# Copyright (c) 2020-2021, NVIDIA CORPORATION.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import pytest
from cuml.preprocessing import LabelBinarizer
from cuml.test.utils import array_equal
from cuml.common import has_scipy

from sklearn.preprocessing import LabelBinarizer as skLB

import numpy as np
import cupy as cp


@pytest.mark.parametrize(
    "labels", [([1, 4, 5, 2, 0, 1, 6, 2, 3, 4],
                [4, 2, 6, 3, 2, 0, 1]),
               ([9, 8, 2, 1, 3, 4],
                [8, 2, 1, 2, 2])]
)
@pytest.mark.parametrize("dtype", [cp.int32, cp.int64])
@pytest.mark.parametrize("sparse_output", [True, False])
def test_basic_functions(labels, dtype, sparse_output):

    fit_labels, xform_labels = labels

    skl_bin = skLB(sparse_output=sparse_output)
    skl_bin.fit(fit_labels)

    fit_labels = cp.asarray(fit_labels, dtype=dtype)
    xform_labels = cp.asarray(xform_labels, dtype=dtype)

    binarizer = LabelBinarizer(sparse_output=sparse_output)
    binarizer.fit(fit_labels)

    assert array_equal(binarizer.classes_.get(),
                       np.unique(fit_labels.get()))

    xformed = binarizer.transform(xform_labels)

    if sparse_output:
        skl_bin_xformed = skl_bin.transform(xform_labels.get())

        if has_scipy():
            import scipy.sparse
        else:
            pytest.skip('Skipping test_basic_functions(sparse_output=True) ' +
                        'because Scipy is missing')

        skl_csr = scipy.sparse.coo_matrix(skl_bin_xformed).tocsr()
        cuml_csr = xformed

        array_equal(skl_csr.data, cuml_csr.data.get())

        # #todo: Support sparse inputs
        # xformed = xformed.todense().astype(dtype)

    assert xformed.shape[1] == binarizer.classes_.shape[0]

    original = binarizer.inverse_transform(xformed)

    assert array_equal(original.get(),
                       xform_labels.get())
