# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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.

from datetime import datetime
from functools import lru_cache, partial
import inspect
import pickle
import pytest
import random
import sys
import textwrap

import numpy as np

try:
    import pandas as pd
except ImportError:
    pd = None

import pyarrow as pa
import pyarrow.compute as pc

all_array_types = [
    ('bool', [True, False, False, True, True]),
    ('uint8', np.arange(5)),
    ('int8', np.arange(5)),
    ('uint16', np.arange(5)),
    ('int16', np.arange(5)),
    ('uint32', np.arange(5)),
    ('int32', np.arange(5)),
    ('uint64', np.arange(5, 10)),
    ('int64', np.arange(5, 10)),
    ('float', np.arange(0, 0.5, 0.1)),
    ('double', np.arange(0, 0.5, 0.1)),
    ('string', ['a', 'b', None, 'ddd', 'ee']),
    ('binary', [b'a', b'b', b'c', b'ddd', b'ee']),
    (pa.binary(3), [b'abc', b'bcd', b'cde', b'def', b'efg']),
    (pa.list_(pa.int8()), [[1, 2], [3, 4], [5, 6], None, [9, 16]]),
    (pa.large_list(pa.int16()), [[1], [2, 3, 4], [5, 6], None, [9, 16]]),
    (pa.struct([('a', pa.int8()), ('b', pa.int8())]), [
        {'a': 1, 'b': 2}, None, {'a': 3, 'b': 4}, None, {'a': 5, 'b': 6}]),
]

exported_functions = [
    func for (name, func) in sorted(pc.__dict__.items())
    if hasattr(func, '__arrow_compute_function__')]

exported_option_classes = [
    cls for (name, cls) in sorted(pc.__dict__.items())
    if (isinstance(cls, type) and
        cls is not pc.FunctionOptions and
        issubclass(cls, pc.FunctionOptions))]

numerical_arrow_types = [
    pa.int8(),
    pa.int16(),
    pa.int64(),
    pa.uint8(),
    pa.uint16(),
    pa.uint64(),
    pa.float32(),
    pa.float64()
]


def test_exported_functions():
    # Check that all exported concrete functions can be called with
    # the right number of arguments.
    # Note that unregistered functions (e.g. with a mismatching name)
    # will raise KeyError.
    functions = exported_functions
    assert len(functions) >= 10
    for func in functions:
        arity = func.__arrow_compute_function__['arity']
        if arity is Ellipsis:
            args = [object()] * 3
        else:
            args = [object()] * arity
        with pytest.raises(TypeError,
                           match="Got unexpected argument type "
                                 "<class 'object'> for compute function"):
            func(*args)


def test_exported_option_classes():
    classes = exported_option_classes
    assert len(classes) >= 10
    for cls in classes:
        # Option classes must have an introspectable constructor signature,
        # and that signature should not have any *args or **kwargs.
        sig = inspect.signature(cls)
        for param in sig.parameters.values():
            assert param.kind not in (param.VAR_POSITIONAL,
                                      param.VAR_KEYWORD)


def test_option_class_equality():
    options = [
        pc.ArraySortOptions(),
        pc.AssumeTimezoneOptions("UTC"),
        pc.CastOptions.safe(pa.int8()),
        pc.CountOptions(),
        pc.DayOfWeekOptions(count_from_zero=False, week_start=0),
        pc.DictionaryEncodeOptions(),
        pc.ElementWiseAggregateOptions(skip_nulls=True),
        pc.ExtractRegexOptions("pattern"),
        pc.FilterOptions(),
        pc.IndexOptions(pa.scalar(1)),
        pc.JoinOptions(),
        pc.MakeStructOptions(["field", "names"],
                             field_nullability=[True, True],
                             field_metadata=[pa.KeyValueMetadata({"a": "1"}),
                                             pa.KeyValueMetadata({"b": "2"})]),
        pc.MatchSubstringOptions("pattern"),
        pc.ModeOptions(),
        pc.NullOptions(),
        pc.PadOptions(5),
        pc.PartitionNthOptions(1, null_placement="at_start"),
        pc.QuantileOptions(),
        pc.ReplaceSliceOptions(0, 1, "a"),
        pc.ReplaceSubstringOptions("a", "b"),
        pc.RoundOptions(2, "towards_infinity"),
        pc.RoundToMultipleOptions(100, "towards_infinity"),
        pc.ScalarAggregateOptions(),
        pc.SelectKOptions(0, sort_keys=[("b", "ascending")]),
        pc.SetLookupOptions(pa.array([1])),
        pc.SliceOptions(0, 1, 1),
        pc.SortOptions([("dummy", "descending")], null_placement="at_start"),
        pc.SplitOptions(),
        pc.SplitPatternOptions("pattern"),
        pc.StrftimeOptions(),
        pc.StrptimeOptions("%Y", "s"),
        pc.TakeOptions(),
        pc.TDigestOptions(),
        pc.TrimOptions(" "),
        pc.VarianceOptions(),
        pc.WeekOptions(week_starts_monday=True, count_from_zero=False,
                       first_week_is_fully_in_year=False),
    ]
    # TODO: We should test on windows once ARROW-13168 is resolved.
    # Timezone database is not available on Windows yet
    if sys.platform != 'win32':
        options.append(pc.AssumeTimezoneOptions("Europe/Ljubljana"))

    classes = {type(option) for option in options}
    for cls in exported_option_classes:
        # Timezone database is not available on Windows yet
        if cls not in classes and sys.platform != 'win32' and \
                cls != pc.AssumeTimezoneOptions:
            try:
                options.append(cls())
            except TypeError:
                pytest.fail(f"Options class is not tested: {cls}")
    for option in options:
        assert option == option
        assert repr(option).startswith(option.__class__.__name__)
        buf = option.serialize()
        deserialized = pc.FunctionOptions.deserialize(buf)
        assert option == deserialized
        assert repr(option) == repr(deserialized)
    for option1, option2 in zip(options, options[1:]):
        assert option1 != option2

    assert repr(pc.IndexOptions(pa.scalar(1))) == "IndexOptions(value=int64:1)"
    assert repr(pc.ArraySortOptions()) == \
        "ArraySortOptions(order=Ascending, null_placement=AtEnd)"


def test_list_functions():
    assert len(pc.list_functions()) > 10
    assert "add" in pc.list_functions()


def _check_get_function(name, expected_func_cls, expected_ker_cls,
                        min_num_kernels=1):
    func = pc.get_function(name)
    assert isinstance(func, expected_func_cls)
    n = func.num_kernels
    assert n >= min_num_kernels
    assert n == len(func.kernels)
    assert all(isinstance(ker, expected_ker_cls) for ker in func.kernels)


def test_get_function_scalar():
    _check_get_function("add", pc.ScalarFunction, pc.ScalarKernel, 8)


def test_get_function_vector():
    _check_get_function("unique", pc.VectorFunction, pc.VectorKernel, 8)


def test_get_function_scalar_aggregate():
    _check_get_function("mean", pc.ScalarAggregateFunction,
                        pc.ScalarAggregateKernel, 8)


def test_get_function_hash_aggregate():
    _check_get_function("hash_sum", pc.HashAggregateFunction,
                        pc.HashAggregateKernel, 1)


def test_call_function_with_memory_pool():
    arr = pa.array(["foo", "bar", "baz"])
    indices = np.array([2, 2, 1])
    result1 = arr.take(indices)
    result2 = pc.call_function('take', [arr, indices],
                               memory_pool=pa.default_memory_pool())
    expected = pa.array(["baz", "baz", "bar"])
    assert result1.equals(expected)
    assert result2.equals(expected)

    result3 = pc.take(arr, indices, memory_pool=pa.default_memory_pool())
    assert result3.equals(expected)


def test_pickle_functions():
    # Pickle registered functions
    for name in pc.list_functions():
        func = pc.get_function(name)
        reconstructed = pickle.loads(pickle.dumps(func))
        assert type(reconstructed) is type(func)
        assert reconstructed.name == func.name
        assert reconstructed.arity == func.arity
        assert reconstructed.num_kernels == func.num_kernels


def test_pickle_global_functions():
    # Pickle global wrappers (manual or automatic) of registered functions
    for name in pc.list_functions():
        func = getattr(pc, name)
        reconstructed = pickle.loads(pickle.dumps(func))
        assert reconstructed is func


def test_function_attributes():
    # Sanity check attributes of registered functions
    for name in pc.list_functions():
        func = pc.get_function(name)
        assert isinstance(func, pc.Function)
        assert func.name == name
        kernels = func.kernels
        assert func.num_kernels == len(kernels)
        assert all(isinstance(ker, pc.Kernel) for ker in kernels)
        if func.arity is not Ellipsis:
            assert func.arity >= 1
        repr(func)
        for ker in kernels:
            repr(ker)


def test_input_type_conversion():
    # Automatic array conversion from Python
    arr = pc.add([1, 2], [4, None])
    assert arr.to_pylist() == [5, None]
    # Automatic scalar conversion from Python
    arr = pc.add([1, 2], 4)
    assert arr.to_pylist() == [5, 6]
    # Other scalar type
    assert pc.equal(["foo", "bar", None],
                    "foo").to_pylist() == [True, False, None]


@pytest.mark.parametrize('arrow_type', numerical_arrow_types)
def test_sum_array(arrow_type):
    arr = pa.array([1, 2, 3, 4], type=arrow_type)
    assert arr.sum().as_py() == 10
    assert pc.sum(arr).as_py() == 10

    arr = pa.array([1, 2, 3, 4, None], type=arrow_type)
    assert arr.sum().as_py() == 10
    assert pc.sum(arr).as_py() == 10

    arr = pa.array([None], type=arrow_type)
    assert arr.sum().as_py() is None  # noqa: E711
    assert pc.sum(arr).as_py() is None  # noqa: E711
    assert arr.sum(min_count=0).as_py() == 0
    assert pc.sum(arr, min_count=0).as_py() == 0

    arr = pa.array([], type=arrow_type)
    assert arr.sum().as_py() is None  # noqa: E711
    assert arr.sum(min_count=0).as_py() == 0
    assert pc.sum(arr, min_count=0).as_py() == 0


