syntax = "proto3";
package treechange;
option go_package = "pkg/acl/treechangeproto";

// RootChange is a root of a tree
message RootChange {
  // AclHeadId is a cid of latest acl record at the time of tree creation
  string aclHeadId = 1;
  // SpaceId is an id of space where the document is placed
  string spaceId = 2;
  // ChangeType is a type of tree which this RootChange is a root of
  string changeType = 3;
  // Timestamp is this change creation timestamp
  int64 timestamp = 4;
  // Seed is a random bytes to make root change unique
  bytes seed = 5;
  // Identity is a public key of the tree's creator
  bytes identity = 6;
}

// TreeChange is a change of a tree
message TreeChange {
  // TreeHeadIds are previous ids for this TreeChange
  repeated string treeHeadIds = 1;
  // AclHeadId is a cid of latest acl record at the time of this change
  string aclHeadId = 2;
  // SnapshotBaseId is a snapshot (root) of the tree where this change is added
  string snapshotBaseId = 3;
  // ChangesData is an arbitrary payload to be read by the client
  bytes changesData = 4;
  // CurrentReadKeyHash is the hash of the read key which is used to encrypt this change
  uint64 currentReadKeyHash = 5;
  // Timestamp is this change creation timestamp
  int64 timestamp = 6;
  // Identity is a public key with which the raw payload of this change is signed
  bytes identity = 7;
  // IsSnapshot indicates whether this change contains a snapshot of state
  bool isSnapshot = 8;
}

// RawTreeChange is a marshalled TreeChange (or RootChange) payload and a signature of this payload
message RawTreeChange {
  // Payload is a byte payload containing TreeChange
  bytes payload = 1;
  // Signature is a signature made by identity indicated in the TreeChange payload
  bytes signature = 2;
}

// RawTreeChangeWithId is a marshalled RawTreeChange with CID
message RawTreeChangeWithId {
  // RawChange is a byte payload of RawTreeChange
  bytes rawChange = 1;
  // Id is a cid made from rawChange payload
  string id = 2;
}

message TreeSyncMessage {
  TreeSyncContentValue content = 1;
  RawTreeChangeWithId rootChange = 2;
}

// TreeSyncContentValue provides different types for tree sync
message TreeSyncContentValue {
  oneof value {
    TreeHeadUpdate headUpdate = 1;
    TreeFullSyncRequest fullSyncRequest = 2;
    TreeFullSyncResponse fullSyncResponse = 3;
    TreeErrorResponse errorResponse = 4;
  }
}

// TreeHeadUpdate is a message sent on document head update
message TreeHeadUpdate {
  repeated string heads = 1;
  repeated RawTreeChangeWithId changes = 2;
  repeated string snapshotPath = 3;
}

// TreeHeadUpdate is a message sent when document needs full sync
message TreeFullSyncRequest {
  repeated string heads = 1;
  repeated RawTreeChangeWithId changes = 2;
  repeated string snapshotPath = 3;
}

// TreeFullSyncResponse is a message sent as a response for a specific full sync
message TreeFullSyncResponse {
  repeated string heads = 1;
  repeated RawTreeChangeWithId changes = 2;
  repeated string snapshotPath = 3;
}

// TreeErrorResponse is an error sent as a response for a full sync request
message TreeErrorResponse {
  string error = 1;
}