syntax = "proto3";
package cluster;

import "cluster.proto";
import "google/protobuf/duration.proto";
import "actor.proto";

// Identifies a subscriber by either ClusterIdentity or PID
message SubscriberIdentity {
  oneof Identity {
    actor.PID pid = 1;
    cluster.ClusterIdentity cluster_identity = 2;
  }
}

// First request to initialize the actor.
message Initialize {
  google.protobuf.Duration idleTimeout = 1;
}

message Acknowledge {}

// A list of subscribers
message Subscribers {
  repeated SubscriberIdentity subscribers = 1;
}

// Sent to topic actor to add a subscriber
message SubscribeRequest {
  SubscriberIdentity subscriber = 1;
}

// Subscribe acknowledgement
message SubscribeResponse {}

// Sent to topic actor to remove a subscriber
message UnsubscribeRequest {
  SubscriberIdentity subscriber = 1;
}

// Unsubscribe acknowledgement
message UnsubscribeResponse {}

// Message sent from publisher to topic actor
// See also PubSubBatch
message PubSubBatchTransport {
  repeated string type_names = 1;
  repeated PubSubEnvelope envelopes = 2;
}

// Contains message byte representation and type reference
message PubSubEnvelope {
  int32 type_id = 1;
  bytes message_data = 2;
  int32 serializer_id = 3;
}

// Message sent from topic to delivery actor
message DeliverBatchRequestTransport {
  Subscribers subscribers = 1;
  PubSubBatchTransport batch = 2;
  string topic = 3;
}

// Message sent from delivery actor to topic to notify of subscribers that fail to process the messages
message NotifyAboutFailingSubscribersRequest {
  repeated SubscriberDeliveryReport invalid_deliveries = 1;
}

// Ack to the delivery actor after notification of subscribers that fail to process the messages
message NotifyAboutFailingSubscribersResponse {}

// Contains information about a failed delivery
message SubscriberDeliveryReport {
  SubscriberIdentity subscriber = 1;
  DeliveryStatus status = 2;
}

// Delivery status as seen by the delivery actor
enum DeliveryStatus {
  // Message was put in the queue of the subscriber
  Delivered = 0;

  // Message did not reach subscriber, because it was dead
  SubscriberNoLongerReachable = 1;

  // Delivery timed out
  Timeout = 2;

  // Some other problem happened
  OtherError = 127;
}

// Message posted to subscriber's mailbox, that is then unrolled to single messages, and has ability to auto respond
// See also PubSubAutoRespondBatch
message PubSubAutoRespondBatchTransport {
  repeated string type_names = 1;
  repeated PubSubEnvelope envelopes = 2;
}

// Status of the whole published batch or single message
enum PublishStatus {
  // Batch or message was successfully published according to the delivery guarantees
  Ok = 0;

  // Topic failed to forward the message
  Failed = 1;
}

// Publish ack/nack response
message PublishResponse {
  // Status of the whole published batch or single message
  PublishStatus status = 1;
}