# Copyright 2018 Alexandru Catrina
#
# 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.


class Storage(object):
    """Runtime temporary storage.

    Arguments:
        memory  (dict): Temporary memory key-value storage.
        last_key (str): Last key-name saved.
        history (list): Save history of each step and it's memory storage.
    """

    __memory = {}
    __last_key = ""
    __history = []

    @classmethod
    def add_key(cls, key, val):
        cls.__last_key = key
        cls.__memory.update({key: value})
        cls.__history.append((key, value))

    @classmethod
    def flush(cls):
        cls.__memory = {}
        cls.__last_key = ""
