using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Threading.Tasks;
using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using Emgu.CV.Util;
using WingServerCommon.Log;

namespace WingAIDiagnosisService.Carotid.Utilities
{
    /// <summary>
    /// 可能是血管的边缘线
    /// </summary>
    public struct EdgeLines
    {
        public List<Point> UpperLinePoints;
        public List<Point> LowerLinePoints;
    }

    //检测血管
    public class DetectVessel
    {
        //相邻血管边缘差
        private const int DiffHeight = 5;
        //候选血管面积差
        private const int DiffArea = 200;

        /// <summary>
        /// 边缘点
        /// </summary>
        private struct EdgePoints
        {
            public Point StartPoint;
            public Point EndPoint;
        }

        /// <summary>
        /// 可能是血管的边缘线
        /// </summary>
        private struct VesselEdgeLines
        {
            public List<Point> StartLine;
            public List<Point> EndLine;
            //血管外接矩阵
            public Rectangle VesselRectangle;
            //血管高度方差
            public float HeightStd;
            //血管平均高度
            public float AvgHeight;
            //血管宽度
            public int VesselWidth;
            //血管面积
            public int Area;
        }

        /// <summary>
        /// 获得血管所在区域rect
        /// </summary>
        /// <param name="imgGray"></param>
        /// <returns></returns>
        public EdgeLines GetVessel(Image<Gray, byte> imgGray)
        {
            try
            {
                //血管最小高度 399 * 0.08
                var minVesselH = (int)(imgGray.Height * VesselConstParameter.MinVesslHeightRatio);
                //血管最小位置 399 * 0.1
                var minVesselPositionY = (int)(imgGray.Height * VesselConstParameter.MinVesselPositionRatio);
                //血管最小宽度 813 * 0.025
                var minVesselW = (int)(imgGray.Width * VesselConstParameter.MinVesselWidthRatio);
                using (var imageBri = ImagePreprocessing(imgGray, minVesselH))
                {
                    //所有可能的上下血管端点
                    var allEdgePoints = GetAllEdgePoints(imageBri);
                    //寻找可能的血管边缘
                    var allVesselLines = GetAllVesselEdgeLines(allEdgePoints, imageBri.Width, minVesselH);
                    //计算相邻连通域间的黑色区域高度的方差和均值 
                    CalculationVesselLinesAttributes(allVesselLines);
                    //血管筛选
                    var vesselLineList = allVesselLines.Where(m =>
                        m.VesselWidth > minVesselW && m.AvgHeight > minVesselH &&
                        m.VesselRectangle.Top > minVesselPositionY).ToList();

                    if (vesselLineList.Count == 0)
                    {
                        return new EdgeLines
                        {
                            UpperLinePoints = new List<Point>(),
                            LowerLinePoints = new List<Point>()
                        };
                    }

                    vesselLineList = FilterVesselByAiResult(vesselLineList).ToList();

                    //得到最符合条件的血管边缘
                    vesselLineList =vesselLineList.OrderByDescending(o => o.Area).ToList();
                    //如果有两个以上候选
                    if (vesselLineList.Count > 1)
                    {
                        //如果两个面积相差不大
                        if (vesselLineList[0].Area - vesselLineList[1].Area < DiffArea)
                        {
                            //如果面积大的比面积小的血管高度方差大很多，则选第二个候选项作为血管
                            if (vesselLineList[0].HeightStd - vesselLineList[1].HeightStd > VesselConstParameter.DiffStd)
                            {
                                return new EdgeLines
                                {
                                    UpperLinePoints = vesselLineList[1].StartLine,
                                    LowerLinePoints = vesselLineList[1].EndLine
                                };
                            }
                        }
                    }

                    return new EdgeLines
                    {
                        UpperLinePoints = vesselLineList[0].StartLine,
                        LowerLinePoints = vesselLineList[0].EndLine
                    };
                }
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel GetVessel error," + e.Message + "," + e.StackTrace);
                return new EdgeLines();
            }
        }

        private IEnumerable<VesselEdgeLines> FilterVesselByAiResult(IEnumerable<VesselEdgeLines> inputLines)
        {
            var vesselYEdge = GetModelVesselAndPlaque.Instance.GetVesselYEdge();
            var filteredVessel = inputLines.Where(m => m.VesselRectangle.Bottom > vesselYEdge.AvgTop && m.VesselRectangle.Top < vesselYEdge.AvgBottom).ToList();
            if (filteredVessel.Count > 0)
            {
                return filteredVessel;
            }

