from collections import abc
import array
import math
import operator
import unittest
import struct
import sys

from test import support

ISBIGENDIAN = sys.byteorder == "big"

integer_codes = 'b', 'B', 'h', 'H', 'i', 'I', 'l', 'L', 'q', 'Q', 'n', 'N'
byteorders = '', '@', '=', '<', '>', '!'

def iter_integer_formats(byteorders=byteorders):
    for code in integer_codes:
        for byteorder in byteorders:
            if (byteorder not in ('', '@') and code in ('n', 'N')):
                continue
            yield code, byteorder

def string_reverse(s):
    return s[::-1]

def bigendian_to_native(value):
    if ISBIGENDIAN:
        return value
    else:
        return string_reverse(value)

class StructTest(unittest.TestCase):
    def test_isbigendian(self):
        self.assertEqual((struct.pack('=i', 1)[0] == 0), ISBIGENDIAN)

    def test_consistence(self):
        self.assertRaises(struct.error, struct.calcsize, 'Z')

        sz = struct.calcsize('i')
        self.assertEqual(sz * 3, struct.calcsize('iii'))

        fmt = 'cbxxxxxxhhhhiillffd?'
        fmt3 = '3c3b18x12h6i6l6f3d3?'
        sz = struct.calcsize(fmt)
        sz3 = struct.calcsize(fmt3)
        self.assertEqual(sz * 3, sz3)

        self.assertRaises(struct.error, struct.pack, 'iii', 3)
        self.assertRaises(struct.error, struct.pack, 'i', 3, 3, 3)
        self.assertRaises((TypeError, struct.error), struct.pack, 'i', 'foo')
        self.assertRaises((TypeError, struct.error), struct.pack, 'P', 'foo')
        self.assertRaises(struct.error, struct.unpack, 'd', b'flap')
        s = struct.pack('ii', 1, 2)
        self.assertRaises(struct.error, struct.unpack, 'iii', s)
        self.assertRaises(struct.error, struct.unpack, 'i', s)

    def test_transitiveness(self):
        c = b'a'
        b = 1
        h = 255
        i = 65535
        l = 65536
        f = 3.1415
        d = 3.1415
        t = True

        for prefix in ('', '@', '<', '>', '=', '!'):
            for format in ('xcbhilfd?', 'xcBHILfd?'):
                format = prefix + format
                s = struct.pack(format, c, b, h, i, l, f, d, t)
                cp, bp, hp, ip, lp, fp, dp, tp = struct.unpack(format, s)
                self.assertEqual(cp, c)
                self.assertEqual(bp, b)
                self.assertEqual(hp, h)
                self.assertEqual(ip, i)
                self.assertEqual(lp, l)
                self.assertEqual(int(100 * fp), int(100 * f))
                self.assertEqual(int(100 * dp), int(100 * d))
                self.assertEqual(tp, t)

    def test_new_features(self):
        # Test some of the new features in detail
        # (format, argument, big-endian result, little-endian result, asymmetric)
        tests = [
            ('c', b'a', b'a', b'a', 0),
            ('xc', b'a', b'\0a', b'\0a', 0),
            ('cx', b'a', b'a\0', b'a\0', 0),
            ('s', b'a', b'a', b'a', 0),
            ('0s', b'helloworld', b'', b'', 1),
            ('1s', b'helloworld', b'h', b'h', 1),
            ('9s', b'helloworld', b'helloworl', b'helloworl', 1),
            ('10s', b'helloworld', b'helloworld', b'helloworld', 0),
            ('11s', b'helloworld', b'helloworld\0', b'helloworld\0', 1),
            ('20s', b'helloworld', b'helloworld'+10*b'\0', b'helloworld'+10*b'\0', 1),
            ('b', 7, b'\7', b'\7', 0),
            ('b', -7, b'\371', b'\371', 0),
            ('B', 7, b'\7', b'\7', 0),
            ('B', 249, b'\371', b'\371', 0),
            ('h', 700, b'\002\274', b'\274\002', 0),
            ('h', -700, b'\375D', b'D\375', 0),
            ('H', 700, b'\002\274', b'\274\002', 0),
            ('H', 0x10000-700, b'\375D', b'D\375', 0),
            ('i', 70000000, b'\004,\035\200', b'\200\035,\004', 0),
            ('i', -70000000, b'\373\323\342\200', b'\200\342\323\373', 0),
            ('I', 70000000, b'\004,\035\200', b'\200\035,\004', 0),
            ('I', 0x100000000-70000000, b'\373\323\342\200', b'\200\342\323\373', 0),
            ('l', 70000000, b'\004,\035\200', b'\200\035,\004', 0),
            ('l', -70000000, b'\373\323\342\200', b'\200\342\323\373', 0),
            ('L', 70000000, b'\004,\035\200', b'\200\035,\004', 0),
            ('L', 0x100000000-70000000, b'\373\323\342\200', b'\200\342\323\373', 0),
            ('f', 2.0, b'@\000\000\000', b'\000\000\000@', 0),
            ('d', 2.0, b'@\000\000\000\000\000\000\000',
                       b'\000\000\000\000\000\000\000@', 0),
            ('f', -2.0, b'\300\000\000\000', b'\000\000\000\300', 0),
            ('d', -2.0, b'\300\000\000\000\000\000\000\000',
                        b'\000\000\000\000\000\000\000\300', 0),
            ('?', 0, b'\0', b'\0', 0),
            ('?', 3, b'\1', b'\1', 1),
            ('?', True, b'\1', b'\1', 0),
            ('?', [], b'\0', b'\0', 1),
            ('?', (1,), b'\1', b'\1', 1),
        ]

