/**
 * render
 * @param string $view テンプレート名
 * @param array $variables テンプレート変数のハッシュ
 * @return \Core\Foundation\Response\RenderResponse
 */
function render(string $view=null, array $variables=[]):Core\Foundation\Response\RenderResponse
{
    $variables['errors'] = errors();
    $html = isset($view) ? Core\View::run($view, $variables) : null;
    return new Core\Foundation\Response\RenderResponse($html);
}

/**
 * redirect
 * @param string $url URL
 * @return \Core\Foundation\Response\RedirectResponse
 */
function redirect(string $url):Core\Foundation\Response\RedirectResponse
{
    return new Core\Foundation\Response\RedirectResponse($url);
}

/**
 * Get old request inputs
 * @param string $key
 * @param mixed $default
 * @return string
 */
function old(string $key, $default = null)
{
    $old_inputs = flash(Core\Foundation\Response::FLASH_KEY_OLD);
    return isset($old_inputs) && array_key_exists($key, $old_inputs) ? $old_inputs[$key] : $default;
}

/**
 * Get old URL Path
 * @return string URL
 */
function back():string
{
    if (array_key_exists('HTTP_REFERER', $_SERVER) && isset($_SERVER['HTTP_REFERER']))
    {
        $url = '/';
        $info = parse_url($_SERVER['HTTP_REFERER']);
        if (array_key_exists('path',$info)) $url = $info['path'];
        if (array_key_exists('query',$info)) $url .= '?'.$info['query'];
        if (array_key_exists('fragment',$info)) $url .= '#'.$info['fragment'];
        return $url;
    }
    else
    {
        return flash(Core\Foundation\Response::FLASH_KEY_BACK, '/');
    }
}

/**
 * Get response errors
 * @return \Core\Foundation\ErrorBag
 */
function errors():Core\Foundation\ErrorBag
{
    $errors = Core\Flash::has(Core\Foundation\Response::FLASH_KEY_ERRORS)
    ? flash(Core\Foundation\Response::FLASH_KEY_ERRORS)
    : new Core\Foundation\ErrorBag();

    return $errors;
}