using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OpenCvSharp;

namespace TeamAAS_VP.Core
{
    public class CameraFocusAnalyzer
    {
        // 清晰度评估方法枚举
        public enum FocusMethod
        {
            Tenengrad,      // Tenengrad梯度法（推荐）
            Laplacian,      // 拉普拉斯方差法
            Brenner,        // Brenner梯度法
            GrayVariance,   // 灰度方差法
            SMD             // 灰度差分法
        }

        /// <summary>
        /// 计算图像清晰度（多种方法）
        /// </summary>
        public static double CalculateImageSharpness(Mat image, FocusMethod method = FocusMethod.Tenengrad, Rect? roi = null)
        {
            if (image == null || image.Empty())
                throw new ArgumentException("输入图像无效");

            // 转换为灰度图
            Mat gray = new Mat();
            if (image.Channels() == 3)
                Cv2.CvtColor(image, gray, ColorConversionCodes.BGR2GRAY);
            else
                gray = image.Clone();

            // 应用ROI
            if (roi.HasValue)
            {
                gray = new Mat(gray, roi.Value);
            }

            double sharpness = 0;

            switch (method)
            {
                case FocusMethod.Tenengrad:
                    sharpness = CalculateTenengrad(gray);
                    break;
                case FocusMethod.Laplacian:
                    sharpness = CalculateLaplacianVariance(gray);
                    break;
                case FocusMethod.Brenner:
                    sharpness = CalculateBrenner(gray);
                    break;
                case FocusMethod.GrayVariance:
                    sharpness = CalculateGrayVariance(gray);
                    break;
                case FocusMethod.SMD:
                    sharpness = CalculateSMD(gray);
                    break;
            }

            gray.Dispose();
            return sharpness;
        }

        /// <summary>
        /// Tenengrad梯度法（对噪声敏感度较低）
        /// </summary>
        private static double CalculateTenengrad(Mat gray)
        {
            Mat gradX = new Mat();
            Mat gradY = new Mat();
            Mat magnitude = new Mat();

            Cv2.Sobel(gray, gradX, MatType.CV_32F, 1, 0, 3);
            Cv2.Sobel(gray, gradY, MatType.CV_32F, 0, 1, 3);
            Cv2.Magnitude(gradX, gradY, magnitude);

            Scalar mean = Cv2.Mean(magnitude);

            gradX.Dispose();
            gradY.Dispose();
            magnitude.Dispose();

            return mean.Val0;
        }

        /// <summary>
        /// 拉普拉斯方差法（对边缘敏感）
        /// </summary>
        private static double CalculateLaplacianVariance(Mat gray)
        {
            Mat laplacian = new Mat();
            Cv2.Laplacian(gray, laplacian, MatType.CV_32F);

            Mat mean = new Mat();
            Mat stdDev = new Mat();
            Cv2.MeanStdDev(laplacian, mean, stdDev);

            double variance = stdDev.Get<double>(0);
            variance = variance * variance;

            laplacian.Dispose();
            mean.Dispose();
            stdDev.Dispose();

            return variance;
        }

        /// <summary>
        /// Brenner梯度法（简单快速）
        /// </summary>
        private static double CalculateBrenner(Mat gray)
        {
            double sum = 0;
            int width = gray.Cols;
            int height = gray.Rows;

            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width - 2; x++)
                {
                    int diff = gray.Get<byte>(y, x + 2) - gray.Get<byte>(y, x);
                    sum += diff * diff;
                }
            }

            return sum / (width * height);
        }

        /// <summary>
        /// 灰度方差法
        /// </summary>
        private static double CalculateGrayVariance(Mat gray)
        {
            Mat mean = new Mat();
            Mat stdDev = new Mat();
            Cv2.MeanStdDev(gray, mean, stdDev);

            double variance = stdDev.Get<double>(0);
            variance = variance * variance;

            mean.Dispose();
            stdDev.Dispose();

            return variance;
        }

        /// <summary>
        /// 灰度差分法（SMD）
        /// </summary>
        private static double CalculateSMD(Mat gray)
        {
            double sum = 0;
            int width = gray.Cols;
            int height = gray.Rows;