            return inputLines;
        }

        /// <summary>
        /// 图像预处理
        /// </summary>
        /// <param name="imgGray"></param>
        /// <returns></returns>
        private Image<Gray, byte> ImagePreprocessing(Image<Gray, byte> imgGray, int minVesselH)
        {
            var imageBri = new Image<Gray, byte>(imgGray.Width, imgGray.Height);
            try
            {
                //图像增强
                CvInvoke.EqualizeHist(imgGray, imgGray);
                //二值化
                var threshold = ImageTools.GetThreshold(imgGray);
                CvInvoke.Threshold(imgGray, imageBri, threshold, 255, ThresholdType.Binary);
                //中值滤波去噪点
                CvInvoke.MedianBlur(imageBri, imageBri, 3);
                //反转二值化图像
                CvInvoke.Threshold(imageBri, imageBri, 100, 255, ThresholdType.BinaryInv);
                //去除杂质
                RemoveNonVessel(imageBri, false, minVesselH);
                //反转二值化图像
                CvInvoke.Threshold(imageBri, imageBri, 100, 255, ThresholdType.BinaryInv);
                //去掉边缘周围的杂质
                RemoveNonVessel(imageBri, true, minVesselH);
                return imageBri;
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel ImagePreprocessing error," + e.Message + "," + e.StackTrace);
                return imageBri;
            }
        }
     
        /// <summary>
        /// 计算血管线的属性
        /// </summary>
        /// <param name="allVesselLines"></param>
        private void CalculationVesselLinesAttributes(List<VesselEdgeLines> allVesselLines)
        {
            var count1 = allVesselLines.Count;
            for (var j = 0; j < count1; ++j)
            {
                var startLine = allVesselLines[j].StartLine;
                var endLine = allVesselLines[j].EndLine;

                var count = startLine.Count;
                var vesselHeight = new int[count];
                var sumHeight = 0;

                var minY = int.MaxValue;
                var maxY = 0;
                for (var i = 0; i < count; ++i)
                {
                    var startY = startLine[i].Y;
                    var endY = endLine[i].Y;
                    if (startY < minY)
                    {
                        minY = startY;
                    }
                    if (endY > maxY)
                    {
                        maxY = endY;
                    }
                    vesselHeight[i] = endY - startY;
                    sumHeight += vesselHeight[i];
                }

                var avgHeight = sumHeight / (float)count;
                float sumStd = 0;
                for (var i = 0; i < count; ++i)
                {
                    var diff = vesselHeight[i] - avgHeight;
                    sumStd += diff * diff;
                }

                sumStd = (float)Math.Sqrt(sumStd / count);
                allVesselLines[j] = new VesselEdgeLines
                {
                    StartLine = startLine,
                    EndLine = endLine,
                    AvgHeight = avgHeight,
                    HeightStd = sumStd,
                    Area = sumHeight,
                    VesselWidth = count,
                    VesselRectangle = new Rectangle(new Point(startLine[0].X, minY), new Size(startLine.Last().X - startLine[0].X, maxY - minY))
                };
            }
        }

        /// <summary>
        /// 获得所有的边缘点
        /// </summary>
        /// <param name="imageGray"></param>
        /// <returns></returns>
        private List<EdgePoints>[] GetAllEdgePoints(Image<Gray, byte> imageGray)
        {
            try
            {
                var parallelOption = new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount };
                var width = imageGray.Width;
                var height = imageGray.Height;
                var allEdgePoints = new List<EdgePoints>[width];

                var dataArray = new byte[width][];
                Parallel.For(0, width, parallelOption, w =>
                {
                    dataArray[w] = new byte[height];
                    for (var h = 1; h != height; ++h)
                    {
                        dataArray[w][h] = imageGray.Data[h, w, 0];
                    }
                    allEdgePoints[w] = GetOneRowEdgePoints(dataArray[w], w);
                });
                return allEdgePoints;
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel GetAllEdgePoints error," + e.Message + "," + e.StackTrace);
                return new List<EdgePoints>[0];
            }
        }

        /// <summary>
        /// 获得一列图像的开始点和结束点
        /// </summary>
        /// <param name="dataArray"></param>
        /// <param name="w"></param>
        /// <returns></returns>
        private List<EdgePoints> GetOneRowEdgePoints(byte[] dataArray, int w)
        {
            var startPoint = new Point();
            var start = false;
            var height = dataArray.Length;
            var edgeList = new List<EdgePoints>();
            var threshold = 100;
            for (var h = 1; h < height - 1; ++h)
            {
                var data = dataArray[h];
                if (data > threshold)
                {
                    if (!start)
                    {
                        start = true;
                    }
                }
                else
                {
                    if (start)
                    {
                        var dataLast = dataArray[h - 1];
                        var dataNext = dataArray[h + 1];
                        if (dataLast > threshold)
                        {
                            startPoint = new Point(w, h);
                        }

                        if (dataNext > threshold)
                        {
                            edgeList.Add(new EdgePoints
                            {
                                StartPoint = startPoint,
                                EndPoint = new Point(w, h)
                            });
                            start = false;
                        }
                    }
                }
            }
            return edgeList;
        }

