"""NetworkX ``GMLDataset`` loads and saves graphs to a graph modelling language (GML)
file using an underlying filesystem (e.g.: local, S3, GCS). NetworkX is used to
create GML data.
"""
import warnings
from copy import deepcopy
from pathlib import PurePosixPath
from typing import Any, Dict

import fsspec
import networkx
from kedro.io.core import Version, get_filepath_str, get_protocol_and_path

from kedro_datasets import KedroDeprecationWarning
from kedro_datasets._io import AbstractVersionedDataset


class GMLDataset(AbstractVersionedDataset[networkx.Graph, networkx.Graph]):
    """``GMLDataset`` loads and saves graphs to a GML file using an
    underlying filesystem (e.g.: local, S3, GCS). NetworkX is used to
    create GML data.
    See https://networkx.org/documentation/stable/tutorial.html for details.

    Example:

    .. code-block:: pycon

        >>> from kedro_datasets.networkx import GMLDataset
        >>> import networkx as nx
        >>> graph = nx.complete_graph(100)
        >>> graph_dataset = GMLDataset(filepath="test.gml")
        >>> graph_dataset.save(graph)
        >>> reloaded = graph_dataset.load()
        >>> assert nx.is_isomorphic(graph, reloaded)

    """

    DEFAULT_LOAD_ARGS: Dict[str, Any] = {}
    DEFAULT_SAVE_ARGS: Dict[str, Any] = {}

    def __init__(  # noqa: PLR0913
        self,
        filepath: str,
        load_args: Dict[str, Any] = None,
        save_args: Dict[str, Any] = None,
        version: Version = None,
        credentials: Dict[str, Any] = None,
        fs_args: Dict[str, Any] = None,
        metadata: Dict[str, Any] = None,
    ) -> None:
        """Creates a new instance of ``GMLDataset``.

        Args:
            filepath: Filepath in POSIX format to the NetworkX GML file.
            load_args: Arguments passed on to ``networkx.read_gml``.
                See the details in
                https://networkx.org/documentation/stable/reference/readwrite/generated/networkx.readwrite.gml.read_gml.html
            save_args: Arguments passed on to ``networkx.write_gml``.
                See the details in
                https://networkx.org/documentation/stable/reference/readwrite/generated/networkx.readwrite.gml.write_gml.html
            version: If specified, should be an instance of
                ``kedro.io.core.Version``. If its ``load`` attribute is
                None, the latest version will be loaded. If its ``save``
                attribute is None, save version will be autogenerated.
            credentials: Credentials required to get access to the underlying filesystem.
                E.g. for ``GCSFileSystem`` it should look like `{"token": None}`.
            fs_args: Extra arguments to pass into underlying filesystem class constructor
                (e.g. `{"project": "my-project"}` for ``GCSFileSystem``), as well as
                to pass to the filesystem's `open` method through nested keys
                `open_args_load` and `open_args_save`.
                Here you can find all available arguments for `open`:
                https://filesystem-spec.readthedocs.io/en/latest/api.html#fsspec.spec.AbstractFileSystem.open
                All defaults are preserved, except `mode`, which is set to `r` when loading
                and to `w` when saving.
            metadata: Any Any arbitrary metadata.
                This is ignored by Kedro, but may be consumed by users or external plugins.
        """
        _fs_args = deepcopy(fs_args) or {}
        _fs_open_args_load = _fs_args.pop("open_args_load", {})
        _fs_open_args_save = _fs_args.pop("open_args_save", {})
        _credentials = deepcopy(credentials) or {}

        protocol, path = get_protocol_and_path(filepath, version)
        if protocol == "file":
            _fs_args.setdefault("auto_mkdir", True)

        self._protocol = protocol
        self._fs = fsspec.filesystem(self._protocol, **_credentials, **_fs_args)

        self.metadata = metadata

        super().__init__(
            filepath=PurePosixPath(path),
            version=version,
            exists_function=self._fs.exists,
            glob_function=self._fs.glob,
        )

        # Handle default load and save arguments
        self._load_args = deepcopy(self.DEFAULT_LOAD_ARGS)
        if load_args is not None:
            self._load_args.update(load_args)
        self._save_args = deepcopy(self.DEFAULT_SAVE_ARGS)
        if save_args is not None:
            self._save_args.update(save_args)
        _fs_open_args_load.setdefault("mode", "rb")
        _fs_open_args_save.setdefault("mode", "wb")
        self._fs_open_args_load = _fs_open_args_load
        self._fs_open_args_save = _fs_open_args_save

    def _load(self) -> networkx.Graph:
        load_path = get_filepath_str(self._get_load_path(), self._protocol)
        with self._fs.open(load_path, **self._fs_open_args_load) as fs_file:
            data = networkx.read_gml(fs_file, **self._load_args)
        return data

    def _save(self, data: networkx.Graph) -> None:
        save_path = get_filepath_str(self._get_save_path(), self._protocol)
        with self._fs.open(save_path, **self._fs_open_args_save) as fs_file:
            networkx.write_gml(data, fs_file, **self._save_args)
        self._invalidate_cache()

    def _exists(self) -> bool:
        load_path = get_filepath_str(self._get_load_path(), self._protocol)
        return self._fs.exists(load_path)

    def _describe(self) -> Dict[str, Any]:
        return {
            "filepath": self._filepath,
            "protocol": self._protocol,
            "load_args": self._load_args,
            "save_args": self._save_args,
            "version": self._version,
        }

    def _release(self) -> None:
        super()._release()
        self._invalidate_cache()

    def _invalidate_cache(self) -> None:
        """Invalidate underlying filesystem caches."""
        filepath = get_filepath_str(self._filepath, self._protocol)
        self._fs.invalidate_cache(filepath)


_DEPRECATED_CLASSES = {
    "GMLDataSet": GMLDataset,
}


def __getattr__(name):
    if name in _DEPRECATED_CLASSES:
        alias = _DEPRECATED_CLASSES[name]
        warnings.warn(
            f"{repr(name)} has been renamed to {repr(alias.__name__)}, "
            f"and the alias will be removed in Kedro-Datasets 2.0.0",
            KedroDeprecationWarning,
            stacklevel=2,
        )
        return alias
    raise AttributeError(f"module {repr(__name__)} has no attribute {repr(name)}")