@pytest.mark.parametrize('arrow_type', numerical_arrow_types)
def test_sum_chunked_array(arrow_type):
    arr = pa.chunked_array([pa.array([1, 2, 3, 4], type=arrow_type)])
    assert pc.sum(arr).as_py() == 10

    arr = pa.chunked_array([
        pa.array([1, 2], type=arrow_type), pa.array([3, 4], type=arrow_type)
    ])
    assert pc.sum(arr).as_py() == 10

    arr = pa.chunked_array([
        pa.array([1, 2], type=arrow_type),
        pa.array([], type=arrow_type),
        pa.array([3, 4], type=arrow_type)
    ])
    assert pc.sum(arr).as_py() == 10

    arr = pa.chunked_array((), type=arrow_type)
    assert arr.num_chunks == 0
    assert pc.sum(arr).as_py() is None  # noqa: E711
    assert pc.sum(arr, min_count=0).as_py() == 0


def test_mode_array():
    # ARROW-9917
    arr = pa.array([1, 1, 3, 4, 3, 5], type='int64')
    mode = pc.mode(arr)
    assert len(mode) == 1
    assert mode[0].as_py() == {"mode": 1, "count": 2}

    mode = pc.mode(arr, n=2)
    assert len(mode) == 2
    assert mode[0].as_py() == {"mode": 1, "count": 2}
    assert mode[1].as_py() == {"mode": 3, "count": 2}

    arr = pa.array([], type='int64')
    assert len(pc.mode(arr)) == 0

    arr = pa.array([1, 1, 3, 4, 3, None], type='int64')
    mode = pc.mode(arr, skip_nulls=False)
    assert len(mode) == 0
    mode = pc.mode(arr, min_count=6)
    assert len(mode) == 0
    mode = pc.mode(arr, skip_nulls=False, min_count=5)
    assert len(mode) == 0


def test_mode_chunked_array():
    # ARROW-9917
    arr = pa.chunked_array([pa.array([1, 1, 3, 4, 3, 5], type='int64')])
    mode = pc.mode(arr)
    assert len(mode) == 1
    assert mode[0].as_py() == {"mode": 1, "count": 2}

    mode = pc.mode(arr, n=2)
    assert len(mode) == 2
    assert mode[0].as_py() == {"mode": 1, "count": 2}
    assert mode[1].as_py() == {"mode": 3, "count": 2}

    arr = pa.chunked_array((), type='int64')
    assert arr.num_chunks == 0
    assert len(pc.mode(arr)) == 0


def test_variance():
    data = [1, 2, 3, 4, 5, 6, 7, 8]
    assert pc.variance(data).as_py() == 5.25
    assert pc.variance(data, ddof=0).as_py() == 5.25
    assert pc.variance(data, ddof=1).as_py() == 6.0


def test_count_substring():
    for (ty, offset) in [(pa.string(), pa.int32()),
                         (pa.large_string(), pa.int64())]:
        arr = pa.array(["ab", "cab", "abcab", "ba", "AB", None], type=ty)

        result = pc.count_substring(arr, "ab")
        expected = pa.array([1, 1, 2, 0, 0, None], type=offset)
        assert expected.equals(result)

        result = pc.count_substring(arr, "ab", ignore_case=True)
        expected = pa.array([1, 1, 2, 0, 1, None], type=offset)
        assert expected.equals(result)


def test_count_substring_regex():
    for (ty, offset) in [(pa.string(), pa.int32()),
                         (pa.large_string(), pa.int64())]:
        arr = pa.array(["ab", "cab", "baAacaa", "ba", "AB", None], type=ty)

        result = pc.count_substring_regex(arr, "a+")
        expected = pa.array([1, 1, 3, 1, 0, None], type=offset)
        assert expected.equals(result)

        result = pc.count_substring_regex(arr, "a+", ignore_case=True)
        expected = pa.array([1, 1, 2, 1, 1, None], type=offset)
        assert expected.equals(result)


def test_find_substring():
    for ty in [pa.string(), pa.binary(), pa.large_string(), pa.large_binary()]:
        arr = pa.array(["ab", "cab", "ba", None], type=ty)
        result = pc.find_substring(arr, "ab")
        assert result.to_pylist() == [0, 1, -1, None]

        result = pc.find_substring_regex(arr, "a?b")
        assert result.to_pylist() == [0, 1, 0, None]

        arr = pa.array(["ab*", "cAB*", "ba", "aB?"], type=ty)
        result = pc.find_substring(arr, "aB*", ignore_case=True)
        assert result.to_pylist() == [0, 1, -1, -1]

        result = pc.find_substring_regex(arr, "a?b", ignore_case=True)
        assert result.to_pylist() == [0, 1, 0, 0]


def test_match_like():
    arr = pa.array(["ab", "ba%", "ba", "ca%d", None])
    result = pc.match_like(arr, r"_a\%%")
    expected = pa.array([False, True, False, True, None])
    assert expected.equals(result)

    arr = pa.array(["aB", "bA%", "ba", "ca%d", None])
    result = pc.match_like(arr, r"_a\%%", ignore_case=True)
    expected = pa.array([False, True, False, True, None])
    assert expected.equals(result)
    result = pc.match_like(arr, r"_a\%%", ignore_case=False)
    expected = pa.array([False, False, False, True, None])
    assert expected.equals(result)


def test_match_substring():
    arr = pa.array(["ab", "abc", "ba", None])
    result = pc.match_substring(arr, "ab")
    expected = pa.array([True, True, False, None])
    assert expected.equals(result)

    arr = pa.array(["áB", "Ábc", "ba", None])
    result = pc.match_substring(arr, "áb", ignore_case=True)
    expected = pa.array([True, True, False, None])
    assert expected.equals(result)
    result = pc.match_substring(arr, "áb", ignore_case=False)
    expected = pa.array([False, False, False, None])
    assert expected.equals(result)


def test_match_substring_regex():
    arr = pa.array(["ab", "abc", "ba", "c", None])
    result = pc.match_substring_regex(arr, "^a?b")
    expected = pa.array([True, True, True, False, None])
    assert expected.equals(result)

    arr = pa.array(["aB", "Abc", "BA", "c", None])
    result = pc.match_substring_regex(arr, "^a?b", ignore_case=True)
    expected = pa.array([True, True, True, False, None])
    assert expected.equals(result)
    result = pc.match_substring_regex(arr, "^a?b", ignore_case=False)
    expected = pa.array([False, False, False, False, None])
    assert expected.equals(result)


def test_trim():
    # \u3000 is unicode whitespace
    arr = pa.array([" foo", None, " \u3000foo bar \t"])
    result = pc.utf8_trim_whitespace(arr)
    expected = pa.array(["foo", None, "foo bar"])
    assert expected.equals(result)

    arr = pa.array([" foo", None, " \u3000foo bar \t"])
    result = pc.ascii_trim_whitespace(arr)
    expected = pa.array(["foo", None, "\u3000foo bar"])
    assert expected.equals(result)

    arr = pa.array([" foo", None, " \u3000foo bar \t"])
    result = pc.utf8_trim(arr, characters=' f\u3000')
    expected = pa.array(["oo", None, "oo bar \t"])
    assert expected.equals(result)


def test_slice_compatibility():
    arr = pa.array(["", "𝑓", "𝑓ö", "𝑓öõ", "𝑓öõḍ", "𝑓öõḍš"])
    for start in range(-6, 6):
        for stop in range(-6, 6):
            for step in [-3, -2, -1, 1, 2, 3]:
                expected = pa.array([k.as_py()[start:stop:step]
                                     for k in arr])
                result = pc.utf8_slice_codeunits(
                    arr, start=start, stop=stop, step=step)
                assert expected.equals(result)


def test_split_pattern():
    arr = pa.array(["-foo---bar--", "---foo---b"])
    result = pc.split_pattern(arr, pattern="---")
    expected = pa.array([["-foo", "bar--"], ["", "foo", "b"]])
    assert expected.equals(result)

    result = pc.split_pattern(arr, pattern="---", max_splits=1)
    expected = pa.array([["-foo", "bar--"], ["", "foo---b"]])
    assert expected.equals(result)

    result = pc.split_pattern(arr, pattern="---", max_splits=1, reverse=True)
    expected = pa.array([["-foo", "bar--"], ["---foo", "b"]])
    assert expected.equals(result)


def test_split_whitespace_utf8():
    arr = pa.array(["foo bar", " foo  \u3000\tb"])
    result = pc.utf8_split_whitespace(arr)
    expected = pa.array([["foo", "bar"], ["", "foo", "b"]])
    assert expected.equals(result)

    result = pc.utf8_split_whitespace(arr, max_splits=1)
    expected = pa.array([["foo", "bar"], ["", "foo  \u3000\tb"]])
    assert expected.equals(result)

    result = pc.utf8_split_whitespace(arr, max_splits=1, reverse=True)
    expected = pa.array([["foo", "bar"], [" foo", "b"]])
    assert expected.equals(result)


def test_split_whitespace_ascii():
    arr = pa.array(["foo bar", " foo  \u3000\tb"])
    result = pc.ascii_split_whitespace(arr)
    expected = pa.array([["foo", "bar"], ["", "foo", "\u3000", "b"]])
    assert expected.equals(result)

    result = pc.ascii_split_whitespace(arr, max_splits=1)
    expected = pa.array([["foo", "bar"], ["", "foo  \u3000\tb"]])
    assert expected.equals(result)

    result = pc.ascii_split_whitespace(arr, max_splits=1, reverse=True)
    expected = pa.array([["foo", "bar"], [" foo  \u3000", "b"]])
    assert expected.equals(result)


def test_split_pattern_regex():
    arr = pa.array(["-foo---bar--", "---foo---b"])
    result = pc.split_pattern_regex(arr, pattern="-+")
    expected = pa.array([["", "foo", "bar", ""], ["", "foo", "b"]])
    assert expected.equals(result)

    result = pc.split_pattern_regex(arr, pattern="-+", max_splits=1)
    expected = pa.array([["", "foo---bar--"], ["", "foo---b"]])
    assert expected.equals(result)

    with pytest.raises(NotImplementedError,
                       match="Cannot split in reverse with regex"):
        result = pc.split_pattern_regex(
            arr, pattern="---", max_splits=1, reverse=True)


def test_min_max():
    # An example generated function wrapper with possible options
    data = [4, 5, 6, None, 1]
    s = pc.min_max(data)
    assert s.as_py() == {'min': 1, 'max': 6}
    s = pc.min_max(data, options=pc.ScalarAggregateOptions())
    assert s.as_py() == {'min': 1, 'max': 6}
    s = pc.min_max(data, options=pc.ScalarAggregateOptions(skip_nulls=True))
    assert s.as_py() == {'min': 1, 'max': 6}
    s = pc.min_max(data, options=pc.ScalarAggregateOptions(skip_nulls=False))
    assert s.as_py() == {'min': None, 'max': None}

    # Options as dict of kwargs
    s = pc.min_max(data, options={'skip_nulls': False})
    assert s.as_py() == {'min': None, 'max': None}
    # Options as named functions arguments
    s = pc.min_max(data, skip_nulls=False)
    assert s.as_py() == {'min': None, 'max': None}

    # Both options and named arguments
    with pytest.raises(TypeError):
        s = pc.min_max(
            data, options=pc.ScalarAggregateOptions(), skip_nulls=False)

    # Wrong options type
    options = pc.TakeOptions()
    with pytest.raises(TypeError):
        s = pc.min_max(data, options=options)

    # Missing argument
    with pytest.raises(ValueError,
                       match="Function min_max accepts 1 argument"):
        s = pc.min_max()


def test_any():
    # ARROW-1846

    options = pc.ScalarAggregateOptions(skip_nulls=False, min_count=0)

    a = pa.array([], type='bool')
    assert pc.any(a).as_py() is None
    assert pc.any(a, min_count=0).as_py() is False
    assert pc.any(a, options=options).as_py() is False

    a = pa.array([False, None, True])
    assert pc.any(a).as_py() is True
    assert pc.any(a, options=options).as_py() is True

    a = pa.array([False, None, False])
    assert pc.any(a).as_py() is False
    assert pc.any(a, options=options).as_py() is None


def test_all():
    # ARROW-10301

    options = pc.ScalarAggregateOptions(skip_nulls=False, min_count=0)

    a = pa.array([], type='bool')
    assert pc.all(a).as_py() is None
    assert pc.all(a, min_count=0).as_py() is True
    assert pc.all(a, options=options).as_py() is True

    a = pa.array([False, True])
    assert pc.all(a).as_py() is False
    assert pc.all(a, options=options).as_py() is False

    a = pa.array([True, None])
    assert pc.all(a).as_py() is True
    assert pc.all(a, options=options).as_py() is None

    a = pa.chunked_array([[True], [True, None]])
    assert pc.all(a).as_py() is True
    assert pc.all(a, options=options).as_py() is None

    a = pa.chunked_array([[True], [False]])
    assert pc.all(a).as_py() is False
    assert pc.all(a, options=options).as_py() is False


def test_is_valid():
    # An example generated function wrapper without options
    data = [4, 5, None]
    assert pc.is_valid(data).to_pylist() == [True, True, False]

    with pytest.raises(TypeError):
        pc.is_valid(data, options=None)


def test_generated_docstrings():
    assert pc.min_max.__doc__ == textwrap.dedent("""\
        Compute the minimum and maximum values of a numeric array.

