using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using OpenCvSharp;
using OpenCvSharp.Extensions;

namespace ImageCoordinateMapper
{
    public class SegmentAnalyzer
    {
        private List<System.Drawing.Point> _pointsOnImage;
        private Bitmap bmp;

        public SegmentAnalyzer(List<System.Drawing.Point> pointsOnImage, Bitmap bitmap)
        {
            _pointsOnImage = pointsOnImage;
            bmp = bitmap;
        }

        public int CalculateSquareSize()
        {
            var mostLeftPoint = _pointsOnImage.Min(p => p.X);
            var mostRightPoint = _pointsOnImage.Max(p => p.X);
            int baseWidth = mostRightPoint - mostLeftPoint;
            return (int)(0.03 * baseWidth); // Adjust the fraction if necessary
        }

        public double CalculateGrayLevelAverage(Rectangle square)
        {
            double sumGrayLevels = 0;
            int pixelCount = 0;

            for (int y = square.Top; y < square.Bottom; y++)
            {
                for (int x = square.Left; x < square.Right; x++)
                {
                    Color pixelColor = bmp.GetPixel(x, y);
                    double grayLevel = (pixelColor.R + pixelColor.G + pixelColor.B) / 3.0;
                    sumGrayLevels += grayLevel;
                    pixelCount++;
                }
            }

            return sumGrayLevels / pixelCount;
        }

        public async Task GenerateCsvFileAsync(int totalFrames, VideoCapture videoCapture, string outputFilePath, IProgress<int> progress)
        {
            int squareSize = CalculateSquareSize();
            using (StreamWriter writer = new StreamWriter(outputFilePath))
            {
                await writer.WriteLineAsync("FRAME_NUMBER,MINUS,LEFTDIGIT_TOP,LEFTDIGIT_LEFTTOP,...,RIGHTDIGIT_RIGHTBOTTOM,RIGHTDIGIT_BOTTOM");

                for (int frameNumber = 0; frameNumber < totalFrames; frameNumber++)
                {
                    videoCapture.Set(VideoCaptureProperties.PosFrames, frameNumber);
                    Mat frame = new Mat();
                    if (videoCapture.Read(frame))
                    {
                        Bitmap bitmap = BitmapConverter.ToBitmap(frame);
                        bmp = bitmap;
                        string line = $"{frameNumber}";

                        foreach (var point in _pointsOnImage)
                        {
                            Rectangle square = new Rectangle(point.X - squareSize / 2, point.Y - squareSize / 2, squareSize, squareSize);
                            double grayLevelAverage = CalculateGrayLevelAverage(square);
                            line += $",{grayLevelAverage}";
                        }

                        await writer.WriteLineAsync(line);
                    }
                    progress?.Report(frameNumber);
                }
            }
        }
    }
}