// Copyright 2017 Google LLC. All Rights Reserved.
//
// 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 gnostic.extension.v1;

import "google/protobuf/any.proto";

// This option lets the proto compiler generate Java code inside the package
// name (see below) instead of inside an outer class. It creates a simpler
// developer experience by reducing one-level of name nesting and be
// consistent with most programming languages that don't support outer classes.
option java_multiple_files = true;

// The Java outer classname should be the filename in UpperCamelCase. This
// class is only used to hold proto descriptor, so developers don't need to
// work with it directly.
option java_outer_classname = "GnosticExtension";

// The Java package name must be proto package name with proper prefix.
option java_package = "org.gnostic.v1";

// A reasonable prefix for the Objective-C symbols generated from the package.
// It should at a minimum be 3 characters long, all uppercase, and convention
// is to use an abbreviation of the package name. Something short, but
// hopefully unique enough to not conflict with things that may come along in
// the future. 'GPB' is reserved for the protocol buffer implementation itself.
//
option objc_class_prefix = "GNX"; // "Gnostic Extension"

// The Go package name.
option go_package = "extensions;gnostic_extension_v1";

// The version number of Gnostic.
message Version {
  int32 major = 1;
  int32 minor = 2;
  int32 patch = 3;
  // A suffix for alpha, beta or rc release, e.g., "alpha-1", "rc2". It should
  // be empty for mainline stable releases.
  string suffix = 4;
}

// An encoded Request is written to the ExtensionHandler's stdin.
message ExtensionHandlerRequest {

  // The extension to process.
  Wrapper wrapper = 1;

  // The version number of Gnostic.
  Version compiler_version = 2;
}

// The extensions writes an encoded ExtensionHandlerResponse to stdout.
message ExtensionHandlerResponse {

  // true if the extension is handled by the extension handler; false otherwise
  bool handled = 1;

  // Error message(s).  If non-empty, the extension handling failed.
  // The extension handler process should exit with status code zero
  // even if it reports an error in this way.
  //
  // This should be used to indicate errors which prevent the extension from
  // operating as intended.  Errors which indicate a problem in gnostic
  // itself -- such as the input Document being unparseable -- should be
  // reported by writing a message to stderr and exiting with a non-zero
  // status code.
  repeated string errors = 2;

  // text output
  google.protobuf.Any value = 3;
}

message Wrapper {
  // version of the OpenAPI specification in which this extension was written.
  string version = 1;

  // Name of the extension.
  string extension_name = 2;

  // YAML-formatted extension value.
  string yaml = 3;
}