<?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/standard compatibility package
 *
 * @package		CodeIgniter
 * @subpackage	CodeIgniter
 * @category	Compatibility
 * @author		Andrey Andreev
 * @link		https://codeigniter.com/user_guide/
 */
// ------------------------------------------------------------------------

if (is_php('5.5')) {
    return;
}

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

if (!function_exists('array_column')) {

    /**
     * array_column()
     *
     * @link	http://php.net/array_column
     * @param	array	$array
     * @param	mixed	$column_key
     * @param	mixed	$index_key
     * @return	array
     */
    function array_column(array $array, $column_key, $index_key = NULL) {
        if (!in_array($type = gettype($column_key), array('integer', 'string', 'NULL'), TRUE)) {
            if ($type === 'double') {
                $column_key = (int) $column_key;
            } elseif ($type === 'object' && method_exists($column_key, '__toString')) {
                $column_key = (string) $column_key;
            } else {
                trigger_error('array_column(): The column key should be either a string or an integer', E_USER_WARNING);
                return FALSE;
            }
        }

        if (!in_array($type = gettype($index_key), array('integer', 'string', 'NULL'), TRUE)) {
            if ($type === 'double') {
                $index_key = (int) $index_key;
            } elseif ($type === 'object' && method_exists($index_key, '__toString')) {
                $index_key = (string) $index_key;
            } else {
                trigger_error('array_column(): The index key should be either a string or an integer', E_USER_WARNING);
                return FALSE;
            }
        }

        $result = array();
        foreach ($array as &$a) {
            if ($column_key === NULL) {
                $value = $a;
            } elseif (is_array($a) && array_key_exists($column_key, $a)) {
                $value = $a[$column_key];
            } else {
                continue;
            }

            if ($index_key === NULL OR ! array_key_exists($index_key, $a)) {
                $result[] = $value;
            } else {
                $result[$a[$index_key]] = $value;
            }
        }

        return $result;
    }

}

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

if (is_php('5.4')) {
    return;
}

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

if (!function_exists('hex2bin')) {

    /**
     * hex2bin()
     *
     * @link	http://php.net/hex2bin
     * @param	string	$data
     * @return	string
     */
    function hex2bin($data) {
        if (in_array($type = gettype($data), array('array', 'double', 'object', 'resource'), TRUE)) {
            if ($type === 'object' && method_exists($data, '__toString')) {
                $data = (string) $data;
            } else {
                trigger_error('hex2bin() expects parameter 1 to be string, ' . $type . ' given', E_USER_WARNING);
                return NULL;
            }
        }

        if (strlen($data) % 2 !== 0) {
            trigger_error('Hexadecimal input string must have an even length', E_USER_WARNING);
            return FALSE;
        } elseif (!preg_match('/^[0-9a-f]*$/i', $data)) {
            trigger_error('Input string must be hexadecimal string', E_USER_WARNING);
            return FALSE;
        }

        return pack('H*', $data);
    }

}
