using OpenCvSharp;
using OpenCvSharp.Aruco;
using TraceCad.Vision.Calibration;
using Xunit;

namespace TraceCad.Tests;

public sealed class SheetCalibratorTests
{
    [Fact]
    public void CalibrateDetectsSyntheticA4SheetMarkers()
    {
        const double pixelsPerMillimetre = 4.0;
        var template = ReferenceSheetTemplate.DefaultA4();
        using var sheet = new Mat(
            (int)Math.Round(template.HeightMm * pixelsPerMillimetre),
            (int)Math.Round(template.WidthMm * pixelsPerMillimetre),
            MatType.CV_8UC3,
            Scalar.White);
        var dictionary = CvAruco.GetPredefinedDictionary(PredefinedDictionaryName.Dict5X5_1000);

        foreach (var marker in template.Markers)
        {
            using var markerImage = new Mat();
            dictionary.GenerateImageMarker(
                marker.Id,
                (int)Math.Round(marker.SizeMm * pixelsPerMillimetre),
                markerImage,
                1);
            using var markerColor = new Mat();
            Cv2.CvtColor(markerImage, markerColor, ColorConversionCodes.GRAY2BGR);

            var target = new Rect(
                (int)Math.Round(marker.TopLeftMm.X * pixelsPerMillimetre),
                (int)Math.Round(marker.TopLeftMm.Y * pixelsPerMillimetre),
                markerColor.Width,
                markerColor.Height);
            markerColor.CopyTo(new Mat(sheet, target));
        }

        var tempDirectory = Directory.CreateTempSubdirectory("easytrace-calibration-test-").FullName;
        try
        {
            var imagePath = Path.Combine(tempDirectory, "sheet.png");
            Cv2.ImWrite(imagePath, sheet);

            var result = new SheetCalibrator().Calibrate(imagePath, tempDirectory, template);

            Assert.True(result.Success, result.Message);
            Assert.Equal(8, result.MatchedMarkerCount);
            Assert.Equal(0.125, result.MmPerPixel, 9);
            Assert.Equal("perspective + marker residual warp", result.CorrectionMode);
            Assert.True(File.Exists(result.CorrectedImagePath));
        }
        finally
        {
            Directory.Delete(tempDirectory, recursive: true);
        }
    }
}