import binascii
import requests

from decouple import config
from pyotp import TOTP
from config import VM_POOL


def check_otp(name, realm, token):
    try:
        data = {
            "auth_name": config("AUTH_NAME", ""),
            "auth_token": TOTP(config("AUTH_SEED", "")).now(),
            "auth_realm": config("AUTH_REALM", ""),
            "name": name,
            "realm": realm,
            "token": token,
        }
    except binascii.Error:
        return 400

    response = requests.get(
        "{OTP_SERVER}{OTP_VERIFY_ENDPOINT}".format(
            OTP_SERVER=config("OTP_SERVER", ""),
            OTP_VERIFY_ENDPOINT=config("OTP_VERIFY_ENDPOINT", "verify"),
        ),
        json=data,
    )
    return response.status_code


def resolve_vm_name(name, owner):
    """Return UUID of Virtual Machine of name == name and owner == owner
    
    Input: name of vm, owner of vm.
    Output: uuid of vm if found otherwise None
    """
    result = next(
        filter(
            lambda vm: vm.value["owner"] == owner and vm.value["name"] == name,
            VM_POOL.vms,
        ),
        None,
    )
    if result:
        return result.key.split("/")[-1]

    return None

import random

def random_bytes(num=6):
    return [random.randrange(256) for _ in range(num)]

def generate_mac(uaa=False, multicast=False, oui=None, separator=':', byte_fmt='%02x'):
    mac = random_bytes()
    if oui:
        if type(oui) == str:
            oui = [int(chunk) for chunk in oui.split(separator)]
        mac = oui + random_bytes(num=6-len(oui))
    else:
        if multicast:
            mac[0] |= 1 # set bit 0
        else:
            mac[0] &= ~1 # clear bit 0
        if uaa:
            mac[0] &= ~(1 << 1) # clear bit 1
        else:
            mac[0] |= 1 << 1 # set bit 1
    return separator.join(byte_fmt % b for b in mac)