import fractions
import operator
import os
import random
import sys
import struct
import time
import unittest

from test import support
from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
                               INVALID_UNDERSCORE_LITERALS)
from math import isinf, isnan, copysign, ldexp

INF = float("inf")
NAN = float("nan")

have_getformat = hasattr(float, "__getformat__")
requires_getformat = unittest.skipUnless(have_getformat,
                                         "requires __getformat__")
requires_setformat = unittest.skipUnless(hasattr(float, "__setformat__"),
                                         "requires __setformat__")

#locate file with float format test values
test_dir = os.path.dirname(__file__) or os.curdir
format_testfile = os.path.join(test_dir, 'formatfloat_testcases.txt')

class FloatSubclass(float):
    pass

class OtherFloatSubclass(float):
    pass

class GeneralFloatCases(unittest.TestCase):

    def test_float(self):
        self.assertEqual(float(3.14), 3.14)
        self.assertEqual(float(314), 314.0)
        self.assertEqual(float("  3.14  "), 3.14)
        self.assertRaises(ValueError, float, "  0x3.1  ")
        self.assertRaises(ValueError, float, "  -0x3.p-1  ")
        self.assertRaises(ValueError, float, "  +0x3.p-1  ")
        self.assertRaises(ValueError, float, "++3.14")
        self.assertRaises(ValueError, float, "+-3.14")
        self.assertRaises(ValueError, float, "-+3.14")
        self.assertRaises(ValueError, float, "--3.14")
        self.assertRaises(ValueError, float, ".nan")
        self.assertRaises(ValueError, float, "+.inf")
        self.assertRaises(ValueError, float, ".")
        self.assertRaises(ValueError, float, "-.")
        self.assertRaises(TypeError, float, {})
        self.assertRaisesRegex(TypeError, "not 'dict'", float, {})
        # Lone surrogate
        self.assertRaises(ValueError, float, '\uD8F0')
        # check that we don't accept alternate exponent markers
        self.assertRaises(ValueError, float, "-1.7d29")
        self.assertRaises(ValueError, float, "3D-14")
        self.assertEqual(float("  \u0663.\u0661\u0664  "), 3.14)
        self.assertEqual(float("\N{EM SPACE}3.14\N{EN SPACE}"), 3.14)
        # extra long strings should not be a problem
        float(b'.' + b'1'*1000)
        float('.' + '1'*1000)
        # Invalid unicode string
        # See bpo-34087
        self.assertRaises(ValueError, float, '\u3053\u3093\u306b\u3061\u306f')

    def test_underscores(self):
        for lit in VALID_UNDERSCORE_LITERALS:
            if not any(ch in lit for ch in 'jJxXoObB'):
                self.assertEqual(float(lit), eval(lit))
                self.assertEqual(float(lit), float(lit.replace('_', '')))
        for lit in INVALID_UNDERSCORE_LITERALS:
            if lit in ('0_7', '09_99'):  # octals are not recognized here
                continue
            if not any(ch in lit for ch in 'jJxXoObB'):
                self.assertRaises(ValueError, float, lit)
        # Additional test cases; nan and inf are never valid as literals,
        # only in the float() constructor, but we don't allow underscores
        # in or around them.
        self.assertRaises(ValueError, float, '_NaN')
        self.assertRaises(ValueError, float, 'Na_N')
        self.assertRaises(ValueError, float, 'IN_F')
        self.assertRaises(ValueError, float, '-_INF')
        self.assertRaises(ValueError, float, '-INF_')
        # Check that we handle bytes values correctly.
        self.assertRaises(ValueError, float, b'0_.\xff9')

    def test_non_numeric_input_types(self):
        # Test possible non-numeric types for the argument x, including
        # subclasses of the explicitly documented accepted types.
        class CustomStr(str): pass
        class CustomBytes(bytes): pass
        class CustomByteArray(bytearray): pass

        factories = [
            bytes,
            bytearray,
            lambda b: CustomStr(b.decode()),
            CustomBytes,
            CustomByteArray,
            memoryview,
        ]
        try:
            from array import array
        except ImportError:
            pass
        else:
            factories.append(lambda b: array('B', b))

        for f in factories:
            x = f(b" 3.14  ")
            with self.subTest(type(x)):
                self.assertEqual(float(x), 3.14)
                with self.assertRaisesRegex(ValueError, "could not convert"):
                    float(f(b'A' * 0x10))

    def test_float_memoryview(self):
        self.assertEqual(float(memoryview(b'12.3')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3\x00')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3 ')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3A')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.34')[1:4]), 2.3)

    def test_error_message(self):
        def check(s):
            with self.assertRaises(ValueError, msg='float(%r)' % (s,)) as cm:
                float(s)
            self.assertEqual(str(cm.exception),
                'could not convert string to float: %r' % (s,))

        check('\xbd')
        check('123\xbd')
        check('  123 456  ')
        check(b'  123 456  ')

