// 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
//
//     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.cloud.pubsublite.v1;

import "google/api/field_behavior.proto";
import "google/api/resource.proto";
import "google/protobuf/duration.proto";
import "google/protobuf/timestamp.proto";

option cc_enable_arenas = true;
option csharp_namespace = "Google.Cloud.PubSubLite.V1";
option go_package = "cloud.google.com/go/pubsublite/apiv1/pubsublitepb;pubsublitepb";
option java_multiple_files = true;
option java_outer_classname = "CommonProto";
option java_package = "com.google.cloud.pubsublite.proto";
option php_namespace = "Google\\Cloud\\PubSubLite\\V1";
option ruby_package = "Google::Cloud::PubSubLite::V1";

// The values associated with a key of an attribute.
message AttributeValues {
  // The list of values associated with a key.
  repeated bytes values = 1;
}

// A message that is published by publishers and delivered to subscribers.
message PubSubMessage {
  // The key used for routing messages to partitions or for compaction (e.g.,
  // keep the last N messages per key). If the key is empty, the message is
  // routed to an arbitrary partition.
  bytes key = 1;

  // The payload of the message.
  bytes data = 2;

  // Optional attributes that can be used for message metadata/headers.
  map<string, AttributeValues> attributes = 3;

  // An optional, user-specified event time.
  google.protobuf.Timestamp event_time = 4;
}

// A cursor that describes the position of a message within a topic partition.
message Cursor {
  // The offset of a message within a topic partition. Must be greater than or
  // equal 0.
  int64 offset = 1;
}

// A message that has been stored and sequenced by the Pub/Sub Lite system.
message SequencedMessage {
  // The position of a message within the partition where it is stored.
  Cursor cursor = 1;

  // The time when the message was received by the server when it was first
  // published.
  google.protobuf.Timestamp publish_time = 2;

  // The user message.
  PubSubMessage message = 3;

  // The size in bytes of this message for flow control and quota purposes.
  int64 size_bytes = 4;
}

// Metadata about a reservation resource.
message Reservation {
  option (google.api.resource) = {
    type: "pubsublite.googleapis.com/Reservation"
    pattern: "projects/{project}/locations/{location}/reservations/{reservation}"
  };

  // The name of the reservation.
  // Structured like:
  // projects/{project_number}/locations/{location}/reservations/{reservation_id}
  string name = 1;

  // The reserved throughput capacity. Every unit of throughput capacity is
  // equivalent to 1 MiB/s of published messages or 2 MiB/s of subscribed
  // messages.
  //
  // Any topics which are declared as using capacity from a Reservation will
  // consume resources from this reservation instead of being charged
  // individually.
  int64 throughput_capacity = 2;
}

// Metadata about a topic resource.
message Topic {
  option (google.api.resource) = {
    type: "pubsublite.googleapis.com/Topic"
    pattern: "projects/{project}/locations/{location}/topics/{topic}"
  };

  // The settings for a topic's partitions.
  message PartitionConfig {
    // The throughput capacity configuration for each partition.
    message Capacity {
      // Publish throughput capacity per partition in MiB/s.
      // Must be >= 4 and <= 16.
      int32 publish_mib_per_sec = 1;

      // Subscribe throughput capacity per partition in MiB/s.
      // Must be >= 4 and <= 32.
      int32 subscribe_mib_per_sec = 2;
    }

    // The number of partitions in the topic. Must be at least 1.
    //
    // Once a topic has been created the number of partitions can be increased
    // but not decreased. Message ordering is not guaranteed across a topic
    // resize. For more information see
    // https://cloud.google.com/pubsub/lite/docs/topics#scaling_capacity
    int64 count = 1;

    // The throughput dimension of this topic.
    oneof dimension {
      // DEPRECATED: Use capacity instead which can express a superset of
      // configurations.
      //
      // Every partition in the topic is allocated throughput equivalent to
      // `scale` times the standard partition throughput (4 MiB/s). This is also
      // reflected in the cost of this topic; a topic with `scale` of 2 and
      // count of 10 is charged for 20 partitions. This value must be in the
      // range [1,4].
      int32 scale = 2 [deprecated = true];

      // The capacity configuration.
      Capacity capacity = 3;
    }
  }

  // The settings for a topic's message retention.
  message RetentionConfig {
    // The provisioned storage, in bytes, per partition. If the number of bytes
    // stored in any of the topic's partitions grows beyond this value, older
    // messages will be dropped to make room for newer ones, regardless of the
    // value of `period`.
    int64 per_partition_bytes = 1;

    // How long a published message is retained. If unset, messages will be
    // retained as long as the bytes retained for each partition is below
    // `per_partition_bytes`.
    google.protobuf.Duration period = 2;
  }

  // The settings for this topic's Reservation usage.
  message ReservationConfig {
    // The Reservation to use for this topic's throughput capacity.
    // Structured like:
    // projects/{project_number}/locations/{location}/reservations/{reservation_id}
    string throughput_reservation = 1 [(google.api.resource_reference) = {
      type: "pubsublite.googleapis.com/Reservation"
    }];
  }

