syntax = "proto3";

package neo.fs.v2.container;

option go_package = "github.com/nspcc-dev/neofs-api-go/v2/container/grpc;container";
option csharp_namespace = "Neo.FileStorage.API.Container";

import "netmap/types.proto";
import "refs/types.proto";

// Container is a structure that defines object placement behaviour. Objects can
// be stored only within containers. They define placement rule, attributes and
// access control information. An ID of a container is a 32 byte long SHA256 hash
// of stable-marshalled container message.
message Container {
  // Container format version. Effectively, the version of API library used to
  // create the container.
  neo.fs.v2.refs.Version version = 1 [json_name = "version"];

  // Identifier of the container owner
  neo.fs.v2.refs.OwnerID owner_id = 2 [json_name = "ownerID"];

  // Nonce is a 16 byte UUIDv4, used to avoid collisions of `ContainerID`s
  bytes nonce = 3 [json_name = "nonce"];

  // `BasicACL` contains access control rules for the owner, system and others groups,
  // as well as permission bits for `BearerToken` and `Extended ACL`
  uint32 basic_acl = 4 [json_name = "basicACL"];

  // `Attribute` is a user-defined Key-Value metadata pair attached to the
  // container. Container attributes are immutable. They are set at the moment of
  // container creation and can never be added or updated.
  //
  // Key name must be a container-unique valid UTF-8 string. Value can't be
  // empty. Containers with duplicated attribute names or attributes with empty
  // values will be considered invalid.
  //
  // There are some "well-known" attributes affecting system behaviour:
  //
  // * __NEOFS__SUBNET \
  //   String ID of a container's storage subnet. Any container can be attached to
  //   one subnet only.
  // * __NEOFS__NAME \
  //   String of a human-friendly container name registered as a domain in
  //   NNS contract.
  // * __NEOFS__ZONE \
  //   String of a zone for `__NEOFS__NAME`. Used as a TLD of a domain name in NNS
  //   contract. If no zone is specified, use default zone: `container`.
  //
  // And some well-known attributes used by applications only:
  //
  // * Name \
  //   Human-friendly name
  // * Timestamp \
  //   User-defined local time of container creation in Unix Timestamp format
  message Attribute {
    // Attribute name key
    string key = 1 [json_name = "key"];

    // Attribute value
    string value = 2 [json_name = "value"];
  }
  // Attributes represent immutable container's meta data
  repeated Attribute attributes = 5 [json_name = "attributes"];

  // Placement policy for the object inside the container
  neo.fs.v2.netmap.PlacementPolicy placement_policy = 6 [json_name = "placementPolicy"];
}