"""Module pygame.tests.test_utils.array

Export the Exporter and Importer classes.

Class Exporter has configurable shape and strides. Exporter objects
provide a convenient target for unit tests on Pygame objects and functions
that import a new buffer interface.

Class Importer imports a buffer interface with the given PyBUF_* flags.
It returns NULL Py_buffer fields as None. The shape, strides, and suboffsets
arrays are returned as tuples of ints. All Py_buffer field properties are
read-only. This class is useful in comparing exported buffer interfaces
with the actual request. The simular Python builtin memoryview currently
does not support configurable PyBUF_* flags.

This module contains its own unit tests. When Pygame is installed, these tests
can be run with the following command line statement:

python -m pygame.tests.test_utils.array

"""

import pygame

if not pygame.HAVE_NEWBUF:
    emsg = "This Pygame build does not support the new buffer protocol"
    raise ImportError(emsg)
import pygame.newbuffer
from pygame.newbuffer import (
    PyBUF_SIMPLE,
    PyBUF_FORMAT,
    PyBUF_ND,
    PyBUF_WRITABLE,
    PyBUF_STRIDES,
    PyBUF_C_CONTIGUOUS,
    PyBUF_F_CONTIGUOUS,
    PyBUF_ANY_CONTIGUOUS,
    PyBUF_INDIRECT,
    PyBUF_STRIDED,
    PyBUF_STRIDED_RO,
    PyBUF_RECORDS,
    PyBUF_RECORDS_RO,
    PyBUF_FULL,
    PyBUF_FULL_RO,
    PyBUF_CONTIG,
    PyBUF_CONTIG_RO,
)

import unittest
import ctypes
import operator
from functools import reduce

__all__ = ["Exporter", "Importer"]

try:
    ctypes.c_ssize_t
except AttributeError:
    void_p_sz = ctypes.sizeof(ctypes.c_void_p)
    if ctypes.sizeof(ctypes.c_short) == void_p_sz:
        ctypes.c_ssize_t = ctypes.c_short
    elif ctypes.sizeof(ctypes.c_int) == void_p_sz:
        ctypes.c_ssize_t = ctypes.c_int
    elif ctypes.sizeof(ctypes.c_long) == void_p_sz:
        ctypes.c_ssize_t = ctypes.c_long
    elif ctypes.sizeof(ctypes.c_longlong) == void_p_sz:
        ctypes.c_ssize_t = ctypes.c_longlong
    else:
        raise RuntimeError("Cannot set c_ssize_t: sizeof(void *) is %i" % void_p_sz)


def _prop_get(fn):
    return property(fn)


class Exporter(pygame.newbuffer.BufferMixin):
    """An object that exports a multi-dimension new buffer interface

    The only array operation this type supports is to export a buffer.
    """

    prefixes = {
        "@": "",
        "=": "=",
        "<": "=",
        ">": "=",
        "!": "=",
        "2": "2",
        "3": "3",
        "4": "4",
        "5": "5",
        "6": "6",
        "7": "7",
        "8": "8",
        "9": "9",
    }
    types = {
        "c": ctypes.c_char,
        "b": ctypes.c_byte,
        "B": ctypes.c_ubyte,
        "=c": ctypes.c_int8,
        "=b": ctypes.c_int8,
        "=B": ctypes.c_uint8,
        "?": ctypes.c_bool,
        "=?": ctypes.c_int8,
        "h": ctypes.c_short,
        "H": ctypes.c_ushort,
        "=h": ctypes.c_int16,
        "=H": ctypes.c_uint16,
        "i": ctypes.c_int,
        "I": ctypes.c_uint,
        "=i": ctypes.c_int32,
        "=I": ctypes.c_uint32,
        "l": ctypes.c_long,
        "L": ctypes.c_ulong,
        "=l": ctypes.c_int32,
        "=L": ctypes.c_uint32,
        "q": ctypes.c_longlong,
        "Q": ctypes.c_ulonglong,
        "=q": ctypes.c_int64,
        "=Q": ctypes.c_uint64,
        "f": ctypes.c_float,
        "d": ctypes.c_double,
        "P": ctypes.c_void_p,
        "x": ctypes.c_ubyte * 1,
        "2x": ctypes.c_ubyte * 2,
        "3x": ctypes.c_ubyte * 3,
        "4x": ctypes.c_ubyte * 4,
        "5x": ctypes.c_ubyte * 5,
        "6x": ctypes.c_ubyte * 6,
        "7x": ctypes.c_ubyte * 7,
        "8x": ctypes.c_ubyte * 8,
        "9x": ctypes.c_ubyte * 9,
    }

