<?php

/**
 * @package     Joomla
 * @subpackage  CoalaWeb Library
 * @author      Steven Palmer <support@coalaweb.com>
 * @link        https://coalaweb.com/
 * @license     GNU/GPL V3 or later; https://www.gnu.org/licenses/gpl-3.0.html
 * @copyright   Copyright (c) 2020 Steven Palmer All rights reserved.
 *
 * CoalaWeb Library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

namespace CoalaWeb;

defined('_JEXEC') or die;

/**
 * Class RegEx
 * @package CoalaWeb
 */
class RegEx
{
	/**
	 * Perform a regular expression search and replace
	 *
	 * @param string $pattern
	 * @param string $replacement
	 * @param string $string
	 * @param string $options
	 * @param int    $limit
	 * @param int    $count
	 *
	 * @return string
	 */
	public static function replace($pattern, $replacement, $string, $options = null, $limit = -1, &$count = null)
	{
		if ( ! is_string($pattern) || $pattern == '' || ! is_string($string) || $string == '')
		{
			return $string;
		}

		$pattern = self::preparePattern($pattern, $options, $string);

		return preg_replace($pattern, $replacement, $string, $limit, $count);
	}

	/**
	 * Perform a regular expression search and replace once
	 *
	 * @param string $pattern
	 * @param string $replacement
	 * @param string $string
	 * @param string $options
	 *
	 * @return string
	 */
	public static function replaceOnce($pattern, $replacement, $string, $options = null)
	{
		return self::replace($pattern, $replacement, $string, $options, 1);
	}

	/**
	 * Perform a regular expression match
	 *
	 * @param string $pattern
	 * @param string $string
	 * @param null   $matches
	 * @param string $options
	 * @param int    $flags
	 *
	 * @return int
	 */
	public static function match($pattern, $string, &$matches = null, $options = null, $flags = 0)
	{
		if ( ! is_string($pattern) || $pattern == '' || ! is_string($string) || $string == '')
		{
			return false;
		}

		$pattern = self::preparePattern($pattern, $options, $string);

		return preg_match($pattern, $string, $matches, $flags);
	}

	/**
	 * Perform a global regular expression match
	 *
	 * @param string $pattern
	 * @param string $string
	 * @param null   $matches
	 * @param string $options
	 * @param int    $flags
	 *
	 * @return int
	 */
	public static function matchAll($pattern, $string, &$matches = null, $options = null, $flags = PREG_SET_ORDER)
	{
		if ( ! is_string($pattern) || $pattern == '' || ! is_string($string) || $string == '')
		{
			$matches = [];

			return false;
		}

		$pattern = self::preparePattern($pattern, $options, $string);

		return preg_match_all($pattern, $string, $matches, $flags);
	}

	/**
	 * preg_quote the given string or array of strings
	 *
	 * @param string|array $data
	 * @param string       $name
	 * @param string       $delimiter
	 *
	 * @return string
	 */
	public static function quote($data, $name = '', $delimiter = '#', $capture = true)
	{
		if (is_array($data))
		{
			$array = self::quoteArray($data, $delimiter);

			$prefix = '?!';
			if ($capture)
			{
				$prefix = $name ? '?<' . $name . '>' : '';
			}

			return '(' . $prefix . implode('|', $array) . ')';
		}

		if ( ! empty($name))
		{
			return '(?<' . $name . '>' . preg_quote($data, $delimiter) . ')';
		}

		return preg_quote($data, $delimiter);
	}

	/**
	 * reverse preg_quote the given string
	 *
	 * @param string $string
	 * @param string $delimiter
	 *
	 * @return string
	 */
	public static function unquote($string, $delimiter = '#')
	{
		return strtr($string, [
			'\\' . $delimiter => $delimiter,
			'\\.'             => '.',
			'\\\\'            => '\\',
			'\\+'             => '+',
			'\\*'             => '*',
			'\\?'             => '?',
			'\\['             => '[',
			'\\^'             => '^',
			'\\]'             => ']',
			'\\$'             => '$',
			'\\('             => '(',
			'\\)'             => ')',
			'\\{'             => '{',
			'\\}'             => '}',
			'\\='             => '=',
			'\\!'             => '!',
			'\\<'             => '<',
			'\\>'             => '>',
			'\\|'             => '|',
			'\\:'             => ':',
			'\\-'             => '-',
		]);
	}

	/**
	 * preg_quote the given array of strings
	 *
	 * @param array  $array
	 * @param string $delimiter
	 *
	 * @return array
	 */
	public static function quoteArray($array = [], $delimiter = '#')
	{
		array_walk($array, function (&$part, $key, $delimiter) {
			$part = self::quote($part, '', $delimiter);
		}, $delimiter);

		return $array;
	}

	/**
	 * Make a string a valid regular expression pattern
	 *
	 * @param string $pattern
	 * @param string $options
	 * @param string $string
	 *
	 * @return string
	 */
	public static function preparePattern($pattern, $options = null, $string = '')
	{
		if (is_array($pattern))
		{
			return self::preparePatternArray($pattern, $options, $string);
		}

		if (substr($pattern, 0, 1) != '#')
		{
			$pattern = '#' . $pattern . '#';
		}

		$options = ! is_null($options) ? $options : 'si';

		if (substr($pattern, -1, 1) == '#')
		{
			$pattern .= $options;
		}

		if (StringHelper::detectUTF8($string))
		{
			// use utf-8
			return $pattern . 'u';
		}

		return $pattern;
	}

	/**
	 * Make an array of strings valid regular expression patterns
	 *
	 * @param array  $pattern
	 * @param string $options
	 * @param string $string
	 *
	 * @return array
	 */
	private static function preparePatternArray($pattern, $options = null, $string = '')
	{
		array_walk($pattern, function (&$subpattern, $key, $string) {
			$subpattern = self::preparePattern($subpattern, $options = null, $string);
		}, $string);

		return $pattern;
	}
}