<?php
/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2006 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\Filter;

\defined('JPATH_PLATFORM') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\Language\Language;
use Joomla\Filter\OutputFilter as BaseOutputFilter;
use Joomla\String\StringHelper;

/**
 * OutputFilter
 *
 * @since  1.7.0
 */
class OutputFilter extends BaseOutputFilter
{
	/**
	 * This method processes a string and replaces all instances of & with &amp; in links only.
	 *
	 * @param   string  $input  String to process
	 *
	 * @return  string  Processed string
	 *
	 * @since   1.7.0
	 */
	public static function linkXHTMLSafe($input)
	{
		$regex = 'href="([^"]*(&(amp;){0})[^"]*)*?"';

		return preg_replace_callback("#$regex#i", array('\\Joomla\\CMS\\Filter\\OutputFilter', 'ampReplaceCallback'), $input);
	}

	/**
	 * This method processes a string and escapes it for use in JavaScript
	 *
	 * @param   string  $string  String to process
	 *
	 * @return  string  Processed text
	 */
	public static function stringJSSafe($string)
	{
		$chars = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY);
		$new_str = '';

		foreach ($chars as $chr)
		{
			$code = str_pad(dechex(StringHelper::ord($chr)), 4, '0', STR_PAD_LEFT);

			if (strlen($code) < 5)
			{
				$new_str .= '\\u' . $code;
			}
			else
			{
				$new_str .= '\\u{' . $code . '}';
			}
		}

		return $new_str;
	}

	/**
	 * This method processes a string and replaces all accented UTF-8 characters by unaccented
	 * ASCII-7 "equivalents", whitespaces are replaced by hyphens and the string is lowercase.
	 *
	 * @param   string  $string    String to process
	 * @param   string  $language  Language to transliterate to
	 *
	 * @return  string  Processed string
	 *
	 * @since   1.7.0
	 */
	public static function stringURLSafe($string, $language = '')
	{
		// Remove any '-' from the string since they will be used as concatenaters
		$str = str_replace('-', ' ', $string);

		// Transliterate on the language requested (fallback to current language if not specified)
		$lang = $language == '' || $language == '*' ? Factory::getLanguage() : Language::getInstance($language);
		$str = $lang->transliterate($str);

		// Trim white spaces at beginning and end of alias and make lowercase
		$str = trim(StringHelper::strtolower($str));

		// Remove any apostrophe. We do it here to ensure it is not replaced by a '-'
		$str = str_replace("'", '', $str);

		// Remove any duplicate whitespace, and ensure all characters are alphanumeric
		$str = preg_replace('/(\s|[^A-Za-z0-9\-])+/', '-', $str);

		// Trim dashes at beginning and end of alias
		$str = trim($str, '-');

		return $str;
	}

	/**
	 * Callback method for replacing & with &amp; in a string
	 *
	 * @param   string  $m  String to process
	 *
	 * @return  string  Replaced string
	 *
	 * @since   3.5
	 */
	public static function ampReplaceCallback($m)
	{
		$rx = '&(?!amp;)';

		return preg_replace('#' . $rx . '#', '&amp;', $m[0]);
	}
}
