/**
  * Manage message flags.
  *
  * @param \Illuminate\Http\Request $request
  *
  * @return \Illuminate\Http\RedirectResponse
  */
 public function postManage(Request $request)
 {
     foreach ($request->input('messages') as $message_id) {
         $message = Message::find($message_id);
         if (is_null($message) || !$request->has('action')) {
             continue;
         }
         switch ($request->input('action')) {
             case 'mark_read':
                 if ($message->read == false) {
                     $message->read = true;
                     $message->save();
                 }
                 break;
             case 'mark_unread':
                 if ($message->read == true) {
                     $message->read = false;
                     $message->save();
                 }
                 break;
             case 'delete':
                 $message->delete();
                 break;
         }
     }
     return redirect()->back();
 }