"""
This file adds basic tests to test the NEP 50 style promotion compatibility
mode.  Most of these test are likely to be simply deleted again once NEP 50
is adopted in the main test suite.  A few may be moved elsewhere.
"""

import operator

import hypothesis
import pytest
from hypothesis import strategies

import numpy as np
from numpy.testing import IS_WASM, assert_array_equal


@pytest.mark.skipif(IS_WASM, reason="wasm doesn't have support for fp errors")
def test_nep50_examples():
    res = np.uint8(1) + 2
    assert res.dtype == np.uint8

    res = np.array([1], np.uint8) + np.int64(1)
    assert res.dtype == np.int64

    res = np.array([1], np.uint8) + np.array(1, dtype=np.int64)
    assert res.dtype == np.int64

    with pytest.warns(RuntimeWarning, match="overflow"):
        res = np.uint8(100) + 200
    assert res.dtype == np.uint8

    with pytest.warns(RuntimeWarning, match="overflow"):
        res = np.float32(1) + 3e100

    assert np.isinf(res)
    assert res.dtype == np.float32

    res = np.array([0.1], np.float32) == np.float64(0.1)
    assert res[0] == False

    res = np.array([0.1], np.float32) + np.float64(0.1)
    assert res.dtype == np.float64

    res = np.array([1.], np.float32) + np.int64(3)
    assert res.dtype == np.float64


@pytest.mark.parametrize("dtype", np.typecodes["AllInteger"])
def test_nep50_weak_integers(dtype):
    # Avoids warning (different code path for scalars)
    scalar_type = np.dtype(dtype).type

    maxint = int(np.iinfo(dtype).max)

    with np.errstate(over="warn"):
        with pytest.warns(RuntimeWarning):
            res = scalar_type(100) + maxint
    assert res.dtype == dtype

    # Array operations are not expected to warn, but should give the same
    # result dtype.
    res = np.array(100, dtype=dtype) + maxint
    assert res.dtype == dtype


@pytest.mark.parametrize("dtype", np.typecodes["AllFloat"])
def test_nep50_weak_integers_with_inexact(dtype):
    # Avoids warning (different code path for scalars)
    scalar_type = np.dtype(dtype).type

    too_big_int = int(np.finfo(dtype).max) * 2

    if dtype in "dDG":
        # These dtypes currently convert to Python float internally, which
        # raises an OverflowError, while the other dtypes overflow to inf.
        # NOTE: It may make sense to normalize the behavior!
        with pytest.raises(OverflowError):
            scalar_type(1) + too_big_int

        with pytest.raises(OverflowError):
            np.array(1, dtype=dtype) + too_big_int
    else:
        # NumPy uses (or used) `int -> string -> longdouble` for the
        # conversion.  But Python may refuse `str(int)` for huge ints.
        # In that case, RuntimeWarning would be correct, but conversion
        # fails earlier (seems to happen on 32bit linux, possibly only debug).
        if dtype in "gG":
            try:
                str(too_big_int)
            except ValueError:
                pytest.skip("`huge_int -> string -> longdouble` failed")

        # Otherwise, we overflow to infinity:
        with pytest.warns(RuntimeWarning):
            res = scalar_type(1) + too_big_int
        assert res.dtype == dtype
        assert res == np.inf

        with pytest.warns(RuntimeWarning):
            # We force the dtype here, since windows may otherwise pick the
            # double instead of the longdouble loop.  That leads to slightly
            # different results (conversion of the int fails as above).
            res = np.add(np.array(1, dtype=dtype), too_big_int, dtype=dtype)
        assert res.dtype == dtype
        assert res == np.inf


@pytest.mark.parametrize("op", [operator.add, operator.pow])
def test_weak_promotion_scalar_path(op):
    # Some additional paths exercising the weak scalars.

    # Integer path:
    res = op(np.uint8(3), 5)
    assert res == op(3, 5)
    assert res.dtype == np.uint8 or res.dtype == bool

    with pytest.raises(OverflowError):
        op(np.uint8(3), 1000)

    # Float path:
    res = op(np.float32(3), 5.)
    assert res == op(3., 5.)
    assert res.dtype == np.float32 or res.dtype == bool


def test_nep50_complex_promotion():
    with pytest.warns(RuntimeWarning, match=".*overflow"):
        res = np.complex64(3) + complex(2**300)

    assert type(res) is np.complex64


def test_nep50_integer_conversion_errors():
    # Implementation for error paths is mostly missing (as of writing)
    with pytest.raises(OverflowError, match=".*uint8"):
        np.array([1], np.uint8) + 300

    with pytest.raises(OverflowError, match=".*uint8"):
        np.uint8(1) + 300

    # Error message depends on platform (maybe unsigned int or unsigned long)
    with pytest.raises(OverflowError,
            match="Python integer -1 out of bounds for uint8"):
        np.uint8(1) + -1


def test_nep50_with_axisconcatenator():
    # Concatenate/r_ does not promote, so this has to error:
    with pytest.raises(OverflowError):
        np.r_[np.arange(5, dtype=np.int8), 255]


