import sys
from io import StringIO

import pytest

import numpy as np
from numpy._core.tests._locales import CommaDecimalPointLocale
from numpy.testing import IS_MUSL, assert_, assert_equal

_REF = {np.inf: 'inf', -np.inf: '-inf', np.nan: 'nan'}


@pytest.mark.parametrize('tp', [np.float32, np.double, np.longdouble])
def test_float_types(tp):
    """ Check formatting.

        This is only for the str function, and only for simple types.
        The precision of np.float32 and np.longdouble aren't the same as the
        python float precision.

    """
    for x in [0, 1, -1, 1e20]:
        assert_equal(str(tp(x)), str(float(x)),
                     err_msg=f'Failed str formatting for type {tp}')

    if tp(1e16).itemsize > 4:
        assert_equal(str(tp(1e16)), str(float('1e16')),
                     err_msg=f'Failed str formatting for type {tp}')
    else:
        ref = '1e+16'
        assert_equal(str(tp(1e16)), ref,
                     err_msg=f'Failed str formatting for type {tp}')


@pytest.mark.parametrize('tp', [np.float32, np.double, np.longdouble])
def test_nan_inf_float(tp):
    """ Check formatting of nan & inf.

        This is only for the str function, and only for simple types.
        The precision of np.float32 and np.longdouble aren't the same as the
        python float precision.

    """
    for x in [np.inf, -np.inf, np.nan]:
        assert_equal(str(tp(x)), _REF[x],
                     err_msg=f'Failed str formatting for type {tp}')


@pytest.mark.parametrize('tp', [np.complex64, np.cdouble, np.clongdouble])
def test_complex_types(tp):
    """Check formatting of complex types.

        This is only for the str function, and only for simple types.
        The precision of np.float32 and np.longdouble aren't the same as the
        python float precision.

    """
    for x in [0, 1, -1, 1e20]:
        assert_equal(str(tp(x)), str(complex(x)),
                     err_msg=f'Failed str formatting for type {tp}')
        assert_equal(str(tp(x * 1j)), str(complex(x * 1j)),
                     err_msg=f'Failed str formatting for type {tp}')
        assert_equal(str(tp(x + x * 1j)), str(complex(x + x * 1j)),
                     err_msg=f'Failed str formatting for type {tp}')

    if tp(1e16).itemsize > 8:
        assert_equal(str(tp(1e16)), str(complex(1e16)),
                     err_msg=f'Failed str formatting for type {tp}')
    else:
        ref = '(1e+16+0j)'
        assert_equal(str(tp(1e16)), ref,
                     err_msg=f'Failed str formatting for type {tp}')


@pytest.mark.parametrize('dtype', [np.complex64, np.cdouble, np.clongdouble])
def test_complex_inf_nan(dtype):
    """Check inf/nan formatting of complex types."""
    TESTS = {
        complex(np.inf, 0): "(inf+0j)",
        complex(0, np.inf): "infj",
        complex(-np.inf, 0): "(-inf+0j)",
        complex(0, -np.inf): "-infj",
        complex(np.inf, 1): "(inf+1j)",
        complex(1, np.inf): "(1+infj)",
        complex(-np.inf, 1): "(-inf+1j)",
        complex(1, -np.inf): "(1-infj)",
        complex(np.nan, 0): "(nan+0j)",
        complex(0, np.nan): "nanj",
        complex(-np.nan, 0): "(nan+0j)",
        complex(0, -np.nan): "nanj",
        complex(np.nan, 1): "(nan+1j)",
        complex(1, np.nan): "(1+nanj)",
        complex(-np.nan, 1): "(nan+1j)",
        complex(1, -np.nan): "(1+nanj)",
    }
    for c, s in TESTS.items():
        assert_equal(str(dtype(c)), s)


# print tests
def _test_redirected_print(x, tp, ref=None):
    file = StringIO()
    file_tp = StringIO()
    stdout = sys.stdout
    try:
        sys.stdout = file_tp
        print(tp(x))
        sys.stdout = file
        if ref:
            print(ref)
        else:
            print(x)
    finally:
        sys.stdout = stdout

    assert_equal(file.getvalue(), file_tp.getvalue(),
                 err_msg=f'print failed for type{tp}')


@pytest.mark.thread_unsafe(reason="sys.stdout not thread-safe")
@pytest.mark.parametrize('tp', [np.float32, np.double, np.longdouble])
def test_float_type_print(tp):
    """Check formatting when using print """
    for x in [0, 1, -1, 1e20]:
        _test_redirected_print(float(x), tp)

    for x in [np.inf, -np.inf, np.nan]:
        _test_redirected_print(float(x), tp, _REF[x])

    if tp(1e16).itemsize > 4:
        _test_redirected_print(1e16, tp)
    else:
        ref = '1e+16'
        _test_redirected_print(1e16, tp, ref)


@pytest.mark.thread_unsafe(reason="sys.stdout not thread-safe")
@pytest.mark.parametrize('tp', [np.complex64, np.cdouble, np.clongdouble])
def test_complex_type_print(tp):
    """Check formatting when using print """
    # We do not create complex with inf/nan directly because the feature is
    # missing in python < 2.6
    for x in [0, 1, -1, 1e20]:
        _test_redirected_print(complex(x), tp)

    if tp(1e16).itemsize > 8:
        _test_redirected_print(complex(1e16), tp)
    else:
        ref = '(1e+16+0j)'
        _test_redirected_print(complex(1e16), tp, ref)

    _test_redirected_print(complex(np.inf, 1), tp, '(inf+1j)')
    _test_redirected_print(complex(-np.inf, 1), tp, '(-inf+1j)')
    _test_redirected_print(complex(-np.nan, 1), tp, '(nan+1j)')


def test_scalar_format():
    """Test the str.format method with NumPy scalar types"""
    tests = [('{0}', True, np.bool),
            ('{0}', False, np.bool),
            ('{0:d}', 130, np.uint8),
            ('{0:d}', 50000, np.uint16),
            ('{0:d}', 3000000000, np.uint32),
            ('{0:d}', 15000000000000000000, np.uint64),
            ('{0:d}', -120, np.int8),
            ('{0:d}', -30000, np.int16),
            ('{0:d}', -2000000000, np.int32),
            ('{0:d}', -7000000000000000000, np.int64),
            ('{0:g}', 1.5, np.float16),
            ('{0:g}', 1.5, np.float32),
            ('{0:g}', 1.5, np.float64),
            ('{0:g}', 1.5, np.longdouble),
            ('{0:g}', 1.5 + 0.5j, np.complex64),
            ('{0:g}', 1.5 + 0.5j, np.complex128),
            ('{0:g}', 1.5 + 0.5j, np.clongdouble)]

    for (fmat, val, valtype) in tests:
        try:
            assert_equal(fmat.format(val), fmat.format(valtype(val)),
                    f"failed with val {val}, type {valtype}")
        except ValueError as e:
            assert_(False,
                    f"format raised exception (fmt='{fmat}', {val=}, "
                    f"type={valtype!r}, exc='{e}')")


#
# Locale tests: scalar types formatting should be independent of the locale
#

class TestCommaDecimalPointLocale(CommaDecimalPointLocale):

    def test_locale_single(self):
        assert_equal(str(np.float32(1.2)), str(1.2))

    def test_locale_double(self):
        assert_equal(str(np.double(1.2)), str(1.2))

    @pytest.mark.skipif(IS_MUSL,
                        reason="test flaky on musllinux")
    def test_locale_longdouble(self):
        assert_equal(str(np.longdouble('1.2')), str(1.2))
