from __future__ import annotations

from app.algorithm_runner.cli import _resolve_source_mode, _stream_time_for_frame


def test_resolve_source_mode_auto_detects_local_video(tmp_path) -> None:
    video = tmp_path / "case.mp4"
    video.write_bytes(b"")

    assert _resolve_source_mode(str(video), "auto") == "file"


def test_resolve_source_mode_auto_keeps_rtsp_realtime() -> None:
    assert _resolve_source_mode("rtsp://127.0.0.1:8554/demo", "auto") == "realtime"


def test_resolve_source_mode_respects_explicit_choice() -> None:
    assert _resolve_source_mode("rtsp://127.0.0.1:8554/demo", "file") == "file"


def test_realtime_stream_time_uses_frame_index_not_wall_clock() -> None:
    assert _stream_time_for_frame(
        source_mode="realtime",
        cap_pos_msec=999_999.0,
        frame_idx=50,
        fps_hint=25.0,
    ) == 2.0


def test_file_stream_time_prefers_capture_timestamp() -> None:
    assert _stream_time_for_frame(
        source_mode="file",
        cap_pos_msec=1234.0,
        frame_idx=50,
        fps_hint=25.0,
    ) == 1.234