import pytest

from ibkr_quant.rebalance import plan_orders


def test_closes_dropped_names_and_sells_before_buys():
    orders = plan_orders(
        target_weights={"AAPL": 0.5, "MSFT": 0.5},
        positions={"AAPL": 10, "NVDA": 7},
        prices={"AAPL": 100.0, "MSFT": 300.0, "NVDA": 50.0},
        investable=10_000,
        min_trade_value=200,
    )
    assert [(o.symbol, o.delta) for o in orders] == [("NVDA", -7), ("AAPL", 40), ("MSFT", 16)]


def test_skips_small_adjustments_but_not_full_exits():
    orders = plan_orders(
        target_weights={"AAPL": 1.0},
        positions={"AAPL": 99, "KO": 1},
        prices={"AAPL": 100.0, "KO": 60.0},
        investable=10_000,
        min_trade_value=200,
    )
    assert [(o.symbol, o.delta) for o in orders] == [("KO", -1)]


def test_refuses_to_plan_without_prices():
    with pytest.raises(ValueError, match="NVDA"):
        plan_orders({"AAPL": 1.0}, {"NVDA": 5}, {"AAPL": 100.0}, 10_000, 0)


def test_resize_band_keeps_near_target_holdings():
    orders = plan_orders(
        target_weights={"AAPL": 0.5, "MSFT": 0.5},
        positions={"AAPL": 46, "MSFT": 10},
        prices={"AAPL": 100.0, "MSFT": 300.0},
        investable=10_000,
        min_trade_value=50,
        resize_band=0.10,
    )
    # AAPL is 8% under target and stays; MSFT is 40% under and tops up.
    assert [(o.symbol, o.delta) for o in orders] == [("MSFT", 6)]