from datetime import datetime, timedelta

import numpy as np
import pytest

import pandas as pd
from pandas import Index, Timedelta, TimedeltaIndex, notna, timedelta_range
import pandas._testing as tm


class TestGetItem:
    def test_ellipsis(self):
        # GH#21282
        idx = timedelta_range("1 day", "31 day", freq="D", name="idx")

        result = idx[...]
        assert result.equals(idx)
        assert result is not idx

    def test_getitem(self):
        idx1 = timedelta_range("1 day", "31 day", freq="D", name="idx")

        for idx in [idx1]:
            result = idx[0]
            assert result == Timedelta("1 day")

            result = idx[0:5]
            expected = timedelta_range("1 day", "5 day", freq="D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx[0:10:2]
            expected = timedelta_range("1 day", "9 day", freq="2D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx[-20:-5:3]
            expected = timedelta_range("12 day", "24 day", freq="3D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx[4::-1]
            expected = TimedeltaIndex(
                ["5 day", "4 day", "3 day", "2 day", "1 day"], freq="-1D", name="idx"
            )
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

    @pytest.mark.parametrize(
        "key",
        [pd.Timestamp("1970-01-01"), pd.Timestamp("1970-01-02"), datetime(1970, 1, 1)],
    )
    def test_timestamp_invalid_key(self, key):
        # GH#20464
        tdi = pd.timedelta_range(0, periods=10)
        with pytest.raises(TypeError):
            tdi.get_loc(key)


class TestWhere:
    def test_where_invalid_dtypes(self):
        tdi = timedelta_range("1 day", periods=3, freq="D", name="idx")

        i2 = tdi.copy()
        i2 = Index([pd.NaT, pd.NaT] + tdi[2:].tolist())

        with pytest.raises(TypeError, match="Where requires matching dtype"):
            tdi.where(notna(i2), i2.asi8)

        with pytest.raises(TypeError, match="Where requires matching dtype"):
            tdi.where(notna(i2), i2 + pd.Timestamp.now())

        with pytest.raises(TypeError, match="Where requires matching dtype"):
            tdi.where(notna(i2), (i2 + pd.Timestamp.now()).to_period("D"))


class TestTake:
    def test_take(self):
        # GH 10295
        idx1 = timedelta_range("1 day", "31 day", freq="D", name="idx")

        for idx in [idx1]:
            result = idx.take([0])
            assert result == Timedelta("1 day")

            result = idx.take([-1])
            assert result == Timedelta("31 day")

            result = idx.take([0, 1, 2])
            expected = timedelta_range("1 day", "3 day", freq="D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx.take([0, 2, 4])
            expected = timedelta_range("1 day", "5 day", freq="2D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx.take([7, 4, 1])
            expected = timedelta_range("8 day", "2 day", freq="-3D", name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq == expected.freq

            result = idx.take([3, 2, 5])
            expected = TimedeltaIndex(["4 day", "3 day", "6 day"], name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq is None

            result = idx.take([-3, 2, 5])
            expected = TimedeltaIndex(["29 day", "3 day", "6 day"], name="idx")
            tm.assert_index_equal(result, expected)
            assert result.freq is None

    def test_take_invalid_kwargs(self):
        idx = timedelta_range("1 day", "31 day", freq="D", name="idx")
        indices = [1, 6, 5, 9, 10, 13, 15, 3]

        msg = r"take\(\) got an unexpected keyword argument 'foo'"
        with pytest.raises(TypeError, match=msg):
            idx.take(indices, foo=2)

        msg = "the 'out' parameter is not supported"
        with pytest.raises(ValueError, match=msg):
            idx.take(indices, out=indices)

        msg = "the 'mode' parameter is not supported"
        with pytest.raises(ValueError, match=msg):
            idx.take(indices, mode="clip")

    # TODO: This method came from test_timedelta; de-dup with version above
    def test_take2(self):
        tds = ["1day 02:00:00", "1 day 04:00:00", "1 day 10:00:00"]
        idx = timedelta_range(start="1d", end="2d", freq="H", name="idx")
        expected = TimedeltaIndex(tds, freq=None, name="idx")

        taken1 = idx.take([2, 4, 10])
        taken2 = idx[[2, 4, 10]]

        for taken in [taken1, taken2]:
            tm.assert_index_equal(taken, expected)
            assert isinstance(taken, TimedeltaIndex)
            assert taken.freq is None
            assert taken.name == expected.name

    def test_take_fill_value(self):
        # GH 12631
        idx = TimedeltaIndex(["1 days", "2 days", "3 days"], name="xxx")
        result = idx.take(np.array([1, 0, -1]))
        expected = TimedeltaIndex(["2 days", "1 days", "3 days"], name="xxx")
        tm.assert_index_equal(result, expected)

