Raw PHP-MySQL Pagination

pagination.php

<?php
// php >= 7.0
function paginate ($total, $per_page, $curr_page)
{
    $url = "https://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

    $result = [];
    $result['html'] = '<div class="pagination">';
    $result['offset'] = ($curr_page - 1) < 0 ? 0 : ($curr_page - 1) * $per_page ;
    
    $numOfPage = ceil($total / $per_page);
    if($numOfPage > 1)
    {
        if($numOfPage < 7 )
        {
            for($i = 1; $i <= $numOfPage; $i++ )
            {
                if($i == $curr_page)
                $result['html'] .= '<a class="active">'.$i.'</a>';
                else
                $result['html'] .= '<a href="'.changeValOfUrl('page', $i).'">'.$i.'</a>';
            }
        }
        else
        {
            //- if the page is in middle
            if(($curr_page-3) >= 1 && ($curr_page+3) <= $numOfPage)
            {
                $from = $curr_page - 3;
                $to = $curr_page + 3;
                for ($i=$from; $i <= $to ; $i++) { 
                    if($i == $curr_page)
                    $result['html'] .= '<a class="active">'.$i.'</a>';
                    else
                    $result['html'] .= '<a href="'.changeValOfUrl('page', $i).'">'.$i.'</a>';
                }

            }
            //- if the page is close to last page
            else if(($curr_page-3) >= 1 && ($curr_page+3) >= $numOfPage)
            {
                $from = $curr_page - 3;
                $to = ($curr_page + 3) > $numOfPage ? $numOfPage : ($curr_page + 3);
                for ($i=$from; $i <= $to ; $i++) { 
                    if($i == $curr_page)
                    $result['html'] .= '<a class="active">'.$i.'</a>';
                    else
                    $result['html'] .= '<a href="'.changeValOfUrl('page', $i).'">'.$i.'</a>';
                }

            }
            //- if the page is close to first page
            else if(($curr_page-3) < 1 && ($curr_page+3) <= $numOfPage)
            {
                $from = ($curr_page - 3) < 1 ? 1 : ($curr_page - 3);
                $to = $curr_page + 3;
                for ($i=$from; $i <= $to ; $i++) { 
                    if($i == $curr_page)
                    $result['html'] .= '<a class="active">'.$i.'</a>';
                    else
                    $result['html'] .= '<a href="'.changeValOfUrl('page', $i).'">'.$i.'</a>';
                }

            }

        }
    }

    $from = ($total == 0) ? 0 : ($result['offset'] + 1);

    $result['html'] .= '</div>';
    $result['html'] .= 'Showing '.$from.' to '. (($result['offset']+$per_page) < $total ? ($result['offset']+$per_page) : $total ).' of '. $total;
    return $result;
}