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="qh"></param>
        /// <param name="equip_pt"></param>
        /// <param name="sect_pt"></param>
        /// <returns></returns>
        static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
             Yw.Geometry.CubicSpline2d qh,
             Yw.Geometry.Point2d equip_pt,
             out Yw.Geometry.Point2d sect_pt)
        {
            return CalcEquipCurve(qh, equip_pt, 0, false, 11, out sect_pt);
        }

        /// <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="qh"></param>
        /// <param name="equip_pt"></param>
        /// <param name="equip_zero_h"></param>
        /// <param name="sect_pt"></param>
        /// <returns></returns>
        static public Yw.Geometry.CubicSpline2d CalcEquipCurve(
             Yw.Geometry.CubicSpline2d qh,
             Yw.Geometry.Point2d equip_pt,
             double equip_zero_h,
             out Yw.Geometry.Point2d sect_pt)
        {
            var equip_paras = CalcEquipCurve(qh, equip_pt, equip_zero_h, false, 11, out sect_pt);
            if (equip_paras != null && equip_paras.EquipCurve.IsValid())
            {
                return equip_paras.EquipCurve;
            }
            return null;
        }


        ///// <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="qh"></param>
        ///// <param name="equip_pt"></param>
        ///// <param name="equip_zero_h"></param>
        ///// <param name="sect_pt"></param>
        ///// <returns></returns>
        //static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
        //     Yw.Geometry.CubicSpline2d qh,
        //     Yw.Geometry.Point2d equip_pt,
        //     double equip_zero_h,
        //     out Yw.Geometry.Point2d sect_pt)
        //{
        //    return CalcEquipCurve(qh, equip_pt, equip_zero_h, false, 11, out sect_pt);
        //}

        /// <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="qh"></param>
        /// <param name="equip_pt"></param>
        /// <param name="equip_zero_h"></param>
        /// <param name="is_exend"></param>
        /// <param name="fit_pt_count"></param>
        /// <param name="sect_pt"></param>
        /// <returns></returns>
        static public Yw.Geometry.EquipCurveParas CalcEquipCurve(
             Yw.Geometry.CubicSpline2d qh,
             Yw.Geometry.Point2d equip_pt,
             double equip_zero_h,
             bool is_exend,//当equip_pt超过曲线时, 是否延长装置线到equip_pt位置
             int fit_pt_count,
             out Yw.Geometry.Point2d sect_pt)
        {
            sect_pt = GetSectPoint(qh, equip_pt, equip_zero_h);
            if (sect_pt == null)
            {
                return null;
            }
            if (is_exend)
            {
                Yw.Geometry.Point2d end_pt;
                if (sect_pt.X > equip_pt.X)
                    end_pt = sect_pt;
                else
                    end_pt = equip_pt;

                //
                return new Yw.Geometry.EquipCurveParas(equip_zero_h, end_pt, fit_pt_count);
            }
            else
            {
                return new Yw.Geometry.EquipCurveParas(equip_zero_h, sect_pt, fit_pt_count);
            }
        }

        /// <summary>
        /// 计算装置曲线与流量扬程曲线的交点
        /// </summary>
        /// <param name="qh"></param>
        /// <param name="equip_pt"></param>
        /// <param name="equip_zero_h"></param>
        /// <returns></returns>
        static public Yw.Geometry.Point2d GetSectPoint(
            Yw.Geometry.CubicSpline2d qh,
            Yw.Geometry.Point2d equip_pt,
            double equip_zero_h)
        {//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 ratio_extend = 1.15;//CurveExpressQH适当延长一点
            var sect_pt = Yw.Geometry.ParabolaCurveHelper.GetSectPoint(qh, equip_pt, equip_zero_h, ratio_extend);
            if (sect_pt == null)
            {
                return null;
            }
            if (sect_pt.X > qh.MaxX * ratio_extend)
            {
                return null;
            }

            return sect_pt;
        }

        /// <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="equip_zero_h"></param>
        /// <param name="ratio_extend"></param>
        /// <returns></returns>
        static public Yw.Geometry.Point2d GetSectPoint(
           Yw.Geometry.CubicSpline2d CurveExpressQH,
           Yw.Geometry.Point2d DesignPoint,
           double equip_zero_h,
           double ratio_extend)
        {//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 sect_pt = Yw.Geometry.ParabolaCurveHelper.GetSectPoint(CurveExpressQH, DesignPoint, equip_zero_h, ratio_extend);
            if (sect_pt == null)
            {
                return null;
            }
            if (sect_pt.X > CurveExpressQH.MaxX * ratio_extend)
            {
                return null;
            }

            return sect_pt;
        }

    }
}