import base64
import os

from cryptography.fernet import Fernet
from cryptography.hazmat.primitives.kdf.scrypt import Scrypt


def fernet_encrypt(value: bytes, key: bytes) -> bytes:
    f = Fernet(key)
    token = f.encrypt(value)
    return token


def fernet_decrypt(value, key, return_bytes=False):
    f = Fernet(key)
    msg = f.decrypt(value)
    if return_bytes:
        return msg
    return msg.decode("utf-8")


def generate_user_passkey(password: str, salt: bytes = None) -> tuple[bytes, bytes]:
    if salt is None:
        salt = os.urandom(128)

    kdf = Scrypt(salt=salt, length=32, n=2**14, r=8, p=1)
    user_passkey = kdf.derive(password.encode("utf-8"))
    return salt, base64.b64encode(user_passkey)


def generate_random_encryption_key():
    return Fernet.generate_key()


def serialize_bytes(byte_value):
    byte_value = base64.b64encode(byte_value)
    return byte_value.decode("utf-8")


def deserialize_into_bytes(string):
    string = string.encode("utf-8")
    return base64.b64decode(string)