Language detection library for CodeIgniter

Lang_detect.php

<?php

/**
 * Lang_detect Class.
 *
 * Language detection library for CodeIgniter.
 *
 * @author        La2ha
 *
 * @version       1.0
 *
 * @see          http://la2ha.ru/dev-seo-diy/web/lang_detect
 */
class Lang_detect
{
    public $language = null;

    public function __construct()
    {
        if ($list = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? strtolower($_SERVER['HTTP_ACCEPT_LANGUAGE']) : null) {
            if (preg_match_all('/([a-z]{1,8}(?:-[a-z]{1,8})?)(?:;q=([0-9.]+))?/', $list, $list)) {
                $this->language = array_combine($list[1], $list[2]);
                foreach ($this->language as $n => $v) {
                    $this->language[$n] = $v ? $v : 1;
                }
                arsort($this->language, SORT_NUMERIC);
            }
        } else {
            $this->language = array();
        }
    }

    public function getBestMatch($default, $langs)
    {
        $languages = array();
        foreach ($langs as $lang => $alias) {
            if (is_array($alias)) {
                foreach ($alias as $alias_lang) {
                    $languages[strtolower($alias_lang)] = strtolower($lang);
                }
            } else {
                $languages[strtolower($alias)] = strtolower($lang);
            }
        }
        foreach ($this->language as $l => $v) {
            $s = strtok($l, '-'); // убираем то что идет после тире в языках вида "en-us, ru-ru"
            if (isset($languages[$s])) {
                return $languages[$s];
            }
        }

        return $default;
    }
}