From 504e11149110e0200d9d5ab76946629b0534b07b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sascha=20K=C3=BChl?= <skuehl1972@gmail.com>
Date: Sun, 9 Feb 2025 20:49:00 +0100
Subject: [PATCH] reference column progress

---
 .../matador/object/attribute_definition.hpp   |  27 ++--
 .../object/attribute_definition_generator.hpp |   4 +-
 include/matador/object/basic_object_info.hpp  |   8 +-
 include/matador/object/object_info.hpp        |  15 +-
 include/matador/object/schema.hpp             | 101 ++++++++++++-
 include/matador/object/schema_node.hpp        |  17 +--
 source/core/object/attribute_definition.cpp   | 139 +++++++-----------
 .../object/attribute_definition_generator.cpp |   2 +-
 source/core/object/basic_object_info.cpp      |  20 ++-
 source/core/object/schema.cpp                 |  47 +++---
 source/core/object/schema_node.cpp            |  77 ++++++----
 11 files changed, 269 insertions(+), 188 deletions(-)

diff --git a/include/matador/object/attribute_definition.hpp b/include/matador/object/attribute_definition.hpp
index 04352e5..d19747a 100644
--- a/include/matador/object/attribute_definition.hpp
+++ b/include/matador/object/attribute_definition.hpp
@@ -1,6 +1,8 @@
 #ifndef QUERY_COLUMN_DEFINITION_HPP
 #define QUERY_COLUMN_DEFINITION_HPP
 
+#include <memory>
+
 #include "matador/utils/basic_type_converter.hpp"
 #include "matador/utils/basic_types.hpp"
 #include "matador/utils/default_type_traits.hpp"
@@ -43,11 +45,11 @@ public:
   attribute_definition(std::string name, utils::basic_type type, const utils::field_attributes&, null_option null_opt, size_t index = 0);
 
   template<typename Type>
-  attribute_definition(std::string name, std::string ref_table, std::string ref_column, const utils::field_attributes& attr, null_option null_opt)
-  : attribute_definition(std::move(name), utils::data_type_traits<Type>::type(attr.size()), ref_table, ref_column, attr, null_opt)
+  attribute_definition(std::string name, const std::shared_ptr<attribute_definition> &ref_column, const utils::field_attributes& attr, null_option null_opt)
+  : attribute_definition(std::move(name), utils::data_type_traits<Type>::type(attr.size()), ref_column, attr, null_opt)
   {}
 
-  attribute_definition(std::string name, utils::basic_type type, size_t index, std::string ref_table, std::string ref_column, const utils::field_attributes& attr, null_option null_opt);
+  attribute_definition(std::string name, utils::basic_type type, size_t index, const std::shared_ptr<attribute_definition> &ref_column, const utils::field_attributes& attr, null_option null_opt);
 
   [[nodiscard]] const std::string& name() const;
   [[nodiscard]] std::string full_name() const;
@@ -56,8 +58,7 @@ public:
   [[nodiscard]] const utils::field_attributes& attributes() const;
   [[nodiscard]] bool is_nullable() const;
   [[nodiscard]] utils::basic_type type() const;
-  [[nodiscard]] const std::string& ref_table() const;
-  [[nodiscard]] const std::string& ref_column() const;
+  [[nodiscard]] std::shared_ptr<attribute_definition> reference_column() const;
   [[nodiscard]] bool is_foreign_reference() const;
 
   [[nodiscard]] bool is_integer() const;
@@ -124,8 +125,9 @@ private:
   utils::field_attributes attributes_;
   null_option null_option_{null_option::NOT_NULL};
   utils::value value_;
-  std::string ref_table_;
-  std::string ref_column_;
+  std::shared_ptr<attribute_definition> reference_column_;
+  // std::string ref_table_;
+  // std::string ref_column_;
 };
 
