import numpy as np
import pytest

import pandas as pd
import pandas.util.testing as tm

from .base import BaseExtensionTests


class BaseMethodsTests(BaseExtensionTests):
    """Various Series and DataFrame methods."""

    @pytest.mark.parametrize('dropna', [True, False])
    def test_value_counts(self, all_data, dropna):
        all_data = all_data[:10]
        if dropna:
            other = np.array(all_data[~all_data.isna()])
        else:
            other = all_data

        result = pd.Series(all_data).value_counts(dropna=dropna).sort_index()
        expected = pd.Series(other).value_counts(
            dropna=dropna).sort_index()

        self.assert_series_equal(result, expected)

    def test_count(self, data_missing):
        df = pd.DataFrame({"A": data_missing})
        result = df.count(axis='columns')
        expected = pd.Series([0, 1])
        self.assert_series_equal(result, expected)

    def test_apply_simple_series(self, data):
        result = pd.Series(data).apply(id)
        assert isinstance(result, pd.Series)

    def test_argsort(self, data_for_sorting):
        result = pd.Series(data_for_sorting).argsort()
        expected = pd.Series(np.array([2, 0, 1], dtype=np.int64))
        self.assert_series_equal(result, expected)

    def test_argsort_missing(self, data_missing_for_sorting):
        result = pd.Series(data_missing_for_sorting).argsort()
        expected = pd.Series(np.array([1, -1, 0], dtype=np.int64))
        self.assert_series_equal(result, expected)

    @pytest.mark.parametrize('ascending', [True, False])
    def test_sort_values(self, data_for_sorting, ascending):
        ser = pd.Series(data_for_sorting)
        result = ser.sort_values(ascending=ascending)
        expected = ser.iloc[[2, 0, 1]]
        if not ascending:
            expected = expected[::-1]

        self.assert_series_equal(result, expected)

    @pytest.mark.parametrize('ascending', [True, False])
    def test_sort_values_missing(self, data_missing_for_sorting, ascending):
        ser = pd.Series(data_missing_for_sorting)
        result = ser.sort_values(ascending=ascending)
        if ascending:
            expected = ser.iloc[[2, 0, 1]]
        else:
            expected = ser.iloc[[0, 2, 1]]
        self.assert_series_equal(result, expected)

    @pytest.mark.parametrize('ascending', [True, False])
    def test_sort_values_frame(self, data_for_sorting, ascending):
        df = pd.DataFrame({"A": [1, 2, 1],
                           "B": data_for_sorting})
        result = df.sort_values(['A', 'B'])
        expected = pd.DataFrame({"A": [1, 1, 2],
                                 'B': data_for_sorting.take([2, 0, 1])},
                                index=[2, 0, 1])
        self.assert_frame_equal(result, expected)

    @pytest.mark.parametrize('box', [pd.Series, lambda x: x])
    @pytest.mark.parametrize('method', [lambda x: x.unique(), pd.unique])
    def test_unique(self, data, box, method):
        duplicated = box(data._from_sequence([data[0], data[0]]))

        result = method(duplicated)

        assert len(result) == 1
        assert isinstance(result, type(data))
        assert result[0] == duplicated[0]

    @pytest.mark.parametrize('na_sentinel', [-1, -2])
    def test_factorize(self, data_for_grouping, na_sentinel):
        labels, uniques = pd.factorize(data_for_grouping,
                                       na_sentinel=na_sentinel)
        expected_labels = np.array([0, 0, na_sentinel,
                                   na_sentinel, 1, 1, 0, 2],
                                   dtype=np.intp)
        expected_uniques = data_for_grouping.take([0, 4, 7])

        tm.assert_numpy_array_equal(labels, expected_labels)
        self.assert_extension_array_equal(uniques, expected_uniques)

