import math

from src.config_loader import HeadPoseSettings
from src.head_pose import HeadPoseEstimator
from src.models import FaceLandmark


def settings(max_angle: float = 90.0) -> HeadPoseSettings:
    return HeadPoseSettings(True, "solvepnp", True, "ema", .4, max_angle)


def landmarks() -> list[FaceLandmark]:
    return [FaceLandmark(index, float(index), float(index + 1), 0.0)
            for index in HeadPoseEstimator.LANDMARK_INDICES]


def test_missing_landmarks_and_input_builders() -> None:
    estimator = HeadPoseEstimator(settings())
    assert estimator.estimate([], 640, 480).failure_reason == "insufficient_landmarks"
    assert len(estimator.build_image_points(landmarks()) or []) == 6
    matrix = estimator.build_camera_matrix(640, 480)
    assert matrix == [[640.0, 0.0, 320.0], [0.0, 640.0, 240.0], [0.0, 0.0, 1.0]]


def test_euler_conversion_returns_floats() -> None:
    angles = HeadPoseEstimator.rotation_matrix_to_euler([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]])
    assert all(isinstance(value, float) for value in angles)
    assert angles == (0.0, -0.0, 0.0)


def test_angle_range_validation() -> None:
    estimator = HeadPoseEstimator(settings(45.0))
    assert estimator.result_from_angles((10.0, 20.0, 5.0)).success
    failed = estimator.result_from_angles((10.0, 60.0, 5.0))
    assert failed.failure_reason == "angle_out_of_range"
    assert (failed.pitch, failed.yaw, failed.roll) == (10.0, 60.0, 5.0)
    assert estimator.result_from_angles((math.nan, 0.0, 0.0)).failure_reason == "angle_out_of_range"


def test_face_model_uses_image_coordinate_y_direction() -> None:
    _, chin, left_eye, right_eye, left_mouth, right_mouth = HeadPoseEstimator.MODEL_POINTS
    assert chin[1] > 0
    assert left_eye[1] < 0 and right_eye[1] < 0
    assert left_mouth[1] > 0 and right_mouth[1] > 0


def test_roll_near_180_is_canonicalized_for_upright_face() -> None:
    estimator = HeadPoseEstimator(settings())
    assert estimator.normalize_angles((2.0, -5.0, -170.0)) == (2.0, -5.0, 10.0)
    assert estimator.normalize_angles((2.0, -5.0, 170.0)) == (2.0, -5.0, -10.0)
    result = estimator.result_from_angles((2.0, -5.0, -170.0))
    assert result.success and result.roll == 10.0