"""Tests for input validation functions"""

import warnings
import os

from tempfile import NamedTemporaryFile
from itertools import product

import pytest
from pytest import importorskip
import numpy as np
import scipy.sparse as sp

from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regex
from sklearn.utils.testing import assert_no_warnings
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import SkipTest
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_allclose_dense_sparse
from sklearn.utils.testing import assert_allclose
from sklearn.utils import as_float_array, check_array, check_symmetric
from sklearn.utils import check_X_y
from sklearn.utils import deprecated
from sklearn.utils.mocking import MockDataFrame
from sklearn.utils.estimator_checks import NotAnArray
from sklearn.random_projection import sparse_random_matrix
from sklearn.linear_model import ARDRegression
from sklearn.neighbors import KNeighborsClassifier
from sklearn.ensemble import RandomForestRegressor
from sklearn.svm import SVR
from sklearn.datasets import make_blobs
from sklearn.utils.validation import (
    has_fit_parameter,
    check_is_fitted,
    check_consistent_length,
    assert_all_finite,
    check_memory,
    check_non_negative,
    _num_samples,
    check_scalar,
    _check_sample_weight)
import sklearn

from sklearn.exceptions import NotFittedError
from sklearn.exceptions import DataConversionWarning

from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import TempMemmap


def test_as_float_array():
    # Test function for as_float_array
    X = np.ones((3, 10), dtype=np.int32)
    X = X + np.arange(10, dtype=np.int32)
    X2 = as_float_array(X, copy=False)
    assert X2.dtype == np.float32
    # Another test
    X = X.astype(np.int64)
    X2 = as_float_array(X, copy=True)
    # Checking that the array wasn't overwritten
    assert as_float_array(X, False) is not X
    assert X2.dtype == np.float64
    # Test int dtypes <= 32bit
    tested_dtypes = [np.bool,
                     np.int8, np.int16, np.int32,
                     np.uint8, np.uint16, np.uint32]
    for dtype in tested_dtypes:
        X = X.astype(dtype)
        X2 = as_float_array(X)
        assert X2.dtype == np.float32

    # Test object dtype
    X = X.astype(object)
    X2 = as_float_array(X, copy=True)
    assert X2.dtype == np.float64

    # Here, X is of the right type, it shouldn't be modified
    X = np.ones((3, 2), dtype=np.float32)
    assert as_float_array(X, copy=False) is X
    # Test that if X is fortran ordered it stays
    X = np.asfortranarray(X)
    assert np.isfortran(as_float_array(X, copy=True))

    # Test the copy parameter with some matrices
    matrices = [
        np.matrix(np.arange(5)),
        sp.csc_matrix(np.arange(5)).toarray(),
        sparse_random_matrix(10, 10, density=0.10).toarray()
    ]
    for M in matrices:
        N = as_float_array(M, copy=True)
        N[0, 0] = np.nan
        assert not np.isnan(M).any()


@pytest.mark.parametrize(
    "X",
    [(np.random.random((10, 2))),
     (sp.rand(10, 2).tocsr())])
def test_as_float_array_nan(X):
    X[5, 0] = np.nan
    X[6, 1] = np.nan
    X_converted = as_float_array(X, force_all_finite='allow-nan')
    assert_allclose_dense_sparse(X_converted, X)


def test_np_matrix():
    # Confirm that input validation code does not return np.matrix
    X = np.arange(12).reshape(3, 4)

    assert not isinstance(as_float_array(X), np.matrix)
    assert not isinstance(as_float_array(np.matrix(X)), np.matrix)
    assert not isinstance(as_float_array(sp.csc_matrix(X)), np.matrix)


def test_memmap():
    # Confirm that input validation code doesn't copy memory mapped arrays

    asflt = lambda x: as_float_array(x, copy=False)

    with NamedTemporaryFile(prefix='sklearn-test') as tmp:
        M = np.memmap(tmp, shape=(10, 10), dtype=np.float32)
        M[:] = 0

        for f in (check_array, np.asarray, asflt):
            X = f(M)
            X[:] = 1
            assert_array_equal(X.ravel(), M.ravel())
            X[:] = 0


def test_ordering():
    # Check that ordering is enforced correctly by validation utilities.
    # We need to check each validation utility, because a 'copy' without
    # 'order=K' will kill the ordering.
    X = np.ones((10, 5))
    for A in X, X.T:
        for copy in (True, False):
            B = check_array(A, order='C', copy=copy)
            assert B.flags['C_CONTIGUOUS']
            B = check_array(A, order='F', copy=copy)
            assert B.flags['F_CONTIGUOUS']
            if copy:
                assert A is not B