    def __init__(self, shape, format=None, strides=None, readonly=None, itemsize=None):
        if format is None:
            format = "B"
        if readonly is None:
            readonly = False
        prefix = ""
        typecode = ""
        i = 0
        if i < len(format):
            try:
                prefix = self.prefixes[format[i]]
                i += 1
            except LookupError:
                pass
        if i < len(format) and format[i] == "1":
            i += 1
        if i == len(format) - 1:
            typecode = format[i]
        if itemsize is None:
            try:
                itemsize = ctypes.sizeof(self.types[prefix + typecode])
            except KeyError:
                raise ValueError("Unknown item format '" + format + "'")
        self.readonly = bool(readonly)
        self.format = format
        self._format = ctypes.create_string_buffer(format.encode("latin_1"))
        self.ndim = len(shape)
        self.itemsize = itemsize
        self.len = reduce(operator.mul, shape, 1) * self.itemsize
        self.shape = tuple(shape)
        self._shape = (ctypes.c_ssize_t * self.ndim)(*self.shape)
        if strides is None:
            self._strides = (ctypes.c_ssize_t * self.ndim)()
            self._strides[self.ndim - 1] = itemsize
            for i in range(self.ndim - 1, 0, -1):
                self._strides[i - 1] = self.shape[i] * self._strides[i]
            self.strides = tuple(self._strides)
        elif len(strides) == self.ndim:
            self.strides = tuple(strides)
            self._strides = (ctypes.c_ssize_t * self.ndim)(*self.strides)
        else:
            raise ValueError("Mismatch in length of strides and shape")
        buflen = max(d * abs(s) for d, s in zip(self.shape, self.strides))
        self.buflen = buflen
        self._buf = (ctypes.c_ubyte * buflen)()
        offset = sum(
            (d - 1) * abs(s) for d, s in zip(self.shape, self.strides) if s < 0
        )
        self.buf = ctypes.addressof(self._buf) + offset

    def buffer_info(self):
        return (ctypes.addressof(self.buffer), self.shape[0])

    def tobytes(self):
        return ctypes.cast(self.buffer, ctypes.POINTER(ctypes.c_char))[0 : self._len]

    def __len__(self):
        return self.shape[0]

    def _get_buffer(self, view, flags):
        from ctypes import addressof

        if (flags & PyBUF_WRITABLE) == PyBUF_WRITABLE and self.readonly:
            raise BufferError("buffer is read-only")
        if (
            flags & PyBUF_C_CONTIGUOUS
        ) == PyBUF_C_CONTIGUOUS and not self.is_contiguous("C"):
            raise BufferError("data is not C contiguous")
        if (
            flags & PyBUF_F_CONTIGUOUS
        ) == PyBUF_F_CONTIGUOUS and not self.is_contiguous("F"):
            raise BufferError("data is not F contiguous")
        if (
            flags & PyBUF_ANY_CONTIGUOUS
        ) == PyBUF_ANY_CONTIGUOUS and not self.is_contiguous("A"):
            raise BufferError("data is not contiguous")
        view.buf = self.buf
        view.readonly = self.readonly
        view.len = self.len
        if flags | PyBUF_WRITABLE == PyBUF_WRITABLE:
            view.ndim = 0
        else:
            view.ndim = self.ndim
        view.itemsize = self.itemsize
        if (flags & PyBUF_FORMAT) == PyBUF_FORMAT:
            view.format = addressof(self._format)
        else:
            view.format = None
        if (flags & PyBUF_ND) == PyBUF_ND:
            view.shape = addressof(self._shape)
        elif self.is_contiguous("C"):
            view.shape = None
        else:
            raise BufferError(f"shape required for {self.ndim} dimensional data")
        if (flags & PyBUF_STRIDES) == PyBUF_STRIDES:
            view.strides = ctypes.addressof(self._strides)
        elif view.shape is None or self.is_contiguous("C"):
            view.strides = None
        else:
            raise BufferError("strides required for none C contiguous data")
        view.suboffsets = None
        view.internal = None
        view.obj = self

