/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

/*
 * Protocol Buffers describing the Expansion API, an api for expanding
 * transforms in a remote SDK.
 */

syntax = "proto3";

package org.apache.beam.model.expansion.v1;

option go_package = "jobmanagement_v1";
option java_package = "org.apache.beam.model.expansion.v1";
option java_outer_classname = "ExpansionApi";

import "beam_runner_api.proto";

message ExpansionRequest {
  // Set of components needed to interpret the transform, or which
  // may be useful for its expansion.  This includes the input
  // PCollections (if any) to the to-be-expanded transform, along
  // with their coders and windowing strategies.
  org.apache.beam.model.pipeline.v1.Components components = 1;

  // The actual PTransform to be expaneded according to its spec.
  // Its input should be set, but its subtransforms and outputs
  // should not be.
  org.apache.beam.model.pipeline.v1.PTransform transform = 2;

  // A namespace (prefix) to use for the id of any newly created
  // components.
  string namespace = 3;
}

message ExpansionResponse {
  // Set of components needed to execute the expanded transform,
  // including the (original) inputs, outputs, and subtransforms.
  org.apache.beam.model.pipeline.v1.Components components = 1;

  // The expanded transform itself, with references to its outputs
  // and subtransforms.
  org.apache.beam.model.pipeline.v1.PTransform transform = 2;

  // A set of requirements that must be appended to this pipeline's
  // requirements.
  repeated string requirements = 3;

  // (Optional) An string representation of any error encountered while
  // attempting to expand this transform.
  string error = 10;
}

// Job Service for constructing pipelines
service ExpansionService {
  rpc Expand (ExpansionRequest) returns (ExpansionResponse);
}