 /**
@@ -156,19 +158,20 @@ template <>
 attribute_definition make_pk_column<std::string>(const std::string &name, size_t size);
 
 template < typename Type >
-attribute_definition make_fk_column(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column)
+attribute_definition make_fk_column(const std::string &name, size_t size, const std::shared_ptr<attribute_definition> &ref_column)
 {
-    return {name, utils::data_type_traits<Type>::type(size), ref_table, ref_column, { size, utils::constraints::FOREIGN_KEY }};
+    return {name, utils::data_type_traits<Type>::type(size), ref_column, { size, utils::constraints::FOREIGN_KEY }};
 }
 
 template < typename Type >
-[[maybe_unused]] attribute_definition make_fk_column(const std::string &name, const std::string &ref_table, const std::string &ref_column)
+[[maybe_unused]] attribute_definition make_fk_column(const std::string &name, const std::shared_ptr<attribute_definition> &ref_column)
 {
-    return {name, utils::data_type_traits<Type>::type(0), 0, ref_table, ref_column, { 0, utils::constraints::FOREIGN_KEY }, null_option::NOT_NULL};
+    return {name, utils::data_type_traits<Type>::type(0), 0, ref_column, { 0, utils::constraints::FOREIGN_KEY }, null_option::NOT_NULL};
 }
 
 template <>
-attribute_definition make_fk_column<std::string>(const std::string &name, size_t size, const std::string &ref_table, const std::string &ref_column);
+attribute_definition make_fk_column<std::string>(const std::string &name, size_t size, const std::shared_ptr<attribute_definition> &ref_column);
 
 }
+
 #endif //QUERY_COLUMN_DEFINITION_HPP
diff --git a/include/matador/object/attribute_definition_generator.hpp b/include/matador/object/attribute_definition_generator.hpp
index 830dd93..6865b9b 100644
--- a/include/matador/object/attribute_definition_generator.hpp
+++ b/include/matador/object/attribute_definition_generator.hpp
@@ -83,7 +83,7 @@ public:
   template<class Pointer>
   void on_belongs_to(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/)
   {
-    const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    const auto ref_column = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
     columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
   }
   template<class Pointer>
@@ -100,7 +100,7 @@ public:
   void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
-  std::pair<std::string, std::string> determine_foreign_ref(const std::type_index &ti);
+  std::shared_ptr<attribute_definition> determine_foreign_ref(const std::type_index &ti);
 
 private:
   size_t index_ = 0;
diff --git a/include/matador/object/basic_object_info.hpp b/include/matador/object/basic_object_info.hpp
index 8c4f8ad..5d1178c 100644
--- a/include/matador/object/basic_object_info.hpp
+++ b/include/matador/object/basic_object_info.hpp
@@ -17,14 +17,16 @@ public:
   [[nodiscard]] std::type_index type_index() const;
   [[nodiscard]] std::string name() const;
   [[nodiscard]] const object_definition& definition() const;
+  [[nodiscard]] std::shared_ptr<attribute_definition> reference_column() const;
 
 protected:
-  basic_object_info(schema_node &node, std::type_index type_index, object_definition &&definition);
+  basic_object_info(schema_node &node, std::type_index type_index, object_definition &&definition, std::shared_ptr<attribute_definition> &&reference_column);
 
 protected:
-  schema_node &node_;        /**< prototype node of the represented object type */
-  std::type_index type_index_; /**< type index of the represented object type */
+  schema_node &node_;            /**< prototype node of the represented object type */
+  std::type_index type_index_;   /**< type index of the represented object type */
   object_definition definition_;
+  std::shared_ptr<attribute_definition> reference_column_;
 };
 
 using basic_object_info_ref = std::reference_wrapper<const basic_object_info>;
diff --git a/include/matador/object/object_info.hpp b/include/matador/object/object_info.hpp
index f8aeff0..6befa7f 100644
--- a/include/matador/object/object_info.hpp
+++ b/include/matador/object/object_info.hpp
@@ -5,30 +5,31 @@
 #include "matador/object/object_definition.hpp"
 
 namespace matador::object {
-
 class schema_node;
 
 template<typename Type>
 class object_info final : public basic_object_info {
 public:
-    explicit object_info(schema_node &node, object_definition &&definition)
-    : basic_object_info(node, typeid(Type), std::move(definition)) {}
+  explicit object_info(schema_node &node, object_definition &&definition,
+                       std::shared_ptr<attribute_definition> &&ref_column)
+  : basic_object_info(node, typeid(Type), std::move(definition), std::move(ref_column)) {
+  }
 
