from pathlib import Path
import sys

import pytest


ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from udp_teleop_bridge.protocol import (  # noqa: E402
    PACKET_SIZE,
    default_server_addr_for_transport,
    normalize_command,
    normalize_transport,
    pack_command,
    unpack_command,
)


def test_pack_unpack_round_trip() -> None:
    command = (0.1, -0.2, 0.3, -0.4, 0.5, -0.6)

    payload = pack_command(command)

    assert len(payload) == PACKET_SIZE
    assert unpack_command(payload) == pytest.approx(command)


@pytest.mark.parametrize('value', [float('nan'), float('inf'), float('-inf')])
def test_normalize_command_rejects_non_finite_values(value: float) -> None:
    with pytest.raises(ValueError, match='non-finite'):
        normalize_command((0.0, 0.0, value, 0.0, 0.0, 0.0))


def test_unpack_command_rejects_wrong_length() -> None:
    with pytest.raises(ValueError, match='Expected'):
        unpack_command(b'\x00' * (PACKET_SIZE - 1))


@pytest.mark.parametrize(
    ('transport', 'expected'),
    [
        ('udp', '127.0.0.1:9001'),
        ('kcp', '127.0.0.1:9002'),
    ],
)
def test_default_server_addr_for_transport(transport: str, expected: str) -> None:
    assert default_server_addr_for_transport(transport) == expected


def test_normalize_transport_rejects_unknown_value() -> None:
    with pytest.raises(ValueError, match='Unsupported transport'):
        normalize_transport('sctp')