Laravel 5 session locale and api middleware

Locale.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Contracts\Session\Session;
use Illuminate\Http\Request;

class Locale {

    const SESSION_KEY = 'locale';

    public function handle(Request $request, Closure $next) {

        $fallbackLocale = config('translatable.fallback_locale');
        $locales = array_keys(config('translatable.locales'));

        $headerLocale = $request->header('Content-Language');

        $session = $request->getSession();

        if(!is_null($headerLocale) && in_array($headerLocale, $locales)){
            $locale = $headerLocale;
        }else if($request->has('lang') && in_array($request->get('lang'), $locales)) {
            $locale = $request->get('lang');
        }else if($session && $session->has(self::SESSION_KEY) && in_array($session->get(self::SESSION_KEY), $locales)){
            $locale = $session->get(self::SESSION_KEY);
        }else{
            $locale = $fallbackLocale;
        }


        if($locale){
            if($session){
                $session->put(self::SESSION_KEY, $locale);
            }
            app()->setLocale($locale);
        }

        return $next($request);
    }
}