-    const Type &prototype() const { return prototype_; }
+  const Type &prototype() const { return prototype_; }
 
 private:
-    Type prototype_;
+  Type prototype_;
 };
 
 template<typename Type>
 using object_info_ref = std::reference_wrapper<const object_info<Type>>;
 
 namespace detail {
-struct null_type {};
+struct null_type {
+};
 }
 
 using null_info = object_info<detail::null_type>;
-
 }
 
 #endif //OBJECT_INFO_HPP
diff --git a/include/matador/object/schema.hpp b/include/matador/object/schema.hpp
index e64aeb3..e8673fa 100644
--- a/include/matador/object/schema.hpp
+++ b/include/matador/object/schema.hpp
@@ -9,11 +9,69 @@
 #include "matador/utils/error.hpp"
 
 #include <memory>
+#include <stack>
 #include <string>
-#include <unordered_map>
+#include <unordered_set>
 
 namespace matador::object {
 
+utils::error make_error(error_code ec, const std::string& msg);
+
+class schema;
+
+template<typename Type>
+class type_analyzer final {
+public:
+  using value_type = Type;
+
+  static void analyze(schema &scm) {
+    type_analyzer analyzer(scm);
+
+    Type obj;
+    const auto ti = std::type_index(typeid(Type));
+    analyzer.known_types_.emplace(ti);
+    access::process(analyzer, obj);
+    analyzer.known_types_.erase(ti);
+  }
+
+  template < class PrimaryKeyType >
+  void on_primary_key(const char * /*id*/, PrimaryKeyType &/*pk*/, std::enable_if_t<std::is_integral_v<PrimaryKeyType> && !std::is_same_v<bool, PrimaryKeyType>>* = nullptr) {}
+  void on_primary_key(const char * /*id*/, std::string &/*pk*/, size_t /*size*/) {}
+  void on_revision(const char * /*id*/, uint64_t &/*rev*/) {}
+
+  template<typename AttributeType>
+  void on_attribute(const char * /*id*/, AttributeType &/*val*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+
+  template<typename AttributeType>
+  void on_attribute(const char * /*id*/, std::optional<AttributeType> &/*val*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+
+  template<class ForeignPointerType>
+  void on_belongs_to(const char * /*id*/, ForeignPointerType &/*obj*/, const utils::foreign_attributes &/*attr*/) {
+    // const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+    // columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+  }
+
+  template<class ForeignPointerType>
+  void on_has_one(const char * /*id*/, ForeignPointerType &/*obj*/, const utils::foreign_attributes &/*attr*/);
+
+  template<class CollectionType>
+  void on_has_many(const char * /*id*/, CollectionType &, const char *, const utils::foreign_attributes &/*attr*/) {}
+  template<class CollectionType>
+  void on_has_many_to_many(const char * /*id*/, CollectionType &/*col*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char * /*id*/, ContainerType &/*col*/, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+  explicit type_analyzer(schema& schema)
+  : schema_(schema) {};
+
+
+private:
+  schema &schema_;
+  std::unordered_set<std::type_index> known_types_;
+};
+
+
 class schema {
 public:
   typedef const_schema_node_iterator const_iterator;  /**< Shortcut for the list const iterator. */
@@ -24,7 +82,14 @@ public:
   explicit schema( const std::string& name = "");
 
   template <typename Type>
-  [[nodiscard]] utils::result<void, utils::error> attach(const std::string name, const std::string &parent = "") {
+  [[nodiscard]] utils::result<void, utils::error> attach(const std::string& name, const std::string &parent = "") {
+    if (has_node(name)) {
+      return utils::failure(make_error(error_code::NodeAlreadyExists, "Node '" + name + "' already exists"));
+    }
+
+    // analyze node (collect unknown types by type index)
+    type_analyzer<Type>::analyze(*this);
+
     auto node = schema_node::make_node<Type>(*this, name);
 
     auto result = attach_node(node, parent);
@@ -37,14 +102,13 @@ public:
 
   template <typename Type, typename ParentType>
   [[nodiscard]] utils::result<void, utils::error> attach(const std::string name) {
-    auto node = schema_node::make_node<Type>(*this, name);
-
-    auto result = attach_node(node, std::type_index(typeid(ParentType)));
+    const auto ti = std::type_index(typeid(ParentType));
+    auto result = find_node(ti);
     if (!result) {
-      return utils::failure(result.err());
+      return utils::failure(make_error(error_code::NodeNotFound, "Parent node '" + std::string(ti.name()) + "' not found"));
     }
 
-    return utils::ok<void>();
+    return attach<Type>(name, (*result)->name());
   }
 
   /**
@@ -103,7 +167,7 @@ public:
       return utils::ok(basic_object_info_ref{result.value()->basic_info()});
   }
 
