syntax = "proto3";
package object;
option go_package = "github.com/nspcc-dev/neofs-api-go/object";
option csharp_namespace = "NeoFS.API.Object";

import "refs/types.proto";
import "service/verify.proto";
import "storagegroup/types.proto";

// Attribute groups the parameters of the object attributes.
message Attribute {
    // Key carries the string key to the object attribute.
    string Key = 1;

    // Value carries the string value of the object attribute.
    string Value = 2;
}

message ExtendedHeader {
    // Attributes carries list of the object attributes in a string key-value format.
    repeated Attribute Attributes = 3;
    // Split carries the position of the object in the split hierarchy.
    SplitHeader SplitHeader = 4;
    // Tombstone header that set up in deleted objects
    Tombstone Tombstone = 5;
    // HomoHash is a homomorphic hash of original object payload
    bytes HomoHash = 7;
    // Integrity header with checksum of all above headers in the object
    IntegrityHeader Integrity = 9;
    // StorageGroup contains meta information for the data audit
    storagegroup.StorageGroup StorageGroup = 10;
    // CreationEpoch carries number of NeoFS epoch on which the object was created.
    uint64 CreationEpoch = 11;
}

message Tombstone {}

message SystemHeader {
    // PayloadLength is an object payload length
    uint64 PayloadLength = 1;
    // Address carries object address in the NeoFS system.
    // It encapsulates the object and the container identifiers.
    refs.Address Address = 2;
    // OwnerID is a wallet address
    bytes OwnerID = 3;
}

message IntegrityHeader {
    // PayloadChecksum carries the checksum of object payload bytes.
    // Changing any byte of the payload changes the checksum.
    // It is calculated as a SHA-256 hash over payload bytes.
    bytes PayloadChecksum = 1;
    // HeaderChecksum carries checksum of the object header structure.
    // It covers all object attributes. Changing any field of the object except
    // CreatorKey and ChecksumSignature changes the checksum.
    // PayloadChecksum and HeaderChecksum cannot be merged due to the need
    // to verify the header in the absence of a payload (e.g. in object.Head rpc).
    // It is calculated as a SHA-256 hash over marshaled object header
    // with cut CreatorKey and ChecksumSignature.
    bytes HeaderChecksum = 2;
    // SessionToken carries token of the session within which the object was created.
    // If session token is presented in object, it acts as the user's proof of the
    // correctness of the CreatorKey.
    service.Token SessionToken = 3;
    // CreatorKey carries public key of the object creator in a binary format.
    bytes CreatorKey = 4;
    // ChecksumSignature is an user's signature of checksum to verify if it is correct
    bytes ChecksumSignature = 5;
}

// SplitHeader groups information about spawning the object through a payload splitting.
message SplitHeader {
    // Parent carries identifier of the origin object.
    refs.ObjectID Parent = 1;

    // Previous carries identifier of the left split neighbor.
    refs.ObjectID Previous = 2;

    // Previous carries identifier of the right split neighbor.
    refs.ObjectID Next = 3;

    // Children carries list of identifiers of the objects generated by splitting the current.
    repeated refs.ObjectID Children = 4;

    // Origin carries the header of the origin object.
    Header Origin = 5;
}

// Header groups the information about the NeoFS object.
message Header {
    // SystemHeader describes system header
    SystemHeader SystemHeader = 1;

    // ExtendedHeader carries the additional part of the header.
    ExtendedHeader ExtendedHeader = 2;
}

message Object {
    // Header carries the object header.
    Header Header = 1;
    // Payload is an object's payload
    bytes Payload = 2;
}