feat: improve file handling by generating default file names and adding mime type detection

bot/utils.go

@@ -18,7 +18,6 @@ import (
 )
 
 var (
-	ErrEmptyFileName   = errors.New("file name is empty")
 	ErrEmptyDocument   = errors.New("document is empty")
 	ErrEmptyPhoto      = errors.New("photo is empty")
 	ErrEmptyPhotoSize  = errors.New("photo size is empty")
@@ -105,9 +104,6 @@ func FileFromMedia(media tg.MessageMediaClass, customFileName string) (*types.Fi
 				break
 			}
 		}
-		if fileName == "" {
-			return nil, ErrEmptyFileName
-		}
 		return &types.File{
 			Location: document.AsInputDocumentFileLocation(),
 			FileSize: document.Size,