            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width - 1; x++)
                {
                    sum += Math.Abs(gray.Get<byte>(y, x + 1) - gray.Get<byte>(y, x));
                }
            }

            for (int y = 0; y < height - 1; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    sum += Math.Abs(gray.Get<byte>(y + 1, x) - gray.Get<byte>(y, x));
                }
            }

            return sum / (width * height);
        }

        /// <summary>
        /// 智能棋盘格对比度分析（简化版）
        /// </summary>
        /// <param name="image">输入图像</param>
        /// <param name="roi">检测区域（可选）</param>
        /// <returns>对比度分析结果，包含黑白均值、对比度和亮度建议</returns>
        public static CheckerboardContrastResult AnalyzeCheckerboardContrast(Mat image, Rect? roi = null)
        {
            var result = new CheckerboardContrastResult
            {
                Success = false,
                BlackMean = 0,
                WhiteMean = 0,
                Contrast = 0,
                OptimalBrightness = 128
            };

            if (image == null || image.Empty())
                return result;

            try
            {
                // 转换为灰度图
                Mat gray = new Mat();
                if (image.Channels() == 3)
                    Cv2.CvtColor(image, gray, ColorConversionCodes.BGR2GRAY);
                else
                    gray = image.Clone();

                // 应用ROI
                if (roi.HasValue)
                {
                    gray = new Mat(gray, roi.Value);
                }

                // 1. 自适应检测棋盘格角点
                var corners = DetectCheckerboardCorners(gray);
                if (corners == null || corners.Length < 20) // 至少需要一定数量的角点
                {
                    gray.Dispose();
                    return result;
                }

                // 2. 自动分析网格结构
                var gridInfo = AnalyzeGridStructure(corners);
                if (!gridInfo.IsValid)
                {
                    gray.Dispose();
                    return result;
                }

                // 3. 采样黑白格子像素
                SampleCheckerboardColors(gray, corners, gridInfo,
                    out double blackMean, out double whiteMean, out int sampleCount);

                if (sampleCount > 0)
                {
                    result.BlackMean = blackMean;
                    result.WhiteMean = whiteMean;
                    result.Contrast = Math.Abs(whiteMean - blackMean);
                    result.OptimalBrightness = CalculateOptimalBrightness(blackMean, whiteMean);
                    result.Success = true;

                    // 计算图像质量评分
                    result.QualityScore = CalculateQualityScore(result.Contrast, blackMean, whiteMean);
                }

                gray.Dispose();
                return result;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"棋盘格分析出错: {ex.Message}");
                return result;
            }
        }

        /// <summary>
        /// 自适应检测棋盘格角点
        /// </summary>
        private static Point2f[] DetectCheckerboardCorners(Mat gray)
        {
            // 首先尝试标准的棋盘格检测
            for (int boardWidth = 5; boardWidth <= 15; boardWidth++)
            {
                for (int boardHeight = 5; boardHeight <= 15; boardHeight++)
                {
                    Size patternSize = new Size(boardWidth, boardHeight);
                    Point2f[] corners;

                    bool found = Cv2.FindChessboardCorners(gray, patternSize, out corners,
                        ChessboardFlags.AdaptiveThresh |
                        ChessboardFlags.NormalizeImage |
                        ChessboardFlags.FastCheck);

                    if (found && corners.Length > 0)
                    {
                        // 提高角点精度
                        Mat grayFloat = new Mat();
                        gray.ConvertTo(grayFloat, MatType.CV_32F);
                        Cv2.CornerSubPix(grayFloat, corners, new Size(5, 5), new Size(-1, -1),
                            new TermCriteria(CriteriaTypes.Eps | CriteriaTypes.MaxIter, 30, 0.1));
                        grayFloat.Dispose();

