import py
import sys
from ctypes import *
from support import BaseCTypesTestChecker

class TestMemFunctions(BaseCTypesTestChecker):
    def test_memmove(self):
        # large buffers apparently increase the chance that the memory
        # is allocated in high address space.
        a = create_string_buffer(1000000)
        p = "Hello, World"
        result = memmove(a, p, len(p))
        assert a.value == "Hello, World"

        assert string_at(result) == "Hello, World"
        assert string_at(result, 5) == "Hello"
        assert string_at(result, 16) == "Hello, World\0\0\0\0"
        assert string_at(result, 0) == ""

    def test_memset(self):
        a = create_string_buffer(1000000)
        result = memset(a, ord('x'), 16)
        assert a.value == "xxxxxxxxxxxxxxxx"

        assert string_at(result) == "xxxxxxxxxxxxxxxx"
        assert string_at(a) == "xxxxxxxxxxxxxxxx"
        assert string_at(a, 20) == "xxxxxxxxxxxxxxxx\0\0\0\0"

    def test_cast(self):
        a = (c_ubyte * 32)(*map(ord, "abcdef"))
        assert cast(a, c_char_p).value == "abcdef"
        assert cast(a, POINTER(c_byte))[:7] == (
                             [97, 98, 99, 100, 101, 102, 0])

    def test_string_at(self):
        s = string_at("foo bar")
        # XXX The following may be wrong, depending on how Python
        # manages string instances
        #assert 2 == sys.getrefcount(s)
        assert s, "foo bar"

        assert string_at("foo bar", 8) == "foo bar\0"
        assert string_at("foo bar", 3) == "foo"

    try:
        create_unicode_buffer
    except NameError:
        pass
    else:
        def test_wstring_at(self):
            p = create_unicode_buffer("Hello, World")
            a = create_unicode_buffer(1000000)
            result = memmove(a, p, len(p) * sizeof(c_wchar))
            assert a.value == "Hello, World"

            assert wstring_at(a) == "Hello, World"
            assert wstring_at(a, 5) == "Hello"
            assert wstring_at(a, 16) == "Hello, World\0\0\0\0"
            assert wstring_at(a, 0) == ""