Catalog/MaddoShared.ImageSharpTests/Tests/TextPositioningTests.cs

using System.IO;
using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using SixLabors.ImageSharp.PixelFormats;
using MaddoShared.ImageSharpTests.Helpers;

namespace MaddoShared.ImageSharpTests.Tests
{
    [TestClass]
    public class TextPositioningTests
    {
        [TestMethod]
        public async Task TextAtBottom_IncreasesNonBackgroundPixelCountInBottomBand()
        {
            using var ws = new TempWorkspace();

            // create white background input
            var inputPath = TestImageFactory.CreateSolidJpeg(ws.SourceDir.FullName, "input.jpg", 800, 600, new Rgba32(255, 255, 255, 255));

            var pic = CreatorFactory.CreateDefaultPicSettings();
            pic.Posizione = "BASSO";
            pic.DimStandard = 48; // big text
            pic.TestoFirmaStart = "SAMPLE TEXT";
            pic.CreaMiniature = false;

            var svc = CreatorFactory.CreateImageCreator(pic);

            var state = new MaddoShared.ImageState
            {
                WorkFile = new FileInfo(inputPath),
                DestDir = ws.DestDir,
                SourceDir = ws.SourceDir
            };

            await svc.CreateImageAsync(state, null);

            var outPath = Path.Combine(ws.DestDir.FullName, state.NomeFileBig);

            // bottom band (lower 25% of image)
            var bottomY = (int)(600 * 0.75);
            var bottomCount = PixelInspector.CountNonBackgroundPixels(outPath, 0, bottomY, 800, 600 - bottomY, new Rgba32(255, 255, 255, 255), tolerance: 10);

            // top band (upper 25%)
            var topCount = PixelInspector.CountNonBackgroundPixels(outPath, 0, 0, 800, (int)(600 * 0.25), new Rgba32(255, 255, 255, 255), tolerance: 10);

            Assert.IsTrue(bottomCount > 50, $"Expected text pixels in bottom band, found {bottomCount}");
            Assert.IsTrue(bottomCount > topCount, "Expected more non-background pixels at bottom than top");
        }
    }
}