    @pytest.mark.parametrize('na_sentinel', [-1, -2])
    def test_factorize_equivalence(self, data_for_grouping, na_sentinel):
        l1, u1 = pd.factorize(data_for_grouping, na_sentinel=na_sentinel)
        l2, u2 = data_for_grouping.factorize(na_sentinel=na_sentinel)

        tm.assert_numpy_array_equal(l1, l2)
        self.assert_extension_array_equal(u1, u2)

    def test_fillna_copy_frame(self, data_missing):
        arr = data_missing.take([1, 1])
        df = pd.DataFrame({"A": arr})

        filled_val = df.iloc[0, 0]
        result = df.fillna(filled_val)

        assert df.A.values is not result.A.values

    def test_fillna_copy_series(self, data_missing):
        arr = data_missing.take([1, 1])
        ser = pd.Series(arr)

        filled_val = ser[0]
        result = ser.fillna(filled_val)

        assert ser._values is not result._values
        assert ser._values is arr

    def test_fillna_length_mismatch(self, data_missing):
        msg = "Length of 'value' does not match."
        with pytest.raises(ValueError, match=msg):
            data_missing.fillna(data_missing.take([1]))

    def test_combine_le(self, data_repeated):
        # GH 20825
        # Test that combine works when doing a <= (le) comparison
        orig_data1, orig_data2 = data_repeated(2)
        s1 = pd.Series(orig_data1)
        s2 = pd.Series(orig_data2)
        result = s1.combine(s2, lambda x1, x2: x1 <= x2)
        expected = pd.Series([a <= b for (a, b) in
                              zip(list(orig_data1), list(orig_data2))])
        self.assert_series_equal(result, expected)

        val = s1.iloc[0]
        result = s1.combine(val, lambda x1, x2: x1 <= x2)
        expected = pd.Series([a <= val for a in list(orig_data1)])
        self.assert_series_equal(result, expected)

    def test_combine_add(self, data_repeated):
        # GH 20825
        orig_data1, orig_data2 = data_repeated(2)
        s1 = pd.Series(orig_data1)
        s2 = pd.Series(orig_data2)
        result = s1.combine(s2, lambda x1, x2: x1 + x2)
        with np.errstate(over='ignore'):
            expected = pd.Series(
                orig_data1._from_sequence([a + b for (a, b) in
                                           zip(list(orig_data1),
                                               list(orig_data2))]))
        self.assert_series_equal(result, expected)

        val = s1.iloc[0]
        result = s1.combine(val, lambda x1, x2: x1 + x2)
        expected = pd.Series(
            orig_data1._from_sequence([a + val for a in list(orig_data1)]))
        self.assert_series_equal(result, expected)

    def test_combine_first(self, data):
        # https://github.com/pandas-dev/pandas/issues/24147
        a = pd.Series(data[:3])
        b = pd.Series(data[2:5], index=[2, 3, 4])
        result = a.combine_first(b)
        expected = pd.Series(data[:5])
        self.assert_series_equal(result, expected)

    @pytest.mark.parametrize('frame', [True, False])
    @pytest.mark.parametrize('periods, indices', [
        (-2, [2, 3, 4, -1, -1]),
        (0, [0, 1, 2, 3, 4]),
        (2, [-1, -1, 0, 1, 2]),
    ])
    def test_container_shift(self, data, frame, periods, indices):
        # https://github.com/pandas-dev/pandas/issues/22386
        subset = data[:5]
        data = pd.Series(subset, name='A')
        expected = pd.Series(subset.take(indices, allow_fill=True), name='A')

        if frame:
            result = data.to_frame(name='A').assign(B=1).shift(periods)
            expected = pd.concat([
                expected,
                pd.Series([1] * 5, name='B').shift(periods)
            ], axis=1)
            compare = self.assert_frame_equal
        else:
            result = data.shift(periods)
            compare = self.assert_series_equal

        compare(result, expected)

    @pytest.mark.parametrize('periods, indices', [
        [-4, [-1, -1]],
        [-1, [1, -1]],
        [0, [0, 1]],
        [1, [-1, 0]],
        [4, [-1, -1]]
    ])
    def test_shift_non_empty_array(self, data, periods, indices):
        # https://github.com/pandas-dev/pandas/issues/23911
        subset = data[:2]
        result = subset.shift(periods)
        expected = subset.take(indices, allow_fill=True)
        self.assert_extension_array_equal(result, expected)

