<?php

namespace common\helpers;

class UUIDHelper
{
    public static function v3($namespace, $name) {
        if(!self::is_valid($namespace)) return false;

        // Get hexadecimal components of namespace
        $nhex = str_replace(array('-','{','}'), '', $namespace);

        // Binary Value
        $nstr = '';

        // Convert Namespace UUID to bits
        for($i = 0; $i < strlen($nhex); $i+=2) {
            $nstr .= chr(hexdec($nhex[$i].$nhex[$i+1]));
        }

        // Calculate hash value
        $hash = md5($nstr . $name);

        return sprintf('%08s-%04s-%04x-%04x-%12s',

            // 32 bits for "time_low"
            substr($hash, 0, 8),

            // 16 bits for "time_mid"
            substr($hash, 8, 4),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 3
            (hexdec(substr($hash, 12, 4)) & 0x0fff) | 0x3000,

            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            (hexdec(substr($hash, 16, 4)) & 0x3fff) | 0x8000,

            // 48 bits for "node"
            substr($hash, 20, 12)
        );
    }

    public static function v4() {
        return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',

            // 32 bits for "time_low"
            mt_rand(0, 0xffff), mt_rand(0, 0xffff),

            // 16 bits for "time_mid"
            mt_rand(0, 0xffff),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 4
            mt_rand(0, 0x0fff) | 0x4000,

            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            mt_rand(0, 0x3fff) | 0x8000,

            // 48 bits for "node"
            mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
        );
    }

    public static function v5($namespace, $name) {
        if(!self::is_valid($namespace)) return false;

        // Get hexadecimal components of namespace
        $nhex = str_replace(array('-','{','}'), '', $namespace);

        // Binary Value
        $nstr = '';

        // Convert Namespace UUID to bits
        for($i = 0; $i < strlen($nhex); $i+=2) {
            $nstr .= chr(hexdec($nhex[$i].$nhex[$i+1]));
        }

        // Calculate hash value
        $hash = sha1($nstr . $name);

        return sprintf('%08s-%04s-%04x-%04x-%12s',

            // 32 bits for "time_low"
            substr($hash, 0, 8),

            // 16 bits for "time_mid"
            substr($hash, 8, 4),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 5
            (hexdec(substr($hash, 12, 4)) & 0x0fff) | 0x5000,

            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            (hexdec(substr($hash, 16, 4)) & 0x3fff) | 0x8000,

            // 48 bits for "node"
            substr($hash, 20, 12)
        );
    }

    public static function is_valid($uuid) {
        return preg_match('/^\{?[0-9a-f]{8}\-?[0-9a-f]{4}\-?[0-9a-f]{4}\-?'.
                '[0-9a-f]{4}\-?[0-9a-f]{12}\}?$/i', $uuid) === 1;
    }

}