    X = sp.csr_matrix(X)
    X.data = X.data[::-1]
    assert not X.data.flags['C_CONTIGUOUS']


@pytest.mark.parametrize(
    "value, force_all_finite",
    [(np.inf, False), (np.nan, 'allow-nan'), (np.nan, False)]
)
@pytest.mark.parametrize(
    "retype",
    [np.asarray, sp.csr_matrix]
)
def test_check_array_force_all_finite_valid(value, force_all_finite, retype):
    X = retype(np.arange(4).reshape(2, 2).astype(np.float))
    X[0, 0] = value
    X_checked = check_array(X, force_all_finite=force_all_finite,
                            accept_sparse=True)
    assert_allclose_dense_sparse(X, X_checked)


@pytest.mark.parametrize(
    "value, force_all_finite, match_msg",
    [(np.inf, True, 'Input contains NaN, infinity'),
     (np.inf, 'allow-nan', 'Input contains infinity'),
     (np.nan, True, 'Input contains NaN, infinity'),
     (np.nan, 'allow-inf', 'force_all_finite should be a bool or "allow-nan"'),
     (np.nan, 1, 'Input contains NaN, infinity')]
)
@pytest.mark.parametrize(
    "retype",
    [np.asarray, sp.csr_matrix]
)
def test_check_array_force_all_finiteinvalid(value, force_all_finite,
                                             match_msg, retype):
    X = retype(np.arange(4).reshape(2, 2).astype(np.float))
    X[0, 0] = value
    with pytest.raises(ValueError, match=match_msg):
        check_array(X, force_all_finite=force_all_finite,
                    accept_sparse=True)


def test_check_array_force_all_finite_object():
    X = np.array([['a', 'b', np.nan]], dtype=object).T

    X_checked = check_array(X, dtype=None, force_all_finite='allow-nan')
    assert X is X_checked

    X_checked = check_array(X, dtype=None, force_all_finite=False)
    assert X is X_checked

    with pytest.raises(ValueError, match='Input contains NaN'):
        check_array(X, dtype=None, force_all_finite=True)


@ignore_warnings
def test_check_array():
    # accept_sparse == False
    # raise error on sparse inputs
    X = [[1, 2], [3, 4]]
    X_csr = sp.csr_matrix(X)
    assert_raises(TypeError, check_array, X_csr)
    # ensure_2d=False
    X_array = check_array([0, 1, 2], ensure_2d=False)
    assert X_array.ndim == 1
    # ensure_2d=True with 1d array
    assert_raise_message(ValueError, 'Expected 2D array, got 1D array instead',
                         check_array, [0, 1, 2], ensure_2d=True)
    # ensure_2d=True with scalar array
    assert_raise_message(ValueError,
                         'Expected 2D array, got scalar array instead',
                         check_array, 10, ensure_2d=True)
    # don't allow ndim > 3
    X_ndim = np.arange(8).reshape(2, 2, 2)
    assert_raises(ValueError, check_array, X_ndim)
    check_array(X_ndim, allow_nd=True)  # doesn't raise

    # dtype and order enforcement.
    X_C = np.arange(4).reshape(2, 2).copy("C")
    X_F = X_C.copy("F")
    X_int = X_C.astype(np.int)
    X_float = X_C.astype(np.float)
    Xs = [X_C, X_F, X_int, X_float]
    dtypes = [np.int32, np.int, np.float, np.float32, None, np.bool, object]
    orders = ['C', 'F', None]
    copys = [True, False]

    for X, dtype, order, copy in product(Xs, dtypes, orders, copys):
        X_checked = check_array(X, dtype=dtype, order=order, copy=copy)
        if dtype is not None:
            assert X_checked.dtype == dtype
        else:
            assert X_checked.dtype == X.dtype
        if order == 'C':
            assert X_checked.flags['C_CONTIGUOUS']
            assert not X_checked.flags['F_CONTIGUOUS']
        elif order == 'F':
            assert X_checked.flags['F_CONTIGUOUS']
            assert not X_checked.flags['C_CONTIGUOUS']
        if copy:
            assert X is not X_checked
        else:
            # doesn't copy if it was already good
            if (X.dtype == X_checked.dtype and
                    X_checked.flags['C_CONTIGUOUS'] == X.flags['C_CONTIGUOUS']
                    and X_checked.flags['F_CONTIGUOUS'] == X.flags['F_CONTIGUOUS']):
                assert X is X_checked

