using Autodesk.Revit.DB;
using ShrlAlgoToolkit.RevitCore.Extensions;

namespace ShrlAlgoToolkit.RevitCore.Assists;

public static class SpatialAssist
{
    //private static List<Curve> _curvesSorted;
    /// <summary>
    /// 拆分线串变成固定长度的曲线段。
    /// </summary>
    /// <param name="curveChain"></param>
    /// <param name="segmentLength"></param>
    /// <returns></returns>
    public static List<ICurveContainer> SplitCurveChainByFixedLength(CurveLoop curveChain, double segmentLength)
    {
        List<ICurveContainer> container = new List<ICurveContainer>();

        if (curveChain.GetExactLength() - segmentLength < 10e-6)//总长度小于分割长度
        {
            return [.. curveChain.Select(c => new SingleCurve(c))];
        }
        //double currentParam = 0.0;
        //Curve currentCurve;
        //Curve remainingCurve;
        //int currentCurveIndex = 0;
        CurveList mergeList = null;
        //double tempLength = 0.0;
        //double currentStartParam = 0.0;
        //还需要的曲线长度才能满足分割长度
        double neededLength = 0.0;
        //List<CurveLoop> loops = new List<CurveLoop>();

        for (int i = 0; i < curveChain.Count(); i++)
        {
            Curve currentCurve = curveChain.ElementAt(i);
            //如果需要的长度大于曲线长度，说明整条曲线都应该被包含在内
            if (neededLength > currentCurve.Length)
            {
                mergeList.Curves.Add(currentCurve);
                neededLength -= currentCurve.Length;
                continue;
            }
            var splitList = currentCurve.SplitByFixedLength(
                neededLength,
                segmentLength,
                out var previousNeedCurve,
                out var remainingCurve);
            //需要将前置分割曲线添加上一段的列表中
            if (previousNeedCurve != null)
            {
                mergeList.Curves.Add(previousNeedCurve);
                //扣除已经添加的曲线长度，得到剩余需要的长度
                neededLength = segmentLength - mergeList.Curves.Sum(c => c.Length);
            }
            //可以分割
            if (splitList.Count > 0)
            {
                container.AddRange(splitList.Select(c => new SingleCurve(c)));
            }

            //已经满足分割长度，新建下一个列表
            if (neededLength < 10e-6)
            {
                mergeList = new CurveList([]);
                container.Add(mergeList);
            }

            if (remainingCurve == null)//完全均分时，重置起点
            {
                neededLength = 0.0;
            }
            else//剩余曲线添加到下一个列表中
            {
                mergeList.Curves.Add(remainingCurve);

                neededLength = segmentLength - mergeList.Curves.Sum(c => c.Length);
            }
        }
        //container.Add(mergeList); // 添加最后的合并列表
        return container;
    }
    /// <summary>
    /// 拆分成点和右侧朝向。
    /// </summary>
    /// <param name="curveChain"></param>
    /// <param name="segmentLength"></param>
    /// <returns></returns>
    public static Dictionary<XYZ, XYZ> EvalutePointCurveChainByFixedLength(CurveLoop curveChain, double segmentLength)
    {
        Dictionary<XYZ, XYZ> container = new();

        if (curveChain.GetExactLength() - segmentLength < 10e-6)//总长度小于分割长度时，取起点
        {
            var curve = curveChain.FirstOrDefault();
            var startPoint = curve.GetEndPoint(0);
            var orientation = curve.ComputeDerivatives(0, true).BasisX.Normalize();
            return new Dictionary<XYZ, XYZ> { { startPoint, orientation } };
        }
        //CurveList mergeList = null;
        double currentLength = 0.0;
        //还需要的曲线长度才能满足分割长度
        double neededLength = 0.0;

        for (int i = 0; i < curveChain.Count(); i++)
        {
            Curve currentCurve = curveChain.ElementAt(i);
            //如果需要的长度大于曲线长度，说明整条曲线都应该被包含在内
            if (neededLength > currentCurve.Length)
            {
                //mergeList.Curves.Add(currentCurve);
                currentLength += currentCurve.Length;
                neededLength -= currentCurve.Length;
                continue;
            }
            var splitList = currentCurve.EvalutePointByFixedLength(
                neededLength,
                segmentLength,
                out var previous,
                out var remaining);
            //需要将前置分割曲线添加上一段的列表中
            if (previous > 0.0)
            {
                currentLength += previous;
                //扣除已经添加的曲线长度，得到剩余需要的长度
                neededLength = segmentLength - currentLength;
            }
            //可以分割
            if (splitList.Count > 0)
            {
                foreach (var item in splitList)
                {
                    if (!container.Any(p => p.Key.IsAlmostEqualTo(item.Key)))//闭合曲线起终点有可能一样
                    {
                        container.Add(item.Key, item.Value);
                    }
                }
            }