        for fmt, arg, big, lil, asy in tests:
            for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil),
                                ('='+fmt, ISBIGENDIAN and big or lil)]:
                res = struct.pack(xfmt, arg)
                self.assertEqual(res, exp)
                self.assertEqual(struct.calcsize(xfmt), len(res))
                rev = struct.unpack(xfmt, res)[0]
                if rev != arg:
                    self.assertTrue(asy)

    def test_calcsize(self):
        expected_size = {
            'b': 1, 'B': 1,
            'h': 2, 'H': 2,
            'i': 4, 'I': 4,
            'l': 4, 'L': 4,
            'q': 8, 'Q': 8,
            }

        # standard integer sizes
        for code, byteorder in iter_integer_formats(('=', '<', '>', '!')):
            format = byteorder+code
            size = struct.calcsize(format)
            self.assertEqual(size, expected_size[code])

        # native integer sizes
        native_pairs = 'bB', 'hH', 'iI', 'lL', 'nN', 'qQ'
        for format_pair in native_pairs:
            for byteorder in '', '@':
                signed_size = struct.calcsize(byteorder + format_pair[0])
                unsigned_size = struct.calcsize(byteorder + format_pair[1])
                self.assertEqual(signed_size, unsigned_size)

        # bounds for native integer sizes
        self.assertEqual(struct.calcsize('b'), 1)
        self.assertLessEqual(2, struct.calcsize('h'))
        self.assertLessEqual(4, struct.calcsize('l'))
        self.assertLessEqual(struct.calcsize('h'), struct.calcsize('i'))
        self.assertLessEqual(struct.calcsize('i'), struct.calcsize('l'))
        self.assertLessEqual(8, struct.calcsize('q'))
        self.assertLessEqual(struct.calcsize('l'), struct.calcsize('q'))
        self.assertGreaterEqual(struct.calcsize('n'), struct.calcsize('i'))
        self.assertGreaterEqual(struct.calcsize('n'), struct.calcsize('P'))

    def test_integers(self):
        # Integer tests (bBhHiIlLqQnN).
        import binascii

        class IntTester(unittest.TestCase):
            def __init__(self, format):
                super(IntTester, self).__init__(methodName='test_one')
                self.format = format
                self.code = format[-1]
                self.byteorder = format[:-1]
                if not self.byteorder in byteorders:
                    raise ValueError("unrecognized packing byteorder: %s" %
                                     self.byteorder)
                self.bytesize = struct.calcsize(format)
                self.bitsize = self.bytesize * 8
                if self.code in tuple('bhilqn'):
                    self.signed = True
                    self.min_value = -(2**(self.bitsize-1))
                    self.max_value = 2**(self.bitsize-1) - 1
                elif self.code in tuple('BHILQN'):
                    self.signed = False
                    self.min_value = 0
                    self.max_value = 2**self.bitsize - 1
                else:
                    raise ValueError("unrecognized format code: %s" %
                                     self.code)

            def test_one(self, x, pack=struct.pack,
                                  unpack=struct.unpack,
                                  unhexlify=binascii.unhexlify):

                format = self.format
                if self.min_value <= x <= self.max_value:
                    expected = x
                    if self.signed and x < 0:
                        expected += 1 << self.bitsize
                    self.assertGreaterEqual(expected, 0)
                    expected = '%x' % expected
                    if len(expected) & 1:
                        expected = "0" + expected
                    expected = expected.encode('ascii')
                    expected = unhexlify(expected)
                    expected = (b"\x00" * (self.bytesize - len(expected)) +
                                expected)
                    if (self.byteorder == '<' or
                        self.byteorder in ('', '@', '=') and not ISBIGENDIAN):
                        expected = string_reverse(expected)
                    self.assertEqual(len(expected), self.bytesize)

