public function getChartData()
    {
        // get all items between dates
        $rows = FeedbackContactUs::where('created_at', '>=', $this->inputDateFrom() . '%')
            ->where('created_at', '<=', $this->inputDateTo() . '  23:59:59')
            ->orderBy('created_at')
            ->get();

        // collection group by date
        $days = $rows->groupBy(function ($row) {
            return $row->created_at->format('l d F');
        })->all();

        // format and add to response
        $response = ['labels' => [], 'total' => 0];
        $line = [];
        foreach ($days as $date => $items) {
            $response['total'] += $items->count();
            $response['labels'][] = $date;

            $line[] = $items->count();
        }

        $response['datasets'][] = $this->getDataSet('Total', $line);

        return json_encode($response);
    }