q^2 + S (流量扬程线)
    /// </summary>
    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equipCurveZeroH装置曲线静扬程)
        //equipCurveZeroH是装置曲线的静扬程,当Q=0时的扬程
        public static IStation.Curve.CurvePoint GetSectPoint(IStation.Curve.CurveExpress curveExpress, IStation.Curve.CurvePoint simularPoint, double equipCurveZeroH)
        {
            //if (curveExpress.FitType == eFitType.ThroughPoint)
            //{
            //    var points = IStation.Curve.BezierCurveHelper.GetMultiplyPoints(curveExpress.DefinePoints, 3);
            //    return GetSectPoint(points, simularPoint, equipCurveZeroH);
            //}
            //else
            {
                var curveExpress2 = new IStation.Curve.CurveExpress(curveExpress);
                curveExpress2.Max = curveExpress2.Max * 1.2;
                var points = IStation.Curve.FitHelper.GetFitPoints(curveExpress2, 50);
                return GetSectPoint(points, simularPoint, equipCurveZeroH);
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="curveExpress"></param>
        /// <param name="simularPoint"></param>
        /// <param name="equipCurveZeroH"></param>
        /// <param name="ratioExtend"></param>
        /// <returns></returns>
        public static IStation.Curve.CurvePoint GetSectPoint(IStation.Curve.CurveExpress curveExpress, IStation.Curve.CurvePoint simularPoint, double equipCurveZeroH,
            double ratioExtend)
        {
            //if (curveExpress.FitType == eFitType.ThroughPoint)
            //{
            //    if (curveExpress.DefinePoints == null || curveExpress.DefinePoints.Count() < 3)
            //        return null;

            //    var points = IStation.Curve.BezierCurveHelper.GetMultiplyPoints(curveExpress.DefinePoints, 3);
            //    return GetSectPoint(points, simularPoint, equipCurveZeroH);
            //}
            //else
            {
                var curveExpress2 = new IStation.Curve.CurveExpress(curveExpress);
                curveExpress2.Max = curveExpress2.Max * ratioExtend;
                var points = IStation.Curve.FitHelper.GetFitPoints(curveExpress2, 50);
                //var points = IStation.Curve.FitHelper.GetFitPointsByExtend(curveExpress, ratioExtend, 50);
                return GetSectPoint(points, simularPoint, equipCurveZeroH);
            }
        }

        //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equipCurveZeroH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 IStation.Curve.CurvePoint GetSectPoint(List<IStation.Curve.CurvePoint> CurvePoints, IStation.Curve.CurvePoint simularPoint, double equipCurveZeroH)
        {
            IStation.Curve.CurvePoint sectPoint = new IStation.Curve.CurvePoint(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 - equipCurveZeroH) / (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 - equipCurveZeroH) / a);
                    if (CurvePoints[i].X.IsMiddle(CurvePoints[i + 1].X, x_j1))
                    {
                        sectPoint.X = x_j1;
                        sectPoint.Y = CurvePoints[i].Y;
                        return sectPoint;
                    }
                }
                else
                {
                    CurveLineHelper.GetKandB(CurvePoints[i], CurvePoints[i + 1], out b, out c, 0.0000000001);
                    c = c - equipCurveZeroH;

                    //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 && CurvePoints[i].X.IsMiddle(CurvePoints[i + 1].X, x_j1))
                    {
                        sectPoint.X = x_j1;
                        sectPoint.Y = b * x_j1 + c + equipCurveZeroH;
                        return sectPoint;
                    }

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

            return sectPoint;
        }




        //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 IStation.Curve.CurvePoint GetSectPointLn(List<IStation.Curve.CurvePoint> CurvePoints, IStation.Curve.CurvePoint simularPoint)
        {
            IStation.Curve.CurvePoint sectPoint = new IStation.Curve.CurvePoint(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<IStation.Curve.CurvePoint> CurvePointsLn = new List<IStation.Curve.CurvePoint>();
            for (int i = 0; i < CurvePoints.Count; i++)
            {
                if (CurvePoints[i].X > 1)//防止第一个点：X=0
                    CurvePointsLn.Add(new IStation.Curve.CurvePoint(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++)
            {
                CurveLineHelper.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 (CurvePointsLn[i].X.IsMiddle(CurvePointsLn[i + 1].X, x))
                {
                    sectPoint.X = Math.Pow(10, x);
                    sectPoint.Y = Math.Pow(10, a * x);

                    return sectPoint;
                }
            }

            return sectPoint;
        }
    }

    /// <summary>
    /// 抛物线 Parabola :  y = K * Q^2 + B * Q;
    /// </summary>
    public class ParabolaECurveHelper
    {
        //任意两点
        public static bool GetCurvePara(IStation.Curve.CurvePoint pt1, IStation.Curve.CurvePoint 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(IStation.Curve.CurvePoint 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;
        }


    }

    /// <summary>
    /// 抛物线 Parabola :  H = K * Q^2   (装置曲线)
    /// </summary>
    public class ParabolaZCurveHelper
    {
        private double _k = 0;
        public double GetK()
        {
            return _k;
        }
        public ParabolaZCurveHelper(IStation.Curve.CurvePoint pt)
        {
            this._k = pt.Y / pt.X / pt.X;
        }
        public ParabolaZCurveHelper(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 IStation.Curve.CurvePoint CalcPointPosiByX(double x1, double x2, double length_ratio)
        {
            if (length_ratio < 0.001)
            {
                return new IStation.Curve.CurvePoint(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 IStation.Curve.CurvePoint(x, y);
                }
            }

            return new IStation.Curve.CurvePoint(x2, GetY(x2));
        }
        public IStation.Curve.CurvePoint CalcPointPosi(IStation.Curve.CurvePoint pt1, IStation.Curve.CurvePoint 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(IStation.Curve.CurvePoint pt1, IStation.Curve.CurvePoint pt2, double x_center)
        {
            double length1 = CalcCurveLengthByX(pt1.X, pt2.X);
            double length2 = CalcCurveLengthByX(pt1.X, x_center);

            return length2 / length1;
        }

    }

    /// <summary>
    /// 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
    /// </summary>
    public class ParabolaZChartCurveHelper
    {
        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 ParabolaZChartCurveHelper(IStation.Curve.CurvePoint 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 ParabolaZChartCurveHelper(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 IStation.Curve.CurvePoint FromChartToReal(double chart_pt_x, double chart_pt_y)
        {
            return new IStation.Curve.CurvePoint(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 IStation.Curve.CurvePoint 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 IStation.Curve.CurvePoint CalcPointPosi(IStation.Curve.CurvePoint pt1, IStation.Curve.CurvePoint 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(IStation.Curve.CurvePoint pt1, IStation.Curve.CurvePoint pt2, double x_center)
        {
            double length1 = CalcCurveLengthByX(pt1.X, pt2.X);
            double length2 = CalcCurveLengthByX(pt1.X, x_center);

            return length2 / length1;
        }

    }

}