    # allowed sparse != None
    X_csc = sp.csc_matrix(X_C)
    X_coo = X_csc.tocoo()
    X_dok = X_csc.todok()
    X_int = X_csc.astype(np.int)
    X_float = X_csc.astype(np.float)

    Xs = [X_csc, X_coo, X_dok, X_int, X_float]
    accept_sparses = [['csr', 'coo'], ['coo', 'dok']]
    for X, dtype, accept_sparse, copy in product(Xs, dtypes, accept_sparses,
                                                 copys):
        with warnings.catch_warnings(record=True) as w:
            X_checked = check_array(X, dtype=dtype,
                                    accept_sparse=accept_sparse, copy=copy)
        if (dtype is object or sp.isspmatrix_dok(X)) and len(w):
            message = str(w[0].message)
            messages = ["object dtype is not supported by sparse matrices",
                        "Can't check dok sparse matrix for nan or inf."]
            assert message in messages
        else:
            assert len(w) == 0
        if dtype is not None:
            assert X_checked.dtype == dtype
        else:
            assert X_checked.dtype == X.dtype
        if X.format in accept_sparse:
            # no change if allowed
            assert X.format == X_checked.format
        else:
            # got converted
            assert X_checked.format == accept_sparse[0]
        if copy:
            assert X is not X_checked
        else:
            # doesn't copy if it was already good
            if X.dtype == X_checked.dtype and X.format == X_checked.format:
                assert X is X_checked

    # other input formats
    # convert lists to arrays
    X_dense = check_array([[1, 2], [3, 4]])
    assert isinstance(X_dense, np.ndarray)
    # raise on too deep lists
    assert_raises(ValueError, check_array, X_ndim.tolist())
    check_array(X_ndim.tolist(), allow_nd=True)  # doesn't raise
    # convert weird stuff to arrays
    X_no_array = NotAnArray(X_dense)
    result = check_array(X_no_array)
    assert isinstance(result, np.ndarray)

    # deprecation warning if string-like array with dtype="numeric"
    expected_warn_regex = r"converted to decimal numbers if dtype='numeric'"
    X_str = [['11', '12'], ['13', 'xx']]
    for X in [X_str, np.array(X_str, dtype='U'), np.array(X_str, dtype='S')]:
        with pytest.warns(FutureWarning, match=expected_warn_regex):
            check_array(X, dtype="numeric")

    # deprecation warning if byte-like array with dtype="numeric"
    X_bytes = [[b'a', b'b'], [b'c', b'd']]
    for X in [X_bytes, np.array(X_bytes, dtype='V1')]:
        with pytest.warns(FutureWarning, match=expected_warn_regex):
            check_array(X, dtype="numeric")


def test_check_array_pandas_dtype_object_conversion():
    # test that data-frame like objects with dtype object
    # get converted
    X = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]], dtype=np.object)
    X_df = MockDataFrame(X)
    assert check_array(X_df).dtype.kind == "f"
    assert check_array(X_df, ensure_2d=False).dtype.kind == "f"
    # smoke-test against dataframes with column named "dtype"
    X_df.dtype = "Hans"
    assert check_array(X_df, ensure_2d=False).dtype.kind == "f"


def test_check_array_on_mock_dataframe():
    arr = np.array([[0.2, 0.7], [0.6, 0.5], [0.4, 0.1], [0.7, 0.2]])
    mock_df = MockDataFrame(arr)
    checked_arr = check_array(mock_df)
    assert checked_arr.dtype == arr.dtype
    checked_arr = check_array(mock_df, dtype=np.float32)
    assert checked_arr.dtype == np.dtype(np.float32)


def test_check_array_dtype_stability():
    # test that lists with ints don't get converted to floats
    X = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
    assert check_array(X).dtype.kind == "i"
    assert check_array(X, ensure_2d=False).dtype.kind == "i"


def test_check_array_dtype_warning():
    X_int_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
    X_float64 = np.asarray(X_int_list, dtype=np.float64)
    X_float32 = np.asarray(X_int_list, dtype=np.float32)
    X_int64 = np.asarray(X_int_list, dtype=np.int64)
    X_csr_float64 = sp.csr_matrix(X_float64)
    X_csr_float32 = sp.csr_matrix(X_float32)
    X_csc_float32 = sp.csc_matrix(X_float32)
    X_csc_int32 = sp.csc_matrix(X_int64, dtype=np.int32)
    y = [0, 0, 1]
    integer_data = [X_int64, X_csc_int32]
    float64_data = [X_float64, X_csr_float64]
    float32_data = [X_float32, X_csr_float32, X_csc_float32]
    for X in integer_data:
        X_checked = assert_no_warnings(check_array, X, dtype=np.float64,
                                       accept_sparse=True)
        assert X_checked.dtype == np.float64

