"""
Replay verification — determinism, mismatch detection, binary search.
"""
import pytest
from malkhut.state import (
    AccountState, MarketWorldState, Mode, OrderBookState, PriceLevel, VenueRules,
)
from malkhut.cwm.core import MinimalCryptoLOBCWM
from malkhut.cwm.replay_verify import ReplayVerifier, ReplayStep
from malkhut.actions import ActionKind, FulfilmentAction


def _venue():
    return VenueRules(
        exchange="bingx", symbol="BTCUSDT", tick_size=0.1, lot_size=0.001,
        min_qty=0.001, min_notional=5.0, maker_fee_bps=-0.2, taker_fee_bps=0.5,
        post_only_supported=True, reduce_only_supported=True,
        max_orders_per_second=100, max_cancels_per_minute=120,
    )


def _state(ts=1_000_000_000):
    return MarketWorldState(
        ts_ns=ts, mode=Mode.REPLAY_NO_IMPACT, venue=_venue(),
        book=OrderBookState(ts_ns=ts, symbol="BTCUSDT",
                            bids=(PriceLevel(50000.0, 1.0),),
                            asks=(PriceLevel(50001.0, 1.0),)),
        account=AccountState(ts_ns=ts, equity=10000.0, wallet_balance=10000.0,
                             available_balance=10000.0, margin_used=0.0, total_notional=0.0),
    )


def _noop():
    return FulfilmentAction(ActionKind.NOOP, None, None, 0, 0.0, 0)


class TestReplayVerifyDeterministic:
    def test_perfect_replay_passes(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))
        s2 = cwm.transition(s1, (a,))

        replay = [
            ReplayStep(s0, (a,), s1),
            ReplayStep(s1, (a,), s2),
        ]
        result = verifier.verify(cwm, replay)
        assert result.passed
        assert len(result.mismatches) == 0

    def test_mismatch_detected(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))
        # Tamper with ground truth
        bad_s1 = MarketWorldState(
            ts_ns=s1.ts_ns + 999, mode=s1.mode, venue=s1.venue,
            book=s1.book, account=s1.account,
        )
        replay = [ReplayStep(s0, (a,), bad_s1)]
        result = verifier.verify(cwm, replay)
        assert not result.passed
        assert len(result.mismatches) > 0

    def test_mismatch_at_correct_index(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))
        s2 = cwm.transition(s1, (a,))
        s3 = cwm.transition(s2, (a,))

        # First step correct, second tampered
        bad_s2 = MarketWorldState(
            ts_ns=s2.ts_ns + 999, mode=s2.mode, venue=s2.venue,
            book=s2.book, account=s2.account,
        )
        replay = [
            ReplayStep(s0, (a,), s1),
            ReplayStep(s1, (a,), bad_s2),
            ReplayStep(s2, (a,), s3),
        ]
        result = verifier.verify(cwm, replay)
        assert not result.passed
        assert result.mismatches[0].index == 1

    def test_empty_replay_passes(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        result = verifier.verify(cwm, [])
        assert result.passed


class TestReplayVerifyDeterminismCheck:
    def test_same_replay_twice_same_result(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))
        replay = [ReplayStep(s0, (a,), s1)]

        r1 = verifier.verify(cwm, replay)
        r2 = verifier.verify(cwm, replay)
        assert r1.passed == r2.passed

    def test_determinism_verification_passes_for_cwm(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))
        replay = [ReplayStep(s0, (a,), s1)]
        result = verifier.verify_determinism(cwm, replay)
        assert result.passed


class TestReplayBisect:
    def test_bisect_returns_first_mismatch(self):
        cwm = MinimalCryptoLOBCWM()
        verifier = ReplayVerifier()
        s0 = _state()
        a = _noop()
        s1 = cwm.transition(s0, (a,))

        from malkhut.cwm.replay_verify import ReplayMismatch
        replay = [ReplayStep(s0, (a,), s1)]
        result = verifier.verify(cwm, replay)
        assert result.passed
        # Bisect on clean replay returns None
        mismatch = verifier.bisect(cwm, replay)
        assert mismatch is None