<?php

function generateCats($n) {
    $categories = [];

    for ($i = 0; $i < $n; $i++) {
        $categories[] = array(
            'name' => 'categoriy-'.uniqid(),
            'id'   => $i
        );
    }
    return $categories;
}

function generateProducts($n, $cats) {

    $products = [];

    for ($i = 0; $i < $n; $i++) {
        $products[] = [
            'name'     => uniqid(),
            'catId'    => $cats[rand(0, count($cats)-1)]['id'],
            'id'       => $i,
            'quantity' => rand(0, 1000)
        ];
    }

    return $products;
}

$categories = generateCats(100);
$products   = generateProducts(100000, $categories);

xhprof_enable(XHPROF_FLAGS_CPU+XHPROF_FLAGS_MEMORY);

$sorted   = [];
$quantity = 0;
foreach ($products as $product) {
    if ($product['quantity'] > 0) {
        if (empty($sorted[$product['catId']])) {
            $sorted[$product['catId']] = [];
        }

        $sorted[$product['catId']][] = $product;
    }
}

foreach ($sorted as $cat => $value) {
    usort($sorted[$cat], function ($a, $b) {
            return $b['quantity']-$a['quantity'];
        });
}

$result = [];

ksort($categories);

foreach ($categories as $category) {
    $result[$category['id']] = [
        'name'     => $category['name'],
        'products' => $sorted[$category['id']]
    ];
}

$xhprof_data = xhprof_disable();

$XHPROF_ROOT = "/usr/local/Cellar/php55-xhprof/254eb24";
include_once $XHPROF_ROOT."/xhprof_lib/utils/xhprof_lib.php";
include_once $XHPROF_ROOT."/xhprof_lib/utils/xhprof_runs.php";

$xhprof_runs = new XHProfRuns_Default();
$run_id      = $xhprof_runs->save_run($xhprof_data, "xhprof_testing");