// Copyright 2018 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
//
//      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.

syntax = "proto3";

package waterfall;

option java_package = "com.google.waterfall";
option java_outer_classname = "WaterfallProto";

import "google/protobuf/empty.proto";

message Message {
  bytes payload = 1;
}

// Keep this as lean as possible. We only care about the payload during most
// of the duration of the session. All other fields are only useful during
// the beginning/end of the transfer
message Transfer {
  // Remote path to for push/pull. Remote path lives in the server fs.
  // There is no need to send local path, since client has this info.
  string path = 1;

  // A stream of bytes. Encoded as a tarball.
  bytes payload = 2;

  // status fields.
  bool success = 3;
  bytes err = 4;
}

message Cmd {
  // Path to the binary to execute.
  // Path should be absolute. Otherwise behavior is not specified.
  // use /system/bin/sh -c to run in a shell.
  // Interactive shell is not supported.
  string path = 1;

  // Args to pass to the command
  repeated string args = 2;

  // Directory to execute the command
  string dir = 3;

  // Whether to pipe stdin to the command
  bool pipeIn = 4;

  // Environment to use
  map<string, string> env = 5;

}

message CmdProgress {

  // Command to execute. Only valid for the initial message of the stream.
  Cmd cmd = 5;

  // the exit code of the command.
  // Only populated when the gRPC stream is done.
  // I.e. the last message before the EOF.
  uint32 exit_code = 1;

  bytes stdout = 2;
  bytes stderr = 3;
  bytes stdin = 4;
}

message ForwardMessage {
  enum Kind {
    UNSET = 0;
    TCP = 1;
    UDP = 2;
    UNIX = 3;
  }

  enum Op {
    OPEN = 0;
    FWD = 1;
    CLOSE = 2;
  }

  // Kind of connection to start (tcp|udp|unix)
  Kind kind = 1;
  Op op = 2;

  // Address to open and redirect payload to.
  string addr = 3;
  // Data to be pushed to connection established on addr.
  bytes payload = 4;
  // Whether or not to rebind the port.
  bool rebind = 5;
}

message VersionMessage {
  string version = 1;
}

service Waterfall {
  // Echo exists solely for test purposes.
  rpc Echo(stream Message) returns (stream Message);

  // Push file/dir from host to device.
  rpc Push(stream Transfer) returns (Transfer);

  // Pull file/dir from device to host.
  rpc Pull(Transfer) returns (stream Transfer);

  // Exec executes cmd in the device and forward stdout and stderr to client
  // Exec expects a single initial CmdProgress message if stdin is not
  // being redirected. Otherwise Exec will read std from the stream.
  rpc Exec(stream CmdProgress) returns (stream CmdProgress);

  // Forward forwards the stream payload to the requested socket
  rpc Forward(stream ForwardMessage) returns (stream ForwardMessage);

  // Version gets the version of the server.
  rpc Version(google.protobuf.Empty) returns (VersionMessage);
}

message ForwardSession {
  string src = 1;
  string dst = 2;
}

message PortForwardRequest {
  bool rebind = 3;
  ForwardSession session = 4;
}

message ForwardedSessions {
  repeated ForwardSession sessions = 1;
}

// PortForwarder service runs a port forwarding session via waterfall.
// It allows start and stop forwarding connections when the waterfall client
// is unable to mantains any state (e.g. the waterfall adb binary).
service PortForwarder {
  rpc ForwardPort(PortForwardRequest) returns (google.protobuf.Empty);
  rpc Stop(PortForwardRequest) returns (google.protobuf.Empty);
  rpc StopAll(google.protobuf.Empty) returns (google.protobuf.Empty);
  rpc List(google.protobuf.Empty) returns (ForwardedSessions);
}