// Copyright 2022 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 = "proto3";

package pandora;

import "google/protobuf/empty.proto";

option java_outer_classname = "HostProto";

// Service to trigger Bluetooth Host procedures
//
// Requirements for the implementer:
// At startup, the Host must be in BR/EDR connectable mode
// (see GAP connectability modes)
service Host {
  // Reset the host.
  // **After** responding to this command, the GRPC server should loose
  // all its state.
  // This is comparable to a process restart or an hardware reset.
  // The GRPC server might take some time to be available after
  // this command.
  rpc Reset(google.protobuf.Empty) returns (google.protobuf.Empty);
  // Create an ACL BR/EDR connection to a peer.
  // This should send a CreateConnection on the HCI level.
  // If the two devices have not established a previous bond,
  // the peer must be discoverable.
  rpc Connect(ConnectRequest) returns (ConnectResponse);
  // Get an active ACL BR/EDR connection to a peer.
  rpc GetConnection(GetConnectionRequest) returns (GetConnectionResponse);
  // Wait for an ACL BR/EDR connection from a peer.
  rpc WaitConnection(WaitConnectionRequest) returns (WaitConnectionResponse);
  // Disconnect an ACL BR/EDR connection. The Connection must not be reused
  // afterwards.
  rpc Disconnect(DisconnectRequest) returns (DisconnectResponse);
  // Read the local Bluetooth device address.
  // This should return the same value as a Read BD_ADDR HCI command.
  rpc ReadLocalAddress(google.protobuf.Empty)
      returns (ReadLocalAddressResponse);
}

// A Token representing an ACL connection.
// It's acquired via a Connect on the Host service.
message Connection {
  // Opaque value filled by the GRPC server, must not
  // be modified nor crafted.
  bytes cookie = 1;
}

// Request of the `Connect` method.
message ConnectRequest {
  // Peer Bluetooth Device Address as array of 6 bytes.
  bytes address = 1;
}

// Response of the `Connect` method.
message ConnectResponse {
  // Result of the `Connect` call:
  // - If successful: a Connection
  oneof result {
    Connection connection = 1;
  }
}

// Request of the `GetConnection` method.
message GetConnectionRequest {
  // Peer Bluetooth Device Address as array of 6 bytes.
  bytes address = 1;
}

// Response of the `GetConnection` method.
message GetConnectionResponse {
  // Result of the `GetConnection` call:
  // - If successful: a Connection
  oneof result {
    Connection connection = 1;
  }
}

// Request of the `WaitConnection` method.
message WaitConnectionRequest {
  // Peer Bluetooth Device Address as array of 6 bytes.
  bytes address = 1;
}

// Response of the `WaitConnection` method.
message WaitConnectionResponse {
  // Result of the `WaitConnection` call:
  // - If successful: a Connection
  oneof result {
    Connection connection = 1;
  }
}

// Request of the `Disconnect` method.
message DisconnectRequest {
  // Connection that should be disconnected.
  Connection connection = 1;
}

// Response of the `Disconnect` method.
message DisconnectResponse {}

// Response of the `ReadLocalAddress` method.
message ReadLocalAddressResponse {
  // Local Bluetooth Device Address as array of 6 bytes.
  bytes address = 1;
}