from __future__ import annotations

from yuxi.gateway.protocol.version import PROTOCOL_VERSION, negotiate_version


class TestProtocolVersion:
    def test_protocol_version_is_one(self):
        assert PROTOCOL_VERSION == 1

    def test_protocol_version_is_int(self):
        assert isinstance(PROTOCOL_VERSION, int)


class TestNegotiateVersion:
    def test_both_v1_returns_1(self):
        assert negotiate_version(1, 1) == 1

    def test_client_supports_1_to_3_returns_1(self):
        assert negotiate_version(1, 3) == 1

    def test_client_too_new_returns_none(self):
        assert negotiate_version(3, 5) is None

    def test_client_expects_future_fails(self):
        assert negotiate_version(2, 2) is None

    def test_client_range_covers_server(self):
        assert negotiate_version(1, 1) == 1

    def test_result_is_int(self):
        result = negotiate_version(1, 1)
        assert isinstance(result, int)

    def test_failure_is_none(self):
        result = negotiate_version(3, 5)
        assert result is None

    def test_client_max_exceeds_server(self):
        assert negotiate_version(1, 10) == 1

    def test_client_min_exceeds_server(self):
        assert negotiate_version(2, 10) is None