<?php

namespace Podlove\PHP;

/**
 * strpos wrapper that prefers mb_strpos but falls back to strpos.
 *
 * @param mixed $haystack
 * @param mixed $needle
 * @param mixed $offset
 * @param mixed $encoding
 */
function strpos($haystack, $needle, $offset = 0, $encoding = 'UTF-8')
{
    if (function_exists('mb_strpos')) {
        return mb_strpos($haystack, $needle, $offset, $encoding);
    }

    return strpos($haystack, $needle, $offset);
}

/**
 * strlen wrapper that prefers mb_strlen but falls back to strlen.
 *
 * @param mixed $str
 * @param mixed $encoding
 */
function strlen($str, $encoding = 'UTF-8')
{
    if (function_exists('mb_strlen')) {
        return mb_strlen($str, $encoding);
    }

    return strlen($str);
}

/**
 * substr wrapper that prefers mb_substr but falls back to substr.
 *
 * @param mixed      $str
 * @param mixed      $start
 * @param null|mixed $length
 * @param mixed      $encoding
 */
function substr($str, $start, $length = null, $encoding = 'UTF-8')
{
    if (function_exists('mb_substr')) {
        return mb_substr($str, $start, $length, $encoding);
    }

    return substr($str, $start, $length);
}

/**
 * Check string ends with a certain character or substring.
 *
 * @param string $haystack String to search
 * @param string $needle   Substring or character
 *
 * @return bool
 */
function ends_with($haystack, $needle)
{
    return $needle === substr($haystack, -strlen($needle));
}

/**
 * Escape WordPress Shortcodes.
 *
 * Replaces the opening square bracket by its HTML code, which is
 * ignored by WordPress.
 *
 * @param string $text
 *
 * @return string
 */
function escape_shortcodes($text)
{
    return preg_replace_callback('/'.get_shortcode_regex().'/', function ($matches) {
        return str_replace('[', '&#x005B;', $matches[0]);
    }, $text);
}

function hex2str($hex)
{
    return pack('H*', $hex);
}

function str2hex($str)
{
    $tmp = unpack('H*', $str);

    return array_shift($tmp);
}