        # fill_value
        result = idx.take(np.array([1, 0, -1]), fill_value=True)
        expected = TimedeltaIndex(["2 days", "1 days", "NaT"], name="xxx")
        tm.assert_index_equal(result, expected)

        # allow_fill=False
        result = idx.take(np.array([1, 0, -1]), allow_fill=False, fill_value=True)
        expected = TimedeltaIndex(["2 days", "1 days", "3 days"], name="xxx")
        tm.assert_index_equal(result, expected)

        msg = (
            "When allow_fill=True and fill_value is not None, "
            "all indices must be >= -1"
        )
        with pytest.raises(ValueError, match=msg):
            idx.take(np.array([1, 0, -2]), fill_value=True)
        with pytest.raises(ValueError, match=msg):
            idx.take(np.array([1, 0, -5]), fill_value=True)

        with pytest.raises(IndexError):
            idx.take(np.array([1, -5]))


class TestTimedeltaIndex:
    def test_insert_empty(self):
        # Corner case inserting with length zero doesnt raise IndexError
        idx = timedelta_range("1 Day", periods=3)
        td = idx[0]

        idx[:0].insert(0, td)
        idx[:0].insert(1, td)
        idx[:0].insert(-1, td)

    def test_insert(self):

        idx = TimedeltaIndex(["4day", "1day", "2day"], name="idx")

        result = idx.insert(2, timedelta(days=5))
        exp = TimedeltaIndex(["4day", "1day", "5day", "2day"], name="idx")
        tm.assert_index_equal(result, exp)

        # insertion of non-datetime should coerce to object index
        result = idx.insert(1, "inserted")
        expected = Index(
            [Timedelta("4day"), "inserted", Timedelta("1day"), Timedelta("2day")],
            name="idx",
        )
        assert not isinstance(result, TimedeltaIndex)
        tm.assert_index_equal(result, expected)
        assert result.name == expected.name

        idx = timedelta_range("1day 00:00:01", periods=3, freq="s", name="idx")

        # preserve freq
        expected_0 = TimedeltaIndex(
            ["1day", "1day 00:00:01", "1day 00:00:02", "1day 00:00:03"],
            name="idx",
            freq="s",
        )
        expected_3 = TimedeltaIndex(
            ["1day 00:00:01", "1day 00:00:02", "1day 00:00:03", "1day 00:00:04"],
            name="idx",
            freq="s",
        )

        # reset freq to None
        expected_1_nofreq = TimedeltaIndex(
            ["1day 00:00:01", "1day 00:00:01", "1day 00:00:02", "1day 00:00:03"],
            name="idx",
            freq=None,
        )
        expected_3_nofreq = TimedeltaIndex(
            ["1day 00:00:01", "1day 00:00:02", "1day 00:00:03", "1day 00:00:05"],
            name="idx",
            freq=None,
        )

        cases = [
            (0, Timedelta("1day"), expected_0),
            (-3, Timedelta("1day"), expected_0),
            (3, Timedelta("1day 00:00:04"), expected_3),
            (1, Timedelta("1day 00:00:01"), expected_1_nofreq),
            (3, Timedelta("1day 00:00:05"), expected_3_nofreq),
        ]

        for n, d, expected in cases:
            result = idx.insert(n, d)
            tm.assert_index_equal(result, expected)
            assert result.name == expected.name
            assert result.freq == expected.freq

    @pytest.mark.parametrize(
        "null", [None, np.nan, np.timedelta64("NaT"), pd.NaT, pd.NA]
    )
    def test_insert_nat(self, null):
        # GH 18295 (test missing)
        idx = timedelta_range("1day", "3day")
        result = idx.insert(1, null)
        expected = TimedeltaIndex(["1day", pd.NaT, "2day", "3day"])
        tm.assert_index_equal(result, expected)

    def test_insert_invalid_na(self):
        idx = TimedeltaIndex(["4day", "1day", "2day"], name="idx")
        with pytest.raises(TypeError, match="incompatible label"):
            idx.insert(0, np.datetime64("NaT"))

    def test_insert_dont_cast_strings(self):
        # To match DatetimeIndex and PeriodIndex behavior, dont try to
        #  parse strings to Timedelta
        idx = timedelta_range("1day", "3day")

        result = idx.insert(0, "1 Day")
        assert result.dtype == object
        assert result[0] == "1 Day"

    def test_delete(self):
        idx = timedelta_range(start="1 Days", periods=5, freq="D", name="idx")

