import os
import stat

from h264_fifo import hold_fifo


def test_hold_fifo_creates_rdwr_pipe(tmp_path):
    path = str(tmp_path / "cam-01.h264")
    fd = hold_fifo(path)
    try:
        st = os.stat(path)
        assert stat.S_ISFIFO(st.st_mode)
        os.write(fd, b"\x00\x01")
        assert os.read(fd, 2) == b"\x00\x01"
    finally:
        os.close(fd)


def test_hold_fifo_does_not_replace_existing_fifo(tmp_path):
    path = str(tmp_path / "cam-02.h264")
    a = hold_fifo(path)
    ino = os.stat(path).st_ino
    b = hold_fifo(path)
    try:
        assert os.stat(path).st_ino == ino
        os.write(a, b"ab")
        assert os.read(b, 2) == b"ab"
    finally:
        os.close(a)
        os.close(b)