<?php

/**

 * WordPress implementation for PHP functions either missing from older PHP versions or not included by default.

 *

 * @package PHP

 * @access private

 */

// If gettext isn't available

if ( !function_exists('_') ) {

	function _($string) {

		return $string;

	}

}

if ( !function_exists('mb_substr') ):

	function mb_substr( $str, $start, $length=null, $encoding=null ) {

		return _mb_substr($str, $start, $length, $encoding);

	}

endif;

function _mb_substr( $str, $start, $length=null, $encoding=null ) {

	// the solution below, works only for utf-8, so in case of a different

	// charset, just use built-in substr

	$charset = get_option( 'blog_charset' );

	if ( !in_array( $charset, array('utf8', 'utf-8', 'UTF8', 'UTF-8') ) ) {

		return is_null( $length )? substr( $str, $start ) : substr( $str, $start, $length);

	}

	// use the regex unicode support to separate the UTF-8 characters into an array

	preg_match_all( '/./us', $str, $match );

	$chars = is_null( $length )? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );

	return implode( '', $chars );

}

if ( !function_exists('hash_hmac') ):

function hash_hmac($algo, $data, $key, $raw_output = false) {

	return _hash_hmac($algo, $data, $key, $raw_output);

}

endif;

function _hash_hmac($algo, $data, $key, $raw_output = false) {

	$packs = array('md5' => 'H32', 'sha1' => 'H40');

	if ( !isset($packs[$algo]) )

		return false;

	$pack = $packs[$algo];

	if (strlen($key) > 64)

		$key = pack($pack, $algo($key));

	$key = str_pad($key, 64, chr(0));

	$ipad = (substr($key, 0, 64) ^ str_repeat(chr(0x36), 64));

	$opad = (substr($key, 0, 64) ^ str_repeat(chr(0x5C), 64));

	$hmac = $algo($opad . pack($pack, $algo($ipad . $data)));

	if ( $raw_output )

		return pack( $pack, $hmac );

	return $hmac;

}

if ( !function_exists('json_encode') ) {

	function json_encode( $string ) {

		global $wp_json;

		if ( !is_a($wp_json, 'Services_JSON') ) {

			require_once( ABSPATH . WPINC . '/class-json.php' );

			$wp_json = new Services_JSON();

		}

		return $wp_json->encodeUnsafe( $string );

	}

}

if ( !function_exists('json_decode') ) {

	function json_decode( $string, $assoc_array = false ) {

		global $wp_json;

		if ( !is_a($wp_json, 'Services_JSON') ) {

			require_once( ABSPATH . WPINC . '/class-json.php' );

			$wp_json = new Services_JSON();

		}

		$res = $wp_json->decode( $string );

		if ( $assoc_array )

			$res = _json_decode_object_helper( $res );

		return $res;

	}

	function _json_decode_object_helper($data) {

		if ( is_object($data) )

			$data = get_object_vars($data);

		return is_array($data) ? array_map(__FUNCTION__, $data) : $data;

	}

}