        X_checked = assert_warns(DataConversionWarning, check_array, X,
                                 dtype=np.float64,
                                 accept_sparse=True, warn_on_dtype=True)
        assert X_checked.dtype == np.float64

        # Check that the warning message includes the name of the Estimator
        X_checked = assert_warns_message(DataConversionWarning,
                                         'SomeEstimator',
                                         check_array, X,
                                         dtype=[np.float64, np.float32],
                                         accept_sparse=True,
                                         warn_on_dtype=True,
                                         estimator='SomeEstimator')
        assert X_checked.dtype == np.float64

        X_checked, y_checked = assert_warns_message(
            DataConversionWarning, 'KNeighborsClassifier',
            check_X_y, X, y, dtype=np.float64, accept_sparse=True,
            warn_on_dtype=True, estimator=KNeighborsClassifier())

        assert X_checked.dtype == np.float64

    for X in float64_data:
        with pytest.warns(None) as record:
            warnings.simplefilter("ignore", DeprecationWarning)  # 0.23
            X_checked = check_array(X, dtype=np.float64,
                                    accept_sparse=True, warn_on_dtype=True)
            assert X_checked.dtype == np.float64
            X_checked = check_array(X, dtype=np.float64,
                                    accept_sparse=True, warn_on_dtype=False)
            assert X_checked.dtype == np.float64
        assert len(record) == 0

    for X in float32_data:
        X_checked = assert_no_warnings(check_array, X,
                                       dtype=[np.float64, np.float32],
                                       accept_sparse=True)
        assert X_checked.dtype == np.float32
        assert X_checked is X

        X_checked = assert_no_warnings(check_array, X,
                                       dtype=[np.float64, np.float32],
                                       accept_sparse=['csr', 'dok'],
                                       copy=True)
        assert X_checked.dtype == np.float32
        assert X_checked is not X

    X_checked = assert_no_warnings(check_array, X_csc_float32,
                                   dtype=[np.float64, np.float32],
                                   accept_sparse=['csr', 'dok'],
                                   copy=False)
    assert X_checked.dtype == np.float32
    assert X_checked is not X_csc_float32
    assert X_checked.format == 'csr'


def test_check_array_warn_on_dtype_deprecation():
    X = np.asarray([[0.0], [1.0]])
    Y = np.asarray([[2.0], [3.0]])
    with pytest.warns(DeprecationWarning,
                      match="'warn_on_dtype' is deprecated"):
        check_array(X, warn_on_dtype=True)
    with pytest.warns(DeprecationWarning,
                      match="'warn_on_dtype' is deprecated"):
        check_X_y(X, Y, warn_on_dtype=True)


def test_check_array_accept_sparse_type_exception():
    X = [[1, 2], [3, 4]]
    X_csr = sp.csr_matrix(X)
    invalid_type = SVR()

    msg = ("A sparse matrix was passed, but dense data is required. "
           "Use X.toarray() to convert to a dense numpy array.")
    assert_raise_message(TypeError, msg,
                         check_array, X_csr, accept_sparse=False)

    msg = ("Parameter 'accept_sparse' should be a string, "
           "boolean or list of strings. You provided 'accept_sparse={}'.")
    assert_raise_message(ValueError, msg.format(invalid_type),
                         check_array, X_csr, accept_sparse=invalid_type)

    msg = ("When providing 'accept_sparse' as a tuple or list, "
           "it must contain at least one string value.")
    assert_raise_message(ValueError, msg.format([]),
                         check_array, X_csr, accept_sparse=[])
    assert_raise_message(ValueError, msg.format(()),
                         check_array, X_csr, accept_sparse=())

    assert_raise_message(TypeError, "SVR",
                         check_array, X_csr, accept_sparse=[invalid_type])


def test_check_array_accept_sparse_no_exception():
    X = [[1, 2], [3, 4]]
    X_csr = sp.csr_matrix(X)

    check_array(X_csr, accept_sparse=True)
    check_array(X_csr, accept_sparse='csr')
    check_array(X_csr, accept_sparse=['csr'])
    check_array(X_csr, accept_sparse=('csr',))


