syntax = "proto3";

package neo.fs.v2.object;

option go_package = "github.com/nspcc-dev/neofs-api-go/v2/object/grpc;object";
option csharp_namespace = "NeoFS.API.v2.Object";

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

// Type of the object payload content. Only `REGULAR` type objects can be split,
// hence `TOMBSTONE` and `STORAGEGROUP` payload is limited by maximal object
// size.
//
// String presentation of object type is PascalCased `ObjectType` enumeration
// item name:
// * Regular
// * Tombstone
// * StorageGroup
enum ObjectType {
  // Just a normal object
  REGULAR = 0;

  // Used internally to identify deleted objects
  TOMBSTONE = 1;

  // StorageGroup information
  STORAGE_GROUP = 2;
}

// Type of match expression
enum MatchType {
  // Unknown. Not used
  MATCH_TYPE_UNSPECIFIED = 0;

  // Full string match
  STRING_EQUAL = 1;
}

// Short header fields
message ShortHeader {
  // Object format version. Effectively the version of API library used to
  // create particular object.
  neo.fs.v2.refs.Version version = 1 [json_name = "version"];

  // Epoch when the object was created
  uint64 creation_epoch = 2 [json_name = "creationEpoch"];

  // Object's owner
  neo.fs.v2.refs.OwnerID owner_id = 3 [json_name = "ownerID"];

  // Type of the object payload content
  ObjectType object_type = 4 [json_name = "objectType"];

  // Size of payload in bytes.
  // `0xFFFFFFFFFFFFFFFF` means `payload_length` is unknown
  uint64 payload_length = 5 [json_name = "payloadLength"];

  // Hash of payload bytes
  neo.fs.v2.refs.Checksum payload_hash = 6 [json_name = "payloadHash"];

  // Homomorphic hash of the object payload
  neo.fs.v2.refs.Checksum homomorphic_hash = 7 [json_name = "homomorphicHash"];
}

// Object Header
message Header {
  // Object format version. Effectively the version of API library used to
  // create particular object
  neo.fs.v2.refs.Version version = 1 [json_name = "version"];

  // Object's container
  neo.fs.v2.refs.ContainerID container_id = 2 [json_name = "containerID"];

  // Object's owner
  neo.fs.v2.refs.OwnerID owner_id = 3 [json_name = "ownerID"];

  // Object creation Epoch
  uint64 creation_epoch = 4 [json_name = "creationEpoch"];

  // Size of payload in bytes.
  // `0xFFFFFFFFFFFFFFFF` means `payload_length` is unknown.
  uint64 payload_length = 5 [json_name = "payloadLength"];

  // Hash of payload bytes
  neo.fs.v2.refs.Checksum payload_hash = 6 [json_name = "payloadHash"];

  // Type of the object payload content
  ObjectType object_type = 7 [json_name = "objectType"];

  // Homomorphic hash of the object payload
  neo.fs.v2.refs.Checksum homomorphic_hash = 8 [json_name = "homomorphicHash"];

  // Session token, if it was used during Object creation. Need it to verify
  // integrity and authenticity out of Request scope.
  neo.fs.v2.session.SessionToken session_token = 9 [json_name = "sessionToken"];

  // `Attribute` is a user-defined Key-Value metadata pair attached to the
  // object.
  //
  // Key name must be a object-unique valid UTF-8 string. Value can't be empty.
  // Objects with duplicated attribute names or attributes with empty values
  // will be considered invalid.
  //
  // There are some "well-known" attributes starting with `__NEOFS__` prefix
  // that affect system behaviour:
  //
  // * __NEOFS__UPLOAD_ID \
  //   Marks smaller parts of a split bigger object
  // * __NEOFS__EXPIRATION_EPOCH \
  //   Tells GC to delete object after that epoch
  //
  // And some well-known attributes used by applications only:
  //
  // * Name \
  //   Human-friendly name
  // * FileName \
  //   File name to be associated with the object on saving
  // * Timestamp \
  //   User-defined local time of object creation in Unix Timestamp format
  //
  // For detailed description of each well-known attribute please see the
  // corresponding section in NeoFS Technical specification.
  message Attribute {
    // string key to the object attribute
    string key = 1 [json_name = "key"];
    // string value of the object attribute
    string value = 2 [json_name = "value"];
  }
  // User-defined object attributes
  repeated Attribute attributes = 10 [json_name = "attributes"];

  // Bigger objects can be split into a chain of smaller objects. Information
  // about inter-dependencies between spawned objects and how to re-construct
  // the original one is in the `Split` headers. Parent and children objects
  // must be within the same container.
  message Split {
    // Identifier of the origin object. Known only to the minor child.
    neo.fs.v2.refs.ObjectID parent = 1 [json_name = "parent"];

    // Identifier of the left split neighbor
    neo.fs.v2.refs.ObjectID previous = 2 [json_name = "previous"];

    // `signature` field of the parent object. Used to reconstruct parent.
    neo.fs.v2.refs.Signature parent_signature = 3 [json_name = "parentSignature"];

    // `header` field of the parent object. Used to reconstruct parent.
    Header parent_header = 4 [json_name = "parentHeader"];

    // List of identifiers of the objects generated by splitting current one.
    repeated neo.fs.v2.refs.ObjectID children = 5 [json_name = "children"];

    // 16 byte UUIDv4 used to identify the split object hierarchy parts. Must be
    // unique inside container. All objects participating in the split must have
    // the same `split_id` value.
    bytes split_id = 6 [json_name = "splitID"];

  }
  // Position of the object in the split hierarchy
  Split split = 11 [json_name = "split"];
}

// Object structure. Object is immutable and content-addressed. It means
// `ObjectID` will change if header or payload changes. It's calculated as a
// hash of header field, which contains hash of object's payload.
message Object {
  // Object's unique identifier.
  neo.fs.v2.refs.ObjectID object_id = 1 [json_name = "objectID"];

  // Signed object_id
  neo.fs.v2.refs.Signature signature = 2 [json_name = "signature"];

  // Object metadata headers
  Header header = 3 [json_name = "header"];

  // Payload bytes
  bytes payload = 4 [json_name = "payload"];
}

// Meta information of split hierarchy for object assembly. With last part
// one can traverse linked list of split hierarchy back to first part and
// assemble original object. With linking object one can assembly object
// straight away from the object parts.
message SplitInfo {
  // 16 byte UUID used to identify the split object hierarchy parts.
  bytes split_id = 1;

  // Identifier of the last object in split hierarchy parts. It contains
  // split header with original object header.
  neo.fs.v2.refs.ObjectID last_part = 2;

  // Identifier of linking object for split hierarchy parts. It contains
  // split header with original object header and sorted list of
  // object parts.
  neo.fs.v2.refs.ObjectID link = 3;
}