PHP Exam - Computer Shop

<?php

$list = trim($_GET['list']);
$minPrice = (double) trim($_GET['minPrice']);
$maxPrice = (double) trim($_GET['maxPrice']);
$filter = trim($_GET['filter']);
$order = trim($_GET['order']);
$result = '';

if ($order == 'ascending') {
    $sort = SORT_ASC;
} else if ($order == 'descending') {
    $sort = SORT_DESC;
}

$prds = preg_split('/\n/', $list);

if (sizeof($prds) > 1 && $minPrice < $maxPrice) {
    $productsListList = array();
    $products = array();

    foreach ($prds as $key => $p) {
        $product = explode(' | ', $p);

        $productsList[$key]['id'] = $key + 1;
        $productsList[$key]['name'] = $product[0];
        $productsList[$key]['type'] = $product[1];
        $productsList[$key]['components'] = explode(', ', $product[2]);
        $productsList[$key]['price'] = (double) $product[3];
    }

    foreach ($productsList as $p) {
        if ($p['price'] >= $minPrice && $p['price'] <= $maxPrice && ($filter == $p['type'] || $filter == 'all')) {
            $cnt = sizeof($products);
            $products[$cnt] = $p;
        }
    }

    $products = multisort($products, SORT_ASC, 'id');
    $products = multisort($products, $sort, 'price');

    foreach ($products as $p) {
        $result .= '<div class="product" id="product' . $p['id'] . '"><h2>' . htmlspecialchars($p['name']) . '</h2><ul>';

        foreach ($p['components'] as $c) {
            $result .= '<li class="component">' . htmlspecialchars($c) . '</li>';
        }

        $result .= '</ul><span class="price">' . number_format($p['price'], 2, '.', '') . '</span></div>';
    }

    echo $result;
}

function multisort($arr, $ord, $property) {
    foreach ($arr as $id => $val) {
        $key[$id] = $val[$property];
    }
    array_multisort($key, $ord, $arr);
    return $arr;
}