        Null values are ignored by default.
        This can be changed through ScalarAggregateOptions.

        Parameters
        ----------
        array : Array-like
            Argument to compute function
        memory_pool : pyarrow.MemoryPool, optional
            If not passed, will allocate memory from the default memory pool.
        options : pyarrow.compute.ScalarAggregateOptions, optional
            Parameters altering compute function semantics.
        skip_nulls : optional
            Parameter for ScalarAggregateOptions constructor. Either `options`
            or `skip_nulls` can be passed, but not both at the same time.
        min_count : optional
            Parameter for ScalarAggregateOptions constructor. Either `options`
            or `min_count` can be passed, but not both at the same time.
        """)
    assert pc.add.__doc__ == textwrap.dedent("""\
        Add the arguments element-wise.

        Results will wrap around on integer overflow.
        Use function "add_checked" if you want overflow
        to return an error.

        Parameters
        ----------
        x : Array-like or scalar-like
            Argument to compute function
        y : Array-like or scalar-like
            Argument to compute function
        memory_pool : pyarrow.MemoryPool, optional
            If not passed, will allocate memory from the default memory pool.
        """)


def test_generated_signatures():
    # The self-documentation provided by signatures should show acceptable
    # options and their default values.
    sig = inspect.signature(pc.add)
    assert str(sig) == "(x, y, *, memory_pool=None)"
    sig = inspect.signature(pc.min_max)
    assert str(sig) == ("(array, *, memory_pool=None, "
                        "options=None, skip_nulls=True, min_count=1)")
    sig = inspect.signature(pc.quantile)
    assert str(sig) == ("(array, *, memory_pool=None, "
                        "options=None, q=0.5, interpolation='linear', "
                        "skip_nulls=True, min_count=0)")
    sig = inspect.signature(pc.binary_join_element_wise)
    assert str(sig) == ("(*strings, memory_pool=None, options=None, "
                        "null_handling='emit_null', null_replacement='')")


# We use isprintable to find about codepoints that Python doesn't know, but
# utf8proc does (or in a future version of Python the other way around).
# These codepoints cannot be compared between Arrow and the Python
# implementation.
@lru_cache()
def find_new_unicode_codepoints():
    new = set()
    characters = [chr(c) for c in range(0x80, 0x11000)
                  if not (0xD800 <= c < 0xE000)]
    is_printable = pc.utf8_is_printable(pa.array(characters)).to_pylist()
    for i, c in enumerate(characters):
        if is_printable[i] != c.isprintable():
            new.add(ord(c))
    return new


# Python claims there are not alpha, not sure why, they are in
#  gc='Other Letter': https://graphemica.com/%E1%B3%B2
unknown_issue_is_alpha = {0x1cf2, 0x1cf3}
# utf8proc does not know if codepoints are lower case
utf8proc_issue_is_lower = {
    0xaa, 0xba, 0x2b0, 0x2b1, 0x2b2, 0x2b3, 0x2b4,
    0x2b5, 0x2b6, 0x2b7, 0x2b8, 0x2c0, 0x2c1, 0x2e0,
    0x2e1, 0x2e2, 0x2e3, 0x2e4, 0x37a, 0x1d2c, 0x1d2d,
    0x1d2e, 0x1d2f, 0x1d30, 0x1d31, 0x1d32, 0x1d33,
    0x1d34, 0x1d35, 0x1d36, 0x1d37, 0x1d38, 0x1d39,
    0x1d3a, 0x1d3b, 0x1d3c, 0x1d3d, 0x1d3e, 0x1d3f,
    0x1d40, 0x1d41, 0x1d42, 0x1d43, 0x1d44, 0x1d45,
    0x1d46, 0x1d47, 0x1d48, 0x1d49, 0x1d4a, 0x1d4b,
    0x1d4c, 0x1d4d, 0x1d4e, 0x1d4f, 0x1d50, 0x1d51,
    0x1d52, 0x1d53, 0x1d54, 0x1d55, 0x1d56, 0x1d57,
    0x1d58, 0x1d59, 0x1d5a, 0x1d5b, 0x1d5c, 0x1d5d,
    0x1d5e, 0x1d5f, 0x1d60, 0x1d61, 0x1d62, 0x1d63,
    0x1d64, 0x1d65, 0x1d66, 0x1d67, 0x1d68, 0x1d69,
    0x1d6a, 0x1d78, 0x1d9b, 0x1d9c, 0x1d9d, 0x1d9e,
    0x1d9f, 0x1da0, 0x1da1, 0x1da2, 0x1da3, 0x1da4,
    0x1da5, 0x1da6, 0x1da7, 0x1da8, 0x1da9, 0x1daa,
    0x1dab, 0x1dac, 0x1dad, 0x1dae, 0x1daf, 0x1db0,
    0x1db1, 0x1db2, 0x1db3, 0x1db4, 0x1db5, 0x1db6,
    0x1db7, 0x1db8, 0x1db9, 0x1dba, 0x1dbb, 0x1dbc,
    0x1dbd, 0x1dbe, 0x1dbf, 0x2071, 0x207f, 0x2090,
    0x2091, 0x2092, 0x2093, 0x2094, 0x2095, 0x2096,
    0x2097, 0x2098, 0x2099, 0x209a, 0x209b, 0x209c,
    0x2c7c, 0x2c7d, 0xa69c, 0xa69d, 0xa770, 0xa7f8,
    0xa7f9, 0xab5c, 0xab5d, 0xab5e, 0xab5f, }
# utf8proc does not store if a codepoint is numeric
numeric_info_missing = {
    0x3405, 0x3483, 0x382a, 0x3b4d, 0x4e00, 0x4e03,
    0x4e07, 0x4e09, 0x4e5d, 0x4e8c, 0x4e94, 0x4e96,
    0x4ebf, 0x4ec0, 0x4edf, 0x4ee8, 0x4f0d, 0x4f70,
    0x5104, 0x5146, 0x5169, 0x516b, 0x516d, 0x5341,
    0x5343, 0x5344, 0x5345, 0x534c, 0x53c1, 0x53c2,
    0x53c3, 0x53c4, 0x56db, 0x58f1, 0x58f9, 0x5e7a,
    0x5efe, 0x5eff, 0x5f0c, 0x5f0d, 0x5f0e, 0x5f10,
    0x62fe, 0x634c, 0x67d2, 0x6f06, 0x7396, 0x767e,
    0x8086, 0x842c, 0x8cae, 0x8cb3, 0x8d30, 0x9621,
    0x9646, 0x964c, 0x9678, 0x96f6, 0xf96b, 0xf973,
    0xf978, 0xf9b2, 0xf9d1, 0xf9d3, 0xf9fd, 0x10fc5,
    0x10fc6, 0x10fc7, 0x10fc8, 0x10fc9, 0x10fca,
    0x10fcb, }
# utf8proc has no no digit/numeric information
digit_info_missing = {
    0xb2, 0xb3, 0xb9, 0x1369, 0x136a, 0x136b, 0x136c,
    0x136d, 0x136e, 0x136f, 0x1370, 0x1371, 0x19da, 0x2070,
    0x2074, 0x2075, 0x2076, 0x2077, 0x2078, 0x2079, 0x2080,
    0x2081, 0x2082, 0x2083, 0x2084, 0x2085, 0x2086, 0x2087,
    0x2088, 0x2089, 0x2460, 0x2461, 0x2462, 0x2463, 0x2464,
    0x2465, 0x2466, 0x2467, 0x2468, 0x2474, 0x2475, 0x2476,
    0x2477, 0x2478, 0x2479, 0x247a, 0x247b, 0x247c, 0x2488,
    0x2489, 0x248a, 0x248b, 0x248c, 0x248d, 0x248e, 0x248f,
    0x2490, 0x24ea, 0x24f5, 0x24f6, 0x24f7, 0x24f8, 0x24f9,
    0x24fa, 0x24fb, 0x24fc, 0x24fd, 0x24ff, 0x2776, 0x2777,
    0x2778, 0x2779, 0x277a, 0x277b, 0x277c, 0x277d, 0x277e,
    0x2780, 0x2781, 0x2782, 0x2783, 0x2784, 0x2785, 0x2786,
    0x2787, 0x2788, 0x278a, 0x278b, 0x278c, 0x278d, 0x278e,
    0x278f, 0x2790, 0x2791, 0x2792, 0x10a40, 0x10a41,
    0x10a42, 0x10a43, 0x10e60, 0x10e61, 0x10e62, 0x10e63,
    0x10e64, 0x10e65, 0x10e66, 0x10e67, 0x10e68, }
numeric_info_missing = {
    0x3405, 0x3483, 0x382a, 0x3b4d, 0x4e00, 0x4e03,
    0x4e07, 0x4e09, 0x4e5d, 0x4e8c, 0x4e94, 0x4e96,
    0x4ebf, 0x4ec0, 0x4edf, 0x4ee8, 0x4f0d, 0x4f70,
    0x5104, 0x5146, 0x5169, 0x516b, 0x516d, 0x5341,
    0x5343, 0x5344, 0x5345, 0x534c, 0x53c1, 0x53c2,
    0x53c3, 0x53c4, 0x56db, 0x58f1, 0x58f9, 0x5e7a,
    0x5efe, 0x5eff, 0x5f0c, 0x5f0d, 0x5f0e, 0x5f10,
    0x62fe, 0x634c, 0x67d2, 0x6f06, 0x7396, 0x767e,
    0x8086, 0x842c, 0x8cae, 0x8cb3, 0x8d30, 0x9621,
    0x9646, 0x964c, 0x9678, 0x96f6, 0xf96b, 0xf973,
    0xf978, 0xf9b2, 0xf9d1, 0xf9d3, 0xf9fd, }

codepoints_ignore = {
    'is_alnum': numeric_info_missing | digit_info_missing |
    unknown_issue_is_alpha,
    'is_alpha': unknown_issue_is_alpha,
    'is_digit': digit_info_missing,
    'is_numeric': numeric_info_missing,
    'is_lower': utf8proc_issue_is_lower
}


