import pytest
from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine

import app.bets.confirmation  # noqa: F401  (registers the "bet" handler)
import app.rounds.confirmation  # noqa: F401  (registers the "payout" handler)
from sqlalchemy import select

from app.config import settings
from app.db.base import Base
from app.db.models import PendingTransaction, Round, RoundParticipant, User
from app.electrum.scripthash import address_to_scripthash
from app.tx.confirmation import poll_once
from app.wallet.hd import derive_user_address


class FakeClient:
    """B-41: poll_once now asks blockchain.scripthash.get_history rather than a
    verbose blockchain.transaction.get, so this hands back a flat history —
    height > 0 means confirmed at that height, 0 (or absent) means still in the
    mempool. The scripthash argument is ignored: every candidate's derived
    address is looked up against the same known universe of txids, which is
    fine since matching happens on tx_hash, not on which address asked."""

    def __init__(self, heights_by_txid: dict[str, int]):
        self._heights = heights_by_txid

    async def get_history(self, scripthash: str) -> list[dict]:
        return [{"tx_hash": txid, "height": height} for txid, height in self._heights.items()]


@pytest.fixture
async def session_factory(tmp_path, monkeypatch):
    # own_address_for (B-41) derives each row's address via the HD wallet, so
    # poll_once now needs a real master key — same bootstrap test_broadcast.py
    # and test_reconcile.py use.
    monkeypatch.setattr(settings, "master_key_path", str(tmp_path / "master.xprv.enc"))
    monkeypatch.setattr(
        settings,
        "xprv_encryption_key",
        __import__("cryptography.fernet", fromlist=["Fernet"]).Fernet.generate_key().decode(),
    )
    from app.wallet import hd

    hd._account_key = None
    hd.generate_master_key()

    engine = create_async_engine("sqlite+aiosqlite:///:memory:")
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    yield async_sessionmaker(engine, expire_on_commit=False)
    await engine.dispose()
    hd._account_key = None


async def _make_user(session, derivation_index: int) -> User:
    user = User(
        username=f"user{derivation_index}",
        password_hash="x",
        derivation_index=derivation_index,
        address=derive_user_address(derivation_index),
    )
    session.add(user)
    await session.flush()
    return user


async def test_bet_confirmation_marks_participant_confirmed(session_factory):
    async with session_factory() as session:
        user = await _make_user(session, 0)
        session.add(Round(id=1, status="open"))
        session.add(
            RoundParticipant(
                round_id=1, user_id=user.id, bet_amount_sats=1_000, bet_txid="tx1", status="broadcast"
            )
        )
        session.add(
            PendingTransaction(
                kind="bet", round_id=1, user_id=user.id, current_txid="tx1", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        await session.commit()

    client = FakeClient({"tx1": 1})
    confirmed = await poll_once(session_factory, client)
    assert confirmed == 1

    async with session_factory() as session:
        participant = (await session.scalars(select(RoundParticipant))).one()
        assert participant.status == "confirmed"
        assert participant.confirmed_at is not None
        pending = (await session.scalars(select(PendingTransaction))).one()
        assert pending.status == "confirmed"


async def test_unconfirmed_tx_is_left_pending(session_factory):
    async with session_factory() as session:
        user = await _make_user(session, 0)
        session.add(Round(id=2, status="open"))
        session.add(
            RoundParticipant(round_id=2, user_id=user.id, bet_amount_sats=1_000, bet_txid="tx2", status="broadcast")
        )
        session.add(
            PendingTransaction(
                kind="bet", round_id=2, user_id=user.id, current_txid="tx2", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        await session.commit()

    client = FakeClient({"tx2": 0})
    confirmed = await poll_once(session_factory, client)
    assert confirmed == 0

    async with session_factory() as session:
        participant = (await session.scalars(select(RoundParticipant))).one()
        assert participant.status == "broadcast"


async def test_payout_confirmation_closes_round(session_factory):
    async with session_factory() as session:
        session.add(Round(id=3, status="paying_out", payout_txid="tx3"))
        session.add(
            PendingTransaction(
                kind="payout", round_id=3, current_txid="tx3", fee_rate_sat_vb=1, raw_tx_hex="00", status="pending"
            )
        )
        await session.commit()

    client = FakeClient({"tx3": 2})
    confirmed = await poll_once(session_factory, client)
    assert confirmed == 1

    async with session_factory() as session:
        round_ = await session.get(Round, 3)
        assert round_.status == "closed"


class ExplodingClient:
    """Answers for one address's history and raises for the other's — the
    get_history equivalent of a server that no longer knows a particular tx
    (dropped from the mempool, replaced by a bump)."""

