Simple Language Switch

<?php

namespace Emicro\Bundle\CoreBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

class LanguageSwitcherController extends Controller
{
    public function switchAction(Request $request)
    {

        $currentLocale = $this->get('translator')->getLocale();
        $prevLocale = ($currentLocale == 'en') ? 'fr' : 'en';


        if ($refer = $request->headers->get('referer')) {
            $url = str_replace("/{$prevLocale}/", "/{$currentLocale}/", $refer);
        } else {
            $url = $this->generateUrl('unit');
        }

        return $this->redirect($url);
    }
}