                        return corners;
                    }
                }
            }

            // 如果标准方法失败，尝试使用角点检测
            return DetectCornersByHarris(gray);
        }

        /// <summary>
        /// 使用Harris角点检测作为备选方案
        /// </summary>
        private static Point2f[] DetectCornersByHarris(Mat gray)
        {
            Mat cornersMat = new Mat();
            Mat grayFloat = new Mat();
            gray.ConvertTo(grayFloat, MatType.CV_32F);

            // Harris角点检测
            Cv2.CornerHarris(grayFloat, cornersMat, 2, 3, 0.04);

            // 找到局部最大值
            var corners = new List<Point2f>();
            double maxVal = 0;
            Cv2.MinMaxLoc(cornersMat, out _, out maxVal);

            float threshold = (float)(maxVal * 0.01);

            for (int y = 0; y < cornersMat.Rows; y++)
            {
                for (int x = 0; x < cornersMat.Cols; x++)
                {
                    float value = cornersMat.Get<float>(y, x);
                    if (value > threshold)
                    {
                        // 检查是否是局部最大值
                        bool isLocalMax = true;
                        int neighborhood = 5;

                        for (int dy = -neighborhood; dy <= neighborhood && isLocalMax; dy++)
                        {
                            for (int dx = -neighborhood; dx <= neighborhood && isLocalMax; dx++)
                            {
                                int ny = y + dy;
                                int nx = x + dx;

                                if (ny >= 0 && ny < cornersMat.Rows &&
                                    nx >= 0 && nx < cornersMat.Cols &&
                                    !(dy == 0 && dx == 0))
                                {
                                    if (cornersMat.Get<float>(ny, nx) > value)
                                    {
                                        isLocalMax = false;
                                    }
                                }
                            }
                        }

                        if (isLocalMax)
                        {
                            corners.Add(new Point2f(x, y));
                        }
                    }
                }
            }

            grayFloat.Dispose();
            cornersMat.Dispose();

            return corners.ToArray();
        }

        /// <summary>
        /// 分析网格结构
        /// </summary>
        private static GridStructureInfo AnalyzeGridStructure(Point2f[] corners)
        {
            var info = new GridStructureInfo();

            if (corners.Length < 9) // 至少3x3网格
                return info;

            // 估计网格间距
            List<double> distances = new List<double>();
            for (int i = 0; i < corners.Length; i++)
            {
                for (int j = i + 1; j < Math.Min(i + 10, corners.Length); j++) // 限制检查数量
                {
                    double dist = Math.Sqrt(Math.Pow(corners[j].X - corners[i].X, 2) +
                                           Math.Pow(corners[j].Y - corners[i].Y, 2));
                    if (dist > 5) // 忽略太近的点
                        distances.Add(dist);
                }
            }

            if (distances.Count == 0)
                return info;

            // 找到最常见的距离作为网格间距
            distances.Sort();
            double estimatedSpacing = distances[distances.Count / 2]; // 中位数

            // 对角落点进行排序（按大致位置）
            var sortedCorners = corners.OrderBy(p => p.Y).ThenBy(p => p.X).ToArray();

            // 尝试分组到行和列
            double tolerance = estimatedSpacing * 0.3;

            info.IsValid = true;
            info.EstimatedSpacing = estimatedSpacing;
            info.Corners = sortedCorners;

            return info;
        }

        /// <summary>
        /// 采样棋盘格颜色
        /// </summary>
        private static void SampleCheckerboardColors(Mat gray, Point2f[] corners, GridStructureInfo gridInfo,
            out double blackMean, out double whiteMean, out int sampleCount)
        {
            blackMean = 0;
            whiteMean = 0;
            int blackCount = 0;
            int whiteCount = 0;
            sampleCount = 0;

            double spacing = gridInfo.EstimatedSpacing;
            int sampleRadius = (int)(spacing * 0.3);

            // 对每个角点区域采样
            for (int i = 0; i < corners.Length; i++)
            {
                int x = (int)corners[i].X;
                int y = (int)corners[i].Y;

