from decimal import Decimal

from app.domain.corporate_actions import calculate_stock_consolidation


def test_stock_consolidation_preserves_cost_and_scales_wac():
    result = calculate_stock_consolidation(Decimal(1452), Decimal(726), Decimal("1086.23"))
    assert result.average_price_after == Decimal("2172.46")
    assert result.total_cost_basis == Decimal("1577205.96000000")
    assert result.ratio == Decimal("0.5")

def test_stock_consolidation_rejects_fractional_result():
    import pytest

    from app.domain.corporate_actions import CorporateActionError
    with pytest.raises(CorporateActionError) as exc:
        calculate_stock_consolidation(Decimal(3), Decimal("1.5"), Decimal(10))
    assert exc.value.code == "FRACTIONAL_RESULT_UNSUPPORTED"