// Copyright 2016 Google Inc.
//
// 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 google.api;

import "google/api/annotations.proto";
import "google/api/metric.proto";

option java_multiple_files = true;
option java_outer_classname = "BillingProto";
option java_package = "com.google.api";


// Billing related configuration of the service.
//
// The following example shows how to configure metrics for billing:
//
//     metrics:
//     - name: library.googleapis.com/read_calls
//       metric_kind: DELTA
//       value_type: INT64
//     - name: library.googleapis.com/write_calls
//       metric_kind: DELTA
//       value_type: INT64
//     billing:
//       metrics:
//       - library.googleapis.com/read_calls
//       - library.googleapis.com/write_calls
//
// The next example shows how to enable billing status check and customize the
// check behavior. It makes sure billing status check is included in the `Check`
// method of [Service Control API](https://cloud.google.com/service-control/).
// In the example, "google.storage.Get" method can be served when the billing
// status is either `current` or `delinquent`, while "google.storage.Write"
// method can only be served when the billing status is `current`:
//
//     billing:
//       rules:
//       - selector: google.storage.Get
//         allowed_statuses:
//         - current
//         - delinquent
//       - selector: google.storage.Write
//         allowed_statuses: current
//
// Mostly services should only allow `current` status when serving requests.
// In addition, services can choose to allow both `current` and `delinquent`
// statuses when serving read-only requests to resources. If there's no
// matching selector for operation, no billing status check will be performed.
//
message Billing {
  // Names of the metrics to report to billing. Each name must
  // be defined in [Service.metrics][google.api.Service.metrics] section.
  repeated string metrics = 1;

  // A list of billing status rules for configuring billing status check.
  repeated BillingStatusRule rules = 5;
}

// Defines the billing status requirements for operations.
//
// When used with
// [Service Control API](https://cloud.google.com/service-control/), the
// following statuses are supported:
//
// - **current**: the associated billing account is up to date and capable of
//                paying for resource usages.
// - **delinquent**: the associated billing account has a correctable problem,
//                   such as late payment.
//
// Mostly services should only allow `current` status when serving requests.
// In addition, services can choose to allow both `current` and `delinquent`
// statuses when serving read-only requests to resources. If the list of
// allowed_statuses is empty, it means no billing requirement.
//
message BillingStatusRule {
  // Selects the operation names to which this rule applies.
  // Refer to [selector][google.api.DocumentationRule.selector] for syntax details.
  string selector = 1;

  // Allowed billing statuses. The billing status check passes if the actual
  // billing status matches any of the provided values here.
  repeated string allowed_statuses = 2;
}