        /// <summary>
        /// 获得所有血管边缘
        /// </summary>
        /// <param name="allEdgePoints"></param>
        /// <param name="width"></param>
        /// <returns></returns>
        private List<VesselEdgeLines> GetAllVesselEdgeLines(List<EdgePoints>[] allEdgePoints, int width, int minVesselH)
        {
            try
            {
                var minH = minVesselH / 3;
                //生成边缘线-----
                var lineList = new List<VesselEdgeLines>();
                for (var w = 0; w < width; ++w)
                {
                    foreach (var edgePoints in allEdgePoints[w])
                    {
                        var h = edgePoints.EndPoint.Y - edgePoints.StartPoint.Y;
                        if (h < minH)
                        {
                            continue;
                        }

                        var index = GetTheClosestContours(lineList, edgePoints);
                        if (index == -1)
                        {
                            lineList.Add(new VesselEdgeLines
                            {
                                StartLine = new List<Point> { edgePoints.StartPoint },
                                EndLine = new List<Point> { edgePoints.EndPoint }
                            });
                        }
                        else
                        {
                            lineList[index].StartLine.Add(edgePoints.StartPoint);
                            lineList[index].EndLine.Add(edgePoints.EndPoint);
                        }
                    }
                }

                return lineList;
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel GetAllVesselEdgeLines error," + e.Message + "," + e.StackTrace);
                return new List<VesselEdgeLines>();
            }
        }

        //寻找合适的points轮廓
        private int GetTheClosestContours(List<VesselEdgeLines> linePoints, EdgePoints edgePoints)
        {
            try
            {
                var count = linePoints.Count;
                if (count == 0)
                {
                    return -1;
                }

                var maxClosePointsNum = -1;
                var maxIndex = -1;
                for (var i = 0; i < count; ++i)
                {
                    var startPoint = linePoints[i].StartLine.Last();
                    var endPoint = linePoints[i].EndLine.Last();

                    var maxStart = Math.Max(startPoint.Y, edgePoints.StartPoint.Y);
                    var minEnd = Math.Min(endPoint.Y, edgePoints.EndPoint.Y);

                    if (maxStart < minEnd && edgePoints.StartPoint.X == startPoint.X + 1)
                    {
                        var height1 = endPoint.Y - startPoint.Y;
                        var height2 = edgePoints.EndPoint.Y - edgePoints.StartPoint.Y;
                        //如果两段的高都小于5，则不考虑2倍的情况
                        if (height2 < DiffHeight && height1 < DiffHeight)
                        {
                            var closePointNum = minEnd - maxStart;
                            if (closePointNum > maxClosePointsNum)
                            {
                                maxClosePointsNum = closePointNum;
                                maxIndex = i;
                            }
                        }
                        else
                        {
                            //血管高度差不超过2倍
                            if (height1 / height2 < 2 && height2 / height1 < 2)
                            {
                                var closePointNum = minEnd - maxStart;
                                if (closePointNum > maxClosePointsNum)
                                {
                                    maxClosePointsNum = closePointNum;
                                    maxIndex = i;
                                }
                            }
                        }
                    }
                }
                return maxIndex;
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel GetTheClosestContours error," + e.Message + "," + e.StackTrace);
                return -1;
            }
        }

        /// <summary>
        /// 再次去除杂质
        /// </summary>
        /// <param name="image"></param>
        private void RemoveNonVessel(Image<Gray, byte> image, bool isRemoveImpurity, int minVesselH)
        {
            try
            {
                //去掉边缘周围的杂质---
                //求连通域
                var contours = ImageTools.FindContours(image);
                var minWidth = image.Width / 5;
                if (isRemoveImpurity)
                {
                    //去掉宽度较小的连通域
                    FillSmallArea(contours, image, rect => rect.Width < minWidth);
                }
                else
                {
                    //去掉宽度或高度较小的连通域
                    FillSmallArea(contours, image, rect => rect.Width < minWidth || rect.Height < minVesselH);
                }
            }
            catch (Exception e)
            {
                Logger.WriteLineError("DetectVessel RemoveNonVessel error," + e.Message + "," + e.StackTrace);
            }
        }

        private void FillSmallArea(VectorOfVectorOfPoint contours, Image<Gray, byte> image, Func<Rectangle, bool> condition)
        {
            for (var i = 0; i < contours.Size; ++i)
            {
                var contour = contours[i];
                var rect = CvInvoke.BoundingRectangle(contour);
                if (condition(rect))
                {
                    var points = contour.ToArray();
                    if (rect.Height > rect.Width)
                    {
                        ImageTools.ChangeImageH(image, points, rect);
                    }
                    else
                    {
                        ImageTools.ChangeImageW(image, points, rect);
                    }
                }
            }
        }
    }
}