        # preserve freq
        expected_0 = timedelta_range(start="2 Days", periods=4, freq="D", name="idx")
        expected_4 = timedelta_range(start="1 Days", periods=4, freq="D", name="idx")

        # reset freq to None
        expected_1 = TimedeltaIndex(
            ["1 day", "3 day", "4 day", "5 day"], freq=None, name="idx"
        )

        cases = {
            0: expected_0,
            -5: expected_0,
            -1: expected_4,
            4: expected_4,
            1: expected_1,
        }
        for n, expected in cases.items():
            result = idx.delete(n)
            tm.assert_index_equal(result, expected)
            assert result.name == expected.name
            assert result.freq == expected.freq

        with pytest.raises((IndexError, ValueError)):
            # either depending on numpy version
            idx.delete(5)

    def test_delete_slice(self):
        idx = timedelta_range(start="1 days", periods=10, freq="D", name="idx")

        # preserve freq
        expected_0_2 = timedelta_range(start="4 days", periods=7, freq="D", name="idx")
        expected_7_9 = timedelta_range(start="1 days", periods=7, freq="D", name="idx")

        # reset freq to None
        expected_3_5 = TimedeltaIndex(
            ["1 d", "2 d", "3 d", "7 d", "8 d", "9 d", "10d"], freq=None, name="idx"
        )

        cases = {
            (0, 1, 2): expected_0_2,
            (7, 8, 9): expected_7_9,
            (3, 4, 5): expected_3_5,
        }
        for n, expected in cases.items():
            result = idx.delete(n)
            tm.assert_index_equal(result, expected)
            assert result.name == expected.name
            assert result.freq == expected.freq

            result = idx.delete(slice(n[0], n[-1] + 1))
            tm.assert_index_equal(result, expected)
            assert result.name == expected.name
            assert result.freq == expected.freq

    def test_get_loc(self):
        idx = pd.to_timedelta(["0 days", "1 days", "2 days"])

        for method in [None, "pad", "backfill", "nearest"]:
            assert idx.get_loc(idx[1], method) == 1
            assert idx.get_loc(idx[1].to_pytimedelta(), method) == 1
            assert idx.get_loc(str(idx[1]), method) == 1

        assert idx.get_loc(idx[1], "pad", tolerance=Timedelta(0)) == 1
        assert idx.get_loc(idx[1], "pad", tolerance=np.timedelta64(0, "s")) == 1
        assert idx.get_loc(idx[1], "pad", tolerance=timedelta(0)) == 1

        with pytest.raises(ValueError, match="unit abbreviation w/o a number"):
            idx.get_loc(idx[1], method="nearest", tolerance="foo")

        with pytest.raises(ValueError, match="tolerance size must match"):
            idx.get_loc(
                idx[1],
                method="nearest",
                tolerance=[
                    Timedelta(0).to_timedelta64(),
                    Timedelta(0).to_timedelta64(),
                ],
            )

        for method, loc in [("pad", 1), ("backfill", 2), ("nearest", 1)]:
            assert idx.get_loc("1 day 1 hour", method) == loc

        # GH 16909
        assert idx.get_loc(idx[1].to_timedelta64()) == 1

        # GH 16896
        assert idx.get_loc("0 days") == 0

    def test_get_loc_nat(self):
        tidx = TimedeltaIndex(["1 days 01:00:00", "NaT", "2 days 01:00:00"])

        assert tidx.get_loc(pd.NaT) == 1
        assert tidx.get_loc(None) == 1
        assert tidx.get_loc(float("nan")) == 1
        assert tidx.get_loc(np.nan) == 1

    def test_get_indexer(self):
        idx = pd.to_timedelta(["0 days", "1 days", "2 days"])
        tm.assert_numpy_array_equal(
            idx.get_indexer(idx), np.array([0, 1, 2], dtype=np.intp)
        )

        target = pd.to_timedelta(["-1 hour", "12 hours", "1 day 1 hour"])
        tm.assert_numpy_array_equal(
            idx.get_indexer(target, "pad"), np.array([-1, 0, 1], dtype=np.intp)
        )
        tm.assert_numpy_array_equal(
            idx.get_indexer(target, "backfill"), np.array([0, 1, 2], dtype=np.intp)
        )
        tm.assert_numpy_array_equal(
            idx.get_indexer(target, "nearest"), np.array([0, 1, 1], dtype=np.intp)
        )

        res = idx.get_indexer(target, "nearest", tolerance=Timedelta("1 hour"))
        tm.assert_numpy_array_equal(res, np.array([0, -1, 1], dtype=np.intp))