protected function readFileContents($language)
    {
        $fileName = $this->getFileName($language);
        $fs = $this->env->getFileSystem();
        if (!$fs->fileExists($fileName)) {
            return array();
        }
        $content = json_decode(preg_replace('/^.*?define\((.*)\);\s*/s', '$1', $fs->getFile($fileName)), true);
        if ($language === $this->baseLang) {
            $content = $content['root'];
        }

        $outdateInfo = [];
        $fileName = $this->getOutdateInfoFileName($language);
        if ($fs->fileExists($fileName)) {
            $outdateInfo = json_decode($fs->getFile($fileName), true);
        }
        foreach ($content as $id => $text) {
            $outdated = isset($outdateInfo[$id]) ? $outdateInfo[$id] : true;
            $content[$id] = array('id' => $id, 'name' => $id, 'content' => $text, 'outdated' => $outdated);
        }

        return $content;
    }