Moved thumbnail generation from media controller to media service

1 files changed, 37 insertions, 0 deletions

diff --git a/Services/MediaService.cs b/Services/MediaService.cs
index 8c2a5e0..ccee027 100644
--- a/Services/MediaService.cs
+++ b/Services/MediaService.cs
@@ -24,6 +24,8 @@ public interface IMediaService {
 
     public void Delete(Guid media);
     public void Delete(Media media);
+    public Stream GetThumbnail(Guid media, int? width, int? height);
+    public Stream GetThumbnail(Media media, int? width, int? height);
     public string GetPath(Media media);
     public string GetPath(Media media, int width, int height);
 
@@ -206,6 +208,41 @@ public class MediaService : IMediaService {
     public void Delete(Media media) =>
         Delete(media.Guid);
 
+    public Stream GetThumbnail(Guid media, int? width, int? height) {
+        using var db = dbFactory.CreateDbContext();
+        var m = db.Media.First(m => m.Guid == media);
+        if(m is null)
+            throw new ObjectNotFoundException(media);
+
+        if(m.MimeType.Split("/")[0] != "image")
+            throw new ThumbnailException("Media object not an image", m);
+
+        using var image = new MagickImage(GetPath(m));
+
+        if(width is null && height is null)
+            throw new ThumbnailException("Both width and height cannot be null!", m);
+
+        if(width > image.Width || height > image.Height)
+            throw new ThumbnailException("Requested thumbnail size is larger than original media", m);
+
+        #pragma warning disable CS8629
+        int w = (int) (width  is not null ? width  : image.Width  * height / image.Height);
+        int h = (int) (height is not null ? height : image.Height * width  / image.Width);
+        #pragma warning restore CS8629
+
+        var thumbPath = GetPath(m, w, h);
+
+        if(!System.IO.File.Exists(thumbPath)) {
+            image.Resize(w, h);
+            image.Write(thumbPath);
+        }
+
+        return System.IO.File.OpenRead(thumbPath);
+    }
+
+    public Stream GetThumbnail(Media media, int? width, int? height) =>
+        GetThumbnail(media.Guid, width, height);
+
     public string GetPath(Media media) {
         var fileInfo = new FileInfo(
             Path.Join(