# Copyright (C) 2019  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/>.


import copy
import json
import uuid


import requests


import ick2


class StoreInterface:  # pragma: no cover

    def create(self, token, obj):
        raise NotImplementedError()

    def update(self, token, rid, obj, revision):
        raise NotImplementedError()

    def show(self, token, rid):
        raise NotImplementedError()

    def delete(self, token, rid):
        raise NotImplementedError()

    def search(self, token, cond):
        raise NotImplementedError()


class MemoryStore(StoreInterface):

    def __init__(self):
        self._objs = {}

    def search(self, token, cond):
        return list(self._objs.keys())

    def _new_id(self):
        return str(uuid.uuid4())

    def _set(self, rid, rev, obj):
        self._objs[rid] = (rev, copy.deepcopy(obj))

    def create(self, token, obj):
        rid = self._new_id()
        rev = self._new_id()
        self._set(rid, rev, obj)
        return rid, rev

    def show(self, token, rid):
        if rid not in self._objs:
            raise ick2.NotFound('unknown.type', rid)
        rev, obj = self._objs[rid]
        return copy.deepcopy(obj), rev

    def update(self, token, rid, obj, revision):
        old_obj, old_rev = self.show(token, rid)
        if old_rev != revision:
            raise ick2.Conflict(rid, old_rev, revision)
        new_rev = self._new_id()
        self._set(rid, new_rev, obj)
        return new_rev

    def delete(self, token, rid):
        del self._objs[rid]


class MuckStore(StoreInterface):  # pragma: no cover

    def __init__(self, muck_url):
        self._url = muck_url
        ick2.log.log('info', msg_text='MuckStore created', muck_url=muck_url)

    def _request(self, func, path, token, headers=None, body=None):
        url = '{}{}'.format(self._url, path)
        if headers is None:
            headers = {}
        headers['Authorization'] = 'Bearer {}'.format(token)
        r = func(url, headers=headers, data=body)
        ick2.log.log(
            'trace', msg_text='Accessing Muck',
            func=repr(func), url=url, path=path, headers=headers, data=body,
            status=r.status_code, text=r.text)
        if not r.ok:
            raise ick2.StoreError(r.text)
        return r

    def search(self, token, cond):
        headers = {
            'Content-Type': 'application/json',
        }
        cond = {
            'cond': [
                {
                    'where': 'meta',
                    'field': 'id',
                    'op': '>=',
                    'pattern': '',
                }
            ],
        }
        body = json.dumps(cond)
        r = self._request(
            requests.get, '/search', token, headers=headers, body=body)
        obj = r.json()
        return obj['resources']

    def create(self, token, obj):
        headers = {
            'Content-Type': 'application/json',
        }
        body = json.dumps(obj)
        r = self._request(
            requests.post, '/res', token, headers=headers, body=body)
        rid = r.headers['Muck-Id']
        rev = r.headers['Muck-Revision']
        return rid, rev

    def show(self, token, rid):
        headers = {
            'Muck-Id': rid,
        }
        r = self._request(requests.get, '/res', token, headers=headers)
        rev = r.headers['Muck-Revision']
        as_dict = r.json()
        return as_dict, rev

    def update(self, token, rid, obj, revision):
        headers = {
            'Content-Type': 'application/json',
            'Muck-Id': rid,
            'Muck-Revision': revision,
        }
        body = json.dumps(obj)
        r = self._request(
            requests.put, '/res', token, headers=headers, body=body)
        rev = r.headers['Muck-Revision']
        return rev

    def delete(self, token, rid):
        headers = {
            'Muck-Id': rid,
        }
        self._request(requests.delete, '/res', token, headers=headers)