    def is_contiguous(self, fortran):
        if fortran in "CA":
            if self.strides[-1] == self.itemsize:
                for i in range(self.ndim - 1, 0, -1):
                    if self.strides[i - 1] != self.shape[i] * self.strides[i]:
                        break
                else:
                    return True
        if fortran in "FA":
            if self.strides[0] == self.itemsize:
                for i in range(0, self.ndim - 1):
                    if self.strides[i + 1] != self.shape[i] * self.strides[i]:
                        break
                else:
                    return True
        return False


class Importer:
    """An object that imports a new buffer interface

    The fields of the Py_buffer C struct are exposed by identically
    named Importer read-only properties.
    """

    def __init__(self, obj, flags):
        self._view = pygame.newbuffer.Py_buffer()
        self._view.get_buffer(obj, flags)

    @property
    def obj(self):
        """return object or None for NULL field"""
        return self._view.obj

    @property
    def buf(self):
        """return int or None for NULL field"""
        return self._view.buf

    @property
    def len(self):
        """return int"""
        return self._view.len

    @property
    def readonly(self):
        """return bool"""
        return self._view.readonly

    @property
    def format(self):
        """return bytes or None for NULL field"""
        format_addr = self._view.format
        if format_addr is None:
            return None
        return ctypes.cast(format_addr, ctypes.c_char_p).value.decode("ascii")

    @property
    def itemsize(self):
        """return int"""
        return self._view.itemsize

    @property
    def ndim(self):
        """return int"""
        return self._view.ndim

    @property
    def shape(self):
        """return int tuple or None for NULL field"""
        return self._to_ssize_tuple(self._view.shape)

    @property
    def strides(self):
        """return int tuple or None for NULL field"""
        return self._to_ssize_tuple(self._view.strides)

    @property
    def suboffsets(self):
        """return int tuple or None for NULL field"""
        return self._to_ssize_tuple(self._view.suboffsets)

    @property
    def internal(self):
        """return int or None for NULL field"""
        return self._view.internal

    def _to_ssize_tuple(self, addr):
        from ctypes import cast, POINTER, c_ssize_t

        if addr is None:
            return None
        return tuple(cast(addr, POINTER(c_ssize_t))[0 : self._view.ndim])


class ExporterTest(unittest.TestCase):
    """Class Exporter unit tests"""

    def test_formats(self):
        char_sz = ctypes.sizeof(ctypes.c_char)
        short_sz = ctypes.sizeof(ctypes.c_short)
        int_sz = ctypes.sizeof(ctypes.c_int)
        long_sz = ctypes.sizeof(ctypes.c_long)
        longlong_sz = ctypes.sizeof(ctypes.c_longlong)
        float_sz = ctypes.sizeof(ctypes.c_float)
        double_sz = ctypes.sizeof(ctypes.c_double)
        voidp_sz = ctypes.sizeof(ctypes.c_void_p)
        bool_sz = ctypes.sizeof(ctypes.c_bool)