        # non-ascii digits (error came from non-digit '!')
        check('\u0663\u0661\u0664!')
        # embedded NUL
        check('123\x00')
        check('123\x00 245')
        check('123\x00245')
        # byte string with embedded NUL
        check(b'123\x00')
        # non-UTF-8 byte string
        check(b'123\xa0')

    @support.run_with_locale('LC_NUMERIC', 'fr_FR', 'de_DE')
    def test_float_with_comma(self):
        # set locale to something that doesn't use '.' for the decimal point
        # float must not accept the locale specific decimal point but
        # it still has to accept the normal python syntax
        import locale
        if not locale.localeconv()['decimal_point'] == ',':
            self.skipTest('decimal_point is not ","')

        self.assertEqual(float("  3.14  "), 3.14)
        self.assertEqual(float("+3.14  "), 3.14)
        self.assertEqual(float("-3.14  "), -3.14)
        self.assertEqual(float(".14  "), .14)
        self.assertEqual(float("3.  "), 3.0)
        self.assertEqual(float("3.e3  "), 3000.0)
        self.assertEqual(float("3.2e3  "), 3200.0)
        self.assertEqual(float("2.5e-1  "), 0.25)
        self.assertEqual(float("5e-1"), 0.5)
        self.assertRaises(ValueError, float, "  3,14  ")
        self.assertRaises(ValueError, float, "  +3,14  ")
        self.assertRaises(ValueError, float, "  -3,14  ")
        self.assertRaises(ValueError, float, "  0x3.1  ")
        self.assertRaises(ValueError, float, "  -0x3.p-1  ")
        self.assertRaises(ValueError, float, "  +0x3.p-1  ")
        self.assertEqual(float("  25.e-1  "), 2.5)
        self.assertAlmostEqual(float("  .25e-1  "), .025)

    def test_floatconversion(self):
        # Make sure that calls to __float__() work properly
        class Foo1(object):
            def __float__(self):
                return 42.

        class Foo2(float):
            def __float__(self):
                return 42.

        class Foo3(float):
            def __new__(cls, value=0.):
                return float.__new__(cls, 2*value)

            def __float__(self):
                return self

        class Foo4(float):
            def __float__(self):
                return 42

        # Issue 5759: __float__ not called on str subclasses (though it is on
        # unicode subclasses).
        class FooStr(str):
            def __float__(self):
                return float(str(self)) + 1

        self.assertEqual(float(Foo1()), 42.)
        self.assertEqual(float(Foo2()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(float(Foo3(21)), 42.)
        self.assertRaises(TypeError, float, Foo4(42))
        self.assertEqual(float(FooStr('8')), 9.)

        class Foo5:
            def __float__(self):
                return ""
        self.assertRaises(TypeError, time.sleep, Foo5())

        # Issue #24731
        class F:
            def __float__(self):
                return OtherFloatSubclass(42.)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(float(F()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertIs(type(float(F())), float)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(FloatSubclass(F()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertIs(type(FloatSubclass(F())), FloatSubclass)

        class MyIndex:
            def __init__(self, value):
                self.value = value
            def __index__(self):
                return self.value

        self.assertEqual(float(MyIndex(42)), 42.0)
        self.assertRaises(OverflowError, float, MyIndex(2**2000))

        class MyInt:
            def __int__(self):
                return 42

        self.assertRaises(TypeError, float, MyInt())

    def test_keyword_args(self):
        with self.assertRaisesRegex(TypeError, 'keyword argument'):
            float(x='3.14')

    def test_is_integer(self):
        self.assertFalse((1.1).is_integer())
        self.assertTrue((1.).is_integer())
        self.assertFalse(float("nan").is_integer())
        self.assertFalse(float("inf").is_integer())

    def test_floatasratio(self):
        for f, ratio in [
                (0.875, (7, 8)),
                (-0.875, (-7, 8)),
                (0.0, (0, 1)),
                (11.5, (23, 2)),
            ]:
            self.assertEqual(f.as_integer_ratio(), ratio)

        for i in range(10000):
            f = random.random()
            f *= 10 ** random.randint(-100, 100)
            n, d = f.as_integer_ratio()
            self.assertEqual(float(n).__truediv__(d), f)

