// Copyright 2020 Google LLC
//
// 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
//
//     https://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.

syntax = "proto2";

package location.nearby.mediums;

option optimize_for = LITE_RUNTIME;
option java_outer_classname = "BleFramesProto";
option java_package = "com.google.location.nearby.mediums.proto";
option objc_class_prefix = "GNCM";

// This should map exactly to BleAdvertisement's socket versions.
// TODO(alexanderkang): Make BleAdvertisement reference this proto.
enum SocketVersion {
  UNKNOWN_SOCKET_VERSION = 0;
  V1 = 1;
  V2 = 2;
}

message SocketControlFrame {
  enum ControlFrameType {
    UNKNOWN_CONTROL_FRAME_TYPE = 0;
    INTRODUCTION = 1;
    DISCONNECTION = 2;
    PACKET_ACKNOWLEDGEMENT = 3;
  }

  optional ControlFrameType type = 1;

  // Exactly one of the following fields will be set.
  optional IntroductionFrame introduction = 2;
  optional DisconnectionFrame disconnection = 3;
  optional PacketAcknowledgementFrame packet_acknowledgement = 4;
}

message IntroductionFrame {
  optional bytes service_id_hash = 1;
  optional SocketVersion socket_version = 2;
  optional string service_id_hash_salt = 3;
}

message DisconnectionFrame {
  optional bytes service_id_hash = 1;
}

message PacketAcknowledgementFrame {
  optional bytes service_id_hash = 1;
  optional int32 received_size = 2;
}