feat(gallery): image detail view

internal/components/gallery/image.go

@@ -129,7 +129,7 @@ func (s *Service) GetImages(ctx context.Context) (images []Image, err error) {
 func (s *Service) GetPrevAndNext(ctx context.Context, uid string) (previous *Image, next *Image, err error) {
 	imgs, err := s.GetImages(ctx)
 	if err != nil {
-		return
+		return nil, nil, err
 	}
 
 	for i := range imgs {
@@ -137,20 +137,20 @@ func (s *Service) GetPrevAndNext(ctx context.Context, uid string) (previous *Ima
 			continue
 		}
 
-		if i-1 >= 0 {
-			previous = &imgs[i-1]
+		if i > 0 {
+			prevImg := imgs[i-1]
+			previous = &prevImg
 		}
-		if i+1 >= len(imgs) {
-			next = &imgs[i+1]
+		if i+1 < len(imgs) {
+			nextImg := imgs[i+1]
+			next = &nextImg
 		}
 
-		return
+		return previous, next, nil
 	}
 
-	err = &rest.Error{
+	return nil, nil, &rest.Error{
 		Type:    rest.ErrorTypeNotFound,
 		Message: "could not find image with uid",
 	}
-
-	return
 }