        R = fractions.Fraction
        self.assertEqual(R(0, 1),
                         R(*float(0.0).as_integer_ratio()))
        self.assertEqual(R(5, 2),
                         R(*float(2.5).as_integer_ratio()))
        self.assertEqual(R(1, 2),
                         R(*float(0.5).as_integer_ratio()))
        self.assertEqual(R(4728779608739021, 2251799813685248),
                         R(*float(2.1).as_integer_ratio()))
        self.assertEqual(R(-4728779608739021, 2251799813685248),
                         R(*float(-2.1).as_integer_ratio()))
        self.assertEqual(R(-2100, 1),
                         R(*float(-2100.0).as_integer_ratio()))

        self.assertRaises(OverflowError, float('inf').as_integer_ratio)
        self.assertRaises(OverflowError, float('-inf').as_integer_ratio)
        self.assertRaises(ValueError, float('nan').as_integer_ratio)

    def test_float_containment(self):
        floats = (INF, -INF, 0.0, 1.0, NAN)
        for f in floats:
            self.assertIn(f, [f])
            self.assertIn(f, (f,))
            self.assertIn(f, {f})
            self.assertIn(f, {f: None})
            self.assertEqual([f].count(f), 1, "[].count('%r') != 1" % f)
            self.assertIn(f, floats)

        for f in floats:
            # nonidentical containers, same type, same contents
            self.assertTrue([f] == [f], "[%r] != [%r]" % (f, f))
            self.assertTrue((f,) == (f,), "(%r,) != (%r,)" % (f, f))
            self.assertTrue({f} == {f}, "{%r} != {%r}" % (f, f))
            self.assertTrue({f : None} == {f: None}, "{%r : None} != "
                                                   "{%r : None}" % (f, f))

            # identical containers
            l, t, s, d = [f], (f,), {f}, {f: None}
            self.assertTrue(l == l, "[%r] not equal to itself" % f)
            self.assertTrue(t == t, "(%r,) not equal to itself" % f)
            self.assertTrue(s == s, "{%r} not equal to itself" % f)
            self.assertTrue(d == d, "{%r : None} not equal to itself" % f)

    def assertEqualAndEqualSign(self, a, b):
        # fail unless a == b and a and b have the same sign bit;
        # the only difference from assertEqual is that this test
        # distinguishes -0.0 and 0.0.
        self.assertEqual((a, copysign(1.0, a)), (b, copysign(1.0, b)))

    @support.requires_IEEE_754
    def test_float_mod(self):
        # Check behaviour of % operator for IEEE 754 special cases.
        # In particular, check signs of zeros.
        mod = operator.mod

        self.assertEqualAndEqualSign(mod(-1.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(-1e-100, 1.0), 1.0)
        self.assertEqualAndEqualSign(mod(-0.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(0.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(1e-100, 1.0), 1e-100)
        self.assertEqualAndEqualSign(mod(1.0, 1.0), 0.0)

        self.assertEqualAndEqualSign(mod(-1.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(-1e-100, -1.0), -1e-100)
        self.assertEqualAndEqualSign(mod(-0.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(0.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(1e-100, -1.0), -1.0)
        self.assertEqualAndEqualSign(mod(1.0, -1.0), -0.0)

    @support.requires_IEEE_754
    def test_float_pow(self):
        # test builtin pow and ** operator for IEEE 754 special cases.
        # Special cases taken from section F.9.4.4 of the C99 specification

        for pow_op in pow, operator.pow:
            # x**NAN is NAN for any x except 1
            self.assertTrue(isnan(pow_op(-INF, NAN)))
            self.assertTrue(isnan(pow_op(-2.0, NAN)))
            self.assertTrue(isnan(pow_op(-1.0, NAN)))
            self.assertTrue(isnan(pow_op(-0.5, NAN)))