feat(thumb): enhance native thumbnail generater with encoding format and quality (#2868)

* feat(thumb): enhance native thumbnail generater with encoding format and quality

* Update thumbnail.go

* Update obs.go

pkg/filemanager/driver/qiniu/qiniu.go

@@ -277,10 +277,20 @@ func (handler *Driver) Delete(ctx context.Context, files ...string) ([]string, e
 // Thumb 获取文件缩略图
 func (handler *Driver) Thumb(ctx context.Context, expire *time.Time, ext string, e fs.Entity) (string, error) {
 	w, h := handler.settings.ThumbSize(ctx)
+	thumbParam := fmt.Sprintf("imageView2/1/w/%d/h/%d", w, h)
+
+	enco := handler.settings.ThumbEncode(ctx)
+	switch enco.Format {
+	case "jpg", "webp":
+		thumbParam += fmt.Sprintf("/format/%s/q/%d", enco.Format, enco.Quality)
+	case "png":
+		thumbParam += fmt.Sprintf("/format/%s", enco.Format)
+	}
+
 	return handler.signSourceURL(
 		e.Source(),
 		url.Values{
-			fmt.Sprintf("imageView2/1/w/%d/h/%d", w, h): []string{},
+			thumbParam: []string{},
 		},
 		expire,
 	), nil