import pickle

import pytest
from distributed.protocol import deserialize, serialize

cupy = pytest.importorskip("cupy")
numpy = pytest.importorskip("numpy")


@pytest.mark.parametrize("shape", [(0,), (5,), (4, 6), (10, 11), (2, 3, 5)])
@pytest.mark.parametrize("dtype", ["u1", "u4", "u8", "f4"])
@pytest.mark.parametrize("order", ["C", "F"])
@pytest.mark.parametrize("serializers", [("cuda",), ("dask",), ("pickle",)])
def test_serialize_cupy(shape, dtype, order, serializers):
    x = cupy.arange(numpy.product(shape), dtype=dtype)
    x = cupy.ndarray(shape, dtype=x.dtype, memptr=x.data, order=order)
    header, frames = serialize(x, serializers=serializers)
    y = deserialize(header, frames, deserializers=serializers)

    if serializers[0] == "cuda":
        assert all(hasattr(f, "__cuda_array_interface__") for f in frames)
    elif serializers[0] == "dask":
        assert all(isinstance(f, memoryview) for f in frames)

    assert (x == y).all()


@pytest.mark.parametrize("dtype", ["u1", "u4", "u8", "f4"])
def test_serialize_cupy_from_numba(dtype):
    cuda = pytest.importorskip("numba.cuda")
    np = pytest.importorskip("numpy")

    if not cuda.is_available():
        pytest.skip("CUDA is not available")

    size = 10
    x_np = np.arange(size, dtype=dtype)
    x = cuda.to_device(x_np)
    header, frames = serialize(x, serializers=("cuda", "dask", "pickle"))
    header["type-serialized"] = pickle.dumps(cupy.ndarray)

    y = deserialize(header, frames, deserializers=("cuda", "dask", "pickle", "error"))

    assert (x_np == cupy.asnumpy(y)).all()


@pytest.mark.parametrize("size", [0, 3, 10])
def test_serialize_cupy_from_rmm(size):
    np = pytest.importorskip("numpy")
    rmm = pytest.importorskip("rmm")

    x_np = np.arange(size, dtype="u1")

    x_np_desc = x_np.__array_interface__
    (x_np_ptr, _) = x_np_desc["data"]
    (x_np_size,) = x_np_desc["shape"]
    x = rmm.DeviceBuffer(ptr=x_np_ptr, size=x_np_size)

    header, frames = serialize(x, serializers=("cuda", "dask", "pickle"))
    header["type-serialized"] = pickle.dumps(cupy.ndarray)

    y = deserialize(header, frames, deserializers=("cuda", "dask", "pickle", "error"))

    assert (x_np == cupy.asnumpy(y)).all()


@pytest.mark.parametrize(
    "sparse_name", ["coo_matrix", "csc_matrix", "csr_matrix", "dia_matrix"]
)
@pytest.mark.parametrize(
    "dtype",
    [numpy.dtype("<f4"), numpy.dtype(">f4"), numpy.dtype("<f8"), numpy.dtype(">f8")],
)
@pytest.mark.parametrize("serializer", ["cuda", "dask", "pickle"])
def test_serialize_cupy_sparse(sparse_name, dtype, serializer):
    scipy_sparse = pytest.importorskip("scipy.sparse")
    cupy_sparse = pytest.importorskip("cupyx.scipy.sparse")

    scipy_sparse_type = getattr(scipy_sparse, sparse_name)
    cupy_sparse_type = getattr(cupy_sparse, sparse_name)

    a_host = numpy.array([[0, 1, 0], [2, 0, 3], [0, 4, 0]], dtype=dtype)
    asp_host = scipy_sparse_type(a_host)
    if sparse_name == "dia_matrix":
        # CuPy `dia_matrix` cannot be created from SciPy one
        # xref: https://github.com/cupy/cupy/issues/3158
        asp_dev = cupy_sparse_type(
            (asp_host.data, asp_host.offsets),
            shape=asp_host.shape,
            dtype=asp_host.dtype,
        )
    else:
        asp_dev = cupy_sparse_type(asp_host)

    header, frames = serialize(asp_dev, serializers=[serializer])
    a2sp_dev = deserialize(header, frames)

    a2sp_host = a2sp_dev.get()
    a2_host = a2sp_host.todense()

    assert (a_host == a2_host).all()