  // The name of the topic.
  // Structured like:
  // projects/{project_number}/locations/{location}/topics/{topic_id}
  string name = 1;

  // The settings for this topic's partitions.
  PartitionConfig partition_config = 2;

  // The settings for this topic's message retention.
  RetentionConfig retention_config = 3;

  // The settings for this topic's Reservation usage.
  ReservationConfig reservation_config = 4;
}

// Metadata about a subscription resource.
message Subscription {
  option (google.api.resource) = {
    type: "pubsublite.googleapis.com/Subscription"
    pattern: "projects/{project}/locations/{location}/subscriptions/{subscription}"
  };

  // The settings for a subscription's message delivery.
  message DeliveryConfig {
    // When this subscription should send messages to subscribers relative to
    // messages persistence in storage. For details, see [Creating Lite
    // subscriptions](https://cloud.google.com/pubsub/lite/docs/subscriptions#creating_lite_subscriptions).
    enum DeliveryRequirement {
      // Default value. This value is unused.
      DELIVERY_REQUIREMENT_UNSPECIFIED = 0;

      // The server does not wait for a published message to be successfully
      // written to storage before delivering it to subscribers.
      DELIVER_IMMEDIATELY = 1;

      // The server will not deliver a published message to subscribers until
      // the message has been successfully written to storage. This will result
      // in higher end-to-end latency, but consistent delivery.
      DELIVER_AFTER_STORED = 2;
    }

    // The DeliveryRequirement for this subscription.
    DeliveryRequirement delivery_requirement = 3;
  }

  // The name of the subscription.
  // Structured like:
  // projects/{project_number}/locations/{location}/subscriptions/{subscription_id}
  string name = 1;

  // The name of the topic this subscription is attached to.
  // Structured like:
  // projects/{project_number}/locations/{location}/topics/{topic_id}
  string topic = 2 [(google.api.resource_reference) = {
    type: "pubsublite.googleapis.com/Topic"
  }];

  // The settings for this subscription's message delivery.
  DeliveryConfig delivery_config = 3;

  // If present, messages are automatically written from the Pub/Sub Lite topic
  // associated with this subscription to a destination.
  ExportConfig export_config = 4;
}

// Configuration for a Pub/Sub Lite subscription that writes messages to a
// destination. User subscriber clients must not connect to this subscription.
message ExportConfig {
  // The desired export state.
  enum State {
    // Default value. This value is unused.
    STATE_UNSPECIFIED = 0;

    // Messages are being exported.
    ACTIVE = 1;

    // Exporting messages is suspended.
    PAUSED = 2;

    // Messages cannot be exported due to permission denied errors. Output only.
    PERMISSION_DENIED = 3;

    // Messages cannot be exported due to missing resources. Output only.
    NOT_FOUND = 4;
  }

  // Configuration for exporting to a Pub/Sub topic.
  message PubSubConfig {
    // The name of the Pub/Sub topic.
    // Structured like: projects/{project_number}/topics/{topic_id}.
    // The topic may be changed.
    string topic = 1;
  }

  // The desired state of this export. Setting this to values other than
  // `ACTIVE` and `PAUSED` will result in an error.
  State desired_state = 1;

  // Output only. The current state of the export, which may be different to the
  // desired state due to errors. This field is output only.
  State current_state = 6 [(google.api.field_behavior) = OUTPUT_ONLY];

  // Optional. The name of an optional Pub/Sub Lite topic to publish messages
  // that can not be exported to the destination. For example, the message can
  // not be published to the Pub/Sub service because it does not satisfy the
  // constraints documented at https://cloud.google.com/pubsub/docs/publisher.
  //
  // Structured like:
  // projects/{project_number}/locations/{location}/topics/{topic_id}.
  // Must be within the same project and location as the subscription. The topic
  // may be changed or removed.
  string dead_letter_topic = 5 [
    (google.api.field_behavior) = OPTIONAL,
    (google.api.resource_reference) = {
      type: "pubsublite.googleapis.com/Topic"
    }
  ];

  // The destination to export to. Required.
  oneof destination {
    // Messages are automatically written from the Pub/Sub Lite topic associated
    // with this subscription to a Pub/Sub topic.
    PubSubConfig pubsub_config = 3;
  }
}

// A target publish or event time. Can be used for seeking to or retrieving the
// corresponding cursor.
message TimeTarget {
  // The type of message time to query.
  oneof time {
    // Request the cursor of the first message with publish time greater than or
    // equal to `publish_time`. All messages thereafter are guaranteed to have
    // publish times >= `publish_time`.
    google.protobuf.Timestamp publish_time = 1;

    // Request the cursor of the first message with event time greater than or
    // equal to `event_time`. If messages are missing an event time, the publish
    // time is used as a fallback. As event times are user supplied, subsequent
    // messages may have event times less than `event_time` and should be
    // filtered by the client, if necessary.
    google.protobuf.Timestamp event_time = 2;
  }
}