from arbitrade.detection.engine import IncrementalCycleDetector
from arbitrade.detection.graph import CurrencyGraph, TriangularCycle
from arbitrade.exchange.models import BookLevel
from arbitrade.market_data.order_book import OrderBook


def _make_book(*, bid: float, ask: float) -> OrderBook:
    book = OrderBook()
    book.apply_bids([BookLevel(price=bid, volume=1.0)])
    book.apply_asks([BookLevel(price=ask, volume=1.0)])
    return book


def test_incremental_detector_scores_only_cycles_touched_by_pair() -> None:
    cycle_a = TriangularCycle(
        currencies=("USD", "BTC", "ETH"),
        pairs=("BTC/USD", "ETH/BTC", "ETH/USD"),
    )
    cycle_b = TriangularCycle(
        currencies=("USD", "BTC", "LTC"),
        pairs=("BTC/USD", "LTC/BTC", "LTC/USD"),
    )
    cycle_c = TriangularCycle(
        currencies=("USD", "SOL", "ADA"),
        pairs=("SOL/USD", "ADA/SOL", "ADA/USD"),
    )

    cycles = [cycle_a, cycle_b, cycle_c]
    index = CurrencyGraph.index_cycles_by_pair(cycles)
    detector = IncrementalCycleDetector(index)

    books = {
        "BTC/USD": _make_book(bid=100.0, ask=100.0),
        "ETH/BTC": _make_book(bid=0.05, ask=0.05),
        "ETH/USD": _make_book(bid=5.20, ask=5.21),
        "LTC/BTC": _make_book(bid=0.01, ask=0.01),
        "LTC/USD": _make_book(bid=1.02, ask=1.03),
        "SOL/USD": _make_book(bid=20.0, ask=20.1),
        "ADA/SOL": _make_book(bid=0.02, ask=0.021),
        "ADA/USD": _make_book(bid=0.42, ask=0.43),
    }

    scores = detector.score_updated_pair("BTC/USD", books)

    assert len(scores) == 2
    assert {score.cycle for score in scores} == {cycle_a, cycle_b}


def test_incremental_detector_uses_best_bid_ask_for_gross_rate() -> None:
    cycle = TriangularCycle(
        currencies=("USD", "BTC", "ETH"),
        pairs=("BTC/USD", "ETH/BTC", "ETH/USD"),
    )
    detector = IncrementalCycleDetector(CurrencyGraph.index_cycles_by_pair([cycle]))

    books = {
        "BTC/USD": _make_book(bid=99.9, ask=100.0),
        "ETH/BTC": _make_book(bid=0.049, ask=0.05),
        "ETH/USD": _make_book(bid=5.20, ask=5.21),
    }

    scores = detector.score_updated_pair("ETH/BTC", books)

    assert len(scores) == 1
    assert scores[0].gross_rate == 1.04
    assert scores[0].is_profitable