        self.check_args(0, (1,), "B", (1,), 1, 1, 1)
        self.check_args(1, (1,), "b", (1,), 1, 1, 1)
        self.check_args(1, (1,), "B", (1,), 1, 1, 1)
        self.check_args(1, (1,), "c", (char_sz,), char_sz, char_sz, char_sz)
        self.check_args(1, (1,), "h", (short_sz,), short_sz, short_sz, short_sz)
        self.check_args(1, (1,), "H", (short_sz,), short_sz, short_sz, short_sz)
        self.check_args(1, (1,), "i", (int_sz,), int_sz, int_sz, int_sz)
        self.check_args(1, (1,), "I", (int_sz,), int_sz, int_sz, int_sz)
        self.check_args(1, (1,), "l", (long_sz,), long_sz, long_sz, long_sz)
        self.check_args(1, (1,), "L", (long_sz,), long_sz, long_sz, long_sz)
        self.check_args(
            1, (1,), "q", (longlong_sz,), longlong_sz, longlong_sz, longlong_sz
        )
        self.check_args(
            1, (1,), "Q", (longlong_sz,), longlong_sz, longlong_sz, longlong_sz
        )
        self.check_args(1, (1,), "f", (float_sz,), float_sz, float_sz, float_sz)
        self.check_args(1, (1,), "d", (double_sz,), double_sz, double_sz, double_sz)
        self.check_args(1, (1,), "x", (1,), 1, 1, 1)
        self.check_args(1, (1,), "P", (voidp_sz,), voidp_sz, voidp_sz, voidp_sz)
        self.check_args(1, (1,), "?", (bool_sz,), bool_sz, bool_sz, bool_sz)
        self.check_args(1, (1,), "@b", (1,), 1, 1, 1)
        self.check_args(1, (1,), "@B", (1,), 1, 1, 1)
        self.check_args(1, (1,), "@c", (char_sz,), char_sz, char_sz, char_sz)
        self.check_args(1, (1,), "@h", (short_sz,), short_sz, short_sz, short_sz)
        self.check_args(1, (1,), "@H", (short_sz,), short_sz, short_sz, short_sz)
        self.check_args(1, (1,), "@i", (int_sz,), int_sz, int_sz, int_sz)
        self.check_args(1, (1,), "@I", (int_sz,), int_sz, int_sz, int_sz)
        self.check_args(1, (1,), "@l", (long_sz,), long_sz, long_sz, long_sz)
        self.check_args(1, (1,), "@L", (long_sz,), long_sz, long_sz, long_sz)
        self.check_args(
            1, (1,), "@q", (longlong_sz,), longlong_sz, longlong_sz, longlong_sz
        )
        self.check_args(
            1, (1,), "@Q", (longlong_sz,), longlong_sz, longlong_sz, longlong_sz
        )
        self.check_args(1, (1,), "@f", (float_sz,), float_sz, float_sz, float_sz)
        self.check_args(1, (1,), "@d", (double_sz,), double_sz, double_sz, double_sz)
        self.check_args(1, (1,), "@?", (bool_sz,), bool_sz, bool_sz, bool_sz)
        self.check_args(1, (1,), "=b", (1,), 1, 1, 1)
        self.check_args(1, (1,), "=B", (1,), 1, 1, 1)
        self.check_args(1, (1,), "=c", (1,), 1, 1, 1)
        self.check_args(1, (1,), "=h", (2,), 2, 2, 2)
        self.check_args(1, (1,), "=H", (2,), 2, 2, 2)
        self.check_args(1, (1,), "=i", (4,), 4, 4, 4)
        self.check_args(1, (1,), "=I", (4,), 4, 4, 4)
        self.check_args(1, (1,), "=l", (4,), 4, 4, 4)
        self.check_args(1, (1,), "=L", (4,), 4, 4, 4)
        self.check_args(1, (1,), "=q", (8,), 8, 8, 8)
        self.check_args(1, (1,), "=Q", (8,), 8, 8, 8)
        self.check_args(1, (1,), "=?", (1,), 1, 1, 1)
        self.check_args(1, (1,), "<h", (2,), 2, 2, 2)
        self.check_args(1, (1,), ">h", (2,), 2, 2, 2)
        self.check_args(1, (1,), "!h", (2,), 2, 2, 2)
        self.check_args(1, (1,), "<q", (8,), 8, 8, 8)
        self.check_args(1, (1,), ">q", (8,), 8, 8, 8)
        self.check_args(1, (1,), "!q", (8,), 8, 8, 8)
        self.check_args(1, (1,), "1x", (1,), 1, 1, 1)
        self.check_args(1, (1,), "2x", (2,), 2, 2, 2)
        self.check_args(1, (1,), "3x", (3,), 3, 3, 3)
        self.check_args(1, (1,), "4x", (4,), 4, 4, 4)
        self.check_args(1, (1,), "5x", (5,), 5, 5, 5)
        self.check_args(1, (1,), "6x", (6,), 6, 6, 6)
        self.check_args(1, (1,), "7x", (7,), 7, 7, 7)
        self.check_args(1, (1,), "8x", (8,), 8, 8, 8)
        self.check_args(1, (1,), "9x", (9,), 9, 9, 9)
        self.check_args(1, (1,), "1h", (2,), 2, 2, 2)
        self.check_args(1, (1,), "=1h", (2,), 2, 2, 2)
        self.assertRaises(ValueError, Exporter, (2, 1), "")
        self.assertRaises(ValueError, Exporter, (2, 1), "W")
        self.assertRaises(ValueError, Exporter, (2, 1), "^Q")
        self.assertRaises(ValueError, Exporter, (2, 1), "=W")
        self.assertRaises(ValueError, Exporter, (2, 1), "=f")
        self.assertRaises(ValueError, Exporter, (2, 1), "=d")
        self.assertRaises(ValueError, Exporter, (2, 1), "<f")
        self.assertRaises(ValueError, Exporter, (2, 1), "<d")
        self.assertRaises(ValueError, Exporter, (2, 1), ">f")
        self.assertRaises(ValueError, Exporter, (2, 1), ">d")
        self.assertRaises(ValueError, Exporter, (2, 1), "!f")
        self.assertRaises(ValueError, Exporter, (2, 1), "!d")
        self.assertRaises(ValueError, Exporter, (2, 1), "0x")
        self.assertRaises(ValueError, Exporter, (2, 1), "11x")
        self.assertRaises(ValueError, Exporter, (2, 1), "BB")

