syntax = "proto3";
package sxchnge.notifications.v1;
option go_package = "git.sendico.io/tech/sxchnge/notifications/interface/notifications/v1;notificationsv1";
import "google/protobuf/timestamp.proto";

// Internal service on the trusted private network; no caller authentication. Send durably queues work.
service NotificationsService {
  rpc Send(SendRequest) returns (SendResponse);
  rpc Get(GetRequest) returns (GetResponse);
}
message SendRequest {
  string idempotency_key = 1; // Required; scoped to the product namespace, retained seven days.
  string user_id = 2; // Caller resolves and authorizes recipient ownership.
  string template_id = 3;
  string template_version = 4;
  map<string, string> parameters = 5;
  string locale = 6;
  repeated Target targets = 7; // V1 accepts exactly one email target.
  google.protobuf.Timestamp expires_at = 8; // Default/max 24h from acceptance.
}
message Target {
  oneof destination {
    EmailTarget email = 1;
    SmsTarget sms = 2;
    PushTarget push = 3;
    TelegramTarget telegram = 4;
  }
}
message EmailTarget { string address = 1; }
message SmsTarget { string phone_number = 1; }
message PushTarget { string endpoint_id = 1; }
message TelegramTarget { string chat_id = 1; }
message SendResponse { Notification notification = 1; }
message GetRequest { string id = 1; }
message GetResponse { Notification notification = 1; }
message Notification {
  string id = 1;
  string user_id = 2;
  string template_id = 3;
  string template_version = 4;
  repeated Delivery deliveries = 5;
  google.protobuf.Timestamp created_at = 6;
  google.protobuf.Timestamp updated_at = 7;
  google.protobuf.Timestamp expires_at = 8;
}
message Delivery {
  string id = 1;
  Channel channel = 2;
  DeliveryState state = 3;
  uint32 attempt_count = 4;
  Failure failure = 5;
  google.protobuf.Timestamp next_attempt_at = 6;
  google.protobuf.Timestamp updated_at = 7;
}
message Failure { string code = 1; string message = 2; }
enum Channel {
  CHANNEL_UNSPECIFIED = 0;
  CHANNEL_EMAIL = 1;
  CHANNEL_SMS = 2;
  CHANNEL_PUSH = 3;
  CHANNEL_TELEGRAM = 4;
}
enum DeliveryState {
  DELIVERY_STATE_UNSPECIFIED = 0;
  DELIVERY_STATE_QUEUED = 1;
  DELIVERY_STATE_SENDING = 2;
  DELIVERY_STATE_RETRY_WAIT = 3;
  DELIVERY_STATE_ACCEPTED = 4;
  DELIVERY_STATE_DELIVERED = 5; // Reserved for future verified receipts.
  DELIVERY_STATE_FAILED = 6;
  DELIVERY_STATE_EXPIRED = 7;
  DELIVERY_STATE_UNKNOWN = 8; // May have sent; no automatic replay.
}