@pytest.mark.parametrize('function_name', ['is_alnum', 'is_alpha',
                                           'is_ascii', 'is_decimal',
                                           'is_digit', 'is_lower',
                                           'is_numeric', 'is_printable',
                                           'is_space', 'is_upper', ])
@pytest.mark.parametrize('variant', ['ascii', 'utf8'])
def test_string_py_compat_boolean(function_name, variant):
    arrow_name = variant + "_" + function_name
    py_name = function_name.replace('_', '')
    ignore = codepoints_ignore.get(function_name, set()) | \
        find_new_unicode_codepoints()
    for i in range(128 if ascii else 0x11000):
        if i in range(0xD800, 0xE000):
            continue  # bug? pyarrow doesn't allow utf16 surrogates
        # the issues we know of, we skip
        if i in ignore:
            continue
        # Compare results with the equivalent Python predicate
        # (except "is_space" where functions are known to be incompatible)
        c = chr(i)
        if hasattr(pc, arrow_name) and function_name != 'is_space':
            ar = pa.array([c])
            arrow_func = getattr(pc, arrow_name)
            assert arrow_func(ar)[0].as_py() == getattr(c, py_name)()


def test_pad():
    arr = pa.array([None, 'a', 'abcd'])
    assert pc.ascii_center(arr, width=3).tolist() == [None, ' a ', 'abcd']
    assert pc.ascii_lpad(arr, width=3).tolist() == [None, '  a', 'abcd']
    assert pc.ascii_rpad(arr, width=3).tolist() == [None, 'a  ', 'abcd']

    arr = pa.array([None, 'á', 'abcd'])
    assert pc.utf8_center(arr, width=3).tolist() == [None, ' á ', 'abcd']
    assert pc.utf8_lpad(arr, width=3).tolist() == [None, '  á', 'abcd']
    assert pc.utf8_rpad(arr, width=3).tolist() == [None, 'á  ', 'abcd']


@pytest.mark.pandas
def test_replace_slice():
    offsets = range(-3, 4)

    arr = pa.array([None, '', 'a', 'ab', 'abc', 'abcd', 'abcde'])
    series = arr.to_pandas()
    for start in offsets:
        for stop in offsets:
            expected = series.str.slice_replace(start, stop, 'XX')
            actual = pc.binary_replace_slice(
                arr, start=start, stop=stop, replacement='XX')
            assert actual.tolist() == expected.tolist()

    arr = pa.array([None, '', 'π', 'πb', 'πbθ', 'πbθd', 'πbθde'])
    series = arr.to_pandas()
    for start in offsets:
        for stop in offsets:
            expected = series.str.slice_replace(start, stop, 'XX')
            actual = pc.utf8_replace_slice(
                arr, start=start, stop=stop, replacement='XX')
            assert actual.tolist() == expected.tolist()


def test_replace_plain():
    ar = pa.array(['foo', 'food', None])
    ar = pc.replace_substring(ar, pattern='foo', replacement='bar')
    assert ar.tolist() == ['bar', 'bard', None]


def test_replace_regex():
    ar = pa.array(['foo', 'mood', None])
    ar = pc.replace_substring_regex(ar, pattern='(.)oo', replacement=r'\100')
    assert ar.tolist() == ['f00', 'm00d', None]


def test_extract_regex():
    ar = pa.array(['a1', 'zb2z'])
    struct = pc.extract_regex(ar, pattern=r'(?P<letter>[ab])(?P<digit>\d)')
    assert struct.tolist() == [{'letter': 'a', 'digit': '1'}, {
        'letter': 'b', 'digit': '2'}]


def test_binary_join():
    ar_list = pa.array([['foo', 'bar'], None, []])
    expected = pa.array(['foo-bar', None, ''])
    assert pc.binary_join(ar_list, '-').equals(expected)

    separator_array = pa.array(['1', '2'], type=pa.binary())
    expected = pa.array(['a1b', 'c2d'], type=pa.binary())
    ar_list = pa.array([['a', 'b'], ['c', 'd']], type=pa.list_(pa.binary()))
    assert pc.binary_join(ar_list, separator_array).equals(expected)


def test_binary_join_element_wise():
    null = pa.scalar(None, type=pa.string())
    arrs = [[None, 'a', 'b'], ['c', None, 'd'], [None, '-', '--']]
    assert pc.binary_join_element_wise(*arrs).to_pylist() == \
        [None, None, 'b--d']
    assert pc.binary_join_element_wise('a', 'b', '-').as_py() == 'a-b'
    assert pc.binary_join_element_wise('a', null, '-').as_py() is None
    assert pc.binary_join_element_wise('a', 'b', null).as_py() is None

    skip = pc.JoinOptions(null_handling='skip')
    assert pc.binary_join_element_wise(*arrs, options=skip).to_pylist() == \
        [None, 'a', 'b--d']
    assert pc.binary_join_element_wise(
        'a', 'b', '-', options=skip).as_py() == 'a-b'
    assert pc.binary_join_element_wise(
        'a', null, '-', options=skip).as_py() == 'a'
    assert pc.binary_join_element_wise(
        'a', 'b', null, options=skip).as_py() is None

    replace = pc.JoinOptions(null_handling='replace', null_replacement='spam')
    assert pc.binary_join_element_wise(*arrs, options=replace).to_pylist() == \
        [None, 'a-spam', 'b--d']
    assert pc.binary_join_element_wise(
        'a', 'b', '-', options=replace).as_py() == 'a-b'
    assert pc.binary_join_element_wise(
        'a', null, '-', options=replace).as_py() == 'a-spam'
    assert pc.binary_join_element_wise(
        'a', 'b', null, options=replace).as_py() is None


@pytest.mark.parametrize(('ty', 'values'), all_array_types)
def test_take(ty, values):
    arr = pa.array(values, type=ty)
    for indices_type in [pa.int8(), pa.int64()]:
        indices = pa.array([0, 4, 2, None], type=indices_type)
        result = arr.take(indices)
        result.validate()
        expected = pa.array([values[0], values[4], values[2], None], type=ty)
        assert result.equals(expected)

        # empty indices
        indices = pa.array([], type=indices_type)
        result = arr.take(indices)
        result.validate()
        expected = pa.array([], type=ty)
        assert result.equals(expected)

    indices = pa.array([2, 5])
    with pytest.raises(IndexError):
        arr.take(indices)

    indices = pa.array([2, -1])
    with pytest.raises(IndexError):
        arr.take(indices)


def test_take_indices_types():
    arr = pa.array(range(5))

    for indices_type in ['uint8', 'int8', 'uint16', 'int16',
                         'uint32', 'int32', 'uint64', 'int64']:
        indices = pa.array([0, 4, 2, None], type=indices_type)
        result = arr.take(indices)
        result.validate()
        expected = pa.array([0, 4, 2, None])
        assert result.equals(expected)

    for indices_type in [pa.float32(), pa.float64()]:
        indices = pa.array([0, 4, 2], type=indices_type)
        with pytest.raises(NotImplementedError):
            arr.take(indices)


def test_take_on_chunked_array():
    # ARROW-9504
    arr = pa.chunked_array([
        [
            "a",
            "b",
            "c",
            "d",
            "e"
        ],
        [
            "f",
            "g",
            "h",
            "i",
            "j"
        ]
    ])

    indices = np.array([0, 5, 1, 6, 9, 2])
    result = arr.take(indices)
    expected = pa.chunked_array([["a", "f", "b", "g", "j", "c"]])
    assert result.equals(expected)

    indices = pa.chunked_array([[1], [9, 2]])
    result = arr.take(indices)
    expected = pa.chunked_array([
        [
            "b"
        ],
        [
            "j",
            "c"
        ]
    ])
    assert result.equals(expected)


@pytest.mark.parametrize('ordered', [False, True])
def test_take_dictionary(ordered):
    arr = pa.DictionaryArray.from_arrays([0, 1, 2, 0, 1, 2], ['a', 'b', 'c'],
                                         ordered=ordered)
    result = arr.take(pa.array([0, 1, 3]))
    result.validate()
    assert result.to_pylist() == ['a', 'b', 'a']
    assert result.dictionary.to_pylist() == ['a', 'b', 'c']
    assert result.type.ordered is ordered


def test_take_null_type():
    # ARROW-10027
    arr = pa.array([None] * 10)
    chunked_arr = pa.chunked_array([[None] * 5] * 2)
    batch = pa.record_batch([arr], names=['a'])
    table = pa.table({'a': arr})

    indices = pa.array([1, 3, 7, None])
    assert len(arr.take(indices)) == 4
    assert len(chunked_arr.take(indices)) == 4
    assert len(batch.take(indices).column(0)) == 4
    assert len(table.take(indices).column(0)) == 4


@pytest.mark.parametrize(('ty', 'values'), all_array_types)
def test_drop_null(ty, values):
    arr = pa.array(values, type=ty)
    result = arr.drop_null()
    result.validate(full=True)
    indices = [i for i in range(len(arr)) if arr[i].is_valid]
    expected = arr.take(pa.array(indices))
    assert result.equals(expected)


def test_drop_null_chunked_array():
    arr = pa.chunked_array([["a", None], ["c", "d", None], [None], []])
    expected_drop = pa.chunked_array([["a"], ["c", "d"], [], []])

    result = arr.drop_null()
    assert result.equals(expected_drop)


def test_drop_null_record_batch():
    batch = pa.record_batch(
        [pa.array(["a", None, "c", "d", None])], names=["a'"])
    result = batch.drop_null()
    expected = pa.record_batch([pa.array(["a", "c", "d"])], names=["a'"])
    assert result.equals(expected)

    batch = pa.record_batch(
        [pa.array(["a", None, "c", "d", None]),
         pa.array([None, None, "c", None, "e"])], names=["a'", "b'"])

    result = batch.drop_null()
    expected = pa.record_batch(
        [pa.array(["c"]), pa.array(["c"])], names=["a'", "b'"])
    assert result.equals(expected)


def test_drop_null_table():
    table = pa.table([pa.array(["a", None, "c", "d", None])], names=["a"])
    expected = pa.table([pa.array(["a", "c", "d"])], names=["a"])
    result = table.drop_null()
    assert result.equals(expected)

    table = pa.table([pa.chunked_array([["a", None], ["c", "d", None]]),
                      pa.chunked_array([["a", None], [None, "d", None]]),
                      pa.chunked_array([["a"], ["b"], [None], ["d", None]])],
                     names=["a", "b", "c"])
    expected = pa.table([pa.array(["a", "d"]),
                         pa.array(["a", "d"]),
                         pa.array(["a", "d"])],
                        names=["a", "b", "c"])
    result = table.drop_null()
    assert result.equals(expected)

    table = pa.table([pa.chunked_array([["a", "b"], ["c", "d", "e"]]),
                      pa.chunked_array([["A"], ["B"], [None], ["D", None]]),
                      pa.chunked_array([["a`", None], ["c`", "d`", None]])],
                     names=["a", "b", "c"])
    expected = pa.table([pa.array(["a", "d"]),
                         pa.array(["A", "D"]),
                         pa.array(["a`", "d`"])],
                        names=["a", "b", "c"])
    result = table.drop_null()
    assert result.equals(expected)


def test_drop_null_null_type():
    arr = pa.array([None] * 10)
    chunked_arr = pa.chunked_array([[None] * 5] * 2)
    batch = pa.record_batch([arr], names=['a'])
    table = pa.table({'a': arr})

    assert len(arr.drop_null()) == 0
    assert len(chunked_arr.drop_null()) == 0
    assert len(batch.drop_null().column(0)) == 0
    assert len(table.drop_null().column(0)) == 0


@pytest.mark.parametrize(('ty', 'values'), all_array_types)
def test_filter(ty, values):
    arr = pa.array(values, type=ty)

    mask = pa.array([True, False, False, True, None])
    result = arr.filter(mask, null_selection_behavior='drop')
    result.validate()
    assert result.equals(pa.array([values[0], values[3]], type=ty))
    result = arr.filter(mask, null_selection_behavior='emit_null')
    result.validate()
    assert result.equals(pa.array([values[0], values[3], None], type=ty))

    # non-boolean dtype
    mask = pa.array([0, 1, 0, 1, 0])
    with pytest.raises(NotImplementedError):
        arr.filter(mask)