@pytest.fixture(params=['csr', 'csc', 'coo', 'bsr'])
def X_64bit(request):
    X = sp.rand(20, 10, format=request.param)
    for attr in ['indices', 'indptr', 'row', 'col']:
        if hasattr(X, attr):
            setattr(X, attr, getattr(X, attr).astype('int64'))
    yield X


def test_check_array_accept_large_sparse_no_exception(X_64bit):
    # When large sparse are allowed
    check_array(X_64bit, accept_large_sparse=True, accept_sparse=True)


def test_check_array_accept_large_sparse_raise_exception(X_64bit):
    # When large sparse are not allowed
    msg = ("Only sparse matrices with 32-bit integer indices "
           "are accepted. Got int64 indices.")
    assert_raise_message(ValueError, msg,
                         check_array, X_64bit,
                         accept_sparse=True,
                         accept_large_sparse=False)


def test_check_array_min_samples_and_features_messages():
    # empty list is considered 2D by default:
    msg = "0 feature(s) (shape=(1, 0)) while a minimum of 1 is required."
    assert_raise_message(ValueError, msg, check_array, [[]])

    # If considered a 1D collection when ensure_2d=False, then the minimum
    # number of samples will break:
    msg = "0 sample(s) (shape=(0,)) while a minimum of 1 is required."
    assert_raise_message(ValueError, msg, check_array, [], ensure_2d=False)

    # Invalid edge case when checking the default minimum sample of a scalar
    msg = "Singleton array array(42) cannot be considered a valid collection."
    assert_raise_message(TypeError, msg, check_array, 42, ensure_2d=False)

    # Simulate a model that would need at least 2 samples to be well defined
    X = np.ones((1, 10))
    y = np.ones(1)
    msg = "1 sample(s) (shape=(1, 10)) while a minimum of 2 is required."
    assert_raise_message(ValueError, msg, check_X_y, X, y,
                         ensure_min_samples=2)

    # The same message is raised if the data has 2 dimensions even if this is
    # not mandatory
    assert_raise_message(ValueError, msg, check_X_y, X, y,
                         ensure_min_samples=2, ensure_2d=False)

    # Simulate a model that would require at least 3 features (e.g. SelectKBest
    # with k=3)
    X = np.ones((10, 2))
    y = np.ones(2)
    msg = "2 feature(s) (shape=(10, 2)) while a minimum of 3 is required."
    assert_raise_message(ValueError, msg, check_X_y, X, y,
                         ensure_min_features=3)

    # Only the feature check is enabled whenever the number of dimensions is 2
    # even if allow_nd is enabled:
    assert_raise_message(ValueError, msg, check_X_y, X, y,
                         ensure_min_features=3, allow_nd=True)

    # Simulate a case where a pipeline stage as trimmed all the features of a
    # 2D dataset.
    X = np.empty(0).reshape(10, 0)
    y = np.ones(10)
    msg = "0 feature(s) (shape=(10, 0)) while a minimum of 1 is required."
    assert_raise_message(ValueError, msg, check_X_y, X, y)

    # nd-data is not checked for any minimum number of features by default:
    X = np.ones((10, 0, 28, 28))
    y = np.ones(10)
    X_checked, y_checked = check_X_y(X, y, allow_nd=True)
    assert_array_equal(X, X_checked)
    assert_array_equal(y, y_checked)


def test_check_array_complex_data_error():
    X = np.array([[1 + 2j, 3 + 4j, 5 + 7j], [2 + 3j, 4 + 5j, 6 + 7j]])
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # list of lists
    X = [[1 + 2j, 3 + 4j, 5 + 7j], [2 + 3j, 4 + 5j, 6 + 7j]]
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # tuple of tuples
    X = ((1 + 2j, 3 + 4j, 5 + 7j), (2 + 3j, 4 + 5j, 6 + 7j))
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # list of np arrays
    X = [np.array([1 + 2j, 3 + 4j, 5 + 7j]),
         np.array([2 + 3j, 4 + 5j, 6 + 7j])]
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # tuple of np arrays
    X = (np.array([1 + 2j, 3 + 4j, 5 + 7j]),
         np.array([2 + 3j, 4 + 5j, 6 + 7j]))
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # dataframe
    X = MockDataFrame(
        np.array([[1 + 2j, 3 + 4j, 5 + 7j], [2 + 3j, 4 + 5j, 6 + 7j]]))
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)

