From b7ad9d539cc70d372143b64477878a47ef382496 Mon Sep 17 00:00:00 2001
From: jamesmoore <jamesmoore@github.com>
Date: Fri, 21 Aug 2026 17:44:35 +0100
Subject: [PATCH] detect mime type

---
 SDMetaUI/Controllers/ImagesController.cs | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/SDMetaUI/Controllers/ImagesController.cs b/SDMetaUI/Controllers/ImagesController.cs
index 5e9a6c9..40d9c04 100644
--- a/SDMetaUI/Controllers/ImagesController.cs
+++ b/SDMetaUI/Controllers/ImagesController.cs
@@ -1,10 +1,13 @@
-using SDMetaUI.Services;
+using Microsoft.AspNetCore.StaticFiles;
+using SDMetaUI.Services;
 using System.IO.Abstractions;
 
 namespace SDMetaUI.Controllers
 {
     public class ImagesController()
     {
+        private static readonly FileExtensionContentTypeProvider ContentTypeProvider = new();
+
         public static IResult GetThumb(
             IFileSystem fileSystem,
             IThumbnailService thumbnailService,
@@ -22,7 +25,7 @@ public static IResult GetThumb(
                     var thumbPath = thumbnailService.GetOrGenerateThumbnail(fileInfo.FullName);
                     httpResponse.Headers.LastModified = fileInfo.LastWriteTimeUtc.ToString("R");
 
-                    return Results.File(thumbPath, "image/jpg");
+                    return Results.File(thumbPath, GetContentType(thumbPath));
                 }
                 else
                 {
@@ -49,7 +52,7 @@ public static IResult GetFull(
                 {
                     EnableCaching(httpResponse);
                     httpResponse.Headers.LastModified = fileSystem.FileInfo.New(physicalPath).LastWriteTimeUtc.ToString("R");
-                    return Results.File(physicalPath, "image/png");
+                    return Results.File(physicalPath, GetContentType(physicalPath));
                 }
                 else
                 {
@@ -69,6 +72,13 @@ private static string Base32Decode(string base32EncodedData)
             return System.Text.Encoding.UTF8.GetString(base32EncodedBytes);
         }
 
+        private static string GetContentType(string path)
+        {
+            return ContentTypeProvider.TryGetContentType(path, out var contentType)
+                ? contentType
+                : "application/octet-stream";
+        }
+
         private static void EnableCaching(HttpResponse httpResponse)
         {
             httpResponse.Headers.CacheControl = "public, max-age=31536000, immutable";