Laravel 5.6 download file ajax

I have a REST API in Laravel 5.6

The users can upload theirs file in a non-public folder.

My problem is that now I want to let the user download the file only if the JWT token is valid and if the user has the right privilege.

My actual code is the following:

jquery:

$.ajaxSetup({
    headers: {
        'Authorization': 'Bearer ' + token
});

$.get('/api//download?' + $.param({
     file: encodeURIComponent(fileNonPublicPath) //e.g. company_id/file.pdf
}))
.done((data) => {
     console.log('file content', data);
})
.fail((err) => {
      console.error(err);
});

Laravel Controller:

$file = urldecode($request->input('file'));
$user = JWTAuth::toUser($request->token);
if(checkUserRole($user,$file){
   $pathToFile = Storage::disk('documents')->getDriver()->getAdapter()->applyPathPrefix($file);
   $finfo = finfo_open(FILEINFO_MIME_TYPE);
   $mime = finfo_file($finfo, $pathToFile);
   finfo_close($finfo);
   $headers = array('Content-Type' => $mime,);
   return response()->download($pathToFile, 'originalfilename', $headers);
}
return response()->json([], 403); //forbidden

This code is working fine except that the browser receive the content of the file in ajax and then the user cannot download it.

What is the solution not compromising the security of the stored files?

via Chebli Mohamed