acceptance_message.py

"""The default terms of service message that is signed.

- The terms of service itself is not signed as it is too big to fit to small input boxes of the wallet.
  Instead, we sign a message that refers to the terms of service.

- Uses EIP-151

- See `EthAccout.sign_message implementation <https://github.com/ethereum/eth-account/blob/b4883627557839bed906c89b93eec0fbbb017ec5/eth_account/account.py#L535>`__.
"""
import datetime

from eth_account.datastructures import SignedMessage
from eth_account.messages import encode_defunct, _hash_eip191_message
from eth_account.signers.local import LocalAccount

DEFAULT_ACCEPTANCE_MESSAGE_TEMPLATE = """
I read and agree on terms of service (version {version}) to use
smart contract software deployed on a blockchain.
The terms of service text was published {human_date} at {link}.
The unique identifier hash for this terms of service tgext was {hash}.
""".strip()

INITIAL_ACCEPTANCE_MESSAGE = """
I read and agree on terms of service (version 1) to use
smart contract software deployed on a blockchain.

The terms of service text was published 10.1.2024 at https://example.com.
The unique identifier hash for this terms of service text was 0x0000000000000000000000000000000000000000.
""".strip()


TRADING_STRATEGY_ACCEPTANCE_MESSAGE = """
I agree on Terms of Service. I understand smart contract trading is risky and I may lose all of my deposits. 

This Terms of Service version {version}, dated {date}, was published at https://tradingstrategy.ai/tos/{date}.txt
""".strip()



def generate_acceptance_message(
        version: int,
        date: datetime.datetime,
        link: str,
        hash: bytes,
        template=DEFAULT_ACCEPTANCE_MESSAGE_TEMPLATE):
    assert type(version) == int
    assert type(link) == str
    assert type(hash) == bytes
    assert len(hash) == 32, "Must be 256-bit sha of terms of service file"
    assert isinstance(date, datetime.datetime)
    human_date = date.strftime("%Y-%m-%d")
    return template.format(version=version, link=link, hash=hash.hex(), human_date=human_date)


def get_signing_hash(message: str) -> bytes:
    assert type(message) == str
    signable_message = encode_defunct(text=message)
    hash = _hash_eip191_message(signable_message)
    return hash


def sign_terms_of_service(
    user: LocalAccount,
    signable_message: str,
) -> tuple[bytes, bytes]:
    """Sign terms of service for a local dev test account.

    :return:
        Tuple (message hash, signed message)
    """

    assert isinstance(user, LocalAccount)
    message_hash = get_signing_hash(signable_message)
    signed_message = user.signHash(message_hash)
    # import ipdb ; ipdb.set_trace()
    return message_hash, signed_message.signature