Fixed aspect ratio of user images wrong, added new user default image

src/Helpers/ImageHelper.cs

@@ -2,6 +2,7 @@ using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.Formats.Webp;
 using SixLabors.ImageSharp.Formats;
 using Berufsschule_HAM.Models;
+using SixLabors.ImageSharp.Processing;
 
 namespace Berufsschule_HAM.Helpers;
 
@@ -30,6 +31,23 @@ public static class ImageHelper
 
             using var image = Image.Load(decoderOptions, inputStream);
 
+            int minDimension = Math.Min(image.Width, image.Height);
+            var cropRectangle = new Rectangle(
+                (image.Width - minDimension) / 2,
+                (image.Height - minDimension) / 2,
+                minDimension,
+                minDimension);
+
+            image.Mutate(x =>
+            {
+                x.Crop(cropRectangle);
+                x.Resize(new ResizeOptions
+                {
+                    Size = new Size(size, size),
+                    Mode = ResizeMode.Crop
+                });
+            });
+
             using var outputStream = new MemoryStream();
             image.Save(outputStream, new WebpEncoder());
             result = outputStream.ToArray();
@@ -38,6 +56,16 @@ public static class ImageHelper
         return result;
     }
 
+    public static byte[] GetDefaultUserImage(int size = 48)
+    {
+        return ResizeAndConvertToWebp(GetDefaultUserImageAsBase64(), size);
+    }
+
+    public static string GetDefaultUserImageAsBase64()
+    {
+        return Convert.ToBase64String(File.ReadAllBytes("wwwroot/user_default.webp"));
+    }
+
     public static async Task PreloadUsers(IEnumerable<UserModel> userModels, UserImagePreloadType? preloadType)
     {
         if (preloadType is null || preloadType == UserImagePreloadType.None) return;