using System.Collections.Generic;
using System.Collections.ObjectModel;
using MultiWheelC.TrajectoryPlanning.CoarsePath;
using MultiWheelC.TrajectoryPlanning.Mapping;

namespace MultiWheelC.TrajectoryPlanning.PathSmoothing;

/// <summary>路径平滑所需的原始粗路径、复核上下文和配置。</summary>
public sealed class PathSmoothingRequest
{
    private readonly VehicleParameters _vehicle;
    private readonly PathSmoothingConfiguration _configuration;

    /// <summary>创建路径平滑请求，并复制粗路径和方向分段集合。</summary>
    public PathSmoothingRequest(
        IReadOnlyList<CoarsePathPoint> coarsePath,
        IReadOnlyList<PathSegment> segments,
        PlanningGridMap map,
        VehicleParameters vehicle,
        PathSmoothingConfiguration configuration)
    {
        CoarsePath = CopyReadOnly(coarsePath);
        Segments = CopyReadOnly(segments);
        Map = map;
        _vehicle = CopyVehicle(vehicle);
        _configuration = CopyConfiguration(configuration);
    }

    /// <summary>原始粗路径的不可变快照。</summary>
    public IReadOnlyList<CoarsePathPoint> CoarsePath { get; }

    /// <summary>原始粗路径方向分段的不可变快照。</summary>
    public IReadOnlyList<PathSegment> Segments { get; }

    /// <summary>用于平滑后完整车体复核的规划栅格地图。</summary>
    public PlanningGridMap Map { get; }

    /// <summary>车辆几何与最大曲率约束的不可变快照副本。</summary>
    public VehicleParameters Vehicle => CopyVehicle(_vehicle);

    /// <summary>本次平滑配置的不可变快照副本。</summary>
    public PathSmoothingConfiguration Configuration => CopyConfiguration(_configuration);

    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);
    }

    private static VehicleParameters CopyVehicle(VehicleParameters source)
    {
        if (source == null) return null;
        return new VehicleParameters
        {
            LengthMeters = source.LengthMeters,
            WidthMeters = source.WidthMeters,
            SafetyMarginMeters = source.SafetyMarginMeters,
            MaximumCurvaturePerMeter = source.MaximumCurvaturePerMeter,
            MinimumTurningRadiusMeters = source.MinimumTurningRadiusMeters,
        };
    }

    private static PathSmoothingConfiguration CopyConfiguration(PathSmoothingConfiguration source)
    {
        if (source == null) return null;
        var copy = new PathSmoothingConfiguration
        {
            Method = source.Method,
            OutputSpacingMeters = source.OutputSpacingMeters,
            MaximumCollisionCheckStepMeters = source.MaximumCollisionCheckStepMeters,
            MinimumClearanceReserveMeters = source.MinimumClearanceReserveMeters,
            SmoothingStrength = source.SmoothingStrength,
            AllowFallbackToCoarsePath = source.AllowFallbackToCoarsePath,
        };
        copy.CubicBSpline.EndpointTangentScale = source.CubicBSpline.EndpointTangentScale;
        copy.LocalCubicBezier.CornerHeadingThresholdRadians = source.LocalCubicBezier.CornerHeadingThresholdRadians;
        copy.LocalCubicBezier.MaximumWindowLengthMeters = source.LocalCubicBezier.MaximumWindowLengthMeters;
        copy.LocalCubicBezier.HandleLengthRatio = source.LocalCubicBezier.HandleLengthRatio;
        copy.PiecewiseQuintic.KnotSpacingMeters = source.PiecewiseQuintic.KnotSpacingMeters;
        copy.PiecewiseQuintic.MinimumKnotSpacingMeters = source.PiecewiseQuintic.MinimumKnotSpacingMeters;
        copy.LocalG2Quintic.MinimumWindowLengthMeters = source.LocalG2Quintic.MinimumWindowLengthMeters;
        copy.LocalG2Quintic.PreferredWindowLengthMeters = source.LocalG2Quintic.PreferredWindowLengthMeters;
        copy.LocalG2Quintic.MaximumWindowLengthMeters = source.LocalG2Quintic.MaximumWindowLengthMeters;
        copy.LocalG2Quintic.MaximumDeviationMeters = source.LocalG2Quintic.MaximumDeviationMeters;
        copy.LocalG2Quintic.AbsoluteCurvatureJumpFloorPerMeter = source.LocalG2Quintic.AbsoluteCurvatureJumpFloorPerMeter;
        copy.LocalG2Quintic.CurvatureJumpRatioOfMaximum = source.LocalG2Quintic.CurvatureJumpRatioOfMaximum;
        copy.LocalG2Quintic.MinimumPeakGradientImprovementRatio = source.LocalG2Quintic.MinimumPeakGradientImprovementRatio;
        copy.LocalG2Quintic.MaximumVariationCostRegressionRatio = source.LocalG2Quintic.MaximumVariationCostRegressionRatio;
        copy.LocalG2Quintic.MaximumCandidatesPerRegion = source.LocalG2Quintic.MaximumCandidatesPerRegion;
        return copy;
    }
}