<?php

if (!function_exists('checkUserId')) {
    function checkUserId($client_id): bool
    {
        return \auth()->hasUser() && !is_null($client_id);
    }
}

if (!function_exists('stats_standard_deviation')) {
    function stats_standard_deviation(array $a, $sample = false): float|bool
    {
        $n = count($a);
        if ($n === 0) {
            trigger_error("The array has zero elements", E_USER_WARNING);
            return false;
        }
        if ($sample && $n === 1) {
            trigger_error("The array has only 1 element", E_USER_WARNING);
            return false;
        }
        $mean = array_sum($a) / $n;
        $carry = 0.0;
        foreach ($a as $val) {
            $d = ((double)$val) - $mean;
            $carry += $d * $d;
        };
        if ($sample) {
            --$n;
        }
        return sqrt($carry / $n);
    }
}

if (!function_exists('xmlToObject')) {

    function xmlToObject($link): SimpleXMLElement|bool
    {
        if (!$link){
           abort(500, 'Error.');
        }
        return @simplexml_load_string(@file_get_contents($link), 'SimpleXMLElement', LIBXML_NOCDATA);
    }
}


if ('format_date_sql'){

    function format_date_sql($params, $model)
    {
        foreach ($params->getFields() as $param) {
            $params->setFields(["TO_CHAR(TO_DATE({$model->qualifyColumn($param)}, 'YYMM'), 'MM/YYYY')"]);
        }
        return $params;
    }

}