    # sparse matrix
    X = sp.coo_matrix([[0, 1 + 2j], [0, 0]])
    assert_raises_regex(
        ValueError, "Complex data not supported", check_array, X)


def test_has_fit_parameter():
    assert not has_fit_parameter(KNeighborsClassifier, "sample_weight")
    assert has_fit_parameter(RandomForestRegressor, "sample_weight")
    assert has_fit_parameter(SVR, "sample_weight")
    assert has_fit_parameter(SVR(), "sample_weight")

    class TestClassWithDeprecatedFitMethod:
        @deprecated("Deprecated for the purpose of testing has_fit_parameter")
        def fit(self, X, y, sample_weight=None):
            pass

    assert has_fit_parameter(TestClassWithDeprecatedFitMethod,
                             "sample_weight"), \
        "has_fit_parameter fails for class with deprecated fit method."


def test_check_symmetric():
    arr_sym = np.array([[0, 1], [1, 2]])
    arr_bad = np.ones(2)
    arr_asym = np.array([[0, 2], [0, 2]])

    test_arrays = {'dense': arr_asym,
                   'dok': sp.dok_matrix(arr_asym),
                   'csr': sp.csr_matrix(arr_asym),
                   'csc': sp.csc_matrix(arr_asym),
                   'coo': sp.coo_matrix(arr_asym),
                   'lil': sp.lil_matrix(arr_asym),
                   'bsr': sp.bsr_matrix(arr_asym)}

    # check error for bad inputs
    assert_raises(ValueError, check_symmetric, arr_bad)

    # check that asymmetric arrays are properly symmetrized
    for arr_format, arr in test_arrays.items():
        # Check for warnings and errors
        assert_warns(UserWarning, check_symmetric, arr)
        assert_raises(ValueError, check_symmetric, arr, raise_exception=True)

        output = check_symmetric(arr, raise_warning=False)
        if sp.issparse(output):
            assert output.format == arr_format
            assert_array_equal(output.toarray(), arr_sym)
        else:
            assert_array_equal(output, arr_sym)


def test_check_is_fitted():
    # Check is ValueError raised when non estimator instance passed
    assert_raises(ValueError, check_is_fitted, ARDRegression, "coef_")
    assert_raises(TypeError, check_is_fitted, "SVR", "support_")

    ard = ARDRegression()
    svr = SVR()

    try:
        assert_raises(NotFittedError, check_is_fitted, ard, "coef_")
        assert_raises(NotFittedError, check_is_fitted, svr, "support_")
    except ValueError:
        assert False, "check_is_fitted failed with ValueError"

    # NotFittedError is a subclass of both ValueError and AttributeError
    try:
        check_is_fitted(ard, "coef_", "Random message %(name)s, %(name)s")
    except ValueError as e:
        assert str(e) == "Random message ARDRegression, ARDRegression"

    try:
        check_is_fitted(svr, "support_", "Another message %(name)s, %(name)s")
    except AttributeError as e:
        assert str(e) == "Another message SVR, SVR"

    ard.fit(*make_blobs())
    svr.fit(*make_blobs())

    assert check_is_fitted(ard, "coef_") is None
    assert check_is_fitted(svr, "support_") is None


def test_check_consistent_length():
    check_consistent_length([1], [2], [3], [4], [5])
    check_consistent_length([[1, 2], [[1, 2]]], [1, 2], ['a', 'b'])
    check_consistent_length([1], (2,), np.array([3]), sp.csr_matrix((1, 2)))
    assert_raises_regex(ValueError, 'inconsistent numbers of samples',
                        check_consistent_length, [1, 2], [1])
    assert_raises_regex(TypeError, r"got <\w+ 'int'>",
                        check_consistent_length, [1, 2], 1)
    assert_raises_regex(TypeError, r"got <\w+ 'object'>",
                        check_consistent_length, [1, 2], object())

    assert_raises(TypeError, check_consistent_length, [1, 2], np.array(1))
    # Despite ensembles having __len__ they must raise TypeError
    assert_raises_regex(TypeError, 'Expected sequence or array-like',
                        check_consistent_length, [1, 2],
                        RandomForestRegressor())
    # XXX: We should have a test with a string, but what is correct behaviour?