    def __init__(self, heights_by_txid: dict[str, int], exploding_scripthash: str):
        self._heights = heights_by_txid
        self._exploding = exploding_scripthash

    async def get_history(self, scripthash: str) -> list[dict]:
        if scripthash == self._exploding:
            raise RuntimeError("server error")
        return [{"tx_hash": txid, "height": height} for txid, height in self._heights.items()]


async def test_one_unresolvable_candidate_does_not_block_the_others(session_factory):
    """B-03: the lookup used to be unguarded, so a single failing candidate aborted
    the whole pass — nothing confirmed again until an operator intervened, which in
    turn meant no round could ever close. B-41 changed the failure unit from "one
    txid" to "one address's history", but the isolation guarantee is the same."""
    async with session_factory() as session:
        good_user = await _make_user(session, 0)
        gone_user = await _make_user(session, 1)
        session.add(Round(id=10, status="open"))
        session.add(
            RoundParticipant(
                round_id=10, user_id=good_user.id, bet_amount_sats=1_000, bet_txid="good", status="broadcast"
            )
        )
        session.add(
            PendingTransaction(
                kind="bet", round_id=10, user_id=gone_user.id, current_txid="gone", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        session.add(
            PendingTransaction(
                kind="bet", round_id=10, user_id=good_user.id, current_txid="good", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        await session.commit()

    exploding_scripthash = address_to_scripthash(derive_user_address(1))
    confirmed = await poll_once(
        session_factory, ExplodingClient({"good": 1}, exploding_scripthash=exploding_scripthash)
    )
    assert confirmed == 1  # the healthy one still got processed

    async with session_factory() as session:
        participant = (await session.scalars(select(RoundParticipant).where(RoundParticipant.round_id == 10))).one()
        assert participant.status == "confirmed"
        rows = {p.current_txid: p.status for p in (await session.scalars(select(PendingTransaction))).all()}
        assert rows["good"] == "confirmed"
        assert rows["gone"] == "pending"  # left for the reconciler to judge, not abandoned here


async def test_bet_confirms_after_an_rbf_bump_changed_the_txid(session_factory):
    """B-02: the handler used to match on bet_txid, so a bumped bet confirmed under
    a txid no participant carried — the participant stayed "broadcast" forever and
    the round could never close. It now resolves by (round_id, user_id)."""
    async with session_factory() as session:
        user = await _make_user(session, 0)
        session.add(Round(id=11, status="open"))
        session.add(
            RoundParticipant(
                round_id=11, user_id=user.id, bet_amount_sats=1_000, bet_txid="old-txid", status="broadcast"
            )
        )
        session.add(
            PendingTransaction(
                kind="bet", round_id=11, user_id=user.id, current_txid="bumped-txid", fee_rate_sat_vb=2,
                raw_tx_hex="00", status="pending", replaced_by_txid="old-txid",
            )
        )
        await session.commit()

    assert await poll_once(session_factory, FakeClient({"bumped-txid": 1})) == 1

    async with session_factory() as session:
        participant = (await session.scalars(select(RoundParticipant).where(RoundParticipant.round_id == 11))).one()
        assert participant.status == "confirmed"


async def test_payout_confirms_after_an_rbf_bump_changed_the_txid(session_factory):
    async with session_factory() as session:
        session.add(Round(id=12, status="paying_out", payout_txid="old-payout"))
        session.add(
            PendingTransaction(
                kind="payout", round_id=12, current_txid="bumped-payout", fee_rate_sat_vb=2,
                raw_tx_hex="00", status="pending",
            )
        )
        await session.commit()

    assert await poll_once(session_factory, FakeClient({"bumped-payout": 1})) == 1

    async with session_factory() as session:
        assert (await session.get(Round, 12)).status == "closed"


async def test_poll_once_caches_history_per_scripthash(session_factory):
    """Two pending bets from the same user share one address — fetching its
    history twice in one pass would be wasteful."""
    async with session_factory() as session:
        user = await _make_user(session, 0)
        session.add(Round(id=20, status="open"))
        session.add(
            PendingTransaction(
                kind="bet", round_id=20, user_id=user.id, current_txid="tx-a", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        session.add(
            PendingTransaction(
                kind="withdrawal", user_id=user.id, current_txid="tx-b", fee_rate_sat_vb=1,
                raw_tx_hex="00", status="pending",
            )
        )
        await session.commit()

    call_count = {"n": 0}

    class CountingClient:
        async def get_history(self, scripthash: str) -> list[dict]:
            call_count["n"] += 1
            return [{"tx_hash": "tx-a", "height": 0}, {"tx_hash": "tx-b", "height": 0}]

    await poll_once(session_factory, CountingClient())

    assert call_count["n"] == 1