import functools
import traceback

import pytest

h5py = pytest.importorskip("h5py")

from distributed.protocol import deserialize, serialize
from distributed.utils import tmpfile


def silence_h5py_issue775(func):
    @functools.wraps(func)
    def wrapper():
        try:
            func()
        except RuntimeError as e:
            # https://github.com/h5py/h5py/issues/775
            if str(e) != "dictionary changed size during iteration":
                raise
            tb = traceback.extract_tb(e.__traceback__)
            filename, lineno, _, _ = tb[-1]
            if not filename.endswith("h5py/_objects.pyx"):
                raise

    return wrapper


@silence_h5py_issue775
def test_serialize_deserialize_file():
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            f.create_dataset("/x", shape=(2, 2), dtype="i4")
        with h5py.File(fn, mode="r") as f:
            g = deserialize(*serialize(f))
            assert f.filename == g.filename
            assert isinstance(g, h5py.File)
            assert f.mode == g.mode

            assert g["x"].shape == (2, 2)


@silence_h5py_issue775
def test_serialize_deserialize_group():
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            f.create_dataset("/group1/group2/x", shape=(2, 2), dtype="i4")
        with h5py.File(fn, mode="r") as f:
            group = f["/group1/group2"]
            group2 = deserialize(*serialize(group))

            assert isinstance(group2, h5py.Group)
            assert group.file.filename == group2.file.filename

            assert group2["x"].shape == (2, 2)


@silence_h5py_issue775
def test_serialize_deserialize_dataset():
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            x = f.create_dataset("/group1/group2/x", shape=(2, 2), dtype="i4")
        with h5py.File(fn, mode="r") as f:
            x = f["group1/group2/x"]
            y = deserialize(*serialize(x))
            assert isinstance(y, h5py.Dataset)
            assert x.name == y.name
            assert x.file.filename == y.file.filename
            assert (x[:] == y[:]).all()


@silence_h5py_issue775
def test_raise_error_on_serialize_write_permissions():
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            x = f.create_dataset("/x", shape=(2, 2), dtype="i4")
            f.flush()
            with pytest.raises(TypeError):
                deserialize(*serialize(x))
            with pytest.raises(TypeError):
                deserialize(*serialize(f))


import dask.array as da

from distributed.utils_test import gen_cluster


@silence_h5py_issue775
@gen_cluster(client=True)
async def test_h5py_serialize(c, s, a, b):
    from dask.utils import SerializableLock

    lock = SerializableLock("hdf5")
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            x = f.create_dataset("/group/x", shape=(4,), dtype="i4", chunks=(2,))
            x[:] = [1, 2, 3, 4]
        with h5py.File(fn, mode="r") as f:
            dset = f["/group/x"]
            x = da.from_array(dset, chunks=dset.chunks, lock=lock)
            y = c.compute(x)
            y = await y
            assert (y[:] == dset[:]).all()


@gen_cluster(client=True)
async def test_h5py_serialize_2(c, s, a, b):
    with tmpfile() as fn:
        with h5py.File(fn, mode="a") as f:
            x = f.create_dataset("/group/x", shape=(12,), dtype="i4", chunks=(4,))
            x[:] = [1, 2, 3, 4] * 3
        with h5py.File(fn, mode="r") as f:
            dset = f["/group/x"]
            x = da.from_array(dset, chunks=(3,))
            y = c.compute(x.sum())
            y = await y
            assert y == (1 + 2 + 3 + 4) * 3
