package main

import "fmt"
import "math"
import "strconv"
import "os"

func init() {
	if len(os.Args) != 3 {
		fmt.Fprintln(os.Stderr, "wrong number of args")
		os.Exit(1)
	}
	mathId = os.Args[1]
	activationKey = os.Args[2]
}

// var mathId = document.getElementById("str").value;
var mathId string

// var activationKey = document.getElementById("act").value;
var activationKey string

func f1(n int, b byte, c int) int {
	for bitIndex := 0; bitIndex <= 7; bitIndex++ {
		bit := (b >> uint8(bitIndex)) & 1
		if int(bit)+((n-int(bit)) & ^1) == n {
			n = (n - int(bit)) >> 1
		} else {
			n = ((c - int(bit)) ^ n) >> 1
		}
	}
	return n
}

// str is fmt.Sprintf("%s$1&%s", mathId, activationKey)
func genPassword(mathId, activationKey string) string {
	str := fmt.Sprintf("%s$1&%s", mathId, activationKey)
	hash := 0xA439
	for byteIndex := len(str) - 1; byteIndex >= 0; byteIndex -= 1 {
		hash = f1(hash, byte(str[byteIndex]), 0x105C3)
	}
	n1 := 0
	for f1(f1(hash, byte(n1&0xFF), 0x105C3), byte(n1>>8), 0x105C3) != 0xA5B6 {
		n1 += 1
		if n1 >= 0xFFFF {
			panic(fmt.Errorf("Error"))
		}
	}
	n1 = int(math.Floor(float64((n1+0x72FA)&0xFFFF) * 99999.0 / 0xFFFF))
	n1str := fmt.Sprintf("0000%d", n1)
	n1str = n1str[len(n1str)-5:]
	temp, _ := strconv.Atoi(n1str[0:2] + n1str[3:] + n1str[2:3]) // 12 + 45 + 3
	temp = int(math.Ceil((float64(temp) / 99999.0) * 0xFFFF))
	temp = f1(f1(0, byte(temp&0xFF), 0x1064B), byte(temp>>8), 0x1064B)
	for byteIndex := len(str) - 1; byteIndex >= 0; byteIndex-- {
		temp = f1(temp, byte(str[byteIndex]), 0x1064B)
	}

	n2 := 0
	for f1(f1(temp, byte(n2&0xFF), 0x1064B), byte(n2>>8), 0x1064B) != 0xA5B6 {
		n2 += 1
		if n2 >= 0xFFFF {
			panic(fmt.Errorf("Error"))
		}
	}
	n2 = int(math.Floor(float64(n2&0xFFFF) * 99999.0 / 0xFFFF))
	n2str := fmt.Sprintf("0000%d", n2)
	n2str = n2str[len(n2str)-5:]

	return n2str[3:4] +
		n1str[3:4] +
		n1str[1:2] +
		n1str[0:1] +
		"-" +
		n2str[4:5] +
		n1str[2:3] +
		n2str[0:1] +
		"-" +
		n2str[2:3] +
		n1str[4:5] +
		n2str[1:2] +
		"::1"
}

func main() {
	fmt.Println(genPassword(mathId, activationKey))
}

function f1(n, byte, c) {
    for (var bitIndex = 0; bitIndex <= 7; bitIndex++) {
        var bit = (byte >> bitIndex) & 1;
        if (bit + ((n - bit) & ~1) === n) {
            n = (n - bit) >> 1;
        } else {
            n = ((c - bit) ^ n) >> 1;
        }
    }
    return n;
}

function genPassword(str) {
    var hash = 0xA439;
    for (var byteIndex = str.length - 1; byteIndex >= 0; byteIndex--) {
        hash = f1(hash, str.charCodeAt(byteIndex), 0x105C3);
    }
    var n1 = 0;
    while (f1(f1(hash, n1 & 0xFF, 0x105C3), n1 >> 8, 0x105C3) !== 0xA5B6) {
        if (++n1 >= 0xFFFF) {
            return "Error";
        }
    }
    n1 = Math.floor(((n1 + 0x72FA) & 0xFFFF) * 99999.0 / 0xFFFF);
    var n1str = ("0000" + n1.toString(10)).slice(-5);
    var temp = parseInt(n1str.slice(0, -3) + n1str.slice(-2) + n1str.slice(-3, -2), 10);
    temp = Math.ceil((temp / 99999.0) * 0xFFFF);
    temp = f1(f1(0, temp & 0xFF, 0x1064B), temp >> 8, 0x1064B);
    for (byteIndex = str.length - 1; byteIndex >= 0; byteIndex--) {
        temp = f1(temp, str.charCodeAt(byteIndex), 0x1064B);
    }
    var n2 = 0;
    while (f1(f1(temp, n2 & 0xFF, 0x1064B), n2 >> 8, 0x1064B) !== 0xA5B6) {
        if (++n2 >= 0xFFFF) {
            return "Error";
        }
    }
    n2 = Math.floor((n2 & 0xFFFF) * 99999.0 / 0xFFFF);
    var n2str = ("0000" + n2.toString(10)).slice(-5);
    return n2str.charAt(3) + n1str.charAt(3) + n1str.charAt(1) + n1str.charAt(0) + "-"
        + n2str.charAt(4) + n1str.charAt(2) + n2str.charAt(0) + "-"
        + n2str.charAt(2) + n1str.charAt(4) + n2str.charAt(1) + "::1";
}

console.log("%s", genPassword("6525-69419-44485"+"$1&"+"1234-4321-123456"))

$ go run keygen.go 6525-69419-44485 1234-4321-123456
0795-616-891::1

$ nodejs keygen.js                                                            
0795-616-891::1