<?php
/* Database connection start */
require_once '../../config.php';
require_once '../../kint.phar';
$db = new SafeMySQL($db_opts);

// storing  request (ie, get/post) global array to a variable
$requestData= $_REQUEST;
$columns = array(
// datatable column index  => database column name
    0 =>'cardName',
    1 => 'clientFIO',
    2=> 'clientNumber'
);

// getting total number records without any search
$totalData = count($db->getAll("SELECT id, cardName, clientFIO, clientNumber FROM clients"));
$totalFiltered = $totalData;  // when there is no search parameter then total number rows = total number filtered rows.

$sql = "SELECT id, cardName, clientFIO, clientNumber ";
$sql.=" FROM clients WHERE 1=1";
if( !empty($requestData['search']['value']) ) {   // if there is a search parameter, $requestData['search']['value'] contains search parameter
    $sql.=" AND ( cardName LIKE '".$requestData['search']['value']."%' ";
    $sql.=" OR clientFIO LIKE '".$requestData['search']['value']."%' ";

    $sql.=" OR clientNumber LIKE '".$requestData['search']['value']."%' ) ";
}
$query=$db->query($sql) or die("getData.php: get employees");
$totalFiltered = $db->numRows($query); // when there is a search parameter then we have to modify total number filtered rows as per search result.
$sql.=" ORDER BY ". $columns[$requestData['order'][0]['column']]."   ".$requestData['order'][0]['dir']."  LIMIT ".$requestData['start']." ,".$requestData['length']."   ";
/* $requestData['order'][0]['column'] contains colmun index, $requestData['order'][0]['dir'] contains order such as asc/desc  */
$query=$db->query($sql) or die("getData.php: get employees");

$data = array();
while( $row=$db->fetch($query) ) {  // preparing an array
    $nestedData=array();
    $nestedData[] = $row["cardName"];
    $nestedData[] = $row["clientFIO"];
    $nestedData[] = $row["clientNumber"];

    $data[] = $nestedData;
}

$json_data = array(
            "draw"            => intval( $requestData['draw'] ),   // for every request/draw by clientside , they send a number as a parameter, when they recieve a response/data they first check the draw number, so we are sending same number in draw.
            "recordsTotal"    => intval( $totalData ),  // total number of records
            "recordsFiltered" => intval( $totalFiltered ), // total number of records after searching, if there is no searching then totalFiltered = totalData
            "data"            => $data   // total data array
            );

echo json_encode($json_data);  // send data as json format

?>