    def test_strides(self):
        self.check_args(1, (10,), "=h", (2,), 20, 20, 2)
        self.check_args(1, (5, 3), "=h", (6, 2), 30, 30, 2)
        self.check_args(1, (7, 3, 5), "=h", (30, 10, 2), 210, 210, 2)
        self.check_args(1, (13, 5, 11, 3), "=h", (330, 66, 6, 2), 4290, 4290, 2)
        self.check_args(3, (7, 3, 5), "=h", (2, 14, 42), 210, 210, 2)
        self.check_args(3, (7, 3, 5), "=h", (2, 16, 48), 210, 240, 2)
        self.check_args(3, (13, 5, 11, 3), "=h", (440, 88, 8, 2), 4290, 5720, 2)
        self.check_args(3, (7, 5), "3x", (15, 3), 105, 105, 3)
        self.check_args(3, (7, 5), "3x", (3, 21), 105, 105, 3)
        self.check_args(3, (7, 5), "3x", (3, 24), 105, 120, 3)

    def test_readonly(self):
        a = Exporter((2,), "h", readonly=True)
        self.assertTrue(a.readonly)
        b = Importer(a, PyBUF_STRIDED_RO)
        self.assertRaises(BufferError, Importer, a, PyBUF_STRIDED)
        b = Importer(a, PyBUF_STRIDED_RO)

