Computer Shop

<?php
$productList = preg_split("/\r?\n/", $_GET['list'], -1, PREG_SPLIT_NO_EMPTY);
$minPrice = (float)$_GET['minPrice'];
$maxPrice = (float)$_GET['maxPrice'];
$filter = $_GET['filter'];
$order = $_GET['order'];

$idCounter = 0;
$filteredList = array();
foreach ($productList as $productInfo) {
    $idCounter++;
    $productInfo = preg_split('/\s*\|\s*/', $productInfo, -1, PREG_SPLIT_NO_EMPTY);
    $price = (float)$productInfo[3];
    if ($price < $minPrice || $price > $maxPrice || ($filter != 'all' && $filter != $productInfo[1])) {
        continue;
    }

    $id = $idCounter;
    $name = htmlspecialchars($productInfo[0]);
    $components = preg_split('/\s*\,\s*/', $productInfo[2], -1, PREG_SPLIT_NO_EMPTY);
    $filteredList[] = array('id' => $id, 'name' => $name, 'components' => $components, 'price' => $price);
}

usort($filteredList, function ($a, $b) use ($order) {
    if ($a['price'] === $b['price']) {
        return ($a['id'] > $b['id']) ? 1 : -1;
    }

    if ($order == 'ascending') {
        return ($a['price'] > $b['price']) ? 1 : -1;
    }

    return $a['price'] < $b['price'] ? 1 : -1;
});

foreach ($filteredList as $productInfo) {
    echo "<div class=\"product\" id=\"product{$productInfo['id']}\"><h2>{$productInfo['name']}</h2><ul>";
    foreach ($productInfo['components'] as $component) {
        echo '<li class="component">' . htmlspecialchars($component) . '</li>';
    }

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