# Copyright (C) 2018  Lars Wirzenius
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


class Change:

    def __init__(self, op, meta, res):
        self._dict = {
            'op': op,
            'meta': meta,
            'res': res,
        }

    def as_dict(self):
        return self._dict

    def get_op(self):
        return self._dict['op']

    def get_id(self):
        return self.get_meta()['id']

    def get_rev(self):
        return self.get_meta()['rev']

    def get_meta(self):
        return self._dict['meta']

    def get_res(self):
        return self._dict['res']


class CreateChange(Change):

    def __init__(self, meta=None, res=None):
        super().__init__(op='create', meta=meta, res=res)


class UpdateChange(Change):

    def __init__(self, meta=None, res=None):
        super().__init__(op='update', meta=meta, res=res)


class DeleteChange(Change):

    def __init__(self, meta=None, res=None):
        super().__init__(op='delete', meta=meta, res={})


def create_change_from_log_entry(entry):
    return Change(op=entry['op'], meta=entry['meta'], res=entry['res'])