    def test_is_contiguous(self):
        a = Exporter((10,), "=h")
        self.assertTrue(a.is_contiguous("C"))
        self.assertTrue(a.is_contiguous("F"))
        self.assertTrue(a.is_contiguous("A"))
        a = Exporter((10, 4), "=h")
        self.assertTrue(a.is_contiguous("C"))
        self.assertTrue(a.is_contiguous("A"))
        self.assertFalse(a.is_contiguous("F"))
        a = Exporter((13, 5, 11, 3), "=h", (330, 66, 6, 2))
        self.assertTrue(a.is_contiguous("C"))
        self.assertTrue(a.is_contiguous("A"))
        self.assertFalse(a.is_contiguous("F"))
        a = Exporter((10, 4), "=h", (2, 20))
        self.assertTrue(a.is_contiguous("F"))
        self.assertTrue(a.is_contiguous("A"))
        self.assertFalse(a.is_contiguous("C"))
        a = Exporter((13, 5, 11, 3), "=h", (2, 26, 130, 1430))
        self.assertTrue(a.is_contiguous("F"))
        self.assertTrue(a.is_contiguous("A"))
        self.assertFalse(a.is_contiguous("C"))
        a = Exporter((2, 11, 6, 4), "=h", (576, 48, 8, 2))
        self.assertFalse(a.is_contiguous("A"))
        a = Exporter((2, 11, 6, 4), "=h", (2, 4, 48, 288))
        self.assertFalse(a.is_contiguous("A"))
        a = Exporter((3, 2, 2), "=h", (16, 8, 4))
        self.assertFalse(a.is_contiguous("A"))
        a = Exporter((3, 2, 2), "=h", (4, 12, 24))
        self.assertFalse(a.is_contiguous("A"))

    def test_PyBUF_flags(self):
        a = Exporter((10, 2), "d")
        b = Importer(a, PyBUF_SIMPLE)
        self.assertTrue(b.obj is a)
        self.assertTrue(b.format is None)
        self.assertEqual(b.len, a.len)
        self.assertEqual(b.itemsize, a.itemsize)
        self.assertTrue(b.shape is None)
        self.assertTrue(b.strides is None)
        self.assertTrue(b.suboffsets is None)
        self.assertTrue(b.internal is None)
        self.assertFalse(b.readonly)
        b = Importer(a, PyBUF_WRITABLE)
        self.assertTrue(b.obj is a)
        self.assertTrue(b.format is None)
        self.assertEqual(b.len, a.len)
        self.assertEqual(b.itemsize, a.itemsize)
        self.assertTrue(b.shape is None)
        self.assertTrue(b.strides is None)
        self.assertTrue(b.suboffsets is None)
        self.assertTrue(b.internal is None)
        self.assertFalse(b.readonly)
        b = Importer(a, PyBUF_ND)
        self.assertTrue(b.obj is a)
        self.assertTrue(b.format is None)
        self.assertEqual(b.len, a.len)
        self.assertEqual(b.itemsize, a.itemsize)
        self.assertEqual(b.shape, a.shape)
        self.assertTrue(b.strides is None)
        self.assertTrue(b.suboffsets is None)
        self.assertTrue(b.internal is None)
        self.assertFalse(b.readonly)
        a = Exporter((5, 10), "=h", (24, 2))
        b = Importer(a, PyBUF_STRIDES)
        self.assertTrue(b.obj is a)
        self.assertTrue(b.format is None)
        self.assertEqual(b.len, a.len)
        self.assertEqual(b.itemsize, a.itemsize)
        self.assertEqual(b.shape, a.shape)
        self.assertEqual(b.strides, a.strides)
        self.assertTrue(b.suboffsets is None)
        self.assertTrue(b.internal is None)
        self.assertFalse(b.readonly)
        b = Importer(a, PyBUF_FULL)
        self.assertTrue(b.obj is a)
        self.assertEqual(b.format, "=h")
        self.assertEqual(b.len, a.len)
        self.assertEqual(b.itemsize, a.itemsize)
        self.assertEqual(b.shape, a.shape)
        self.assertEqual(b.strides, a.strides)
        self.assertTrue(b.suboffsets is None)
        self.assertTrue(b.internal is None)
        self.assertFalse(b.readonly)
        self.assertRaises(BufferError, Importer, a, PyBUF_SIMPLE)
        self.assertRaises(BufferError, Importer, a, PyBUF_WRITABLE)
        self.assertRaises(BufferError, Importer, a, PyBUF_ND)
        self.assertRaises(BufferError, Importer, a, PyBUF_C_CONTIGUOUS)
        self.assertRaises(BufferError, Importer, a, PyBUF_F_CONTIGUOUS)
        self.assertRaises(BufferError, Importer, a, PyBUF_ANY_CONTIGUOUS)
        self.assertRaises(BufferError, Importer, a, PyBUF_CONTIG)