    # wrong length
    mask = pa.array([True, False, True])
    with pytest.raises(ValueError, match="must all be the same length"):
        arr.filter(mask)


def test_filter_chunked_array():
    arr = pa.chunked_array([["a", None], ["c", "d", "e"]])
    expected_drop = pa.chunked_array([["a"], ["e"]])
    expected_null = pa.chunked_array([["a"], [None, "e"]])

    for mask in [
        # mask is array
        pa.array([True, False, None, False, True]),
        # mask is chunked array
        pa.chunked_array([[True, False, None], [False, True]]),
        # mask is python object
        [True, False, None, False, True]
    ]:
        result = arr.filter(mask)
        assert result.equals(expected_drop)
        result = arr.filter(mask, null_selection_behavior="emit_null")
        assert result.equals(expected_null)


def test_filter_record_batch():
    batch = pa.record_batch(
        [pa.array(["a", None, "c", "d", "e"])], names=["a'"])

    # mask is array
    mask = pa.array([True, False, None, False, True])
    result = batch.filter(mask)
    expected = pa.record_batch([pa.array(["a", "e"])], names=["a'"])
    assert result.equals(expected)

    result = batch.filter(mask, null_selection_behavior="emit_null")
    expected = pa.record_batch([pa.array(["a", None, "e"])], names=["a'"])
    assert result.equals(expected)


def test_filter_table():
    table = pa.table([pa.array(["a", None, "c", "d", "e"])], names=["a"])
    expected_drop = pa.table([pa.array(["a", "e"])], names=["a"])
    expected_null = pa.table([pa.array(["a", None, "e"])], names=["a"])

    for mask in [
        # mask is array
        pa.array([True, False, None, False, True]),
        # mask is chunked array
        pa.chunked_array([[True, False], [None, False, True]]),
        # mask is python object
        [True, False, None, False, True]
    ]:
        result = table.filter(mask)
        assert result.equals(expected_drop)
        result = table.filter(mask, null_selection_behavior="emit_null")
        assert result.equals(expected_null)


def test_filter_errors():
    arr = pa.chunked_array([["a", None], ["c", "d", "e"]])
    batch = pa.record_batch(
        [pa.array(["a", None, "c", "d", "e"])], names=["a'"])
    table = pa.table([pa.array(["a", None, "c", "d", "e"])], names=["a"])

    for obj in [arr, batch, table]:
        # non-boolean dtype
        mask = pa.array([0, 1, 0, 1, 0])
        with pytest.raises(NotImplementedError):
            obj.filter(mask)

        # wrong length
        mask = pa.array([True, False, True])
        with pytest.raises(pa.ArrowInvalid,
                           match="must all be the same length"):
            obj.filter(mask)


def test_filter_null_type():
    # ARROW-10027
    arr = pa.array([None] * 10)
    chunked_arr = pa.chunked_array([[None] * 5] * 2)
    batch = pa.record_batch([arr], names=['a'])
    table = pa.table({'a': arr})

    mask = pa.array([True, False] * 5)
    assert len(arr.filter(mask)) == 5
    assert len(chunked_arr.filter(mask)) == 5
    assert len(batch.filter(mask).column(0)) == 5
    assert len(table.filter(mask).column(0)) == 5


@pytest.mark.parametrize("typ", ["array", "chunked_array"])
def test_compare_array(typ):
    if typ == "array":
        def con(values):
            return pa.array(values)
    else:
        def con(values):
            return pa.chunked_array([values])

    arr1 = con([1, 2, 3, 4, None])
    arr2 = con([1, 1, 4, None, 4])

    result = pc.equal(arr1, arr2)
    assert result.equals(con([True, False, False, None, None]))

    result = pc.not_equal(arr1, arr2)
    assert result.equals(con([False, True, True, None, None]))

    result = pc.less(arr1, arr2)
    assert result.equals(con([False, False, True, None, None]))

    result = pc.less_equal(arr1, arr2)
    assert result.equals(con([True, False, True, None, None]))

    result = pc.greater(arr1, arr2)
    assert result.equals(con([False, True, False, None, None]))

    result = pc.greater_equal(arr1, arr2)
    assert result.equals(con([True, True, False, None, None]))


@pytest.mark.parametrize("typ", ["array", "chunked_array"])
def test_compare_string_scalar(typ):
    if typ == "array":
        def con(values):
            return pa.array(values)
    else:
        def con(values):
            return pa.chunked_array([values])

    arr = con(['a', 'b', 'c', None])
    scalar = pa.scalar('b')

    result = pc.equal(arr, scalar)
    assert result.equals(con([False, True, False, None]))

    if typ == "array":
        nascalar = pa.scalar(None, type="string")
        result = pc.equal(arr, nascalar)
        isnull = pc.is_null(result)
        assert isnull.equals(con([True, True, True, True]))

    result = pc.not_equal(arr, scalar)
    assert result.equals(con([True, False, True, None]))

    result = pc.less(arr, scalar)
    assert result.equals(con([True, False, False, None]))

    result = pc.less_equal(arr, scalar)
    assert result.equals(con([True, True, False, None]))

    result = pc.greater(arr, scalar)
    assert result.equals(con([False, False, True, None]))

    result = pc.greater_equal(arr, scalar)
    assert result.equals(con([False, True, True, None]))


@pytest.mark.parametrize("typ", ["array", "chunked_array"])
def test_compare_scalar(typ):
    if typ == "array":
        def con(values):
            return pa.array(values)
    else:
        def con(values):
            return pa.chunked_array([values])

    arr = con([1, 2, 3, None])
    scalar = pa.scalar(2)

    result = pc.equal(arr, scalar)
    assert result.equals(con([False, True, False, None]))

    if typ == "array":
        nascalar = pa.scalar(None, type="int64")
        result = pc.equal(arr, nascalar)
        assert result.to_pylist() == [None, None, None, None]

    result = pc.not_equal(arr, scalar)
    assert result.equals(con([True, False, True, None]))

    result = pc.less(arr, scalar)
    assert result.equals(con([True, False, False, None]))

    result = pc.less_equal(arr, scalar)
    assert result.equals(con([True, True, False, None]))

    result = pc.greater(arr, scalar)
    assert result.equals(con([False, False, True, None]))

    result = pc.greater_equal(arr, scalar)
    assert result.equals(con([False, True, True, None]))


def test_compare_chunked_array_mixed():
    arr = pa.array([1, 2, 3, 4, None])
    arr_chunked = pa.chunked_array([[1, 2, 3], [4, None]])
    arr_chunked2 = pa.chunked_array([[1, 2], [3, 4, None]])

    expected = pa.chunked_array([[True, True, True, True, None]])

    for left, right in [
        (arr, arr_chunked),
        (arr_chunked, arr),
        (arr_chunked, arr_chunked2),
    ]:
        result = pc.equal(left, right)
        assert result.equals(expected)


def test_arithmetic_add():
    left = pa.array([1, 2, 3, 4, 5])
    right = pa.array([0, -1, 1, 2, 3])
    result = pc.add(left, right)
    expected = pa.array([1, 1, 4, 6, 8])
    assert result.equals(expected)


def test_arithmetic_subtract():
    left = pa.array([1, 2, 3, 4, 5])
    right = pa.array([0, -1, 1, 2, 3])
    result = pc.subtract(left, right)
    expected = pa.array([1, 3, 2, 2, 2])
    assert result.equals(expected)


def test_arithmetic_multiply():
    left = pa.array([1, 2, 3, 4, 5])
    right = pa.array([0, -1, 1, 2, 3])
    result = pc.multiply(left, right)
    expected = pa.array([0, -2, 3, 8, 15])
    assert result.equals(expected)


@pytest.mark.parametrize("ty", ["round", "round_to_multiple"])
def test_round_to_integer(ty):
    if ty == "round":
        round = pc.round
        RoundOptions = partial(pc.RoundOptions, ndigits=0)
    elif ty == "round_to_multiple":
        round = pc.round_to_multiple
        RoundOptions = partial(pc.RoundToMultipleOptions, multiple=1)

    values = [3.2, 3.5, 3.7, 4.5, -3.2, -3.5, -3.7, None]
    rmode_and_expected = {
        "down": [3, 3, 3, 4, -4, -4, -4, None],
        "up": [4, 4, 4, 5, -3, -3, -3, None],
        "towards_zero": [3, 3, 3, 4, -3, -3, -3, None],
        "towards_infinity": [4, 4, 4, 5, -4, -4, -4, None],
        "half_down": [3, 3, 4, 4, -3, -4, -4, None],
        "half_up": [3, 4, 4, 5, -3, -3, -4, None],
        "half_towards_zero": [3, 3, 4, 4, -3, -3, -4, None],
        "half_towards_infinity": [3, 4, 4, 5, -3, -4, -4, None],
        "half_to_even": [3, 4, 4, 4, -3, -4, -4, None],
        "half_to_odd": [3, 3, 4, 5, -3, -3, -4, None],
    }
    for round_mode, expected in rmode_and_expected.items():
        options = RoundOptions(round_mode=round_mode)
        result = round(values, options=options)
        np.testing.assert_array_equal(result, pa.array(expected))


def test_round():
    values = [320, 3.5, 3.075, 4.5, -3.212, -35.1234, -3.045, None]
    ndigits_and_expected = {
        -2: [300, 0, 0, 0, -0, -0, -0, None],
        -1: [320, 0, 0, 0, -0, -40, -0, None],
        0: [320, 4, 3, 5, -3, -35, -3, None],
        1: [320, 3.5, 3.1, 4.5, -3.2, -35.1, -3, None],
        2: [320, 3.5, 3.08, 4.5, -3.21, -35.12, -3.05, None],
    }
    for ndigits, expected in ndigits_and_expected.items():
        options = pc.RoundOptions(ndigits, "half_towards_infinity")
        result = pc.round(values, options=options)
        np.testing.assert_allclose(result, pa.array(expected), equal_nan=True)


def test_round_to_multiple():
    values = [320, 3.5, 3.075, 4.5, -3.212, -35.1234, -3.045, None]
    multiple_and_expected = {
        2: [320, 4, 4, 4, -4, -36, -4, None],
        0.05: [320, 3.5, 3.1, 4.5, -3.2, -35.1, -3.05, None],
        0.1: [320, 3.5, 3.1, 4.5, -3.2, -35.1, -3, None],
        10: [320, 0, 0, 0, -0, -40, -0, None],
        100: [300, 0, 0, 0, -0, -0, -0, None],
    }
    for multiple, expected in multiple_and_expected.items():
        options = pc.RoundToMultipleOptions(multiple, "half_towards_infinity")
        result = pc.round_to_multiple(values, options=options)
        np.testing.assert_allclose(result, pa.array(expected), equal_nan=True)

    with pytest.raises(pa.ArrowInvalid, match="multiple must be positive"):
        pc.round_to_multiple(values, multiple=-2)


def test_is_null():
    arr = pa.array([1, 2, 3, None])
    result = arr.is_null()
    expected = pa.array([False, False, False, True])
    assert result.equals(expected)
    assert result.equals(pc.is_null(arr))
    result = arr.is_valid()
    expected = pa.array([True, True, True, False])
    assert result.equals(expected)
    assert result.equals(pc.is_valid(arr))

    arr = pa.chunked_array([[1, 2], [3, None]])
    result = arr.is_null()
    expected = pa.chunked_array([[False, False], [False, True]])
    assert result.equals(expected)
    result = arr.is_valid()
    expected = pa.chunked_array([[True, True], [True, False]])
    assert result.equals(expected)

    arr = pa.array([1, 2, 3, None, np.nan])
    result = arr.is_null()
    expected = pa.array([False, False, False, True, False])
    assert result.equals(expected)

    result = arr.is_null(nan_is_null=True)
    expected = pa.array([False, False, False, True, True])
    assert result.equals(expected)


def test_fill_null():
    arr = pa.array([1, 2, None, 4], type=pa.int8())
    fill_value = pa.array([5], type=pa.int8())
    with pytest.raises(pa.ArrowInvalid,
                       match="Array arguments must all be the same length"):
        arr.fill_null(fill_value)

    arr = pa.array([None, None, None, None], type=pa.null())
    fill_value = pa.scalar(None, type=pa.null())
    result = arr.fill_null(fill_value)
    expected = pa.array([None, None, None, None])
    assert result.equals(expected)

    arr = pa.array(['a', 'bb', None])
    result = arr.fill_null('ccc')
    expected = pa.array(['a', 'bb', 'ccc'])
    assert result.equals(expected)

    arr = pa.array([b'a', b'bb', None], type=pa.large_binary())
    result = arr.fill_null('ccc')
    expected = pa.array([b'a', b'bb', b'ccc'], type=pa.large_binary())
    assert result.equals(expected)

    arr = pa.array(['a', 'bb', None])
    result = arr.fill_null(None)
    expected = pa.array(['a', 'bb', None])
    assert result.equals(expected)