-  [[nodiscard]] utils::result<std::pair<std::string, std::string>, utils::error> reference(const std::type_index &type_index) const;
+  [[nodiscard]] utils::result<std::shared_ptr<attribute_definition>, utils::error> reference(const std::type_index &type_index) const;
 
 private:
   using node_ptr = std::shared_ptr<schema_node>;
@@ -117,11 +181,16 @@ private:
   [[nodiscard]] utils::result<std::shared_ptr<schema_node>, utils::error> find_node(const std::string &name) const;
   [[nodiscard]] utils::result<std::shared_ptr<schema_node>, utils::error> find_node(const std::type_index &type_index) const;
 
+  [[nodiscard]] bool has_node(const std::string &name) const;
+  [[nodiscard]] bool has_node(const std::type_index& index) const;
   [[nodiscard]] bool has_node(const std::type_index& index, const std::string &name) const;
 
   static void push_back_child(const node_ptr &parent, const node_ptr &child);
 
 private:
+  template <typename Type>
+  friend class type_analyzer;
+
   std::string name_;
   std::shared_ptr<schema_node> root_;
 
@@ -129,6 +198,22 @@ private:
   t_type_index_node_map type_index_node_map_;
 };
 
+template<typename Type>
+template<class ForeignPointerType>
+void type_analyzer<Type>::on_has_one(const char *, ForeignPointerType &, const utils::foreign_attributes &) {
+  auto ti = std::type_index(typeid(typename ForeignPointerType::value_type));
+  if (schema_.has_node(ti)) {
+    return;
+  }
+
+  auto info = std::make_unique<object_info<typename ForeignPointerType::value_type>>();
+
+  known_types_.insert(ti);
+
+  // const auto [ref_table, ref_column] = determine_foreign_ref(std::type_index(typeid(typename Pointer::value_type)));
+  // columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
+}
+
 }
 
 #endif //SCHEMA_HPP
diff --git a/include/matador/object/schema_node.hpp b/include/matador/object/schema_node.hpp
index 870ccc5..48a286b 100644
--- a/include/matador/object/schema_node.hpp
+++ b/include/matador/object/schema_node.hpp
@@ -15,10 +15,7 @@ class schema_node final {
 public:
   using node_ptr = std::shared_ptr<schema_node>;
 
-  template < typename Type >
-  static std::shared_ptr<schema_node> make_node(schema& tree, const std::string& name) {
-    return std::shared_ptr<schema_node>(new schema_node(tree, name, static_cast<Type*>(nullptr)));
-  }
+  static std::shared_ptr<schema_node> make_node(schema& tree, const std::string& name, std::unique_ptr<basic_object_info> &&info);
 
   schema_node(const schema_node& other) = delete;
   schema_node(schema_node&& other) = default;
@@ -41,17 +38,7 @@ public:
 
 private:
   explicit schema_node(schema& tree);
-  template < typename Type >
-  schema_node(schema& tree, std::string name, Type *obj)
-  : schema_(tree)
-  , info_(std::make_unique<object_info<Type>>(*this, object_definition(attribute_definition_generator::generate<Type>(schema_))))
-  , first_child_(std::shared_ptr<schema_node>(new schema_node(tree)))
-  , last_child_(std::shared_ptr<schema_node>(new schema_node(tree)))
-  , name_(std::move(name)) {
-    first_child_->next_sibling_ = last_child_;
-    last_child_->previous_sibling_ = first_child_;
-  }
-
+  schema_node(schema& tree, std::string name, std::unique_ptr<basic_object_info> &&info);
 
 private:
   friend class schema;
diff --git a/source/core/object/attribute_definition.cpp b/source/core/object/attribute_definition.cpp
index b081819..3c7e941 100644
--- a/source/core/object/attribute_definition.cpp
+++ b/source/core/object/attribute_definition.cpp
@@ -4,173 +4,146 @@
 #include <utility>
 
 namespace matador::object {
-
 attribute_definition::attribute_definition(const char *name)
   : name_(name)
-  , attributes_(utils::null_attributes)
-{}
+    , attributes_(utils::null_attributes) {
+}
 
 attribute_definition::attribute_definition(std::string name)
   : name_(std::move(name))
-  , attributes_(utils::null_attributes)
-{}
+    , attributes_(utils::null_attributes) {
+}
 
