using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using MultiWheelC.TrajectoryPlanning.PathSmoothing;

namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.Processing;

/// <summary>同一几何分析器产生的路径、方向段和未验证质量统计。</summary>
public sealed class PathGeometryAnalysis
{
    /// <summary>创建一次几何重算的只读结果快照。</summary>
    /// <param name="path">重算后的完整路径点集合。</param>
    /// <param name="segments">完整覆盖 <paramref name="path"/> 的方向段集合。</param>
    /// <param name="pathLengthMeters">路径总弧长，单位 m。</param>
    /// <param name="maximumAbsoluteVehicleCurvaturePerMeter">车辆曲率绝对值峰值，单位 1/m。</param>
    /// <param name="maximumAbsoluteVehicleCurvatureDerivativePerSquareMeter">车辆曲率导数绝对值峰值，单位 1/m²。</param>
    /// <param name="rootMeanSquareVehicleCurvaturePerMeter">车辆曲率均方根，单位 1/m。</param>
    /// <param name="totalAbsoluteCurvatureVariationPerMeter">不跨换向点的累计绝对曲率变化，单位 1/m。</param>
    /// <param name="curvatureVariationEnergy">不跨换向点的曲率变化代价。</param>
    /// <param name="minimumBodyClearanceMeters">输入点携带的最小保守车体净空，单位 m。</param>
    internal PathGeometryAnalysis(
        IReadOnlyList<SmoothedPathPoint> path,
        IReadOnlyList<SmoothedPathSegment> segments,
        double pathLengthMeters,
        double maximumAbsoluteVehicleCurvaturePerMeter,
        double maximumAbsoluteVehicleCurvatureDerivativePerSquareMeter,
        double rootMeanSquareVehicleCurvaturePerMeter,
        double totalAbsoluteCurvatureVariationPerMeter,
        double curvatureVariationEnergy,
        double minimumBodyClearanceMeters)
    {
        Path = CopyReadOnly(path);
        Segments = CopyReadOnly(segments);
        PathLengthMeters = pathLengthMeters;
        MaximumAbsoluteVehicleCurvaturePerMeter = maximumAbsoluteVehicleCurvaturePerMeter;
        MaximumAbsoluteVehicleCurvatureDerivativePerSquareMeter = maximumAbsoluteVehicleCurvatureDerivativePerSquareMeter;
        RootMeanSquareVehicleCurvaturePerMeter = rootMeanSquareVehicleCurvaturePerMeter;
        TotalAbsoluteCurvatureVariationPerMeter = totalAbsoluteCurvatureVariationPerMeter;
        CurvatureVariationEnergy = curvatureVariationEnergy;
        MinimumBodyClearanceMeters = minimumBodyClearanceMeters;
    }

    /// <summary>完成几何重计算的不可变路径。</summary>
    public IReadOnlyList<SmoothedPathPoint> Path { get; }

    /// <summary>完整覆盖 <see cref="Path"/> 的不可变方向段。</summary>
    public IReadOnlyList<SmoothedPathSegment> Segments { get; }

    /// <summary>路径总长度，单位 m。</summary>
    public double PathLengthMeters { get; }

    /// <summary>车辆曲率绝对值峰值，单位 1/m。</summary>
    public double MaximumAbsoluteVehicleCurvaturePerMeter { get; }

    /// <summary>车辆曲率导数绝对值峰值，单位 1/m²。</summary>
    public double MaximumAbsoluteVehicleCurvatureDerivativePerSquareMeter { get; }

    /// <summary>车辆曲率均方根，单位 1/m。</summary>
    public double RootMeanSquareVehicleCurvaturePerMeter { get; }

    /// <summary>不跨换向点累计的绝对曲率变化，单位 1/m。</summary>
    public double TotalAbsoluteCurvatureVariationPerMeter { get; }

    /// <summary>不跨换向点累计的曲率变化代价。</summary>
    public double CurvatureVariationEnergy { get; }

    /// <summary>曲率变化代价的面向用户名称；保留 <see cref="CurvatureVariationEnergy"/> 以兼容既有调用方。</summary>
    public double CurvatureVariationCost => CurvatureVariationEnergy;

    /// <summary>输入点携带的最小保守净空，单位 m。</summary>
    public double MinimumBodyClearanceMeters { get; }

    private static IReadOnlyList<T> CopyReadOnly<T>(IReadOnlyList<T> source)
    {
        var copy = new List<T>(source == null ? 0 : source.Count);
        if (source != null)
        {
            for (int index = 0; index < source.Count; index++) copy.Add(source[index]);
        }
        return new ReadOnlyCollection<T>(copy);
    }
}