    def test_negative_strides(self):
        self.check_args(3, (3, 5, 4), "B", (20, 4, -1), 60, 60, 1, 3)
        self.check_args(3, (3, 5, 3), "B", (20, 4, -1), 45, 60, 1, 2)
        self.check_args(3, (3, 5, 4), "B", (20, -4, 1), 60, 60, 1, 16)
        self.check_args(3, (3, 5, 4), "B", (-20, -4, -1), 60, 60, 1, 59)
        self.check_args(3, (3, 5, 3), "B", (-20, -4, -1), 45, 60, 1, 58)

    def test_attributes(self):
        a = Exporter((13, 5, 11, 3), "=h", (440, 88, 8, 2))
        self.assertEqual(a.ndim, 4)
        self.assertEqual(a.itemsize, 2)
        self.assertFalse(a.readonly)
        self.assertEqual(a.shape, (13, 5, 11, 3))
        self.assertEqual(a.format, "=h")
        self.assertEqual(a.strides, (440, 88, 8, 2))
        self.assertEqual(a.len, 4290)
        self.assertEqual(a.buflen, 5720)
        self.assertEqual(a.buf, ctypes.addressof(a._buf))
        a = Exporter((8,))
        self.assertEqual(a.ndim, 1)
        self.assertEqual(a.itemsize, 1)
        self.assertFalse(a.readonly)
        self.assertEqual(a.shape, (8,))
        self.assertEqual(a.format, "B")
        self.assertTrue(isinstance(a.strides, tuple))
        self.assertEqual(a.strides, (1,))
        self.assertEqual(a.len, 8)
        self.assertEqual(a.buflen, 8)
        a = Exporter([13, 5, 11, 3], "=h", [440, 88, 8, 2])
        self.assertTrue(isinstance(a.shape, tuple))
        self.assertTrue(isinstance(a.strides, tuple))
        self.assertEqual(a.shape, (13, 5, 11, 3))
        self.assertEqual(a.strides, (440, 88, 8, 2))

    def test_itemsize(self):
        exp = Exporter((4, 5), format="B", itemsize=8)
        imp = Importer(exp, PyBUF_RECORDS)
        self.assertEqual(imp.itemsize, 8)
        self.assertEqual(imp.format, "B")
        self.assertEqual(imp.strides, (40, 8))
        exp = Exporter((4, 5), format="weird", itemsize=5)
        imp = Importer(exp, PyBUF_RECORDS)
        self.assertEqual(imp.itemsize, 5)
        self.assertEqual(imp.format, "weird")
        self.assertEqual(imp.strides, (25, 5))

    def check_args(
        self, call_flags, shape, format, strides, length, bufsize, itemsize, offset=0
    ):
        format_arg = format if call_flags & 1 else None
        strides_arg = strides if call_flags & 2 else None
        a = Exporter(shape, format_arg, strides_arg)
        self.assertEqual(a.buflen, bufsize)
        self.assertEqual(a.buf, ctypes.addressof(a._buf) + offset)
        m = Importer(a, PyBUF_RECORDS_RO)
        self.assertEqual(m.buf, a.buf)
        self.assertEqual(m.len, length)
        self.assertEqual(m.format, format)
        self.assertEqual(m.itemsize, itemsize)
        self.assertEqual(m.shape, shape)
        self.assertEqual(m.strides, strides)


if __name__ == "__main__":
    unittest.main()