                // 采样区域
                int x1 = Math.Max(0, x - sampleRadius);
                int y1 = Math.Max(0, y - sampleRadius);
                int x2 = Math.Min(gray.Cols - 1, x + sampleRadius);
                int y2 = Math.Min(gray.Rows - 1, y + sampleRadius);

                if (x2 > x1 && y2 > y1)
                {
                    Rect roi = new Rect(x1, y1, x2 - x1, y2 - y1);
                    Mat sample = new Mat(gray, roi);
                    Scalar mean = Cv2.Mean(sample);
                    sample.Dispose();

                    double value = mean.Val0;

                    // 根据位置判断黑白（奇偶性）
                    int gridX = (int)(x / spacing);
                    int gridY = (int)(y / spacing);

                    bool isBlack = (gridX + gridY) % 2 == 0;

                    if (isBlack)
                    {
                        blackMean += value;
                        blackCount++;
                    }
                    else
                    {
                        whiteMean += value;
                        whiteCount++;
                    }

                    sampleCount++;
                }
            }

            if (blackCount > 0) blackMean /= blackCount;
            if (whiteCount > 0) whiteMean /= whiteCount;

            // 确保黑色比白色暗
            if (blackMean > whiteMean)
            {
                // 交换
                double temp = blackMean;
                blackMean = whiteMean;
                whiteMean = temp;
            }
        }

        /// <summary>
        /// 计算最佳亮度
        /// </summary>
        private static int CalculateOptimalBrightness(double blackMean, double whiteMean)
        {
            double currentMid = (blackMean + whiteMean) / 2;
            int optimal = (int)Clamp(128 + (128 - currentMid), 30, 225);
            return optimal;
        }

        public static double Clamp(double value, double min, double max)
        {
            return value < min ? min : (value > max ? max : value);
        }

        /// <summary>
        /// 计算图像质量评分
        /// </summary>
        private static double CalculateQualityScore(double contrast, double blackMean, double whiteMean)
        {
            // 对比度评分（0-100）
            double contrastScore = Math.Min(100, contrast / 2.55);

            // 亮度范围评分
            double blackScore = Math.Max(0, 100 - Math.Abs(blackMean - 30));
            double whiteScore = Math.Max(0, 100 - Math.Abs(whiteMean - 220));
            double rangeScore = (blackScore + whiteScore) / 2;

            // 综合评分
            double qualityScore = contrastScore * 0.6 + rangeScore * 0.4;

            return Math.Min(100, Math.Max(0, qualityScore));
        }

        /// <summary>
        /// 一键获取图像质量报告
        /// </summary>
        public static ImageQualityReport GetImageQualityReport(Mat image, Rect? roi = null)
        {
            var report = new ImageQualityReport();

            if (image == null || image.Empty())
                return report;

            // 计算清晰度
            report.Sharpness = CalculateImageSharpness(image, FocusMethod.Tenengrad, roi);

            // 分析棋盘格对比度
            var contrastResult = AnalyzeCheckerboardContrast(image, roi);
            if (contrastResult.Success)
            {
                report.HasCheckerboard = true;
                report.BlackMean = contrastResult.BlackMean;
                report.WhiteMean = contrastResult.WhiteMean;
                report.Contrast = contrastResult.Contrast;
                report.OptimalBrightness = contrastResult.OptimalBrightness;
                report.QualityScore = contrastResult.QualityScore;
            }
            else
            {
                // 如果没有检测到棋盘格，使用图像整体对比度
                report.HasCheckerboard = false;
                report.Contrast = CalculateGlobalContrast(image, roi);
                report.OptimalBrightness = EstimateOptimalBrightness(image, roi);
                report.QualityScore = Math.Min(100, report.Contrast / 2.0);
            }

