"""一致性监控测试（规格 §6.7/§11.4：N 帧降级、M 帧判 invalid、正常帧清零、每目标隔离）。"""

import pytest

from stereo_ranger import ConsistencyMonitor


def _monitor() -> ConsistencyMonitor:
    return ConsistencyMonitor(jump_px=3.0, degrade_frames=3, invalid_frames=5)


def test_first_frame_has_no_reference_jump():
    status = _monitor().advance("t", 10.0)
    assert status.jump_px is None
    assert status.abnormal is False
    assert status.streak == 0


def test_normal_jump_resets_streak():
    monitor = _monitor()
    monitor.advance("t", 10.0)
    abnormal = monitor.advance("t", 16.0)
    assert abnormal.abnormal and abnormal.streak == 1
    normal = monitor.advance("t", 17.0)
    assert not normal.abnormal and normal.streak == 0


def test_jump_at_threshold_is_normal():
    monitor = _monitor()
    monitor.advance("t", 10.0)
    assert not monitor.advance("t", 13.0).abnormal  # |ΔD| = 3.0 不超门限


def test_degrades_at_n_frames_and_invalidates_at_m_frames():
    monitor = _monitor()
    monitor.advance("t", 10.0)
    disparities = [14.0, 18.0, 22.0, 26.0, 30.0]  # 每帧跳变 4 px > 3 px
    statuses = [monitor.advance("t", d) for d in disparities]
    assert [s.streak for s in statuses] == [1, 2, 3, 4, 5]
    assert [s.confidence_degraded for s in statuses] == [False, False, True, True, True]
    assert [s.invalid for s in statuses] == [False, False, False, False, True]


def test_targets_are_isolated():
    monitor = _monitor()
    monitor.advance("a", 10.0)
    monitor.advance("b", 20.0)
    monitor.advance("a", 15.0)  # a 跳变异常
    assert monitor.streak("a") == 1
    assert monitor.streak("b") == 0


def test_drop_clears_only_target():
    monitor = _monitor()
    monitor.advance("a", 10.0)
    monitor.advance("a", 20.0)
    monitor.drop("a")
    assert monitor.streak("a") == 0
    assert monitor.advance("a", 40.0).jump_px is None  # 状态已清空，重新起始


def test_clear_resets_all():
    monitor = _monitor()
    monitor.advance("a", 10.0)
    monitor.advance("a", 20.0)
    monitor.clear()
    assert monitor.streak("a") == 0


@pytest.mark.parametrize(
    "kwargs",
    [
        {"jump_px": 0.0, "degrade_frames": 3, "invalid_frames": 5},
        {"jump_px": 3.0, "degrade_frames": 0, "invalid_frames": 5},
        {"jump_px": 3.0, "degrade_frames": 5, "invalid_frames": 3},
    ],
)
def test_invalid_ctor_args(kwargs):
    with pytest.raises(ValueError):
        ConsistencyMonitor(**kwargs)