            //已经满足分割长度
            if (neededLength < 10e-6)
            {
                currentLength = 0;
                //var point = currentCurve.Evaluate(1, false);
                //var orientation = currentCurve.Evaluate(1, false);
                //var p = new XYZ(-411.791042284402, 1330.9543320873, 0);
                //if (p.IsAlmostEqualTo(point))
                //{
                //}
                //container.Add(point,orientation);
            }

            if (remaining == 0.0)//完全均分时，重置起点
            {
                neededLength = 0.0;
                currentLength = 0.0;
                if (i < curveChain.Count() - 1)//如果还有下一个的时候，移除最后一个点
                {
                    var last = container.Last();
                    container.Remove(last.Key);
                }
            }
            else//剩余曲线添加到下一个列表中
            {
                currentLength += remaining;
                neededLength = segmentLength - currentLength;
            }
        }
        //container.Add(mergeList); // 添加最后的合并列表
        return container;
    }
    public static Transform GetProfileTransform(Curve referCurve)
    {
        //非刚性变换，会改变原几何,此变换在曲线计算导数时，为非刚性变换，各个basis的模不等于1
        var point = referCurve.GetEndPoint(0);
        var transform = referCurve.ComputeDerivatives(0, true);

        var tangent = transform.BasisX.Normalize();
        var rightBasis = tangent.CrossProduct(XYZ.BasisZ).Normalize();
        var topBasis = rightBasis.CrossProduct(tangent).Normalize();

        //构造新的变换
        var profileTransform = Transform.Identity;
        profileTransform.Origin = point;
        profileTransform.BasisX = rightBasis;
        profileTransform.BasisY = topBasis;
        profileTransform.BasisZ = tangent;
        return profileTransform;
    }

    /// <summary>
    /// 多段线
    /// </summary>
    /// <param name="curves"></param>
    /// <returns></returns>
    public static PolyLine ByJoinedCurves(List<Curve> curves)
    {
        List<XYZ> points = [];
        foreach (var c in curves)
        {
            points.Add(c.GetEndPoint(0));
        }
        points.Add(curves.Last().GetEndPoint(1));
        if (points.Count == 0)
        {
            return null;
        }
        return PolyLine.Create(points);
    }
    /// <summary>
    /// 将一组离散的曲线整理成多条连续的线串。
    /// </summary>
    /// <param name="curves">输入的曲线集合，可能包含直线、圆弧、样条曲线等。</param>
    /// <returns>一个包含多条线串的列表，每条线串本身也是一个曲线列表，且内部曲线方向连续。</returns>
    public static List<List<Curve>> GroupContinuousCurves(IEnumerable<Curve> curves)
    {
        // 最终返回的所有线串集合
        var allChains = new List<List<Curve>>();
        // 可被消耗的曲线列表
        var remainingCurves = new List<Curve>(curves);
        // Revit API 中用于几何比较的默认精度
        double tolerance = 1e-9;

        // 当还有未处理的曲线时，持续循环
        while (remainingCurves.Any())
        {
            // 开始一条新的线串
            var currentChain = new List<Curve>();

            // 从剩余曲线中取第一条作为新线串的起点
            var firstCurve = remainingCurves[0];
            currentChain.Add(firstCurve);
            remainingCurves.RemoveAt(0);

            // 持续延长当前线串，直到无法再延长
            while (true)
            {
                bool chainExtended = false;

                // 获取当前线串的头尾端点
                XYZ chainStartPoint = currentChain.First().GetEndPoint(0);
                XYZ chainEndPoint = currentChain.Last().GetEndPoint(1);

                // 从后向前遍历以安全地在循环中移除元素
                for (int i = remainingCurves.Count - 1; i >= 0; i--)
                {
                    var candidate = remainingCurves[i];
                    XYZ candidateStartPoint = candidate.GetEndPoint(0);
                    XYZ candidateEndPoint = candidate.GetEndPoint(1);

                    // 尝试连接到线串的尾部
                    if (chainEndPoint.IsAlmostEqualTo(candidateStartPoint, tolerance))
                    {
                        currentChain.Add(candidate);
                        remainingCurves.RemoveAt(i);
                        chainExtended = true;
                        break; // 找到一个后就跳出内层for循环，重新获取线串端点
                    }
                    else if (chainEndPoint.IsAlmostEqualTo(candidateEndPoint, tolerance))
                    {
                        currentChain.Add(candidate.CreateReversed()); // 反向后添加
                        remainingCurves.RemoveAt(i);
                        chainExtended = true;
                        break;
                    }
                    // 尝试连接到线串的头部
                    else if (chainStartPoint.IsAlmostEqualTo(candidateEndPoint, tolerance))
                    {
                        currentChain.Insert(0, candidate); // 插入到头部
                        remainingCurves.RemoveAt(i);
                        chainExtended = true;
                        break;
                    }
                    else if (chainStartPoint.IsAlmostEqualTo(candidateStartPoint, tolerance))
                    {
                        currentChain.Insert(0, candidate.CreateReversed()); // 反向后插入到头部
                        remainingCurves.RemoveAt(i);
                        chainExtended = true;
                        break;
                    }
                }

                // 如果本轮没有延长线串，说明这条线串已经构建完毕
                if (!chainExtended)
                {
                    break; // 跳出 while(true) 循环
                }
            }

            // 将构建完成的线串添加到最终结果中
            allChains.Add(currentChain);
        }

        return allChains;
    }
}

public interface ICurveContainer
{
}

public class SingleCurve : ICurveContainer
{
    public SingleCurve(Curve curve)
    {
        Curve = curve;
    }

    public Curve Curve { get; }
}
public class CurveList : ICurveContainer
{
    public List<Curve> Curves { get; }
    public CurveList(List<Curve> curves) => Curves = curves;
}