public function new_sales_report()
 {
     $receipts_repo = new Receipts_Repository($this->db);
     $unreported_receipts = $receipts_repo->get_all_unreported_receipts();
     if (count($unreported_receipts) >= 1) {
         $this->db->insert('sales_reports', array('status' => Sales_Report_Status::Failed, 'created_at' => date('Y-m-d H:i:s'), 'updated_at' => date('Y-m-d H:i:s')));
         $sales_report_id = $this->db->insert_id();
         $receipts = array();
         foreach ($unreported_receipts as $unreported_receipt) {
             $receipts_repo->update_sales_report_info($unreported_receipt->id, $sales_report_id);
         }
         return $sales_report_id;
         // returns the sales_report_id
     } else {
         return 0;
         // there are no new sales to report
     }
 }