# -*- coding: utf-8 -*-

# Copyright (c) 2012 Santiago Lezica
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of this
# software and associated documentation files (the "Software"), to deal in the Software
# without restriction, including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software, and to permit
# persons to whom the Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all copies or
# substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
# PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
# FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.

# source: https://raw.githubusercontent.com/slezica/python-frozendict/c5d16bafcca7b72ff3e8f40d3a9081e4c9233f1b/frozendict/__init__.py
# version: 1.2
# date: 2018-06-29

try:
    from collections.abc import Mapping
except ImportError:
    from collections import Mapping

try:
    from collections import OrderedDict
except ImportError:  # python < 2.7
    OrderedDict = NotImplemented


iteritems = getattr(dict, 'iteritems', dict.items) # py2-3 compatibility


class frozendict(Mapping):
    """
    An immutable wrapper around dictionaries that implements the complete :py:class:`collections.Mapping`
    interface. It can be used as a drop-in replacement for dictionaries where immutability is desired.
    """

    dict_cls = dict

    def __init__(self, *args, **kwargs):
        self._dict = self.dict_cls(*args, **kwargs)
        self._hash = None

    def __getitem__(self, key):
        return self._dict[key]

    def __contains__(self, key):
        return key in self._dict

    def copy(self, **add_or_replace):
        return self.__class__(self, **add_or_replace)

    def __iter__(self):
        return iter(self._dict)

    def __len__(self):
        return len(self._dict)

    def __repr__(self):
        return '<%s %r>' % (self.__class__.__name__, self._dict)

    def __hash__(self):
        if self._hash is None:
            h = 0
            for key, value in iteritems(self._dict):
                h ^= hash((key, value))
            self._hash = h
        return self._hash

    def __json__(self):
        # Works with auxlib's EntityEncoder.
        return self._dict


class FrozenOrderedDict(frozendict):
    """
    A frozendict subclass that maintains key order
    """

    dict_cls = OrderedDict


if OrderedDict is NotImplemented:
    del FrozenOrderedDict