-attribute_definition::attribute_definition(std::string name, const utils::basic_type type, const utils::field_attributes& attr, const null_option null_opt, const size_t index)
+attribute_definition::attribute_definition(std::string name, const utils::basic_type type,
+                                           const utils::field_attributes &attr, const null_option null_opt,
+                                           const size_t index)
   : name_(std::move(name))
-  , index_(index)
-  , attributes_(attr)
-  , null_option_(null_opt)
-  , value_(type, attr.size())
-{}
+    , index_(index)
+    , attributes_(attr)
+    , null_option_(null_opt)
+    , value_(type, attr.size()) {
+}
 
 attribute_definition::attribute_definition(std::string name,
-                                     const utils::basic_type type,
-                                     const size_t index,
-                                     std::string ref_table,
-                                     std::string ref_column,
-                                     const utils::field_attributes& attr, const null_option null_opt)
+                                           const utils::basic_type type,
+                                           const size_t index,
+                                           const std::shared_ptr<attribute_definition> &ref_column,
+                                           const utils::field_attributes &attr, const null_option null_opt)
   : name_(std::move(name))
-  , index_(index)
-  , attributes_(attr)
-  , null_option_(null_opt)
-  , value_(type, attr.size())
-  , ref_table_(std::move(ref_table))
-  , ref_column_(std::move(ref_column))
-{}
+    , index_(index)
+    , attributes_(attr)
+    , null_option_(null_opt)
+    , value_(type, attr.size())
+    , reference_column_(ref_column) {
+}
 
-const std::string &attribute_definition::name() const
-{
+const std::string &attribute_definition::name() const {
   return name_;
 }
 
-std::string attribute_definition::full_name() const
-{
+std::string attribute_definition::full_name() const {
   return table_ + "." + name_;
 }
 
-std::string attribute_definition::table_name() const
-{
+std::string attribute_definition::table_name() const {
   return table_;
 }
 
-int attribute_definition::index() const
-{
+int attribute_definition::index() const {
   return index_;
 }
 
-const utils::field_attributes &attribute_definition::attributes() const
-{
+const utils::field_attributes &attribute_definition::attributes() const {
   return attributes_;
 }
 
-bool attribute_definition::is_nullable() const
-{
+bool attribute_definition::is_nullable() const {
   return null_option_ == null_option::NULLABLE;
 }
 
-utils::basic_type attribute_definition::type() const
-{
+utils::basic_type attribute_definition::type() const {
   return value_.type();
 }
 
-const std::string &attribute_definition::ref_table() const
-{
-  return ref_table_;
+std::shared_ptr<attribute_definition> attribute_definition::reference_column() const {
+  return reference_column_;
 }
 
-const std::string &attribute_definition::ref_column() const
-{
-  return ref_column_;
+bool attribute_definition::is_foreign_reference() const {
+  return reference_column_ != nullptr;
 }
 
-bool attribute_definition::is_foreign_reference() const
-{
-  return !ref_column_.empty() && !ref_table_.empty();
-}
-
-bool attribute_definition::is_integer() const
-{
+bool attribute_definition::is_integer() const {
   return value_.is_integer();
 }
 
-bool attribute_definition::is_floating_point() const
-{
+bool attribute_definition::is_floating_point() const {
   return value_.is_floating_point();
 }
 
-bool attribute_definition::is_bool() const
-{
+bool attribute_definition::is_bool() const {
   return value_.is_bool();
 }
 
-bool attribute_definition::is_string() const
-{
+bool attribute_definition::is_string() const {
   return value_.is_string();
 }
 
-bool attribute_definition::is_varchar() const
-{
+bool attribute_definition::is_varchar() const {
   return value_.is_varchar();
 }
 
-bool attribute_definition::is_date() const
-{
+bool attribute_definition::is_date() const {
   return value_.is_date();
 }
 
-bool attribute_definition::is_time() const
-{
+bool attribute_definition::is_time() const {
   return value_.is_time();
 }
 
-bool attribute_definition::is_blob() const
-{
+bool attribute_definition::is_blob() const {
   return value_.is_blob();
 }
 
-bool attribute_definition::is_null() const
-{
+bool attribute_definition::is_null() const {
   return value_.is_null();
 }
 