            // 给出建议
            report.Suggestions = GenerateSuggestions(report);

            return report;
        }

        /// <summary>
        /// 计算全局对比度（无棋盘格时使用）
        /// </summary>
        private static double CalculateGlobalContrast(Mat image, Rect? roi = null)
        {
            Mat gray = new Mat();
            if (image.Channels() == 3)
                Cv2.CvtColor(image, gray, ColorConversionCodes.BGR2GRAY);
            else
                gray = image.Clone();

            if (roi.HasValue)
            {
                gray = new Mat(gray, roi.Value);
            }

            Mat mean = new Mat();
            Mat stdDev = new Mat();
            Cv2.MeanStdDev(gray, mean, stdDev);

            double contrast = stdDev.Get<double>(0) * 2; // 标准差的两倍作为对比度估计

            gray.Dispose();
            mean.Dispose();
            stdDev.Dispose();

            return contrast;
        }

        /// <summary>
        /// 估计最佳亮度（无棋盘格时使用）
        /// </summary>
        private static int EstimateOptimalBrightness(Mat image, Rect? roi = null)
        {
            Mat gray = new Mat();
            if (image.Channels() == 3)
                Cv2.CvtColor(image, gray, ColorConversionCodes.BGR2GRAY);
            else
                gray = image.Clone();

            if (roi.HasValue)
            {
                gray = new Mat(gray, roi.Value);
            }

            Scalar mean = Cv2.Mean(gray);
            double avgGray = mean.Val0;

            // 根据平均灰度调整
            int optimal;
            if (avgGray < 80)
                optimal = (int)Math.Min(255, avgGray + 80);
            else if (avgGray > 180)
                optimal = (int)Math.Max(0, avgGray - 80);
            else
                optimal = 128;

            gray.Dispose();
            return optimal;
        }

        /// <summary>
        /// 生成调整建议
        /// </summary>
        private static List<string> GenerateSuggestions(ImageQualityReport report)
        {
            var suggestions = new List<string>();

            // 清晰度建议
            if (report.Sharpness < 10)
                suggestions.Add("图像模糊，请调整焦距使图像变清晰");
            else if (report.Sharpness < 20)
                suggestions.Add("清晰度一般，可以继续微调焦距");
            else
                suggestions.Add("图像清晰度良好");

            // 对比度建议
            if (report.HasCheckerboard)
            {
                if (report.Contrast < 50)
                    suggestions.Add("棋盘格对比度过低，建议调整光源或相机参数");
                else if (report.Contrast < 100)
                    suggestions.Add("棋盘格对比度适中");
                else
                    suggestions.Add("棋盘格对比度很好");

                suggestions.Add($"建议亮度值: {report.OptimalBrightness}");
            }
            else
            {
                if (report.Contrast < 30)
                    suggestions.Add("图像整体对比度较低");
                else
                    suggestions.Add("图像对比度正常");
            }

            // 质量评分建议
            if (report.QualityScore < 60)
                suggestions.Add($"图像质量需要改进，当前评分: {report.QualityScore:F1}/100");
            else if (report.QualityScore < 80)
                suggestions.Add($"图像质量良好，当前评分: {report.QualityScore:F1}/100");
            else
                suggestions.Add($"图像质量优秀，当前评分: {report.QualityScore:F1}/100");

            return suggestions;
        }
    }

    // 辅助数据结构
    public class CheckerboardContrastResult
    {
        public bool Success { get; set; }
        public double BlackMean { get; set; }
        public double WhiteMean { get; set; }
        public double Contrast { get; set; }
        public int OptimalBrightness { get; set; }
        public double QualityScore { get; set; }
    }

    public class GridStructureInfo
    {
        public bool IsValid { get; set; }
        public double EstimatedSpacing { get; set; }
        public Point2f[] Corners { get; set; }
    }

    public class ImageQualityReport
    {
        public double Sharpness { get; set; }
        public bool HasCheckerboard { get; set; }
        public double BlackMean { get; set; }
        public double WhiteMean { get; set; }
        public double Contrast { get; set; }
        public int OptimalBrightness { get; set; }
        public double QualityScore { get; set; }
        public List<string> Suggestions { get; set; } = new List<string>();
    }
}