// Copyright 2018-present MongoDB Inc.
//
// 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.

#pragma once

#include <bsoncxx/oid.hpp>
#include <mongocxx/events/topology_description.hpp>

#include <mongocxx/config/prelude.hpp>

namespace mongocxx {
MONGOCXX_INLINE_NAMESPACE_BEGIN

namespace events {

///
/// An event notification sent when the driver observes a change in any of the servers it is
/// connected to or a change in the overall server topology.
///
/// @see "TopologyDescriptionChangedEvent" in
/// https://github.com/mongodb/specifications/blob/master/source/server-discovery-and-monitoring/server-discovery-and-monitoring-monitoring.rst
///
class MONGOCXX_API topology_changed_event {
   public:
    MONGOCXX_PRIVATE explicit topology_changed_event(const void* event);

    ///
    /// Destroys a topology_changed_event.
    ///
    ~topology_changed_event();

    ///
    /// An opaque id, unique to this topology for this mongocxx::client or mongocxx::pool.
    ///
    /// @return The id.
    ///
    bsoncxx::oid topology_id() const;

    ///
    /// The server's description before it changed.
    ///
    /// @return The topology_description.
    ///
    topology_description previous_description() const;

    ///
    /// The server's description after it changed.
    ///
    /// @return The topology_description.
    ///
    topology_description new_description() const;

   private:
    const void* _event;
};

}  // namespace events
MONGOCXX_INLINE_NAMESPACE_END
}  // namespace mongocxx

#include <mongocxx/config/postlude.hpp>