-void attribute_definition::type(utils::basic_type /*type*/)
-{
+void attribute_definition::type(utils::basic_type /*type*/) {
   // type_ = type;
-//  utils::initialize_by_utils::basic_type(type, value_);
+  //  utils::initialize_by_utils::basic_type(type, value_);
 }
 
-std::string attribute_definition::str() const
-{
+std::string attribute_definition::str() const {
   return value_.str();
 }
 
-std::ostream& operator<<(std::ostream &out, const attribute_definition &col)
-{
+std::ostream &operator<<(std::ostream &out, const attribute_definition &col) {
   out << col.str();
   return out;
 }
 
-attribute_definition make_column(const std::string &name, utils::basic_type type, utils::field_attributes attr, null_option null_opt)
-{
+attribute_definition make_column(const std::string &name, utils::basic_type type, utils::field_attributes attr,
+                                 null_option null_opt) {
   return {name, type, attr, null_opt};
 }
 
 template<>
-attribute_definition make_column<std::string>(const std::string &name, utils::field_attributes attr, null_option null_opt)
-{
+attribute_definition make_column<std::string>(const std::string &name, utils::field_attributes attr,
+                                              null_option null_opt) {
   return make_column(name, utils::data_type_traits<std::string>::type(attr.size()), attr, null_opt);
 }
 
 template<>
-attribute_definition make_pk_column<std::string>(const std::string &name, size_t size)
-{
+attribute_definition make_pk_column<std::string>(const std::string &name, size_t size) {
   return make_column<std::string>(name, {size, utils::constraints::FOREIGN_KEY});
 }
 
 template<>
-[[maybe_unused]] attribute_definition make_fk_column<std::string>(const std::string &name, size_t size, const std::string &ref_table,
-                                                               const std::string &ref_column)
-{
-  return {name, utils::data_type_traits<std::string>::type(size), 0, ref_table, ref_column, {size, utils::constraints::FOREIGN_KEY}, null_option::NOT_NULL};
+[[maybe_unused]] attribute_definition make_fk_column<std::string>(const std::string &name, size_t size, const std::shared_ptr<attribute_definition> &ref_column) {
+  return {
+    name, utils::data_type_traits<std::string>::type(size), 0, ref_column,
+    {size, utils::constraints::FOREIGN_KEY}, null_option::NOT_NULL
+  };
 }
 }
diff --git a/source/core/object/attribute_definition_generator.cpp b/source/core/object/attribute_definition_generator.cpp
index 9f040a7..d700816 100644
--- a/source/core/object/attribute_definition_generator.cpp
+++ b/source/core/object/attribute_definition_generator.cpp
@@ -18,7 +18,7 @@ void attribute_definition_generator::on_revision(const char *id, uint64_t &rev)
     on_attribute(id, rev);
 }
 
-std::pair<std::string, std::string> attribute_definition_generator::determine_foreign_ref(const std::type_index &ti)
+std::shared_ptr<attribute_definition> attribute_definition_generator::determine_foreign_ref(const std::type_index &ti)
 {
     return repo_.reference(ti).value();
 }
diff --git a/source/core/object/basic_object_info.cpp b/source/core/object/basic_object_info.cpp
index f56f10f..71a2b7d 100644
--- a/source/core/object/basic_object_info.cpp
+++ b/source/core/object/basic_object_info.cpp
@@ -5,22 +5,30 @@
 #include <algorithm>
 
 namespace matador::object {
-
-basic_object_info::basic_object_info(schema_node &node, const std::type_index type_index, object_definition &&definition)
+basic_object_info::basic_object_info(schema_node &node,
+                                     const std::type_index type_index,
+                                     object_definition &&definition,
+                                     std::shared_ptr<attribute_definition> &&reference_column)
 : node_(node)
 , type_index_(type_index)
-, definition_(std::move(definition)) {}
+, definition_(std::move(definition))
+, reference_column_(std::move(reference_column)) {
+}
 
 std::type_index basic_object_info::type_index() const {
-    return type_index_;
+  return type_index_;
 }
 
 std::string basic_object_info::name() const {
-    return node_.name();
+  return node_.name();
 }
 
-const object_definition& basic_object_info::definition() const {
+const object_definition &basic_object_info::definition() const {
   return definition_;
 }
 
