import numpy as np

from behavision.capture import VideoSource


def _source_with_frame(ts=100.0):
    """VideoSource opens nothing until run(), so the frame slot can be
    populated directly — no camera needed."""
    src = VideoSource("cam1", 0)
    src._frame = np.zeros((4, 4, 3), dtype=np.uint8)
    src._frame_ts = ts
    return src


def test_latest_since_skips_an_already_seen_frame():
    src = _source_with_frame(ts=100.0)
    frame, ts = src.latest_since(100.0)
    assert frame is None
    assert ts == 100.0


def test_latest_since_returns_a_newer_frame():
    src = _source_with_frame(ts=100.0)
    frame, ts = src.latest_since(99.0)
    assert frame is not None
    assert ts == 100.0


def test_latest_since_returns_a_copy():
    src = _source_with_frame()
    frame, _ = src.latest_since(0.0)
    frame[0, 0, 0] = 255
    assert src._frame[0, 0, 0] == 0


def test_latest_since_with_no_frame_yet():
    frame, ts = VideoSource("cam1", 0).latest_since(0.0)
    assert frame is None
    assert ts == 0.0


def test_first_connect_is_not_counted_as_a_reconnect():
    assert VideoSource("cam1", 0).stats()["reconnects"] == 0


def _elapsed(fn):
    import time
    t = time.perf_counter()
    result = fn()
    return result, time.perf_counter() - t


def test_probe_fails_fast_on_an_unroutable_host():
    """The Test button must answer, not hang. cv2.VideoCapture blocks in its
    constructor on TCP connect (~75s OS timeout), so a pre-flight check is the
    only thing that bounds this."""
    from behavision.capture import probe_source

    result, seconds = _elapsed(lambda: probe_source(
        "rtsp://10.255.255.1:554/x", connect_timeout=1.0))
    assert result["ok"] is False
    assert "10.255.255.1:554" in result["error"]
    assert seconds < 5, f"took {seconds:.1f}s - the pre-flight is not working"


def test_probe_reports_connection_refused_immediately():
    from behavision.capture import probe_source

    result, seconds = _elapsed(lambda: probe_source("rtsp://127.0.0.1:1/x"))
    assert result["ok"] is False
    assert seconds < 5


def test_tcp_precheck_passes_through_non_url_sources():
    """A webcam index has no host to check; it must not be blocked."""
    from behavision.capture import _tcp_reachable

    assert _tcp_reachable(0, 1.0) == (True, "")
    assert _tcp_reachable("not-a-url", 1.0)[0] is True