import migraphx, struct, array, sys
try:
    from functools import reduce
except:
    pass


def assert_eq(x, y):
    if x == y:
        pass
    else:
        raise Exception(str(x) + " != " + str(y))


def read_float(b, index):
    return struct.unpack_from('f', b, index * 4)[0]


def write_float(b, index):
    struct.pack_into('f', b, index * 4)


def nelements(lens):
    return reduce(lambda x, y: x * y, lens, 1)


def create_buffer(t, data, shape):
    a = array.array(t, data)
    if sys.version_info >= (3, 0):
        m = memoryview(a.tobytes())
        return m.cast(t, shape)
    else:
        m = memoryview(a.tostring())
        return m


def check_argument(a):
    l = a.tolist()
    for i in range(len(l)):
        assert_eq(l[i], read_float(a, i))


def check_shapes(r, m):
    lens = list(m.shape)
    strides = [int(s / m.itemsize) for s in m.strides]
    elements = nelements(lens)
    assert_eq(r.get_shape().elements(), elements)
    assert_eq(r.get_shape().lens(), lens)
    assert_eq(r.get_shape().strides(), strides)


def run(p):
    params = {}
    for key, value in p.get_parameter_shapes().items():
        params[key] = migraphx.to_gpu(migraphx.generate_argument(value))

    return migraphx.from_gpu(p.run(params))


def test_shape(shape):
    data = list(range(nelements(shape)))
    m = create_buffer('f', data, shape)
    a = migraphx.argument(m)
    check_shapes(a, m)
    assert_eq(a.tolist(), data)


def test_input():
    if sys.version_info >= (3, 0):
        test_shape([4])
        test_shape([2, 3])
    else:
        data = list(range(4))
        m = create_buffer('f', data, [4])
        a1 = migraphx.argument(m)
        a2 = migraphx.argument(bytearray(a1))
        check_shapes(a2, m)
        assert_eq(a1.tolist(), m.tolist())


def test_output():
    p = migraphx.parse_onnx("conv_relu_maxpool_test.onnx")
    p.compile(migraphx.get_target("gpu"))

    r1 = run(p)
    r2 = run(p)
    assert_eq(r1, r2)
    assert_eq(r1.tolist(), r2.tolist())

    check_argument(r1)
    check_argument(r2)

    m1 = memoryview(r1)
    m2 = memoryview(r2)

    check_shapes(r1, m1)
    check_shapes(r2, m2)


test_input()
test_output()