using System;
using System.Collections.Generic;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.BoundaryRepresentation;
using BrepFace = Autodesk.AutoCAD.BoundaryRepresentation.Face;

namespace FurnitureExporter;

/// <summary>
/// 倒角检测器 - 从板材实体中提取倒角/圆角信息
/// </summary>
public class ChamferDetector
{
    private readonly Database _db;
    private Point3d _originOffset = Point3d.Origin;

    // 检测参数
    private const double MIN_CHAMFER_SIZE = 0.5;   // 最小倒角尺寸 0.5mm
    private const double MAX_CHAMFER_SIZE = 50;     // 最大倒角尺寸 50mm
    private const double MIN_FILLET_RADIUS = 1;     // 最小圆角半径 1mm
    private const double MAX_FILLET_RADIUS = 100;   // 最大圆角半径 100mm

    public ChamferDetector(Database db)
    {
        _db = db;
    }

    /// <summary>
    /// 从板材实体中检测倒角和圆角
    /// </summary>
    public List<EdgeFeatureInfo> DetectEdgeFeatures(ObjectId solidId, string panelId, Point3d? originOffset = null)
    {
        _originOffset = originOffset ?? Point3d.Origin;
        var features = new List<EdgeFeatureInfo>();

        using var tr = _db.TransactionManager.StartTransaction();
        
        var solid = tr.GetObject(solidId, OpenMode.ForRead) as Solid3d;
        if (solid == null)
        {
            tr.Commit();
            return features;
        }

        try
        {
            using var brep = new Brep(solid);
            int featureIndex = 0;

            // 遍历所有面，检测圆柱面（圆角）和平面相交的特殊边
            foreach (var face in brep.Faces)
            {
                try
                {
                    // face.Surface 常常是修剪/偏移表面，先剥离到基础几何类型
                    var surface = BrepSurfaceUtils.Unwrap(face.Surface);
                    
                    // 检测圆角（圆柱面）
                    if (surface is Cylinder cylinder)
                    {
                        var radius = cylinder.Radius;
                        
                        // 过滤：圆角的半径通常较小，而孔的半径通常大于5mm
                        if (radius >= MIN_FILLET_RADIUS && radius <= MAX_FILLET_RADIUS)
                        {
                            // 判断是圆角还是孔
                            if (IsFilletFace(face, cylinder, solid))
                            {
                                var feature = ExtractFilletInfo(cylinder, face, panelId, featureIndex++);
                                if (feature != null)
                                {
                                    features.Add(feature);
                                }
                            }
                        }
                    }
                    // 检测倒角（倾斜平面）
                    else if (surface is Plane plane)
                    {
                        if (IsChamferFace(face, plane, solid))
                        {
                            var feature = ExtractChamferInfo(plane, face, panelId, featureIndex++);
                            if (feature != null)
                            {
                                features.Add(feature);
                            }
                        }
                    }
                }
                catch
                {
                    continue;
                }
            }
        }
        catch (System.Exception ex)
        {
            System.Diagnostics.Debug.WriteLine($"[ChamferDetector] Error: {ex.Message}");
        }

        tr.Commit();
        return features;
    }

    /// <summary>
    /// 判断圆柱面是否为圆角（而非孔的侧面）
    /// </summary>
    private bool IsFilletFace(BrepFace face, Cylinder cylinder, Solid3d solid)
    {
        try
        {
            // 获取圆柱半径
            var radius = cylinder.Radius;
            
            // 获取实体尺寸
            var solidExt = solid.GeometricExtents;
            var solidSize = solidExt.MaxPoint - solidExt.MinPoint;
            var maxSolidDim = Math.Max(solidSize.X, Math.Max(solidSize.Y, solidSize.Z));
            
            // 圆角特征：半径较小（相对于实体尺寸）
            var radiusRatio = radius / maxSolidDim;
            
            // 如果半径小于实体最大尺寸的10%，很可能是圆角
            if (radiusRatio < 0.1)
            {
                return true;
            }
            
            return false;
        }
        catch
        {
            return false;
        }
    }

    /// <summary>
    /// 判断平面是否为倒角面
    /// </summary>
    private bool IsChamferFace(BrepFace face, Plane plane, Solid3d solid)
    {
        try
        {
            // 获取平面法向量
            var normal = plane.Normal.GetNormal();
            
