import sys

import pytest

from app.discounts import NoDiscount, discount_for
from app.service import Order, OrderService


def make_order() -> Order:
    return Order({"чай": 300, "кофе": 700})


def test_vip_discount() -> None:
    service = OrderService(discount_for("vip"))
    assert service.total(make_order()) == pytest.approx(900.0)


def test_employee_discount() -> None:
    service = OrderService(discount_for("employee"))
    assert service.total(make_order()) == pytest.approx(700.0)


def test_regular_has_no_discount() -> None:
    service = OrderService(discount_for("regular"))
    assert service.total(make_order()) == pytest.approx(1000.0)


def test_unknown_type_falls_back_to_regular() -> None:
    assert isinstance(discount_for("unknown"), NoDiscount)


def test_python_version_supported() -> None:
    # Для акта с матрицей: на Python 3.11 этот тест падает
    assert sys.version_info >= (3, 12), (
        f"нужен Python 3.12+, получено {sys.version.split()[0]}"
    )