import ecdsa
import hashlib
import base64

from community_qa_bot.settings import ECDSA_PRIVATE_KEY, ECDSA_PUBLIC_KEY


private_key = ecdsa.SigningKey.from_pem(ECDSA_PRIVATE_KEY)
public_key = ecdsa.VerifyingKey.from_pem(ECDSA_PUBLIC_KEY)


def sign(payload: str) -> str:
    sha_msg = hashlib.sha256(payload.encode()).digest()
    signature = private_key.sign(sha_msg)
    return base64.urlsafe_b64encode(signature).decode()


def verify(payload: str, signature: str) -> bool:
    sha_msg = hashlib.sha256(payload.encode()).digest()
    try:
        signature = base64.urlsafe_b64decode(signature)
        return public_key.verify(signature, sha_msg)
    except ecdsa.BadSignatureError:
        return False
    except Exception:
        return False