            // 倒角面的法向量不会与主轴完全平行
            var absNormal = new Vector3d(Math.Abs(normal.X), Math.Abs(normal.Y), Math.Abs(normal.Z));
            
            // 如果法向量与任意主轴的夹角在25°-65°之间，可能是倒角
            var maxComponent = Math.Max(absNormal.X, Math.Max(absNormal.Y, absNormal.Z));
            var minComponent = Math.Min(absNormal.X, Math.Min(absNormal.Y, absNormal.Z));
            
            // 倒角面的法向量不会太接近主轴（>0.9）也不会太远离（<0.4）
            if (maxComponent > 0.4 && maxComponent < 0.9 && minComponent > 0.1)
            {
                return true;
            }
            
            return false;
        }
        catch
        {
            return false;
        }
    }

    /// <summary>
    /// 提取圆角信息
    /// </summary>
    private EdgeFeatureInfo? ExtractFilletInfo(Cylinder cylinder, BrepFace face, string panelId, int index)
    {
        try
        {
            // 使用圆柱原点作为圆角位置
            var origin = cylinder.Origin;
            var center = new Point3d(
                origin.X + _originOffset.X,
                origin.Y + _originOffset.Y,
                origin.Z + _originOffset.Z
            );

            var axis = cylinder.AxisOfSymmetry.GetNormal();

            return new EdgeFeatureInfo
            {
                Id = $"{panelId}_fillet_{index:D3}",
                Type = "fillet",
                Position = new double[] 
                { 
                    Math.Round(center.X, 2), 
                    Math.Round(center.Y, 2), 
                    Math.Round(center.Z, 2) 
                },
                Direction = new double[] 
                { 
                    Math.Round(axis.X, 4), 
                    Math.Round(axis.Y, 4), 
                    Math.Round(axis.Z, 4) 
                },
                Radius = Math.Round(cylinder.Radius, 2),
                Length = 0, // 长度无法准确获取
                PanelId = panelId
            };
        }
        catch
        {
            return null;
        }
    }

    /// <summary>
    /// 提取倒角信息
    /// </summary>
    private EdgeFeatureInfo? ExtractChamferInfo(Plane plane, BrepFace face, string panelId, int index)
    {
        try
        {
            // 使用平面原点作为倒角位置
            var origin = plane.PointOnPlane;
            var center = new Point3d(
                origin.X + _originOffset.X,
                origin.Y + _originOffset.Y,
                origin.Z + _originOffset.Z
            );

            var normal = plane.Normal.GetNormal();

            return new EdgeFeatureInfo
            {
                Id = $"{panelId}_chamfer_{index:D3}",
                Type = "chamfer",
                Position = new double[] 
                { 
                    Math.Round(center.X, 2), 
                    Math.Round(center.Y, 2), 
                    Math.Round(center.Z, 2) 
                },
                Direction = new double[] 
                { 
                    Math.Round(normal.X, 4), 
                    Math.Round(normal.Y, 4), 
                    Math.Round(normal.Z, 4) 
                },
                Size = 0,  // 倒角尺寸（无法准确获取）
                Length = 0,
                PanelId = panelId
            };
        }
        catch
        {
            return null;
        }
    }
}

/// <summary>
/// 边缘特征信息（倒角/圆角）
/// </summary>
public class EdgeFeatureInfo
{
    /// <summary>
    /// 特征 ID
    /// </summary>
    public string Id { get; set; } = "";

    /// <summary>
    /// 特征类型: "fillet"（圆角）| "chamfer"（倒角）
    /// </summary>
    public string Type { get; set; } = "";

    /// <summary>
    /// 特征中心位置 [X, Y, Z] (mm)
    /// </summary>
    public double[] Position { get; set; } = new double[3];

    /// <summary>
    /// 特征方向/法向量 [X, Y, Z]
    /// </summary>
    public double[] Direction { get; set; } = new double[3];

    /// <summary>
    /// 圆角半径 (mm)，仅用于 fillet 类型
    /// </summary>
    public double? Radius { get; set; }

    /// <summary>
    /// 倒角尺寸 (mm)，仅用于 chamfer 类型
    /// </summary>
    public double? Size { get; set; }

    /// <summary>
    /// 特征长度 (mm)
    /// </summary>
    public double Length { get; set; }

    /// <summary>
    /// 所属板材 ID
    /// </summary>
    public string PanelId { get; set; } = "";
}