import time
import hmac
import hashlib
from dataclasses import dataclass
from typing import Any


@dataclass
class AuditLogEntry:
    timestamp: float
    action: str
    details: str


class Signer:
    def __init__(self, key: str) -> None:
        self.key = key.encode("utf-8")

    def sign(self, message: str) -> str:
        return hmac.new(self.key, message.encode("utf-8"), hashlib.sha256).hexdigest()