namespace Yw.Geometry
{
    public class EquipCurveHelper
    {
        /// <summary>
        /// 根据流量扬程线,以及给定设计点, 返回交点和装置曲线
        /// </summary>
        /// <param name="CurveExpressQH"></param>
        /// <param name="designPoint"></param>
        /// <param name="sectPoint"></param>
        /// <returns></returns>
        static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
             Yw.Geometry.CubicSpline2d CurveExpressQH,
             Yw.Geometry.Point2d designPoint,
             out Yw.Geometry.Point2d sectPoint)
        {
            return CalcEquipCurve(CurveExpressQH, designPoint, 0, false, 11, out sectPoint);
        }

        /// <summary>
        /// 根据流量扬程线,以及给定设计点,以及装置曲线0流量时的扬程点, 返回交点和装置曲线
        /// </summary>
        /// <param name="CurveExpressQH"></param>
        /// <param name="designPoint"></param>
        /// <param name="equipCurveZeroH"></param>
        /// <param name="sectPoint"></param>
        /// <returns></returns>
        static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
             Yw.Geometry.CubicSpline2d CurveExpressQH,
             Yw.Geometry.Point2d designPoint,
             double equipCurveZeroH,
             out Yw.Geometry.Point2d sectPoint)
        {
            return CalcEquipCurve(CurveExpressQH, designPoint, equipCurveZeroH, false, 11, out sectPoint);
        }
        /// <summary>
        /// 根据流量扬程线,以及给定设计点,以及装置曲线0流量时的扬程点, 返回交点和装置曲线
        /// </summary>
        /// <param name="CurveExpressQH"></param>
        /// <param name="designPoint"></param>
        /// <param name="equipCurveZeroH"></param>
        /// <param name="isExendCurve"></param>
        /// <param name="fitPointNum"></param>
        /// <param name="sectPoint"></param>
        /// <returns></returns>
        static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
             Yw.Geometry.CubicSpline2d CurveExpressQH,
             Yw.Geometry.Point2d designPoint,
             double equipCurveZeroH,
             bool isExendCurve,//当designPoint超过曲线时, 是否延长装置线到designPoint位置
             int fitPointNum,
             out Yw.Geometry.Point2d sectPoint)
        {
            sectPoint = GetSectPoint(CurveExpressQH, designPoint, equipCurveZeroH);
            if (sectPoint == null)
            {
                return null;
            }
            if (isExendCurve)
            {
                Yw.Geometry.Point2d endPt;
                if (sectPoint.X > designPoint.X)
                    endPt = sectPoint;
                else
                    endPt = designPoint;

                //
                return new Yw.Geometry.EquipCurveParas(equipCurveZeroH, endPt, fitPointNum);
            }
            else
            {
                return new Yw.Geometry.EquipCurveParas(equipCurveZeroH, sectPoint, fitPointNum);
            }
        }

        /// <summary>
        /// 计算装置曲线与流量扬程曲线的交点
        /// </summary>
        /// <param name="CurveExpressQH"></param>
        /// <param name="designPoint"></param>
        /// <param name="equipCurveZeroH"></param>
        /// <returns></returns>
        static public Yw.Geometry.Point2d GetSectPoint(
            Yw.Geometry.CubicSpline2d CurveExpressQH,
            Yw.Geometry.Point2d designPoint,
            double equipCurveZeroH)
        {//有一种情况: 用包络法有交点(在最末尾),但用装置曲线绘制时,与装置曲线没有交点,因为交点已超过曲线最大值
            double ratioExtend = 1.15;//CurveExpressQH适当延长一点
            var sectPoint = Yw.Geometry.ParabolaCurveHelper_H.GetSectPoint(CurveExpressQH, designPoint, equipCurveZeroH, ratioExtend);
            if (sectPoint == null)
            {
                return null;
            }
            if (sectPoint.X > CurveExpressQH.MaxX * ratioExtend)
            {
                return null;
            }

            return sectPoint;
        }

        /// <summary>
        /// 计算装置曲线与流量扬程曲线的交点
        /// </summary>
        /// <param name="CurveExpressQH"></param>
        /// <param name="DesignPoint"></param>
        /// <param name="equipCurveZeroH"></param>
        /// <param name="ratioExtend"></param>
        /// <returns></returns>
        static public Yw.Geometry.Point2d GetSectPoint(
           Yw.Geometry.CubicSpline2d CurveExpressQH,
           Yw.Geometry.Point2d DesignPoint,
           double equipCurveZeroH,
           double ratioExtend)
        {//有一种情况: 用包络法有交点(在最末尾),但用装置曲线绘制时,与装置曲线没有交点,因为交点已超过曲线最大值

            var sectPoint = Yw.Geometry.ParabolaCurveHelper_H.GetSectPoint(CurveExpressQH, DesignPoint, equipCurveZeroH, ratioExtend);
            if (sectPoint == null)
            {
                return null;
            }
            if (sectPoint.X > CurveExpressQH.MaxX * ratioExtend)
            {
                return null;
            }

            return sectPoint;
        }

    }
}