from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.audit.log import write_audit_log
from app.db.models import UtxoEvent
from app.rounds.events import broadcaster
from app.wallet.balance import recompute_balance


async def credit_confirmed_utxos(session: AsyncSession, user_id: int, entries: list[dict]) -> int:
    """Insert utxo_events for newly-confirmed entries from an Electrum
    `listunspent` response (idempotent on txid+vout), refresh the user's cached
    balance. Returns the number of newly-credited UTXOs.

    entries: [{"tx_hash": ..., "tx_pos": ..., "height": ..., "value": ...}, ...]
    height <= 0 means unconfirmed (mempool) per the Electrum protocol convention —
    skipped, since the spec requires 1 confirmation before crediting.
    """
    existing_keys = {
        (txid, vout)
        for txid, vout in (
            await session.execute(select(UtxoEvent.txid, UtxoEvent.vout).where(UtxoEvent.user_id == user_id))
        ).all()
    }

    newly_credited = 0
    for entry in entries:
        if entry["height"] <= 0:
            continue
        key = (entry["tx_hash"], entry["tx_pos"])
        if key in existing_keys:
            continue
        session.add(
            UtxoEvent(
                user_id=user_id,
                txid=entry["tx_hash"],
                vout=entry["tx_pos"],
                amount_sats=entry["value"],
                confirmed_height=entry["height"],
            )
        )
        await write_audit_log(
            session,
            "deposit_credited",
            {"txid": entry["tx_hash"], "vout": entry["tx_pos"], "amount_sats": entry["value"]},
            user_id=user_id,
        )
        newly_credited += 1

    if newly_credited:
        await session.flush()
        await recompute_balance(session, user_id)
        await session.commit()
        broadcaster.publish()  # nudges this user's dashboard to refetch its balance instantly

    return newly_credited