import ecdsa
from hashlib import sha256, sha512

from google.protobuf.message import Message

from frostfs_sdk.client.models.ecdsa_model import ECDSA
from frostfs_sdk.protos.models.refs.types_pb2 import SignatureRFC6979, Signature


class Signer:
    @staticmethod
    def sign_message_rfc_6979(key: ECDSA, message: Message) -> SignatureRFC6979:
        return SignatureRFC6979(
            key=key.public_key,
            sign=Signer.sign_rfc6979(key.private_key, message.SerializeToString())
        )

    @staticmethod
    def sign_rfc6979(private_key: bytes, message: bytes) -> bytes:
        if len(private_key) == 0 or private_key is None:
            raise ValueError(f"Incorrect private_key: {private_key}")

        sk = ecdsa.SigningKey.from_string(private_key, curve=ecdsa.NIST256p, hashfunc=sha256)

        signature = sk.sign_deterministic(message)

        return signature

    @staticmethod
    def sign_message(key: ECDSA, message: Message) -> SignatureRFC6979:
        return SignatureRFC6979(
            key=key.public_key,
            sign=Signer.sign(key.private_key, message.SerializeToString())
        )

    @staticmethod
    def sign(private_key: bytes, message: bytes) -> bytes:
        if len(private_key) == 0 or private_key is None:
            raise ValueError(f"Incorrect private key: {private_key}")

        sk = ecdsa.SigningKey.from_string(private_key, curve=ecdsa.NIST256p, hashfunc=sha512)
        signature = sk.sign(message)

        # the first byte indicates the node version marker
        signature_with_marker = bytes([0x04]) + signature

        return signature_with_marker

    @staticmethod
    def _sign_message_part(key: ECDSA, data: Message) -> Signature:
        return Signature(
            key=key.public_key,
            sign=Signature.sign(key.private_key, data.SerializeToString())
        )