import numpy as np
import pytest

from sklearn.utils._testing import _convert_container

from sklearn.inspection._pd_utils import _check_feature_names, _get_feature_index


@pytest.mark.parametrize(
    "feature_names, array_type, expected_feature_names",
    [
        (None, "array", ["x0", "x1", "x2"]),
        (None, "dataframe", ["a", "b", "c"]),
        (np.array(["a", "b", "c"]), "array", ["a", "b", "c"]),
    ],
)
def test_check_feature_names(feature_names, array_type, expected_feature_names):
    X = np.random.randn(10, 3)
    column_names = ["a", "b", "c"]
    X = _convert_container(X, constructor_name=array_type, columns_name=column_names)
    feature_names_validated = _check_feature_names(X, feature_names)
    assert feature_names_validated == expected_feature_names


def test_check_feature_names_error():
    X = np.random.randn(10, 3)
    feature_names = ["a", "b", "c", "a"]
    msg = "feature_names should not contain duplicates."
    with pytest.raises(ValueError, match=msg):
        _check_feature_names(X, feature_names)


@pytest.mark.parametrize("fx, idx", [(0, 0), (1, 1), ("a", 0), ("b", 1), ("c", 2)])
def test_get_feature_index(fx, idx):
    feature_names = ["a", "b", "c"]
    assert _get_feature_index(fx, feature_names) == idx


@pytest.mark.parametrize(
    "fx, feature_names, err_msg",
    [
        ("a", None, "Cannot plot partial dependence for feature 'a'"),
        ("d", ["a", "b", "c"], "Feature 'd' not in feature_names"),
    ],
)
def test_get_feature_names_error(fx, feature_names, err_msg):
    with pytest.raises(ValueError, match=err_msg):
        _get_feature_index(fx, feature_names)