from setprotocol import Frame, FrameFlag, MessageType, build_frame, decode_datagram
from setprotocol.can import CanAddress, CanFrame, CanReassembler, segment


def test_can_id_roundtrip():
    value = CanAddress(destination=13, source=0, priority=1, channel=7)
    assert CanAddress.unpack(value.pack()) == value


def test_segmented_setp_frame_roundtrip():
    packet = build_frame(
        Frame(
            message_type=MessageType.FW_DATA,
            sequence=0x1234,
            payload=bytes(range(76)),
            flags=FrameFlag.ACK_REQUIRED | FrameFlag.PRIORITY,
            source=0,
            destination=13,
        )
    )
    frames = segment(packet, CanAddress(13, 0, priority=1, channel=1))
    assert len(frames) == 14
    reassembler = CanReassembler()
    restored = None
    for now_ms, frame in enumerate(frames):
        restored = reassembler.feed(frame, now_ms)
    assert restored == packet
    assert decode_datagram(restored).payload == bytes(range(76))


def test_reassembler_rejects_wrong_sequence():
    packet = build_frame(Frame(MessageType.PING, 1, source=0, destination=13))
    frames = segment(packet, CanAddress(13, 0))
    reassembler = CanReassembler()
    assert reassembler.feed(frames[0], 0) is None
    damaged = CanFrame(frames[1].can_id, bytes((0x22,)) + frames[1].data[1:])
    try:
        reassembler.feed(damaged, 1)
    except ValueError as error:
        assert "последовательность" in str(error)
    else:
        raise AssertionError("wrong sequence must fail")