def test_check_dataframe_fit_attribute():
    # check pandas dataframe with 'fit' column does not raise error
    # https://github.com/scikit-learn/scikit-learn/issues/8415
    try:
        import pandas as pd
        X = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
        X_df = pd.DataFrame(X, columns=['a', 'b', 'fit'])
        check_consistent_length(X_df)
    except ImportError:
        raise SkipTest("Pandas not found")


def test_suppress_validation():
    X = np.array([0, np.inf])
    assert_raises(ValueError, assert_all_finite, X)
    sklearn.set_config(assume_finite=True)
    assert_all_finite(X)
    sklearn.set_config(assume_finite=False)
    assert_raises(ValueError, assert_all_finite, X)


def test_check_array_series():
    # regression test that check_array works on pandas Series
    pd = importorskip("pandas")
    res = check_array(pd.Series([1, 2, 3]), ensure_2d=False)
    assert_array_equal(res, np.array([1, 2, 3]))

    # with categorical dtype (not a numpy dtype) (GH12699)
    s = pd.Series(['a', 'b', 'c']).astype('category')
    res = check_array(s, dtype=None, ensure_2d=False)
    assert_array_equal(res, np.array(['a', 'b', 'c'], dtype=object))


def test_check_dataframe_warns_on_dtype():
    # Check that warn_on_dtype also works for DataFrames.
    # https://github.com/scikit-learn/scikit-learn/issues/10948
    pd = importorskip("pandas")

    df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], dtype=object)
    assert_warns_message(DataConversionWarning,
                         "Data with input dtype object were all converted to "
                         "float64.",
                         check_array, df, dtype=np.float64, warn_on_dtype=True)
    assert_warns(DataConversionWarning, check_array, df,
                 dtype='numeric', warn_on_dtype=True)
    with pytest.warns(None) as record:
        warnings.simplefilter("ignore", DeprecationWarning)  # 0.23
        check_array(df, dtype='object', warn_on_dtype=True)
    assert len(record) == 0

    # Also check that it raises a warning for mixed dtypes in a DataFrame.
    df_mixed = pd.DataFrame([['1', 2, 3], ['4', 5, 6]])
    assert_warns(DataConversionWarning, check_array, df_mixed,
                 dtype=np.float64, warn_on_dtype=True)
    assert_warns(DataConversionWarning, check_array, df_mixed,
                 dtype='numeric', warn_on_dtype=True)
    assert_warns(DataConversionWarning, check_array, df_mixed,
                 dtype=object, warn_on_dtype=True)

    # Even with numerical dtypes, a conversion can be made because dtypes are
    # uniformized throughout the array.
    df_mixed_numeric = pd.DataFrame([[1., 2, 3], [4., 5, 6]])
    assert_warns(DataConversionWarning, check_array, df_mixed_numeric,
                 dtype='numeric', warn_on_dtype=True)
    with pytest.warns(None) as record:
        warnings.simplefilter("ignore", DeprecationWarning)  # 0.23
        check_array(df_mixed_numeric.astype(int),
                    dtype='numeric', warn_on_dtype=True)
    assert len(record) == 0


class DummyMemory:
    def cache(self, func):
        return func


class WrongDummyMemory:
    pass


@pytest.mark.filterwarnings("ignore:The 'cachedir' attribute")
def test_check_memory():
    memory = check_memory("cache_directory")
    assert memory.cachedir == os.path.join('cache_directory', 'joblib')
    memory = check_memory(None)
    assert memory.cachedir is None
    dummy = DummyMemory()
    memory = check_memory(dummy)
    assert memory is dummy
    assert_raises_regex(ValueError, "'memory' should be None, a string or"
                        " have the same interface as joblib.Memory."
                        " Got memory='1' instead.", check_memory, 1)
    dummy = WrongDummyMemory()
    assert_raises_regex(ValueError, "'memory' should be None, a string or"
                        " have the same interface as joblib.Memory."
                        " Got memory='{}' instead.".format(dummy),
                        check_memory, dummy)


@pytest.mark.parametrize('copy', [True, False])
def test_check_array_memmap(copy):
    X = np.ones((4, 4))
    with TempMemmap(X, mmap_mode='r') as X_memmap:
        X_checked = check_array(X_memmap, copy=copy)
        assert np.may_share_memory(X_memmap, X_checked) == (not copy)
        assert X_checked.flags['WRITEABLE'] == copy


