fix: ext issues

internal/client_channel.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"mime"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"exporter/pkg/errorx"
@@ -197,9 +198,11 @@ func (t *TClient) savePhoto(ctx context.Context, cfg *DBChannel, photo *tg.Photo
 
 func (t *TClient) getExtByFilenameAndMimeType(filename, mimeType string) string {
 	ext := ""
-	if filename != "" {
-		ext = filename[strings.LastIndex(filename, "."):]
-		return ext
+	if filename != "" && strings.Contains(filename, ".") {
+		ext = filepath.Ext(filename)
+		if ext != "" {
+			return ext
+		}
 	}
 
 	exts, err := mime.ExtensionsByType(mimeType)