<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2017 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;

use Joomla\CMS\Form\Form;
use Joomla\CMS\Form\FormRule;
use Joomla\Database\DatabaseAwareInterface;
use Joomla\Database\DatabaseAwareTrait;
use Joomla\Database\ParameterType;
use Joomla\Registry\Registry;

/**
 * Form Rule class for the Joomla Platform.
 *
 * @since  1.7.0
 */
class UsernameRule extends FormRule implements DatabaseAwareInterface
{
    use DatabaseAwareTrait;

    /**
     * Method to test the username for uniqueness.
     *
     * @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, false otherwise.
     *
     * @since   1.7.0
     */
    public function test(\SimpleXMLElement $element, $value, $group = null, Registry $input = null, Form $form = null)
    {
        // Get the database object and a new query object.
        $db    = $this->getDatabase();
        $query = $db->getQuery(true);

        // Get the extra field check attribute.
        $userId = ($form instanceof Form) ? (int) $form->getValue('id') : 0;

        // Build the query.
        $query->select('COUNT(*)')
            ->from($db->quoteName('#__users'))
            ->where(
                [
                    $db->quoteName('username') . ' = :username',
                    $db->quoteName('id') . ' <> :userId',
                ]
            )
            ->bind(':username', $value)
            ->bind(':userId', $userId, ParameterType::INTEGER);

        // Set and query the database.
        $db->setQuery($query);
        $duplicate = (bool) $db->loadResult();

        if ($duplicate) {
            return false;
        }

        return true;
    }
}