from dbsettings.functions import getValue

from random import SystemRandom

import baluhn

def generate_voucher_code(prefix=getValue("payment.voucher.prefix", "9011"), length=getValue("payment.voucher.length", 16)):
    if length <= len(str(prefix)):
        raise ValueError("Voucher code length must be longer than its prefix!")

    length_randpart = length - len(str(prefix)) - 1

    base_code = prefix

    for i in range(length_randpart):
        base_code += str(SystemRandom().randint(0, 9))

    return baluhn.generate(base_code)