Import Excel dengan Phpspreadsheet

public function read_xls( $file_name = null )
    {
        $inputFileName = './assets/uploads/files/'.$file_name;
        // $helper->log('Loading file ' . pathinfo($inputFileName, PATHINFO_BASENAME) . ' using IOFactory to identify the format');
        $spreadsheet = IOFactory::load($inputFileName);
        $worksheet = $spreadsheet->getActiveSheet();
        // echo date("Y-m-d H:i:s", strtotime( $worksheet->getCell('G2')->getValue() ) );

        $highestRow = $worksheet->getHighestRow(); // e.g. 10
        $highestColumn = $worksheet->getHighestColumn(); // e.g 'F'
        $highestColumnIndex = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::columnIndexFromString($highestColumn); // e.g. 5
        $data_input = array();
        $data_uncrew = array();

        for ($row = 2; $row <= $highestRow; ++$row)
        {
            $id_teknisi = $this->admin->get_id_teknisi_by_kode( $worksheet->getCell('M'.$row)->getValue() );
            $input = array(
                'id_insiden' => $worksheet->getCell('A'.$row)->getValue(),
                'customer_name' => $worksheet->getCell('B'.$row)->getValue(),
                'contact_name' => $worksheet->getCell('C'.$row)->getValue(),
                'contact_phone' => $worksheet->getCell('D'.$row)->getValue(),
                'contact_email' => $worksheet->getCell('E'.$row)->getValue(),
                'summary' => $worksheet->getCell('F'.$row)->getValue(),
                'owner_group' => implode('_', explode(' ',  filter_var($worksheet->getCell('G'.$row)->getValue(), FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH ) ) ),
                'owner' => $worksheet->getCell('H'.$row)->getValue(),
                'last_updated_work_log' => $worksheet->getCell('I'.$row)->getValue(),
                'last_work_log_date' => date("Y-m-d H:i:s", strtotime( $worksheet->getCell('J'.$row)->getValue() ) ),
                'count_customer_info' => $worksheet->getCell('K'.$row)->getValue(),
                'last_customer_info' => $worksheet->getCell('L'.$row)->getValue(),
                'id_teknisi' => $id_teknisi,
                'kode_teknisi' => $worksheet->getCell('M'.$row)->getValue(),
                'booking_date' => date("Y-m-d H:i:s", strtotime( $worksheet->getCell('N'.$row)->getValue() ) ),
                'assigned_by' => $worksheet->getCell('O'.$row)->getValue(),
                'reported_priority' => $worksheet->getCell('P'.$row)->getValue(),
                'source' => $worksheet->getCell('Q'.$row)->getValue(),
                'subsidiary' => $worksheet->getCell('R'.$row)->getValue(),
                'external_ticked_id' => $worksheet->getCell('S'.$row)->getValue(),
                'external_ticket_status' => $worksheet->getCell('T'.$row)->getValue(),
                'segment' => $worksheet->getCell('U'.$row)->getValue(),
                'channel' => $worksheet->getCell('V'.$row)->getValue(),
                'customer_segment' => $worksheet->getCell('W'.$row)->getValue(),
                'customer_id' => $worksheet->getCell('X'.$row)->getValue(),
                'service_id' => $worksheet->getCell('Y'.$row)->getValue(),
                'service_no' => $worksheet->getCell('Z'.$row)->getValue(),
                'service_type' => $worksheet->getCell('AA'.$row)->getValue(),
                'top_priority' => $worksheet->getCell('AB'.$row)->getValue(),
                'slg' => $worksheet->getCell('AC'.$row)->getValue(),
                'technology' => $worksheet->getCell('AD'.$row)->getValue(),
                'datek' => $worksheet->getCell('AE'.$row)->getValue(),
                'rk_name' => $worksheet->getCell('AF'.$row)->getValue(),
                'induk_gamas' => $worksheet->getCell('AG'.$row)->getValue(),
                'reported_date' => date("Y-m-d H:i:s", strtotime( $worksheet->getCell('AH'.$row)->getValue() ) ),
                'ttr_customer' => $worksheet->getCell('AK'.$row)->getValue(),
                'ttr_nasional' => $worksheet->getCell('AL'.$row)->getValue(),
                'ttr_regional' => $worksheet->getCell('AM'.$row)->getValue(),
                'ttr_witel' => $worksheet->getCell('AN'.$row)->getValue(),
                'ttr_mitra' => $worksheet->getCell('AO'.$row)->getValue(),
                'ttr_agent' => $worksheet->getCell('AP'.$row)->getValue(),
                'ttr_pending' => $worksheet->getCell('AQ'.$row)->getValue(),
                'status' => filter_var($worksheet->getCell('AR'.$row)->getValue(), FILTER_SANITIZE_STRING, array(FILTER_FLAG_STRIP_LOW)),
                'hasil_ukur' => $worksheet->getCell('AS'.$row)->getValue(),
                'osm_resolved_code' => $worksheet->getCell('AT'.$row)->getValue(),
                'last_update_ticket' => date("Y-m-d H:i:s", strtotime( $worksheet->getCell('AU'.$row)->getValue() ) ),
                'status_date' => date("Y-m-d H:i:s", strtotime( $worksheet->getCell('AV'.$row)->getValue() ) ),
                'closed_reopen_by' => $worksheet->getCell('AW'.$row)->getValue(),
                'resolved_by' => $worksheet->getCell('AX'.$row)->getValue(),
                'workzone' => $worksheet->getCell('AY'.$row)->getValue(),
                'incindents_symptom' => $worksheet->getCell('BB'.$row)->getValue(),
                'solutions_segment' => $worksheet->getCell('BC'.$row)->getValue(),
                'actual_solution' => $worksheet->getCell('BD'.$row)->getValue(),
                'import_time' => date("Y-m-d H:i:s", now()),
                'user_id' => $this->session->userdata('user_id'),
            );
            array_push( $data_input, $input );
        }
        $this->admin->import_tiket($data_input);
        redirect('admin/tiket');
    }