import numpy as np

from src.detector import MotionDetector
from src.models import DetectionConfig, DetectionState


def detector() -> MotionDetector:
    return MotionDetector(DetectionConfig(movement_threshold=2.0, alert_after=3.0, capture_interval=1.0), downscale_step=1)


def test_identical_images_score_near_zero() -> None:
    image = np.zeros((10, 10, 3), dtype=np.uint8)
    assert detector().calculate_motion_score(image, image) == 0.0


def test_different_images_score_is_higher() -> None:
    first = np.zeros((10, 10, 3), dtype=np.uint8)
    second = np.full((10, 10, 3), 255, dtype=np.uint8)
    assert detector().calculate_motion_score(first, second) > 90.0


def test_still_time_accumulates_below_threshold() -> None:
    det = detector()
    image = np.zeros((10, 10, 3), dtype=np.uint8)
    det.update(image, 1.0)
    status = det.update(image, 1.0)
    assert status.state == DetectionState.STILL_WAITING
    assert status.still_time == 1.0
    status = det.update(image, 1.0)
    assert status.still_time == 2.0


def test_still_time_resets_when_movement_returns() -> None:
    det = detector()
    still = np.zeros((10, 10, 3), dtype=np.uint8)
    moved = np.full((10, 10, 3), 255, dtype=np.uint8)
    det.update(still, 1.0)
    det.update(still, 1.0)
    status = det.update(moved, 1.0)
    assert status.state == DetectionState.MOVING
    assert status.still_time == 0.0


def test_only_one_alert_during_one_still_period() -> None:
    det = detector()
    image = np.zeros((10, 10, 3), dtype=np.uint8)
    det.update(image, 1.0)
    assert not det.update(image, 1.0).should_alert
    assert not det.update(image, 1.0).should_alert
    assert det.update(image, 1.0).should_alert
    assert not det.update(image, 1.0).should_alert
    assert not det.update(image, 1.0).should_alert
    assert det.state == DetectionState.ALERTED


def test_alert_rearms_after_movement_resumes() -> None:
    det = detector()
    still = np.zeros((10, 10, 3), dtype=np.uint8)
    moved = np.full((10, 10, 3), 255, dtype=np.uint8)
    det.update(still, 1.0)
    det.update(still, 1.0)
    det.update(still, 1.0)
    assert det.update(still, 1.0).should_alert
    assert det.update(moved, 1.0).state == DetectionState.MOVING
    det.update(moved, 1.0)
    det.update(moved, 1.0)
    assert det.update(moved, 1.0).should_alert