+std::shared_ptr<attribute_definition> basic_object_info::reference_column() const {
+  return reference_column_;
+}
+
 } // namespace matador::object
diff --git a/source/core/object/schema.cpp b/source/core/object/schema.cpp
index 12a6ef6..f43f54c 100644
--- a/source/core/object/schema.cpp
+++ b/source/core/object/schema.cpp
@@ -1,14 +1,13 @@
 #include "matador/object/schema.hpp"
 
 namespace matador::object {
-
-utils::error make_error(const error_code ec, const std::string& msg) {
+utils::error make_error(const error_code ec, const std::string &msg) {
   return utils::error(ec, msg);
 }
 
-schema::schema( const std::string& name)
-: name_(name)
-, root_(std::shared_ptr<schema_node>(new schema_node(*this))) {
+schema::schema(const std::string &name)
+  : name_(name)
+    , root_(std::shared_ptr<schema_node>(new schema_node(*this))) {
   root_->first_child_ = std::shared_ptr<schema_node>(new schema_node(*this));
   root_->last_child_ = std::shared_ptr<schema_node>(new schema_node(*this));
   root_->first_child_->next_sibling_ = root_->last_child_;
@@ -35,16 +34,18 @@ std::string schema::name() const {
   return name_;
 }
 
-utils::result<std::pair<std::string, std::string>, utils::error> schema::reference( const std::type_index& type_index ) const {
-    const auto result = find_node(type_index);
-    if (!result) {
-        return utils::failure(result.err());
-    }
-    if (!result->get()->basic_info().definition().has_primary_key()) {
-        return utils::failure(make_error( error_code::Failure, "Primary key not found" ));
-    }
+utils::result<std::shared_ptr<attribute_definition>, utils::error> schema::reference(const std::type_index &type_index) const {
+  const auto result = find_node(type_index);
+  if (!result) {
+    return utils::failure(result.err());
+  }
 
-    return utils::ok(std::make_pair(result->get()->name(), result->get()->basic_info().definition().primary_key()->name()));
+  const auto &node = *result;
+  if (!node->basic_info().definition().has_primary_key()) {
+    return utils::failure(make_error(error_code::Failure, "Primary key not found"));
+  }
+
+  return utils::ok(std::make_pair(node->name(), node->basic_info().definition().primary_key()->name()));
 }
 
 utils::result<std::shared_ptr<schema_node>, utils::error> schema::attach_node(const std::shared_ptr<schema_node> &node,
@@ -72,8 +73,8 @@ utils::result<std::shared_ptr<schema_node>, utils::error> schema::attach_node(co
   return utils::ok(node);
 }
 
-utils::result<std::shared_ptr<schema_node>, utils::error> schema::attach_node( const std::shared_ptr<schema_node>& node,
-                                                                               const std::type_index& type_index ) {
+utils::result<std::shared_ptr<schema_node>, utils::error> schema::attach_node(const std::shared_ptr<schema_node> &node,
+                                                                              const std::type_index &type_index) {
   if (has_node(node->type_index(), node->name())) {
     return utils::failure(make_error(error_code::NodeAlreadyExists, "Node '" + node->name() + "' already exists."));
   }
@@ -100,10 +101,11 @@ utils::result<std::shared_ptr<schema_node>, utils::error> schema::find_node(cons
   return utils::ok(i->second);
 }
 
-utils::result<std::shared_ptr<schema_node>, utils::error> schema::find_node( const std::type_index& type_index ) const {
+utils::result<std::shared_ptr<schema_node>, utils::error> schema::find_node(const std::type_index &type_index) const {
   const auto i = type_index_node_map_.find(type_index);
   if (i == type_index_node_map_.end()) {
-    return utils::failure(make_error(error_code::NodeNotFound, "Couldn't find node by type '" + std::string(type_index.name()) + "'"));
+    return utils::failure(make_error(error_code::NodeNotFound,
+                                     "Couldn't find node by type '" + std::string(type_index.name()) + "'"));
   }
   return utils::ok(i->second);
 }
@@ -124,8 +126,15 @@ void schema::push_back_child(const node_ptr &parent, const node_ptr &child) {
   // child->depth = depth + 1;
 }
 
