<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 3.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * PHP ext/mbstring compatibility package
 *
 * @package		CodeIgniter
 * @subpackage	CodeIgniter
 * @category	Compatibility
 * @author		Andrey Andreev
 * @link		https://codeigniter.com/user_guide/
 * @link		http://php.net/mbstring
 */
// ------------------------------------------------------------------------

if (MB_ENABLED === TRUE) {
    return;
}

// ------------------------------------------------------------------------

if (!function_exists('mb_strlen')) {

    /**
     * mb_strlen()
     *
     * WARNING: This function WILL fall-back to strlen()
     * if iconv is not available!
     *
     * @link	http://php.net/mb_strlen
     * @param	string	$str
     * @param	string	$encoding
     * @return	string
     */
    function mb_strlen($str, $encoding = NULL) {
        if (ICONV_ENABLED === TRUE) {
            return iconv_strlen($str, isset($encoding) ? $encoding : config_item('charset'));
        }

        log_message('debug', 'Compatibility (mbstring): iconv_strlen() is not available, falling back to strlen().');
        return strlen($str);
    }

}

// ------------------------------------------------------------------------

if (!function_exists('mb_strpos')) {

    /**
     * mb_strpos()
     *
     * WARNING: This function WILL fall-back to strpos()
     * if iconv is not available!
     *
     * @link	http://php.net/mb_strpos
     * @param	string	$haystack
     * @param	string	$needle
     * @param	int	$offset
     * @param	string	$encoding
     * @return	mixed
     */
    function mb_strpos($haystack, $needle, $offset = 0, $encoding = NULL) {
        if (ICONV_ENABLED === TRUE) {
            return iconv_strpos($haystack, $needle, $offset, isset($encoding) ? $encoding : config_item('charset'));
        }

        log_message('debug', 'Compatibility (mbstring): iconv_strpos() is not available, falling back to strpos().');
        return strpos($haystack, $needle, $offset);
    }

}

// ------------------------------------------------------------------------

if (!function_exists('mb_substr')) {

    /**
     * mb_substr()
     *
     * WARNING: This function WILL fall-back to substr()
     * if iconv is not available.
     *
     * @link	http://php.net/mb_substr
     * @param	string	$str
     * @param	int	$start
     * @param	int 	$length
     * @param	string	$encoding
     * @return	string
     */
    function mb_substr($str, $start, $length = NULL, $encoding = NULL) {
        if (ICONV_ENABLED === TRUE) {
            isset($encoding) OR $encoding = config_item('charset');
            return iconv_substr(
                    $str, $start, isset($length) ? $length : iconv_strlen($str, $encoding), // NULL doesn't work
                    $encoding
            );
        }

        log_message('debug', 'Compatibility (mbstring): iconv_substr() is not available, falling back to substr().');
        return isset($length) ? substr($str, $start, $length) : substr($str, $start);
    }

}
