<?php
/**
 * Joomla! Content Management System
 *
 * @copyright   (C) 2021 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Form\Rule;

defined('JPATH_PLATFORM') or die;

use Joomla\CMS\Filesystem\Folder;
use Joomla\CMS\Filesystem\Path;
use Joomla\CMS\Form\Form;
use Joomla\CMS\Form\Rule\FilePathRule;
use Joomla\Registry\Registry;

/**
 * Form Rule class for the Joomla CMS.
 *
 * @since  4.0.0
 */
class FolderPathExistsRule extends FilePathRule
{
	/**
	 * Method to test if the folder path is valid and points to an existing folder below the Joomla root
	 *
	 * @param   \SimpleXMLElement  $element  The SimpleXMLElement object representing the `<field>` tag for the form field object.
	 * @param   mixed              $value    The form field value to validate.
	 * @param   string             $group    The field name group control value. This acts as an array container for the field.
	 *                                       For example if the field has name="foo" and the group value is set to "bar" then the
	 *                                       full field name would end up being "bar[foo]".
	 * @param   Registry           $input    An optional Registry object with the entire data set to validate against the entire form.
	 * @param   Form               $form     The form object for which the field is being tested.
	 *
	 * @return  boolean  True if the value is valid and points to an existing folder below the Joomla root, false otherwise.
	 *
	 * @since   4.0.0
	 */
	public function test(\SimpleXMLElement $element, $value, $group = null, Registry $input = null, Form $form = null)
	{
		if (!parent::test($element, $value, $group, $input, $form))
		{
			return false;
		}

		// If the field is empty and not required so the previous test hasn't failed, the field is valid.
		if ($value === '' || $value === null)
		{
			return true;
		}

		// Spaces only would result in Joomla root which is not allowed
		if (!trim($value))
		{
			return false;
		}

		$pathCleaned = rtrim(Path::clean(JPATH_ROOT . '/' . $value), \DIRECTORY_SEPARATOR);
		$rootCleaned = rtrim(Path::clean(JPATH_ROOT), \DIRECTORY_SEPARATOR);

		// JPATH_ROOT is not allowed
		if ($pathCleaned === $rootCleaned)
		{
			return false;
		}

		return Folder::exists($pathCleaned);
	}
}
