syntax = "proto3";
package eu.zettoit.rebacs;

service RelationService {
  rpc Create(RelationCreateReq) returns (RelationCreateRes);
  rpc Delete(RelationDeleteReq) returns (RelationDeleteRes);
  rpc Exists(RelationExistsReq) returns (RelationExistsRes);
}

service QueryService {
  // check if one object or objectset is related to another by a relation
  rpc IsRelatedTo(QueryIsRelatedToReq) returns (QueryIsRelatedToRes);

  // get all objects that are related to one object by a relation
  rpc GetRelated(QueryGetRelatedReq) returns (QueryGetRelatedRes);

  // get all objects that the given object has a relation with
  rpc GetRelations(QueryGetRelationsReq) returns (QueryGetRelationsRes);
}

message RelationCreateReq{
  ObjectOrSet src = 1;
  Object dst = 2;
  string relation = 3;
}
message RelationCreateRes{}

message RelationDeleteReq{
  ObjectOrSet src = 1;
  Object dst = 3;
  string relation = 4;
}
message RelationDeleteRes{}

message RelationExistsReq{
  ObjectOrSet src = 1;
  Object dst = 2;
  string relation = 3;
}
message RelationExistsRes{
  bool exists = 1;
}

message QueryIsRelatedToReq{
  ObjectOrSet src = 1;
  Object dst = 2;
  string relation = 3;
}
message QueryIsRelatedToRes{
  bool related = 1;
}

message QueryGetRelatedReq{
  Object dst = 1;
  optional string relation = 2;
  optional string namespace = 3;
  optional uint32 depth = 4;
}
message QueryGetRelatedRes{
  repeated QueryGetRelatedItem objects = 1;
}
message QueryGetRelatedItem{
  string relation = 1;
  Object src = 2;
}

message QueryGetRelationsReq{
  Object src = 1;
  optional string relation = 2;
  optional string namespace = 3;
  optional uint32 depth = 4;
}
message QueryGetRelationsRes{
  repeated QueryGetRelationsItem related = 1;
}
message QueryGetRelationsItem{
  string relation = 1;
  Object dst = 2;
}

message Object{
  string namespace = 1;
  string id = 2;
}
message Set{
  string namespace = 1;
  string id = 2;
  string relation = 3;
}

message ObjectOrSet {
  string namespace = 1;
  string id = 2;
  optional string relation = 3;
}