<?php

/**
 * Generates version 4 UUIDs
 * from https://github.com/ramsey/uuid/blob/2.8/src/Uuid.php
 * and http://stackoverflow.com/a/2040279
 *
 * @return string
 */
function genUuid4() {

    if (function_exists('openssl_random_pseudo_bytes')) {
        $bytes = openssl_random_pseudo_bytes(16);
    }
    else {
        $bytes = '';
        mt_srand(crc32(serialize([microtime(true), 'USER_IP', 'ETC'])));
        for ($i = 1; $i <= $length; $i++) {
            $bytes = chr(mt_rand(0, 255)) . $bytes;
        }
    }


    $bytes[6] = chr(ord($bytes[6]) & 0x0f | 0x40); // set version to 0100
    $bytes[8] = chr(ord($bytes[8]) & 0x3f | 0x80); // set bits 6-7 to 10

    return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($bytes), 4));
}


/**
 * get page self url
 * from http://stackoverflow.com/a/2236887
 */
function strleft($s1, $s2) { return substr($s1, 0, strpos($s1, $s2)); }
function selfURL()
{
    $s = empty($_SERVER["HTTPS"]) ? '' : ($_SERVER["HTTPS"] == "on") ? "s" : "";
    $protocol = strleft(strtolower($_SERVER["SERVER_PROTOCOL"]), "/").$s;
    $port = ($_SERVER["SERVER_PORT"] == "80") ? "" : (":".$_SERVER["SERVER_PORT"]);
    return $protocol."://".$_SERVER['SERVER_NAME'].$port.$_SERVER['REQUEST_URI'];
}

function selfBaseURL()
{
    $s = empty($_SERVER["HTTPS"]) ? '' : ($_SERVER["HTTPS"] == "on") ? "s" : "";
    $protocol = strleft(strtolower($_SERVER["SERVER_PROTOCOL"]), "/").$s;
    $port = ($_SERVER["SERVER_PORT"] == "80") ? "" : (":".$_SERVER["SERVER_PORT"]);
    return $protocol."://".$_SERVER['SERVER_NAME'].$port.dirname($_SERVER['REQUEST_URI']);
}