from app.services.crm_settlement_clause import default_settlement_clause


def test_advance_payment_clause():
    assert "款到发货" in default_settlement_clause("advance_payment")


def test_arrive_payment_clause():
    assert "货到付款" in default_settlement_clause("arrive_payment")


def test_monthly_settlement_clause_uses_label():
    text = default_settlement_clause("monthly_settlement")
    assert text.startswith("请根据双方约定的结算方式：月结。")
    assert "增值税专用发票" in text
    assert "13%" not in text


def test_volume_quarterly_other_labels():
    assert "按量结算" in default_settlement_clause("volume_settlement")
    assert "季结" in default_settlement_clause("quarterly_settlement")
    assert "其他" in default_settlement_clause("other_settlement")


def test_unknown_falls_back_to_arrive():
    assert default_settlement_clause("weird") == default_settlement_clause("arrive_payment")


def test_empty_falls_back_to_arrive():
    assert default_settlement_clause("") == default_settlement_clause("arrive_payment")
    assert default_settlement_clause(None) == default_settlement_clause("arrive_payment")