# Copyright (c) 2020-2021 by Fraunhofer Institute for Energy Economics
# and Energy System Technology (IEE), Kassel, and University of Kassel. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

import json
import os
import pickle
from functools import partial

from pandapower.io_utils import PPJSONEncoder, to_dict_with_coord_transform, \
    get_raw_data_from_pickle, transform_net_with_df_and_geo, PPJSONDecoder
from pandapower.io_utils import pp_hook, encrypt_string, decrypt_string

from pandapipes.io.convert_format import convert_format
from pandapipes.io.io_utils import isinstance_partial, FromSerializableRegistryPpipe
from pandapipes.pandapipes_net import pandapipesNet


def to_pickle(net, filename):
    """
    Saves a pandapipes Network with the pickle library.

    :param net: The pandapipes Network to save.
    :type net:  pandapipesNet
    :param filename: The absolute or relative path to the output file or a writable file-like object
    :type filename: str, file-object
    :return: No output.

    :Example:
        >>> pandapipes.to_pickle(net, os.path.join("C:", "example_folder", "example1.p"))  # absolute path
        >>> pandapipes.to_pickle(net, "example2.p")  # relative path

    """
    if hasattr(filename, 'write'):
        pickle.dump(dict(net), filename, protocol=2)
        return
    if not filename.endswith(".p"):
        raise Exception("Please use .p to save pandapipes networks!")
    save_net = to_dict_with_coord_transform(net, ["junction_geodata"], ["pipe_geodata"])

    with open(filename, "wb") as f:
        pickle.dump(save_net, f, protocol=2)  # use protocol 2 for py2 / py3 compatibility


def to_json(net, filename=None, encryption_key=None):
    """
    Saves a pandapipes Network in JSON format. The index columns of all pandas DataFrames will be
    saved in ascending order. net elements which name begins with "_" (internal elements) will not
    be saved. Std types will also not be saved.

    :param net: The pandapipes Network to save.
    :type net: pandapipesNet
    :param filename: The absolute or relative path to the output file or a writable file-like \
            object. If None, a JSON string is returned.
    :type filename: str, file-object, default None
    :param encryption_key: If given, the pandapipes network is stored as an encrypted json string
    :type encryption_key: str, default None
    :return: JSON string of the Network (only if filename is None)

    :Example:

        >>> pandapipes.to_json(net, "example.json")

    """
    json_string = json.dumps(net, cls=PPJSONEncoder, indent=2, isinstance_func=isinstance_partial)
    if encryption_key is not None:
        json_string = encrypt_string(json_string, encryption_key)
    if filename is None:
        return json_string
    if hasattr(filename, 'write'):
        filename.write(json_string)
    else:
        with open(filename, "w") as fp:
            fp.write(json_string)


def from_pickle(filename):
    """
    Load a pandapipes format Network from pickle file.

    :param filename: The absolute or relative path to the input file or file-like object
    :type filename: str, file-object
    :return: net - The pandapipes Network which was saved as pickle
    :rtype: pandapipesNet

    :Example:

        >>> net1 = pandapipes.from_pickle(os.path.join("C:", "example_folder", "example1.p"))
        >>> net2 = pandapipes.from_pickle("example2.p") #relative path

    """
    net = pandapipesNet(get_raw_data_from_pickle(filename))
    transform_net_with_df_and_geo(net, ["junction_geodata"], ["pipe_geodata"])
    return net


def from_json(filename, convert=True, encryption_key=None):
    """
    Load a pandapipes network from a JSON file or string.
    The index of the returned network is not necessarily in the same order as the original network.
    Index columns of all pandas DataFrames are sorted in ascending order.

    :param filename: The absolute or relative path to the input file or file-like object
    :type filename: str, file-object
    :param convert: whether or not to convert the format from earlier versions
    :type convert: bool
    :param encryption_key: if given, key to decrypt an encrypted pandapower network
    :type encryption_key: str
    :return: net - The pandapipes network that was saved as JSON
    :rtype: pandapipesNet

    :Example:

        >>> net = pandapipes.from_json("example.json")

    """
    if hasattr(filename, 'read'):
        json_string = filename.read()
    elif not os.path.isfile(filename):
        raise UserWarning("File {} does not exist!!".format(filename))
    else:
        with open(filename) as fp:
            json_string = fp.read()
    return from_json_string(json_string, convert=convert, encryption_key=encryption_key)


def from_json_string(json_string, convert=False, encryption_key=None):
    """
    Load a pandapipes network from a JSON string.
    The index of the returned network is not necessarily in the same order as the original network.
    Index columns of all pandas DataFrames are sorted in ascending order.

    :param json_string: The JSON string representation of the network
    :type json_string: str
    :param convert: whether or not to convert the format from earlier versions
    :type convert: bool
    :param encryption_key: if given, key to decrypt an encrypted pandapower network
    :type encryption_key: str
    :return: net - The pandapipes network that was contained in the JSON string
    :rtype: pandapipesNet

    :Example:

        >>> net = pandapipes.from_json_string(json_str)

    """
    if encryption_key is not None:
        json_string = decrypt_string(json_string, encryption_key)

    net = json.loads(json_string, cls=PPJSONDecoder, object_hook=partial(pp_hook,
                                                                         registry_class=FromSerializableRegistryPpipe))

    if convert:
        convert_format(net)
    return net
