import inspect

import numpy as np
import pytest

from napari._tests.utils import are_objects_equal, layer_test_data


@pytest.mark.parametrize('Layer, data, ndim', layer_test_data)
def test_attrs_arrays(Layer, data, ndim):
    """Test layer attributes and arrays."""
    np.random.seed(0)
    layer = Layer(data)
    # Check layer has been correctly created
    assert layer.ndim == ndim

    properties = layer._get_state()

    # Check every property is in call signature
    signature = inspect.signature(Layer)

    # Check every property is also a parameter.
    for prop in properties:
        assert prop in signature.parameters

    # Check number of properties is same as number in signature
    # excluding `cache` which is not yet in `_get_state`
    assert len(properties) == len(signature.parameters) - 1

    # Check new layer can be created
    new_layer = Layer(**properties)

    # Check that new layer matches old on all properties:
    for prop in properties:
        assert are_objects_equal(
            getattr(layer, prop), getattr(new_layer, prop)
        )


@pytest.mark.parametrize('Layer, data, ndim', layer_test_data)
def test_no_callbacks(Layer, data, ndim):
    """Test no internal callbacks for layer emitters."""
    layer = Layer(data)
    # Check layer has been correctly created
    assert layer.ndim == ndim

    # Check that no internal callbacks have been registered
    assert len(layer.events.callbacks) == 0
    for em in layer.events.emitters.values():
        assert len(em.callbacks) == 0
