# -*- coding: utf-8 -*-
# Copyright 2019 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import re

from twisted.internet import defer

from synapse.api.constants import EventTypes
from synapse.api.errors import SynapseError
from synapse.http.servlet import (
    RestServlet,
    assert_params_in_dict,
    parse_json_object_from_request,
)
from synapse.rest.admin import assert_requester_is_admin
from synapse.rest.client.transactions import HttpTransactionCache
from synapse.types import UserID


class SendServerNoticeServlet(RestServlet):
    """Servlet which will send a server notice to a given user

    POST /_synapse/admin/v1/send_server_notice
    {
        "user_id": "@target_user:server_name",
        "content": {
            "msgtype": "m.text",
            "body": "This is my message"
        }
    }

    returns:

    {
        "event_id": "$1895723857jgskldgujpious"
    }
    """

    def __init__(self, hs):
        """
        Args:
            hs (synapse.server.HomeServer): server
        """
        self.hs = hs
        self.auth = hs.get_auth()
        self.txns = HttpTransactionCache(hs)
        self.snm = hs.get_server_notices_manager()

    def register(self, json_resource):
        PATTERN = "^/_synapse/admin/v1/send_server_notice"
        json_resource.register_paths(
            "POST", (re.compile(PATTERN + "$"),), self.on_POST, self.__class__.__name__
        )
        json_resource.register_paths(
            "PUT",
            (re.compile(PATTERN + "/(?P<txn_id>[^/]*)$"),),
            self.on_PUT,
            self.__class__.__name__,
        )

    @defer.inlineCallbacks
    def on_POST(self, request, txn_id=None):
        yield assert_requester_is_admin(self.auth, request)
        body = parse_json_object_from_request(request)
        assert_params_in_dict(body, ("user_id", "content"))
        event_type = body.get("type", EventTypes.Message)
        state_key = body.get("state_key")

        if not self.snm.is_enabled():
            raise SynapseError(400, "Server notices are not enabled on this server")

        user_id = body["user_id"]
        UserID.from_string(user_id)
        if not self.hs.is_mine_id(user_id):
            raise SynapseError(400, "Server notices can only be sent to local users")

        event = yield self.snm.send_notice(
            user_id=body["user_id"],
            type=event_type,
            state_key=state_key,
            event_content=body["content"],
        )

        return 200, {"event_id": event.event_id}

    def on_PUT(self, request, txn_id):
        return self.txns.fetch_or_execute_request(
            request, self.on_POST, request, txn_id
        )
