# Copyright 2016-2017  Lars Wirzenius
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# =*= License: GPL-3+ =*=


import obnamlib


class LeafStoreInterface(object):  # pragma: no cover

    def put_leaf(self, leaf):
        raise NotImplementedError()

    def get_leaf(self, leaf_id):
        raise NotImplementedError()

    def remove_leaf(self, leaf_id):
        raise NotImplementedError()

    def flush(self):
        raise NotImplementedError()


class InMemoryLeafStore(LeafStoreInterface):

    def __init__(self):
        self._leaves = {}
        self._counter = 0

    def put_leaf(self, leaf):
        self._counter += 1
        self._leaves[self._counter] = leaf
        return self._counter

    def get_leaf(self, leaf_id):
        return self._leaves.get(leaf_id, None)

    def remove_leaf(self, leaf_id):
        if leaf_id in self._leaves:
            del self._leaves[leaf_id]

    def flush(self):
        pass


class LeafStore(LeafStoreInterface):  # pragma: no cover

    def __init__(self):
        self._blob_store = None

    def set_blob_store(self, blob_store):
        self._blob_store = blob_store

    def put_leaf(self, leaf):
        return self._blob_store.put_blob(leaf.as_dict())

    def get_leaf(self, leaf_id):
        leaf = obnamlib.CowLeaf()
        leaf.from_dict(self._blob_store.get_blob(leaf_id))
        return leaf

    def remove_leaf(self, leaf_id):
        # FIXME: This is a bit ugly, since we need to break the
        # bag/blob store abstraction.
        bag_id, _ = obnamlib.parse_object_id(leaf_id)
        self._blob_store._bag_store.remove_bag(bag_id)

    def flush(self):
        self._blob_store.flush()