"""Frames acquired from the pipeline own their memory: nothing points into the SDK's buffers."""

import numpy as np
import pytest

pytest.importorskip("pyrealsense2")

from src.backend.services.camera import RealSenseD435, _owned  # noqa: E402
from tests.fake_realsense import FakeFrameset, FakePipeline, open_fake_camera  # noqa: E402


def test_the_fake_hands_out_views_like_the_sdk():
    """Control: without the copy, the driver's arrays WOULD share the SDK frame's memory."""
    color = FakeFrameset(1).get_color_frame()
    assert np.shares_memory(np.asanyarray(color.get_data()), color.array)


def test_captured_frame_does_not_share_memory_with_the_sdk_frame():
    cam = RealSenseD435()
    pipe = FakePipeline()
    open_fake_camera(cam, pipe)
    try:
        frame = cam.capture()
        sdk = pipe.last_frameset
        assert frame is not None
        assert not np.shares_memory(frame.rgb, sdk.get_color_frame().array)
        assert not np.shares_memory(frame.depth, sdk.get_depth_frame().array)
        assert frame.rgb.base is None and frame.depth.base is None
        np.testing.assert_array_equal(frame.rgb, sdk.get_color_frame().array)   # same pixels
    finally:
        cam.close()


def test_owned_copies_views_only():
    owned = np.zeros((4, 4), np.uint16)
    view = np.asanyarray(memoryview(owned))
    assert _owned(owned) is owned
    copy = _owned(view)
    assert copy is not view and not np.shares_memory(copy, owned)