    @pytest.mark.parametrize('periods', [
        -4, -1, 0, 1, 4
    ])
    def test_shift_empty_array(self, data, periods):
        # https://github.com/pandas-dev/pandas/issues/23911
        empty = data[:0]
        result = empty.shift(periods)
        expected = empty
        self.assert_extension_array_equal(result, expected)

    def test_shift_fill_value(self, data):
        arr = data[:4]
        fill_value = data[0]
        result = arr.shift(1, fill_value=fill_value)
        expected = data.take([0, 0, 1, 2])
        self.assert_extension_array_equal(result, expected)

        result = arr.shift(-2, fill_value=fill_value)
        expected = data.take([2, 3, 0, 0])
        self.assert_extension_array_equal(result, expected)

    @pytest.mark.parametrize("as_frame", [True, False])
    def test_hash_pandas_object_works(self, data, as_frame):
        # https://github.com/pandas-dev/pandas/issues/23066
        data = pd.Series(data)
        if as_frame:
            data = data.to_frame()
        a = pd.util.hash_pandas_object(data)
        b = pd.util.hash_pandas_object(data)
        self.assert_equal(a, b)

    @pytest.mark.parametrize("as_frame", [True, False])
    def test_where_series(self, data, na_value, as_frame):
        assert data[0] != data[1]
        cls = type(data)
        a, b = data[:2]

        ser = pd.Series(cls._from_sequence([a, a, b, b], dtype=data.dtype))
        cond = np.array([True, True, False, False])

        if as_frame:
            ser = ser.to_frame(name='a')
            cond = cond.reshape(-1, 1)

        result = ser.where(cond)
        expected = pd.Series(cls._from_sequence([a, a, na_value, na_value],
                                                dtype=data.dtype))

        if as_frame:
            expected = expected.to_frame(name='a')
        self.assert_equal(result, expected)

        # array other
        cond = np.array([True, False, True, True])
        other = cls._from_sequence([a, b, a, b], dtype=data.dtype)
        if as_frame:
            other = pd.DataFrame({"a": other})
            cond = pd.DataFrame({"a": cond})
        result = ser.where(cond, other)
        expected = pd.Series(cls._from_sequence([a, b, b, b],
                                                dtype=data.dtype))
        if as_frame:
            expected = expected.to_frame(name='a')
        self.assert_equal(result, expected)

    @pytest.mark.parametrize("use_numpy", [True, False])
    @pytest.mark.parametrize("as_series", [True, False])
    @pytest.mark.parametrize("repeats", [0, 1, 2, [1, 2, 3]])
    def test_repeat(self, data, repeats, as_series, use_numpy):
        arr = type(data)._from_sequence(data[:3], dtype=data.dtype)
        if as_series:
            arr = pd.Series(arr)

        result = np.repeat(arr, repeats) if use_numpy else arr.repeat(repeats)

        repeats = [repeats] * 3 if isinstance(repeats, int) else repeats
        expected = [x for x, n in zip(arr, repeats) for _ in range(n)]
        expected = type(data)._from_sequence(expected, dtype=data.dtype)
        if as_series:
            expected = pd.Series(expected, index=arr.index.repeat(repeats))

        self.assert_equal(result, expected)

    @pytest.mark.parametrize("use_numpy", [True, False])
    @pytest.mark.parametrize('repeats, kwargs, error, msg', [
        (2, dict(axis=1), ValueError, "'axis"),
        (-1, dict(), ValueError, "negative"),
        ([1, 2], dict(), ValueError, "shape"),
        (2, dict(foo='bar'), TypeError, "'foo'")])
    def test_repeat_raises(self, data, repeats, kwargs, error, msg, use_numpy):
        with pytest.raises(error, match=msg):
            if use_numpy:
                np.repeat(data, repeats, **kwargs)
            else:
                data.repeat(repeats, **kwargs)