@pytest.mark.parametrize("ufunc", [np.add, np.power])
def test_nep50_huge_integers(ufunc):
    # Very large integers are complicated, because they go to uint64 or
    # object dtype.  This tests covers a few possible paths.
    with pytest.raises(OverflowError):
        ufunc(np.int64(0), 2**63)  # 2**63 too large for int64

    with pytest.raises(OverflowError):
        ufunc(np.uint64(0), 2**64)  # 2**64 cannot be represented by uint64

    # However, 2**63 can be represented by the uint64 (and that is used):
    res = ufunc(np.uint64(1), 2**63)

    assert res.dtype == np.uint64
    assert res == ufunc(1, 2**63, dtype=object)

    # The following paths fail to warn correctly about the change:
    with pytest.raises(OverflowError):
        ufunc(np.int64(1), 2**63)  # np.array(2**63) would go to uint

    with pytest.raises(OverflowError):
        ufunc(np.int64(1), 2**100)  # np.array(2**100) would go to object

    # This would go to object and thus a Python float, not a NumPy one:
    res = ufunc(1.0, 2**100)
    assert isinstance(res, np.float64)


def test_nep50_in_concat_and_choose():
    res = np.concatenate([np.float32(1), 1.], axis=None)
    assert res.dtype == "float32"

    res = np.choose(1, [np.float32(1), 1.])
    assert res.dtype == "float32"


@pytest.mark.parametrize("expected,dtypes,optional_dtypes", [
        (np.float32, [np.float32],
            [np.float16, 0.0, np.uint16, np.int16, np.int8, 0]),
        (np.complex64, [np.float32, 0j],
            [np.float16, 0.0, np.uint16, np.int16, np.int8, 0]),
        (np.float32, [np.int16, np.uint16, np.float16],
            [np.int8, np.uint8, np.float32, 0., 0]),
        (np.int32, [np.int16, np.uint16],
            [np.int8, np.uint8, 0, np.bool]),
        ])
@hypothesis.given(data=strategies.data())
def test_expected_promotion(expected, dtypes, optional_dtypes, data):
    # Sample randomly while ensuring "dtypes" is always present:
    optional = data.draw(strategies.lists(
            strategies.sampled_from(dtypes + optional_dtypes)))
    all_dtypes = dtypes + optional
    dtypes_sample = data.draw(strategies.permutations(all_dtypes))

    res = np.result_type(*dtypes_sample)
    assert res == expected


@pytest.mark.parametrize("sctype",
        [np.int8, np.int16, np.int32, np.int64,
         np.uint8, np.uint16, np.uint32, np.uint64])
@pytest.mark.parametrize("other_val",
        [-2 * 100, -1, 0, 9, 10, 11, 2**63, 2 * 100])
@pytest.mark.parametrize("comp",
        [operator.eq, operator.ne, operator.le, operator.lt,
         operator.ge, operator.gt])
def test_integer_comparison(sctype, other_val, comp):
    # Test that comparisons with integers (especially out-of-bound) ones
    # works correctly.
    val_obj = 10
    val = sctype(val_obj)
    # Check that the scalar behaves the same as the python int:
    assert comp(10, other_val) == comp(val, other_val)
    assert comp(val, other_val) == comp(10, other_val)
    # Except for the result type:
    assert type(comp(val, other_val)) is np.bool

    # Check that the integer array and object array behave the same:
    val_obj = np.array([10, 10], dtype=object)
    val = val_obj.astype(sctype)
    assert_array_equal(comp(val_obj, other_val), comp(val, other_val))
    assert_array_equal(comp(other_val, val_obj), comp(other_val, val))


@pytest.mark.parametrize("arr", [
    np.ones((100, 100), dtype=np.uint8)[::2],  # not trivially iterable
    np.ones(20000, dtype=">u4"),  # cast and >buffersize
    np.ones(100, dtype=">u4"),  # fast path compatible with cast
])
def test_integer_comparison_with_cast(arr):
    # Similar to above, but mainly test a few cases that cover the slow path
    # the test is limited to unsigned ints and -1 for simplicity.
    res = arr >= -1
    assert_array_equal(res, np.ones_like(arr, dtype=bool))
    res = arr < -1
    assert_array_equal(res, np.zeros_like(arr, dtype=bool))


@pytest.mark.parametrize("comp",
        [np.equal, np.not_equal, np.less_equal, np.less,
         np.greater_equal, np.greater])
def test_integer_integer_comparison(comp):
    # Test that the NumPy comparison ufuncs work with large Python integers
    assert comp(2**200, -2**200) == comp(2**200, -2**200, dtype=object)


def create_with_scalar(sctype, value):
    return sctype(value)


def create_with_array(sctype, value):
    return np.array([value], dtype=sctype)


@pytest.mark.parametrize("sctype",
        [np.int8, np.int16, np.int32, np.int64,
         np.uint8, np.uint16, np.uint32, np.uint64])
@pytest.mark.parametrize("create", [create_with_scalar, create_with_array])
def test_oob_creation(sctype, create):
    iinfo = np.iinfo(sctype)

    with pytest.raises(OverflowError):
        create(sctype, iinfo.min - 1)

    with pytest.raises(OverflowError):
        create(sctype, iinfo.max + 1)

    with pytest.raises(OverflowError):
        create(sctype, str(iinfo.min - 1))

    with pytest.raises(OverflowError):
        create(sctype, str(iinfo.max + 1))

    assert create(sctype, iinfo.min) == iinfo.min
    assert create(sctype, iinfo.max) == iinfo.max
