import hashlib

import hmac

import uuid

from datetime import datetime as dt

from imagekitio.constants import ERRORS

DEFAULT_TIME_DIFF = 60 * 30

def hamming_distance(first: str, second: str) -> int:

"""Calculate Hamming Distance between to hex string

"""

try:

a = bin(int(first, 16))[2:].zfill(64)

b = bin(int(second, 16))[2:].zfill(64)

except TypeError:

raise TypeError(ERRORS.INVALID_PHASH_VALUE.value)

return len(list(filter(lambda x: ord(x[0]) ^ ord(x[1]), zip(a, b))))

def get_authenticated_params(token, expire, private_key):

default_expire = int(dt.now().strftime("%s")) + DEFAULT_TIME_DIFF

auth_params = {"token": token, "expire": expire, "signature": ""}

if not private_key:

return

signature = hmac.new(

key=private_key.encode(),

msg=(token + str(expire)).encode(),

digestmod=hashlib.sha1,

).hexdigest()

auth_params["token"] = token or str(uuid.uuid4())

auth_params["expire"] = expire or default_expire

auth_params["signature"] = signature

return auth_params