@pytest.mark.parametrize('arrow_type', numerical_arrow_types)
def test_fill_null_array(arrow_type):
    arr = pa.array([1, 2, None, 4], type=arrow_type)
    fill_value = pa.scalar(5, type=arrow_type)
    result = arr.fill_null(fill_value)
    expected = pa.array([1, 2, 5, 4], type=arrow_type)
    assert result.equals(expected)

    # Implicit conversions
    result = arr.fill_null(5)
    assert result.equals(expected)

    # ARROW-9451: Unsigned integers allow this for some reason
    if not pa.types.is_unsigned_integer(arr.type):
        with pytest.raises((ValueError, TypeError)):
            arr.fill_null('5')

    result = arr.fill_null(pa.scalar(5, type='int8'))
    assert result.equals(expected)


@pytest.mark.parametrize('arrow_type', numerical_arrow_types)
def test_fill_null_chunked_array(arrow_type):
    fill_value = pa.scalar(5, type=arrow_type)
    arr = pa.chunked_array([pa.array([None, 2, 3, 4], type=arrow_type)])
    result = arr.fill_null(fill_value)
    expected = pa.chunked_array([pa.array([5, 2, 3, 4], type=arrow_type)])
    assert result.equals(expected)

    arr = pa.chunked_array([
        pa.array([1, 2], type=arrow_type),
        pa.array([], type=arrow_type),
        pa.array([None, 4], type=arrow_type)
    ])
    expected = pa.chunked_array([
        pa.array([1, 2], type=arrow_type),
        pa.array([], type=arrow_type),
        pa.array([5, 4], type=arrow_type)
    ])
    result = arr.fill_null(fill_value)
    assert result.equals(expected)

    # Implicit conversions
    result = arr.fill_null(5)
    assert result.equals(expected)

    result = arr.fill_null(pa.scalar(5, type='int8'))
    assert result.equals(expected)


def test_logical():
    a = pa.array([True, False, False, None])
    b = pa.array([True, True, False, True])

    assert pc.and_(a, b) == pa.array([True, False, False, None])
    assert pc.and_kleene(a, b) == pa.array([True, False, False, None])

    assert pc.or_(a, b) == pa.array([True, True, False, None])
    assert pc.or_kleene(a, b) == pa.array([True, True, False, True])

    assert pc.xor(a, b) == pa.array([False, True, False, None])

    assert pc.invert(a) == pa.array([False, True, True, None])


def test_cast():
    arr = pa.array([2 ** 63 - 1], type='int64')

    with pytest.raises(pa.ArrowInvalid):
        pc.cast(arr, 'int32')

    assert pc.cast(arr, 'int32', safe=False) == pa.array([-1], type='int32')

    arr = pa.array([datetime(2010, 1, 1), datetime(2015, 1, 1)])
    expected = pa.array([1262304000000, 1420070400000], type='timestamp[ms]')
    assert pc.cast(arr, 'timestamp[ms]') == expected

    arr = pa.array([[1, 2], [3, 4, 5]], type=pa.large_list(pa.int8()))
    expected = pa.array([["1", "2"], ["3", "4", "5"]],
                        type=pa.list_(pa.utf8()))
    assert pc.cast(arr, expected.type) == expected


def test_strptime():
    arr = pa.array(["5/1/2020", None, "12/13/1900"])

    got = pc.strptime(arr, format='%m/%d/%Y', unit='s')
    expected = pa.array([datetime(2020, 5, 1), None, datetime(1900, 12, 13)],
                        type=pa.timestamp('s'))
    assert got == expected


# TODO: We should test on windows once ARROW-13168 is resolved.
@pytest.mark.pandas
@pytest.mark.skipif(sys.platform == 'win32',
                    reason="Timezone database is not available on Windows yet")
def test_strftime():
    from pyarrow.vendored.version import Version

    def _fix_timestamp(s):
        if Version(pd.__version__) < Version("1.0.0"):
            return s.to_series().replace("NaT", pd.NaT)
        else:
            return s

    times = ["2018-03-10 09:00", "2038-01-31 12:23", None]
    timezones = ["CET", "UTC", "Europe/Ljubljana"]

    formats = ["%a", "%A", "%w", "%d", "%b", "%B", "%m", "%y", "%Y", "%H",
               "%I", "%p", "%M", "%z", "%Z", "%j", "%U", "%W", "%c", "%x",
               "%X", "%%", "%G", "%V", "%u"]

    for timezone in timezones:
        ts = pd.to_datetime(times).tz_localize(timezone)
        for unit in ["s", "ms", "us", "ns"]:
            tsa = pa.array(ts, type=pa.timestamp(unit, timezone))
            for fmt in formats:
                options = pc.StrftimeOptions(fmt)
                result = pc.strftime(tsa, options=options)
                expected = pa.array(_fix_timestamp(ts.strftime(fmt)))
                assert result.equals(expected)

        fmt = "%Y-%m-%dT%H:%M:%S"

        # Default format
        tsa = pa.array(ts, type=pa.timestamp("s", timezone))
        result = pc.strftime(tsa, options=pc.StrftimeOptions())
        expected = pa.array(_fix_timestamp(ts.strftime(fmt)))
        assert result.equals(expected)

        # Default format plus timezone
        tsa = pa.array(ts, type=pa.timestamp("s", timezone))
        result = pc.strftime(tsa, options=pc.StrftimeOptions(fmt + "%Z"))
        expected = pa.array(_fix_timestamp(ts.strftime(fmt + "%Z")))
        assert result.equals(expected)

        # Pandas %S is equivalent to %S in arrow for unit="s"
        tsa = pa.array(ts, type=pa.timestamp("s", timezone))
        options = pc.StrftimeOptions("%S")
        result = pc.strftime(tsa, options=options)
        expected = pa.array(_fix_timestamp(ts.strftime("%S")))
        assert result.equals(expected)

        # Pandas %S.%f is equivalent to %S in arrow for unit="us"
        tsa = pa.array(ts, type=pa.timestamp("us", timezone))
        options = pc.StrftimeOptions("%S")
        result = pc.strftime(tsa, options=options)
        expected = pa.array(_fix_timestamp(ts.strftime("%S.%f")))
        assert result.equals(expected)

        # Test setting locale
        tsa = pa.array(ts, type=pa.timestamp("s", timezone))
        options = pc.StrftimeOptions(fmt, locale="C")
        result = pc.strftime(tsa, options=options)
        expected = pa.array(_fix_timestamp(ts.strftime(fmt)))
        assert result.equals(expected)

    # Test timestamps without timezone
    fmt = "%Y-%m-%dT%H:%M:%S"
    ts = pd.to_datetime(times)
    tsa = pa.array(ts, type=pa.timestamp("s"))
    result = pc.strftime(tsa, options=pc.StrftimeOptions(fmt))
    expected = pa.array(_fix_timestamp(ts.strftime(fmt)))

    assert result.equals(expected)
    with pytest.raises(pa.ArrowInvalid,
                       match="Timezone not present, cannot convert to string"):
        pc.strftime(tsa, options=pc.StrftimeOptions(fmt + "%Z"))
    with pytest.raises(pa.ArrowInvalid,
                       match="Timezone not present, cannot convert to string"):
        pc.strftime(tsa, options=pc.StrftimeOptions(fmt + "%z"))


def _check_datetime_components(timestamps, timezone=None):
    from pyarrow.vendored.version import Version

    ts = pd.to_datetime(timestamps).tz_localize(
        "UTC").tz_convert(timezone).to_series()
    tsa = pa.array(ts, pa.timestamp("ns", tz=timezone))

    subseconds = ((ts.dt.microsecond * 10 ** 3 +
                   ts.dt.nanosecond) * 10 ** -9).round(9)
    iso_calendar_fields = [
        pa.field('iso_year', pa.int64()),
        pa.field('iso_week', pa.int64()),
        pa.field('iso_day_of_week', pa.int64())
    ]

    if Version(pd.__version__) < Version("1.1.0"):
        # https://github.com/pandas-dev/pandas/issues/33206
        iso_year = ts.map(lambda x: x.isocalendar()[0]).astype("int64")
        iso_week = ts.map(lambda x: x.isocalendar()[1]).astype("int64")
        iso_day = ts.map(lambda x: x.isocalendar()[2]).astype("int64")
    else:
        # Casting is required because pandas isocalendar returns int32
        # while arrow isocalendar returns int64.
        iso_year = ts.dt.isocalendar()["year"].astype("int64")
        iso_week = ts.dt.isocalendar()["week"].astype("int64")
        iso_day = ts.dt.isocalendar()["day"].astype("int64")

    iso_calendar = pa.StructArray.from_arrays(
        [iso_year, iso_week, iso_day],
        fields=iso_calendar_fields)

    assert pc.year(tsa).equals(pa.array(ts.dt.year))
    assert pc.month(tsa).equals(pa.array(ts.dt.month))
    assert pc.day(tsa).equals(pa.array(ts.dt.day))
    assert pc.day_of_week(tsa).equals(pa.array(ts.dt.dayofweek))
    assert pc.day_of_year(tsa).equals(pa.array(ts.dt.dayofyear))
    assert pc.iso_year(tsa).equals(pa.array(iso_year))
    assert pc.iso_week(tsa).equals(pa.array(iso_week))
    assert pc.iso_calendar(tsa).equals(iso_calendar)
    assert pc.quarter(tsa).equals(pa.array(ts.dt.quarter))
    assert pc.hour(tsa).equals(pa.array(ts.dt.hour))
    assert pc.minute(tsa).equals(pa.array(ts.dt.minute))
    assert pc.second(tsa).equals(pa.array(ts.dt.second.values))
    assert pc.millisecond(tsa).equals(pa.array(ts.dt.microsecond // 10 ** 3))
    assert pc.microsecond(tsa).equals(pa.array(ts.dt.microsecond % 10 ** 3))
    assert pc.nanosecond(tsa).equals(pa.array(ts.dt.nanosecond))
    assert pc.subsecond(tsa).equals(pa.array(subseconds))

    day_of_week_options = pc.DayOfWeekOptions(
        count_from_zero=False, week_start=1)
    assert pc.day_of_week(tsa, options=day_of_week_options).equals(
        pa.array(ts.dt.dayofweek + 1))

    week_options = pc.WeekOptions(
        week_starts_monday=True, count_from_zero=False,
        first_week_is_fully_in_year=False)
    assert pc.week(tsa, options=week_options).equals(pa.array(iso_week))


