using System;
using System.IO;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Formats.Jpeg;
using SixLabors.ImageSharp.PixelFormats;

namespace MaddoShared.Benchmarks.Helpers;

/// <summary>
/// Helper class to generate test images for benchmarking.
/// </summary>
public static class TestImageGenerator
{
    public static void GenerateTestImages(
        string outputDirectory,
        int imageCount,
        int width = 4000,
        int height = 3000,
        bool includeSubfolders = false)
    {
        Directory.CreateDirectory(outputDirectory);

        var random = new Random(42);
        var encoder = new JpegEncoder { Quality = 85 };

        for (var i = 0; i < imageCount; i++)
        {
            var targetDir = outputDirectory;

            if (includeSubfolders && i % 10 == 0)
            {
                targetDir = Path.Combine(outputDirectory, $"Subfolder_{i / 10}");
                Directory.CreateDirectory(targetDir);
            }

            var filePath = Path.Combine(targetDir, $"test_image_{i:D5}.jpg");
            if (File.Exists(filePath))
            {
                continue;
            }

            using var image = new Image<Rgba32>(width, height, RandomColor(random));
            AddBenchmarkTexture(image, random);
            image.Save(filePath, encoder);
        }
    }

    public static void CleanupTestImages(string directory)
    {
        if (Directory.Exists(directory))
        {
            Directory.Delete(directory, recursive: true);
        }
    }

    private static void AddBenchmarkTexture(Image<Rgba32> image, Random random)
    {
        image.ProcessPixelRows(accessor =>
        {
            for (var shape = 0; shape < 20; shape++)
            {
                var color = RandomColor(random);
                var startX = random.Next(image.Width);
                var startY = random.Next(image.Height);
                var width = random.Next(200, Math.Min(800, image.Width) + 1);
                var height = random.Next(200, Math.Min(800, image.Height) + 1);
                var endX = Math.Min(accessor.Width, startX + width);
                var endY = Math.Min(accessor.Height, startY + height);

                for (var y = startY; y < endY; y++)
                {
                    var row = accessor.GetRowSpan(y);
                    for (var x = startX; x < endX; x++)
                    {
                        row[x] = color;
                    }
                }
            }
        });
    }

    private static Rgba32 RandomColor(Random random)
    {
        return new Rgba32(
            (byte)random.Next(256),
            (byte)random.Next(256),
            (byte)random.Next(256),
            255);
    }
}