@pytest.mark.parametrize('retype', [
    np.asarray, sp.csr_matrix, sp.csc_matrix, sp.coo_matrix, sp.lil_matrix,
    sp.bsr_matrix, sp.dok_matrix, sp.dia_matrix
])
def test_check_non_negative(retype):
    A = np.array([[1, 1, 0, 0],
                  [1, 1, 0, 0],
                  [0, 0, 0, 0],
                  [0, 0, 0, 0]])
    X = retype(A)
    check_non_negative(X, "")
    X = retype([[0, 0], [0, 0]])
    check_non_negative(X, "")

    A[0, 0] = -1
    X = retype(A)
    assert_raises_regex(ValueError, "Negative ", check_non_negative, X, "")


def test_check_X_y_informative_error():
    X = np.ones((2, 2))
    y = None
    assert_raise_message(ValueError, "y cannot be None", check_X_y, X, y)


def test_retrieve_samples_from_non_standard_shape():
    class TestNonNumericShape:
        def __init__(self):
            self.shape = ("not numeric",)

        def __len__(self):
            return len([1, 2, 3])

    X = TestNonNumericShape()
    assert _num_samples(X) == len(X)

    # check that it gives a good error if there's no __len__
    class TestNoLenWeirdShape:
        def __init__(self):
            self.shape = ("not numeric",)

    with pytest.raises(TypeError, match="Expected sequence or array-like"):
        _num_samples(TestNoLenWeirdShape())


@pytest.mark.parametrize('x, target_type, min_val, max_val',
                         [(3, int, 2, 5),
                          (2.5, float, 2, 5)])
def test_check_scalar_valid(x, target_type, min_val, max_val):
    """Test that check_scalar returns no error/warning if valid inputs are
    provided"""
    with pytest.warns(None) as record:
        check_scalar(x, "test_name", target_type, min_val, max_val)
    assert len(record) == 0


@pytest.mark.parametrize('x, target_name, target_type, min_val, max_val, '
                         'err_msg',
                         [(1, "test_name1", float, 2, 4,
                           TypeError("`test_name1` must be an instance of "
                                     "<class 'float'>, not <class 'int'>.")),
                          (1, "test_name2", int, 2, 4,
                           ValueError('`test_name2`= 1, must be >= 2.')),
                          (5, "test_name3", int, 2, 4,
                           ValueError('`test_name3`= 5, must be <= 4.'))])
def test_check_scalar_invalid(x, target_name, target_type, min_val, max_val,
                              err_msg):
    """Test that check_scalar returns the right error if a wrong input is
    given"""
    with pytest.raises(Exception) as raised_error:
        check_scalar(x, target_name, target_type=target_type,
                     min_val=min_val, max_val=max_val)
    assert str(raised_error.value) == str(err_msg)
    assert type(raised_error.value) == type(err_msg)


def test_check_sample_weight():
    # check array order
    sample_weight = np.ones(10)[::2]
    assert not sample_weight.flags["C_CONTIGUOUS"]
    sample_weight = _check_sample_weight(sample_weight, X=np.ones((5, 1)))
    assert sample_weight.flags["C_CONTIGUOUS"]

    # check None input
    sample_weight = _check_sample_weight(None, X=np.ones((5, 2)))
    assert_allclose(sample_weight, np.ones(5))

    # check numbers input
    sample_weight = _check_sample_weight(2.0, X=np.ones((5, 2)))
    assert_allclose(sample_weight, 2 * np.ones(5))

    # check wrong number of dimensions
    with pytest.raises(ValueError,
                       match="Sample weights must be 1D array or scalar"):
        _check_sample_weight(np.ones((2, 4)), X=np.ones((2, 2)))

    # check incorrect n_samples
    msg = r"sample_weight.shape == \(4,\), expected \(2,\)!"
    with pytest.raises(ValueError, match=msg):
        _check_sample_weight(np.ones(4), X=np.ones((2, 2)))

    # float32 dtype is preserved
    X = np.ones((5, 2))
    sample_weight = np.ones(5, dtype=np.float32)
    sample_weight = _check_sample_weight(sample_weight, X)
    assert sample_weight.dtype == np.float32

    # int dtype will be converted to float64 instead
    X = np.ones((5, 2), dtype=np.int)
    sample_weight = _check_sample_weight(None, X, dtype=X.dtype)
    assert sample_weight.dtype == np.float64
