Kynareth/src/Managers/ImageMagiker.cs

using Exsersewo.Common.Utilities;
using ImageMagick;

namespace Kynareth.Managers;

public class ImageMagiker : ImageModifier
{
	public async Task<(MemoryStream data, string contentType)> GetLiquidRescaledImageAsync(string image, CancellationToken cancellationToken)
	{
		while (true)
		{
			if (cancellationToken.IsCancellationRequested)
			{
				return (null, null);
			}
			
			var imageStream = await HttpWebClient.GetStreamAsync(new Uri(image)).ConfigureAwait(false);
		
			using var magikImage = new MagickImageCollection(imageStream);

			Parallel.ForEach(magikImage, LiquidResizeFrame);

			MemoryStream stream = new();

			magikImage.Write(stream);

			stream.Position = 0;

			magikImage.Dispose();

			string cType = "image/png";

			if (magikImage.Count > 1) cType = "image/gif";

			return (stream, cType);
		}
	}

	static void LiquidResizeFrame(IMagickImage<byte> frame)
	{
		int originalWidth = frame.Width;
		int originalHeight = frame.Height;

		frame.Resize(800, 600);

		frame.LiquidRescale(new MagickGeometry
		{
			X = 1,
			Width = Convert.ToInt32(frame.Width * 0.5),
			Height = Convert.ToInt32(frame.Height * 0.5)
		});

		frame.LiquidRescale(new MagickGeometry
		{
			X = 2,
			Width = Convert.ToInt32(frame.Width * 1.5),
			Height = Convert.ToInt32(frame.Height * 1.5)
		});

		frame.Resize(originalWidth, originalHeight);
	}
}