@pytest.mark.pandas
def test_extract_datetime_components():
    from pyarrow.vendored.version import Version

    timestamps = ["1970-01-01T00:00:59.123456789",
                  "2000-02-29T23:23:23.999999999",
                  "2033-05-18T03:33:20.000000000",
                  "2020-01-01T01:05:05.001",
                  "2019-12-31T02:10:10.002",
                  "2019-12-30T03:15:15.003",
                  "2009-12-31T04:20:20.004132",
                  "2010-01-01T05:25:25.005321",
                  "2010-01-03T06:30:30.006163",
                  "2010-01-04T07:35:35",
                  "2006-01-01T08:40:40",
                  "2005-12-31T09:45:45",
                  "2008-12-28",
                  "2008-12-29",
                  "2012-01-01 01:02:03"]
    timezones = ["UTC", "US/Central", "Asia/Kolkata",
                 "Etc/GMT-4", "Etc/GMT+4", "Australia/Broken_Hill"]

    # Test timezone naive timestamp array
    _check_datetime_components(timestamps)

    # Test timezone aware timestamp array
    if sys.platform == 'win32':
        # TODO: We should test on windows once ARROW-13168 is resolved.
        pytest.skip('Timezone database is not available on Windows yet')
    elif Version(pd.__version__) < Version('1.0.0'):
        pytest.skip('Pandas < 1.0 extracts time components incorrectly.')
    else:
        for timezone in timezones:
            _check_datetime_components(timestamps, timezone)


# TODO: We should test on windows once ARROW-13168 is resolved.
@pytest.mark.pandas
@pytest.mark.skipif(sys.platform == 'win32',
                    reason="Timezone database is not available on Windows yet")
def test_assume_timezone():
    from pyarrow.vendored.version import Version

    ts_type = pa.timestamp("ns")
    timestamps = pd.to_datetime(["1970-01-01T00:00:59.123456789",
                                 "2000-02-29T23:23:23.999999999",
                                 "2033-05-18T03:33:20.000000000",
                                 "2020-01-01T01:05:05.001",
                                 "2019-12-31T02:10:10.002",
                                 "2019-12-30T03:15:15.003",
                                 "2009-12-31T04:20:20.004132",
                                 "2010-01-01T05:25:25.005321",
                                 "2010-01-03T06:30:30.006163",
                                 "2010-01-04T07:35:35",
                                 "2006-01-01T08:40:40",
                                 "2005-12-31T09:45:45",
                                 "2008-12-28",
                                 "2008-12-29",
                                 "2012-01-01 01:02:03"])
    nonexistent = pd.to_datetime(["2015-03-29 02:30:00",
                                  "2015-03-29 03:30:00"])
    ambiguous = pd.to_datetime(["2018-10-28 01:20:00",
                                "2018-10-28 02:36:00",
                                "2018-10-28 03:46:00"])
    ambiguous_array = pa.array(ambiguous, type=ts_type)
    nonexistent_array = pa.array(nonexistent, type=ts_type)

    for timezone in ["UTC", "US/Central", "Asia/Kolkata"]:
        options = pc.AssumeTimezoneOptions(timezone)
        ta = pa.array(timestamps, type=ts_type)
        expected = timestamps.tz_localize(timezone)
        result = pc.assume_timezone(ta, options=options)
        assert result.equals(pa.array(expected))

        ta_zoned = pa.array(timestamps, type=pa.timestamp("ns", timezone))
        with pytest.raises(pa.ArrowInvalid, match="already have a timezone:"):
            pc.assume_timezone(ta_zoned, options=options)

    invalid_options = pc.AssumeTimezoneOptions("Europe/Brusselsss")
    with pytest.raises(ValueError, match="not found in timezone database"):
        pc.assume_timezone(ta, options=invalid_options)

    timezone = "Europe/Brussels"

    # nonexistent parameter was introduced in Pandas 0.24.0
    if Version(pd.__version__) >= Version("0.24.0"):
        options_nonexistent_raise = pc.AssumeTimezoneOptions(timezone)
        options_nonexistent_earliest = pc.AssumeTimezoneOptions(
            timezone, ambiguous="raise", nonexistent="earliest")
        options_nonexistent_latest = pc.AssumeTimezoneOptions(
            timezone, ambiguous="raise", nonexistent="latest")

        with pytest.raises(ValueError,
                           match="Timestamp doesn't exist in "
                                 f"timezone '{timezone}'"):
            pc.assume_timezone(nonexistent_array,
                               options=options_nonexistent_raise)

        expected = pa.array(nonexistent.tz_localize(
            timezone, nonexistent="shift_forward"))
        result = pc.assume_timezone(
            nonexistent_array, options=options_nonexistent_latest)
        expected.equals(result)

        expected = pa.array(nonexistent.tz_localize(
            timezone, nonexistent="shift_backward"))
        result = pc.assume_timezone(
            nonexistent_array, options=options_nonexistent_earliest)
        expected.equals(result)

    options_ambiguous_raise = pc.AssumeTimezoneOptions(timezone)
    options_ambiguous_latest = pc.AssumeTimezoneOptions(
        timezone, ambiguous="latest", nonexistent="raise")
    options_ambiguous_earliest = pc.AssumeTimezoneOptions(
        timezone, ambiguous="earliest", nonexistent="raise")

    with pytest.raises(ValueError,
                       match="Timestamp is ambiguous in "
                             f"timezone '{timezone}'"):
        pc.assume_timezone(ambiguous_array, options=options_ambiguous_raise)

    expected = ambiguous.tz_localize(timezone, ambiguous=[True, True, True])
    result = pc.assume_timezone(
        ambiguous_array, options=options_ambiguous_earliest)
    result.equals(pa.array(expected))

    expected = ambiguous.tz_localize(timezone, ambiguous=[False, False, False])
    result = pc.assume_timezone(
        ambiguous_array, options=options_ambiguous_latest)
    result.equals(pa.array(expected))


def test_count():
    arr = pa.array([1, 2, 3, None, None])
    assert pc.count(arr).as_py() == 3
    assert pc.count(arr, mode='only_valid').as_py() == 3
    assert pc.count(arr, mode='only_null').as_py() == 2
    assert pc.count(arr, mode='all').as_py() == 5


def test_index():
    arr = pa.array([0, 1, None, 3, 4], type=pa.int64())
    assert pc.index(arr, pa.scalar(0)).as_py() == 0
    assert pc.index(arr, pa.scalar(2, type=pa.int8())).as_py() == -1
    assert pc.index(arr, 4).as_py() == 4
    assert arr.index(3, start=2).as_py() == 3
    assert arr.index(None).as_py() == -1

    arr = pa.chunked_array([[1, 2], [1, 3]], type=pa.int64())
    assert arr.index(1).as_py() == 0
    assert arr.index(1, start=2).as_py() == 2
    assert arr.index(1, start=1, end=2).as_py() == -1


def check_partition_nth(data, indices, pivot, null_placement):
    indices = indices.to_pylist()
    assert len(indices) == len(data)
    assert sorted(indices) == list(range(len(data)))
    until_pivot = [data[indices[i]] for i in range(pivot)]
    after_pivot = [data[indices[i]] for i in range(pivot, len(data))]
    p = data[indices[pivot]]
    if p is None:
        if null_placement == "at_start":
            assert all(v is None for v in until_pivot)
        else:
            assert all(v is None for v in after_pivot)
    else:
        if null_placement == "at_start":
            assert all(v is None or v <= p for v in until_pivot)
            assert all(v >= p for v in after_pivot)
        else:
            assert all(v <= p for v in until_pivot)
            assert all(v is None or v >= p for v in after_pivot)


def test_partition_nth():
    data = list(range(100, 140))
    random.shuffle(data)
    pivot = 10
    indices = pc.partition_nth_indices(data, pivot=pivot)
    check_partition_nth(data, indices, pivot, "at_end")


def test_partition_nth_null_placement():
    data = list(range(10)) + [None] * 10
    random.shuffle(data)

    for pivot in (0, 7, 13, 19):
        for null_placement in ("at_start", "at_end"):
            indices = pc.partition_nth_indices(data, pivot=pivot,
                                               null_placement=null_placement)
            check_partition_nth(data, indices, pivot, null_placement)


def test_select_k_array():
    def validate_select_k(select_k_indices, arr, order, stable_sort=False):
        sorted_indices = pc.sort_indices(arr, sort_keys=[("dummy", order)])
        head_k_indices = sorted_indices.slice(0, len(select_k_indices))
        if stable_sort:
            assert select_k_indices == head_k_indices
        else:
            expected = pc.take(arr, head_k_indices)
            actual = pc.take(arr, select_k_indices)
            assert actual == expected

    arr = pa.array([1, 2, None, 0])
    for k in [0, 2, 4]:
        for order in ["descending", "ascending"]:
            result = pc.select_k_unstable(
                arr, k=k, sort_keys=[("dummy", order)])
            validate_select_k(result, arr, order)

        result = pc.top_k_unstable(arr, k=k)
        validate_select_k(result, arr, "descending")

        result = pc.bottom_k_unstable(arr, k=k)
        validate_select_k(result, arr, "ascending")

    result = pc.select_k_unstable(
        arr, options=pc.SelectKOptions(
            k=2, sort_keys=[("dummy", "descending")])
    )
    validate_select_k(result, arr, "descending")

    result = pc.select_k_unstable(
        arr, options=pc.SelectKOptions(k=2, sort_keys=[("dummy", "ascending")])
    )
    validate_select_k(result, arr, "ascending")


def test_select_k_table():
    def validate_select_k(select_k_indices, tbl, sort_keys, stable_sort=False):
        sorted_indices = pc.sort_indices(tbl, sort_keys=sort_keys)
        head_k_indices = sorted_indices.slice(0, len(select_k_indices))
        if stable_sort:
            assert select_k_indices == head_k_indices
        else:
            expected = pc.take(tbl, head_k_indices)
            actual = pc.take(tbl, select_k_indices)
            assert actual == expected

    table = pa.table({"a": [1, 2, 0], "b": [1, 0, 1]})
    for k in [0, 2, 4]:
        result = pc.select_k_unstable(
            table, k=k, sort_keys=[("a", "ascending")])
        validate_select_k(result, table, sort_keys=[("a", "ascending")])

        result = pc.select_k_unstable(
            table, k=k, sort_keys=[("a", "ascending"), ("b", "ascending")])
        validate_select_k(
            result, table, sort_keys=[("a", "ascending"), ("b", "ascending")])

        result = pc.top_k_unstable(table, k=k, sort_keys=["a"])
        validate_select_k(result, table, sort_keys=[("a", "descending")])

        result = pc.bottom_k_unstable(table, k=k, sort_keys=["a", "b"])
        validate_select_k(
            result, table, sort_keys=[("a", "ascending"), ("b", "ascending")])

    with pytest.raises(ValueError,
                       match="select_k_unstable requires a nonnegative `k`"):
        pc.select_k_unstable(table)

