try:
    from ucollections import OrderedDict
    import uctypes
except ImportError:
    print("SKIP")
    raise SystemExit

desc = OrderedDict({
    # arr is array at offset 0, of UINT8 elements, array size is 2
    "arr": (uctypes.ARRAY | 0, uctypes.UINT8 | 2),
    # arr2 is array at offset 0, size 2, of structures defined recursively
    "arr2": (uctypes.ARRAY | 0, 2, {"b": uctypes.UINT8 | 0}),
    "arr3": (uctypes.ARRAY | 2, uctypes.UINT16 | 2),
    "arr4": (uctypes.ARRAY | 0, 2, {"b": uctypes.UINT8 | 0, "w": uctypes.UINT16 | 1}),
    "sub": (0, {
        'b1': uctypes.BFUINT8 | 0 | 4 << uctypes.BF_POS | 4 << uctypes.BF_LEN,
        'b2': uctypes.BFUINT8 | 0 | 0 << uctypes.BF_POS | 4 << uctypes.BF_LEN,
    }),
})

data = bytearray(b"01234567")

S = uctypes.struct(uctypes.addressof(data), desc, uctypes.LITTLE_ENDIAN)

print(uctypes.sizeof(S.arr))
assert uctypes.sizeof(S.arr) == 2

print(uctypes.sizeof(S.arr2))
assert uctypes.sizeof(S.arr2) == 2

print(uctypes.sizeof(S.arr3))

try:
    print(uctypes.sizeof(S.arr3[0]))
except TypeError:
    print("TypeError")

print(uctypes.sizeof(S.arr4))
assert uctypes.sizeof(S.arr4) == 6

print(uctypes.sizeof(S.sub))
assert uctypes.sizeof(S.sub) == 1

# invalid descriptor
try:
    print(uctypes.sizeof([]))
except TypeError:
    print("TypeError")
