import hmac
import hashlib
from typing import Any, Dict


def verify_signature(secret: str, payload: bytes, signature: str) -> bool:
    if not secret:
        return False
    computed = hmac.new(secret.encode("utf-8"), payload, hashlib.sha256).hexdigest()
    return hmac.compare_digest(computed, signature)


def parse_webhook(payload: Dict[str, Any]) -> Dict[str, Any]:
    return {
        "event": payload.get("action") or payload.get("event"),
        "repository": payload.get("repository", {}).get("full_name"),
        "ref": payload.get("ref"),
    }