syntax = "proto3";
package spacesync;

option go_package = "commonspace/spacesyncproto";

enum ErrCodes {
    Unexpected = 0;
    SpaceMissing = 1;
    SpaceExists = 2;
    SpaceNotInCache = 3;
    ErrorOffset = 100;
}

service SpaceSync {
    // HeadSync compares all objects and their hashes in a space
    rpc HeadSync(HeadSyncRequest) returns (HeadSyncResponse);
    // SpacePush sends new space to the node
    rpc SpacePush(SpacePushRequest) returns (SpacePushResponse);
    // SpacePull gets space from the remote peer
    rpc SpacePull(SpacePullRequest) returns (SpacePullResponse);
    // ObjectSyncStream opens object sync stream with node or client
    rpc ObjectSyncStream(stream ObjectSyncMessage) returns (stream ObjectSyncMessage);
}

// HeadSyncRange presenting a request for one range
message HeadSyncRange {
    uint64 from = 1;
    uint64 to = 2;
    uint32 limit = 3;
}

// HeadSyncResult presenting a response for one range
message HeadSyncResult {
    bytes hash = 1;
    repeated HeadSyncResultElement elements = 2;
    uint32 count = 3;
}

// HeadSyncResultElement presenting state of one object
message HeadSyncResultElement {
    string id = 1;
    string head = 2;
}

// HeadSyncRequest is a request for HeadSync
message HeadSyncRequest {
    string spaceId = 1;
    repeated HeadSyncRange ranges = 2;
}

// HeadSyncResponse is a response for HeadSync
message HeadSyncResponse {
    repeated HeadSyncResult results = 1;
}

// ObjectSyncMessage is a message sent on object sync
message ObjectSyncMessage {
    string spaceId = 1;
    string requestId = 2;
    string replyId = 3;
    bytes payload = 4;
    string objectId = 5;
    //  string identity = 5;
    //  string peerSignature = 6;
}

// SpacePushRequest is a request to add space on a node containing only one acl record
message SpacePushRequest {
    SpacePayload payload = 1;
}

// SpacePushResponse is an empty response
message SpacePushResponse {}

// SpacePullRequest is a request to request a space on a node that doesn't have it
message SpacePullRequest {
    string id = 1;
}

// SpacePullResponse is a response with header and acl root
message SpacePullResponse {
    SpacePayload payload = 1;
}

// SpacePayload is a payload for pushing a space
message SpacePayload {
    RawSpaceHeaderWithId spaceHeader = 1;
    bytes aclPayload = 2;
    string aclPayloadId = 3;
    bytes spaceSettingsPayload = 4;
    string spaceSettingsPayloadId = 5;
}

// SpaceHeader is a header for a space
message SpaceHeader {
    bytes identity = 1;
    int64 timestamp = 2;
    string spaceType = 3;
    uint64 replicationKey = 4;
    bytes seed = 5;
}

// RawSpaceHeader is raw header for SpaceHeader
message RawSpaceHeader {
    bytes spaceHeader = 1;
    bytes signature = 2;
}

// RawSpaceHeaderWithId is a marshalled RawSpaceHeader with its content id
message RawSpaceHeaderWithId {
    bytes rawHeader = 1;
    string id = 2;
}

// SpaceSettingsContent is a payload for a space settings object
message SpaceSettingsContent {
    oneof value {
        ObjectDelete objectDelete = 1;
    }
}

// ObjectDelete is a message containing an object id which should be deleted
message ObjectDelete {
    string id = 1;
}

// SpaceSettingsSnapshot contains all the deleted ids in a snapshot
message SpaceSettingsSnapshot {
    repeated string deletedIds = 1;
}

// SettingsData contains ObjectTree change payload
message SettingsData {
    repeated SpaceSettingsContent content = 1;
    SpaceSettingsSnapshot snapshot = 2;
}

// SpaceSubscription contains in ObjectSyncMessage.Payload and indicates that we need to subscribe or unsubscribe the current stream to this space
enum SpaceSubscriptionAction {
    Subscribe = 0;
    Unsubscribe = 1;
}

message SpaceSubscription {
    repeated string spaceIds = 1;
    SpaceSubscriptionAction action = 2;
}