    with pytest.raises(ValueError,
                       match="select_k_unstable requires a "
                             "non-empty `sort_keys`"):
        pc.select_k_unstable(table, k=2, sort_keys=[])

    with pytest.raises(ValueError, match="not a valid sort order"):
        pc.select_k_unstable(table, k=k, sort_keys=[("a", "nonscending")])

    with pytest.raises(ValueError, match="Nonexistent sort key column"):
        pc.select_k_unstable(table, k=k, sort_keys=[("unknown", "ascending")])


def test_array_sort_indices():
    arr = pa.array([1, 2, None, 0])
    result = pc.array_sort_indices(arr)
    assert result.to_pylist() == [3, 0, 1, 2]
    result = pc.array_sort_indices(arr, order="ascending")
    assert result.to_pylist() == [3, 0, 1, 2]
    result = pc.array_sort_indices(arr, order="descending")
    assert result.to_pylist() == [1, 0, 3, 2]
    result = pc.array_sort_indices(arr, order="descending",
                                   null_placement="at_start")
    assert result.to_pylist() == [2, 1, 0, 3]

    with pytest.raises(ValueError, match="not a valid sort order"):
        pc.array_sort_indices(arr, order="nonscending")


def test_sort_indices_array():
    arr = pa.array([1, 2, None, 0])
    result = pc.sort_indices(arr)
    assert result.to_pylist() == [3, 0, 1, 2]
    result = pc.sort_indices(arr, sort_keys=[("dummy", "ascending")])
    assert result.to_pylist() == [3, 0, 1, 2]
    result = pc.sort_indices(arr, sort_keys=[("dummy", "descending")])
    assert result.to_pylist() == [1, 0, 3, 2]
    result = pc.sort_indices(arr, sort_keys=[("dummy", "descending")],
                             null_placement="at_start")
    assert result.to_pylist() == [2, 1, 0, 3]
    # Using SortOptions
    result = pc.sort_indices(
        arr, options=pc.SortOptions(sort_keys=[("dummy", "descending")])
    )
    assert result.to_pylist() == [1, 0, 3, 2]
    result = pc.sort_indices(
        arr, options=pc.SortOptions(sort_keys=[("dummy", "descending")],
                                    null_placement="at_start")
    )
    assert result.to_pylist() == [2, 1, 0, 3]


def test_sort_indices_table():
    table = pa.table({"a": [1, 1, None, 0], "b": [1, 0, 0, 1]})

    result = pc.sort_indices(table, sort_keys=[("a", "ascending")])
    assert result.to_pylist() == [3, 0, 1, 2]
    result = pc.sort_indices(table, sort_keys=[("a", "ascending")],
                             null_placement="at_start")
    assert result.to_pylist() == [2, 3, 0, 1]

    result = pc.sort_indices(
        table, sort_keys=[("a", "descending"), ("b", "ascending")]
    )
    assert result.to_pylist() == [1, 0, 3, 2]
    result = pc.sort_indices(
        table, sort_keys=[("a", "descending"), ("b", "ascending")],
        null_placement="at_start"
    )
    assert result.to_pylist() == [2, 1, 0, 3]

    with pytest.raises(ValueError, match="Must specify one or more sort keys"):
        pc.sort_indices(table)

    with pytest.raises(ValueError, match="Nonexistent sort key column"):
        pc.sort_indices(table, sort_keys=[("unknown", "ascending")])

    with pytest.raises(ValueError, match="not a valid sort order"):
        pc.sort_indices(table, sort_keys=[("a", "nonscending")])


def test_is_in():
    arr = pa.array([1, 2, None, 1, 2, 3])

    result = pc.is_in(arr, value_set=pa.array([1, 3, None]))
    assert result.to_pylist() == [True, False, True, True, False, True]

    result = pc.is_in(arr, value_set=pa.array([1, 3, None]), skip_nulls=True)
    assert result.to_pylist() == [True, False, False, True, False, True]

    result = pc.is_in(arr, value_set=pa.array([1, 3]))
    assert result.to_pylist() == [True, False, False, True, False, True]

    result = pc.is_in(arr, value_set=pa.array([1, 3]), skip_nulls=True)
    assert result.to_pylist() == [True, False, False, True, False, True]


def test_index_in():
    arr = pa.array([1, 2, None, 1, 2, 3])

    result = pc.index_in(arr, value_set=pa.array([1, 3, None]))
    assert result.to_pylist() == [0, None, 2, 0, None, 1]

    result = pc.index_in(arr, value_set=pa.array([1, 3, None]),
                         skip_nulls=True)
    assert result.to_pylist() == [0, None, None, 0, None, 1]

    result = pc.index_in(arr, value_set=pa.array([1, 3]))
    assert result.to_pylist() == [0, None, None, 0, None, 1]

    result = pc.index_in(arr, value_set=pa.array([1, 3]), skip_nulls=True)
    assert result.to_pylist() == [0, None, None, 0, None, 1]


def test_quantile():
    arr = pa.array([1, 2, 3, 4])

    result = pc.quantile(arr)
    assert result.to_pylist() == [2.5]

    result = pc.quantile(arr, interpolation='lower')
    assert result.to_pylist() == [2]
    result = pc.quantile(arr, interpolation='higher')
    assert result.to_pylist() == [3]
    result = pc.quantile(arr, interpolation='nearest')
    assert result.to_pylist() == [3]
    result = pc.quantile(arr, interpolation='midpoint')
    assert result.to_pylist() == [2.5]
    result = pc.quantile(arr, interpolation='linear')
    assert result.to_pylist() == [2.5]

    arr = pa.array([1, 2])

    result = pc.quantile(arr, q=[0.25, 0.5, 0.75])
    assert result.to_pylist() == [1.25, 1.5, 1.75]

    result = pc.quantile(arr, q=[0.25, 0.5, 0.75], interpolation='lower')
    assert result.to_pylist() == [1, 1, 1]
    result = pc.quantile(arr, q=[0.25, 0.5, 0.75], interpolation='higher')
    assert result.to_pylist() == [2, 2, 2]
    result = pc.quantile(arr, q=[0.25, 0.5, 0.75], interpolation='midpoint')
    assert result.to_pylist() == [1.5, 1.5, 1.5]
    result = pc.quantile(arr, q=[0.25, 0.5, 0.75], interpolation='nearest')
    assert result.to_pylist() == [1, 1, 2]
    result = pc.quantile(arr, q=[0.25, 0.5, 0.75], interpolation='linear')
    assert result.to_pylist() == [1.25, 1.5, 1.75]

    with pytest.raises(ValueError, match="Quantile must be between 0 and 1"):
        pc.quantile(arr, q=1.1)
    with pytest.raises(ValueError, match="not a valid quantile interpolation"):
        pc.quantile(arr, interpolation='zzz')


def test_tdigest():
    arr = pa.array([1, 2, 3, 4])
    result = pc.tdigest(arr)
    assert result.to_pylist() == [2.5]

    arr = pa.chunked_array([pa.array([1, 2]), pa.array([3, 4])])
    result = pc.tdigest(arr)
    assert result.to_pylist() == [2.5]

    arr = pa.array([1, 2, 3, 4])
    result = pc.tdigest(arr, q=[0, 0.5, 1])
    assert result.to_pylist() == [1, 2.5, 4]

    arr = pa.chunked_array([pa.array([1, 2]), pa.array([3, 4])])
    result = pc.tdigest(arr, q=[0, 0.5, 1])
    assert result.to_pylist() == [1, 2.5, 4]


def test_fill_null_segfault():
    # ARROW-12672
    arr = pa.array([None], pa.bool_()).fill_null(False)
    result = arr.cast(pa.int8())
    assert result == pa.array([0], pa.int8())


def test_min_max_element_wise():
    arr1 = pa.array([1, 2, 3])
    arr2 = pa.array([3, 1, 2])
    arr3 = pa.array([2, 3, None])

    result = pc.max_element_wise(arr1, arr2)
    assert result == pa.array([3, 2, 3])
    result = pc.min_element_wise(arr1, arr2)
    assert result == pa.array([1, 1, 2])

    result = pc.max_element_wise(arr1, arr2, arr3)
    assert result == pa.array([3, 3, 3])
    result = pc.min_element_wise(arr1, arr2, arr3)
    assert result == pa.array([1, 1, 2])

    # with specifying the option
    result = pc.max_element_wise(arr1, arr3, skip_nulls=True)
    assert result == pa.array([2, 3, 3])
    result = pc.min_element_wise(arr1, arr3, skip_nulls=True)
    assert result == pa.array([1, 2, 3])
    result = pc.max_element_wise(
        arr1, arr3, options=pc.ElementWiseAggregateOptions())
    assert result == pa.array([2, 3, 3])
    result = pc.min_element_wise(
        arr1, arr3, options=pc.ElementWiseAggregateOptions())
    assert result == pa.array([1, 2, 3])

    # not skipping nulls
    result = pc.max_element_wise(arr1, arr3, skip_nulls=False)
    assert result == pa.array([2, 3, None])
    result = pc.min_element_wise(arr1, arr3, skip_nulls=False)
    assert result == pa.array([1, 2, None])


def test_make_struct():
    assert pc.make_struct(1, 'a').as_py() == {'0': 1, '1': 'a'}

    assert pc.make_struct(1, 'a', field_names=['i', 's']).as_py() == {
        'i': 1, 's': 'a'}

    assert pc.make_struct([1, 2, 3],
                          "a b c".split()) == pa.StructArray.from_arrays([
                              [1, 2, 3],
                              "a b c".split()], names='0 1'.split())

    with pytest.raises(ValueError,
                       match="Array arguments must all be the same length"):
        pc.make_struct([1, 2, 3, 4], "a b c".split())

    with pytest.raises(ValueError, match="0 arguments but 2 field names"):
        pc.make_struct(field_names=['one', 'two'])


def test_case_when():
    assert pc.case_when(pc.make_struct([True, False, None],
                                       [False, True, None]),
                        [1, 2, 3],
                        [11, 12, 13]) == pa.array([1, 12, None])


def test_list_element():
    element_type = pa.struct([('a', pa.float64()), ('b', pa.int8())])
    list_type = pa.list_(element_type)
    l1 = [{'a': .4, 'b': 2}, None, {'a': .2, 'b': 4}, None, {'a': 5.6, 'b': 6}]
    l2 = [None, {'a': .52, 'b': 3}, {'a': .7, 'b': 4}, None, {'a': .6, 'b': 8}]
    lists = pa.array([l1, l2], list_type)

    index = 1
    result = pa.compute.list_element(lists, index)
    expected = pa.array([None, {'a': 0.52, 'b': 3}], element_type)
    assert result.equals(expected)

    index = 4
    result = pa.compute.list_element(lists, index)
    expected = pa.array([{'a': 5.6, 'b': 6}, {'a': .6, 'b': 8}], element_type)
    assert result.equals(expected)


def test_count_distinct():
    seed = datetime.now()
    samples = [seed.replace(year=y) for y in range(1992, 2092)]
    arr = pa.array(samples, pa.timestamp("ns"))
    result = pa.compute.count_distinct(arr)
    expected = pa.scalar(len(samples), type=pa.int64())
    assert result.equals(expected)


def test_count_distinct_options():
    arr = pa.array([1, 2, 3, None, None])
    assert pc.count_distinct(arr).as_py() == 3
    assert pc.count_distinct(arr, mode='only_valid').as_py() == 3
    assert pc.count_distinct(arr, mode='only_null').as_py() == 1
    assert pc.count_distinct(arr, mode='all').as_py() == 4