+bool schema::has_node(const std::string &name) const {
+  return node_map_.count(name) > 0;
+}
+
+bool schema::has_node(const std::type_index &index) const {
+  return type_index_node_map_.count(index) > 0;
+}
+
 bool schema::has_node(const std::type_index &index, const std::string &name) const {
   return node_map_.count(name) > 0 || type_index_node_map_.count(index) > 0;
 }
-
 } // namespace matador::object
diff --git a/source/core/object/schema_node.cpp b/source/core/object/schema_node.cpp
index afee774..1c38fcc 100644
--- a/source/core/object/schema_node.cpp
+++ b/source/core/object/schema_node.cpp
@@ -3,11 +3,25 @@
 #include "matador/object/schema_node.hpp"
 
 namespace matador::object {
-
-schema_node::schema_node(object::schema &tree)
+schema_node::schema_node(schema &tree)
 : schema_(tree)
-, info_(std::make_unique<null_info>(*this, object_definition{}))
-{}
+, info_(std::make_unique<null_info>(*this, object_definition{})) {
+}
+
+schema_node::schema_node(schema &tree, std::string name, std::unique_ptr<basic_object_info> &&info)
+: schema_(tree)
+, info_(std::move(info))
+// , info_(std::make_unique<object_info<Type>>(*this, object_definition(attribute_definition_generator::generate<Type>(schema_))))
+, first_child_(std::shared_ptr<schema_node>(new schema_node(tree)))
+, last_child_(std::shared_ptr<schema_node>(new schema_node(tree)))
+, name_(std::move(name)) {
+  first_child_->next_sibling_ = last_child_;
+  last_child_->previous_sibling_ = first_child_;
+}
+
+std::shared_ptr<schema_node> schema_node::make_node(schema &tree, const std::string &name, std::unique_ptr<basic_object_info> &&info) {
+  return std::shared_ptr<schema_node>(new schema_node(tree, name, std::move(info)));
+}
 
 std::string schema_node::name() const {
   return name_;
@@ -17,41 +31,40 @@ std::type_index schema_node::type_index() const {
   return info_->type_index();
 }
 
-const basic_object_info& schema_node::basic_info() const {
+const basic_object_info &schema_node::basic_info() const {
   return *info_;
 }
 
 schema_node::node_ptr schema_node::next() const {
-    // if we have a child, child is the next iterator to return
-    // (if we don't do iterate over the siblings)
-    if (first_child_ && first_child_->next_sibling_ != last_child_) {
-        return first_child_->next_sibling_;
-    }
-    // if there is no child, we check for sibling
-    // if there is a sibling, this is our next iterator to return
-    // if not, we go back to the parent
-    auto *node = this;
-    while (node->parent_ && node->next_sibling_ == node->parent_->last_child_) {
-        node = node->parent_.get();
-    }
-    return node->parent_ ? node->next_sibling_ : node->last_child_;
+  // if we have a child, child is the next iterator to return
+  // (if we don't do iterate over the siblings)
+  if (first_child_ && first_child_->next_sibling_ != last_child_) {
+    return first_child_->next_sibling_;
+  }
+  // if there is no child, we check for sibling
+  // if there is a sibling, this is our next iterator to return
+  // if not, we go back to the parent
+  auto *node = this;
+  while (node->parent_ && node->next_sibling_ == node->parent_->last_child_) {
+    node = node->parent_.get();
+  }
+  return node->parent_ ? node->next_sibling_ : node->last_child_;
 }
 
 schema_node::node_ptr schema_node::prev() const {
-    // if node has a previous sibling, we set it
-    // as our next iterator. then we check if there
-    // are last children. if so, we set the last-last
-    // child as our iterator
-    if (previous_sibling_ && previous_sibling_->previous_sibling_) {
-        auto node = previous_sibling_;
-        while (node->last_child_ && node->first_child_->next_sibling_ != node->last_child_) {
-            node = node->last_child_->previous_sibling_;
-        }
-        return node;
+  // if node has a previous sibling, we set it
+  // as our next iterator. then we check if there
+  // are last children. if so, we set the last-last
+  // child as our iterator
+  if (previous_sibling_ && previous_sibling_->previous_sibling_) {
+    auto node = previous_sibling_;
+    while (node->last_child_ && node->first_child_->next_sibling_ != node->last_child_) {
+      node = node->last_child_->previous_sibling_;
     }
-    // if there is no previous sibling, our next iterator
-    // is the parent of the node
-    return parent_->parent_ ? parent_ : parent_->first_child_->next_sibling_;
+    return node;
+  }
+  // if there is no previous sibling, our next iterator
+  // is the parent of the node
+  return parent_->parent_ ? parent_ : parent_->first_child_->next_sibling_;
 }
-
 }