"""B-90 (REG-15, OPS-27): a restored backup must not hand out derivation indexes that already
have history, and START_PAUSED starts the lottery paused."""

import json

import pytest
from sqlalchemy import select

from app.db.models import AuditLog, RoundConfig, User
from app.electrum.listener import ElectrumListener
from app.electrum.scripthash import address_to_scripthash
from app.wallet.hd import derive_user_address
from tests.unit.test_electrum_listener import _ENDPOINTS, session_factory  # noqa: F401  (fixture)


class _Server:
    """Answers get_history: the given scripthashes have a transaction, the rest none."""

    def __init__(self, used=(), fail=False):
        self.used = set(used)
        self.fail = fail

    async def connect(self):
        if self.fail:
            raise ConnectionRefusedError("down")

    async def request(self, method, params=None):
        assert method == "blockchain.scripthash.get_history"
        return [{"tx_hash": "aa" * 32, "height": 5}] if params[0] in self.used else []

    async def close(self):
        pass


def _listener(session_factory, active, others):
    servers = {"second.example": others[0], "third.example": others[1]}
    listener = ElectrumListener(lambda endpoint: servers[endpoint.host], session_factory, _ENDPOINTS)
    listener.client = active
    listener.registration_open = False
    return listener


async def _users(session_factory, count):
    async with session_factory() as session:
        for i in range(count):
            session.add(User(username=f"u{i}", password_hash="x", derivation_index=i, address=derive_user_address(i)))
        await session.commit()


def _hash(index):
    return address_to_scripthash(derive_user_address(index))


async def _audit(session_factory):
    async with session_factory() as session:
        return list((await session.execute(select(AuditLog).where(AuditLog.event_type == "restore_gap_detected"))).scalars())


async def test_registration_opens_when_the_next_20_indexes_are_unused(session_factory):
    await _users(session_factory, 3)
    listener = _listener(session_factory, _Server(), [_Server(), _Server()])
    await listener._check_restore_gap()
    assert listener.registration_open and await _audit(session_factory) == []


async def test_one_server_reporting_history_is_enough_to_keep_it_closed(session_factory):
    """REG-15: the checked window is highest + 1 … highest + 20; any server's word counts."""
    await _users(session_factory, 3)  # highest assigned index 2 -> checks 3..22
    listener = _listener(session_factory, _Server(), [_Server(used={_hash(22)}), _Server()])
    await listener._check_restore_gap()
    assert not listener.registration_open
    (row,) = await _audit(session_factory)
    payload = json.loads(row.payload_json)
    assert payload["highest_assigned_index"] == 2
    assert payload["used"] == [{"derivation_index": 22, "address": derive_user_address(22)}]


async def test_an_index_just_past_the_window_is_not_looked_at(session_factory):
    await _users(session_factory, 3)
    listener = _listener(session_factory, _Server(used={_hash(23)}), [_Server(), _Server()])
    await listener._check_restore_gap()
    assert listener.registration_open


async def test_an_empty_database_checks_indexes_0_to_19(session_factory):
    listener = _listener(session_factory, _Server(used={_hash(0)}), [_Server(), _Server()])
    await listener._check_restore_gap()
    (row,) = await _audit(session_factory)
    assert json.loads(row.payload_json)["highest_assigned_index"] is None


async def test_without_the_active_servers_answer_nothing_is_decided(session_factory):
    """The check is simply tried again on the next session; registration stays closed."""
    listener = _listener(session_factory, None, [_Server(), _Server()])
    with pytest.raises(RuntimeError):
        await listener._check_restore_gap()
    assert not listener.registration_open and not listener._restore_checked


async def test_an_unreachable_quorum_server_does_not_block_a_clean_result(session_factory):
    listener = _listener(session_factory, _Server(), [_Server(fail=True), _Server()])
    await listener._check_restore_gap()
    assert listener.registration_open


async def test_register_is_refused_while_the_check_has_not_passed(session_factory, monkeypatch):
    from httpx import ASGITransport, AsyncClient

    from app.main import app

    listener = ElectrumListener(lambda endpoint: None, session_factory, _ENDPOINTS)
    monkeypatch.setattr(ElectrumListener, "registration_open", False)
    app.state.electrum_listener = listener
    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://t") as client:
        response = await client.post("/auth/register", json={"username": "alice", "password": "password123"})
    assert response.status_code == 503
    assert response.json()["detail"]["code"] == "registration_unavailable"


async def test_start_paused_pauses_as_the_operator_without_overwriting_an_automatic_reason(session_factory):
    from app.rounds.pause import pause_automatically, pause_by_operator

    async with session_factory() as session:
        await pause_by_operator(session, "START_PAUSED")
        await session.commit()
        config = (await session.execute(select(RoundConfig))).scalar_one()
        assert config.paused and config.paused_reason == "operator"
        await pause_automatically(session, "reorg")
        await pause_by_operator(session, "START_PAUSED")
        await session.commit()
        assert config.paused_reason == "reorg"  # an automatic reason is the one that needs a look
        events = (await session.execute(select(AuditLog).where(AuditLog.event_type == "lottery_paused"))).scalars().all()
        assert [json.loads(e.payload_json)["reason"] for e in events] == ["operator", "reorg", "operator"]