                    # Pack work?
                    got = pack(format, x)
                    self.assertEqual(got, expected)

                    # Unpack work?
                    retrieved = unpack(format, got)[0]
                    self.assertEqual(x, retrieved)

                    # Adding any byte should cause a "too big" error.
                    self.assertRaises((struct.error, TypeError), unpack, format,
                                                                 b'\x01' + got)
                else:
                    # x is out of range -- verify pack realizes that.
                    self.assertRaises((OverflowError, ValueError, struct.error),
                                      pack, format, x)

            def run(self):
                from random import randrange

                # Create all interesting powers of 2.
                values = []
                for exp in range(self.bitsize + 3):
                    values.append(1 << exp)

                # Add some random values.
                for i in range(self.bitsize):
                    val = 0
                    for j in range(self.bytesize):
                        val = (val << 8) | randrange(256)
                    values.append(val)

                # Values absorbed from other tests
                values.extend([300, 700000, sys.maxsize*4])

                # Try all those, and their negations, and +-1 from
                # them.  Note that this tests all power-of-2
                # boundaries in range, and a few out of range, plus
                # +-(2**n +- 1).
                for base in values:
                    for val in -base, base:
                        for incr in -1, 0, 1:
                            x = val + incr
                            self.test_one(x)

                # Some error cases.
                class NotAnInt:
                    def __int__(self):
                        return 42

                # Objects with an '__index__' method should be allowed
                # to pack as integers.  That is assuming the implemented
                # '__index__' method returns an 'int'.
                class Indexable(object):
                    def __init__(self, value):
                        self._value = value

                    def __index__(self):
                        return self._value

                # If the '__index__' method raises a type error, then
                # '__int__' should be used with a deprecation warning.
                class BadIndex(object):
                    def __index__(self):
                        raise TypeError

                    def __int__(self):
                        return 42

                self.assertRaises((TypeError, struct.error),
                                  struct.pack, self.format,
                                  "a string")
                self.assertRaises((TypeError, struct.error),
                                  struct.pack, self.format,
                                  randrange)
                self.assertRaises((TypeError, struct.error),
                                  struct.pack, self.format,
                                  3+42j)
                self.assertRaises((TypeError, struct.error),
                                  struct.pack, self.format,
                                  NotAnInt())
                self.assertRaises((TypeError, struct.error),
                                  struct.pack, self.format,
                                  BadIndex())

                # Check for legitimate values from '__index__'.
                for obj in (Indexable(0), Indexable(10), Indexable(17),
                            Indexable(42), Indexable(100), Indexable(127)):
                    try:
                        struct.pack(format, obj)
                    except:
                        self.fail("integer code pack failed on object "
                                  "with '__index__' method")

                # Check for bogus values from '__index__'.
                for obj in (Indexable(b'a'), Indexable('b'), Indexable(None),
                            Indexable({'a': 1}), Indexable([1, 2, 3])):
                    self.assertRaises((TypeError, struct.error),
                                      struct.pack, self.format,
                                      obj)

        for code, byteorder in iter_integer_formats():
            format = byteorder+code
            t = IntTester(format)
            t.run()

    def test_nN_code(self):
        # n and N don't exist in standard sizes
        def assertStructError(func, *args, **kwargs):
            with self.assertRaises(struct.error) as cm:
                func(*args, **kwargs)
            self.assertIn("bad char in struct format", str(cm.exception))
        for code in 'nN':
            for byteorder in ('=', '<', '>', '!'):
                format = byteorder+code
                assertStructError(struct.calcsize, format)
                assertStructError(struct.pack, format, 0)
                assertStructError(struct.unpack, format, b"")

    def test_p_code(self):
        # Test p ("Pascal string") code.
        for code, input, expected, expectedback in [
                ('p',  b'abc', b'\x00',            b''),
                ('1p', b'abc', b'\x00',            b''),
                ('2p', b'abc', b'\x01a',           b'a'),
                ('3p', b'abc', b'\x02ab',          b'ab'),
                ('4p', b'abc', b'\x03abc',         b'abc'),
                ('5p', b'abc', b'\x03abc\x00',     b'abc'),
                ('6p', b'abc', b'\x03abc\x00\x00', b'abc'),
                ('1000p', b'x'*1000, b'\xff' + b'x'*999, b'x'*255)]: