<?php

    /**
     * @param $a
     * @param $b
     * @return int
     */
    public function sortUsersByTeam($a, $b)
    {
        if (empty($a['teams']) && !empty($b['teams'])) {
            return 1;
        }

        if (empty($a['teams']) && empty($b['teams'])) {
            return 0;
        }

        if (!empty($a['teams']) && empty($b['teams'])) {
            return -1;
        }

        if (count($a['teams']) > count($b['teams'])) {
            return 1;
        }

        if (count($a['teams']) < count($b['teams'])) {
            return -1;
        }

        $comparison = strcmp($a['teams'][0]['name'], $b['teams'][0]['name']);

        if ($comparison !== 0) {
            return $comparison < 0 ? -1 : 1;
        }

        return strcmp($a['email'], $b['email']);
    }