from sqlalchemy.ext.asyncio import AsyncSession

from app.db.models import Round, User
from app.wallet.hd import derive_user_address


async def own_address_for(
    session: AsyncSession, kind: str, user_id: int | None, round_id: int | None = None
) -> str:
    """The address that owns every input of a PendingTransaction of this kind —
    a user's own address for a bet/withdrawal, the pool address of the round for a
    payout (B-80: each round has its own, stored on the round).
    All our builders only ever spend one address's UTXOs per tx (see
    tx/broadcast.py:_signing_context, which derives the same address alongside
    the signing key it also needs).

    Shared by tx/confirmation.py and tx/reconcile.py (B-41): both now check
    blockchain.scripthash.get_history for this address instead of asking
    blockchain.transaction.get for a verbose reply, so the two can't derive
    different addresses for the same row.
    """
    if kind == "payout":
        round_ = await session.get(Round, round_id) if round_id is not None else None
        if round_ is None or not round_.pool_address:
            raise ValueError(f"payout of round {round_id}: the round has no pool address")
        return round_.pool_address
    user = await session.get(User, user_id)
    return derive_user_address(user.derivation_index)