insert query builder has many to many progress

include/matador/query/insert_query_builder.hpp

@@ -128,14 +128,14 @@ public:
   }
   template<class CollectionType>
   static void on_has_many(const char * /*id*/, object::collection<CollectionType> &/*con*/, const char *, const utils::foreign_attributes &/*attr*/) {}
-  template<class Collection>
-  void on_has_many_to_many(const char *id, Collection &container, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes & ) {
+
+  template<class ForeignType>
+  void on_has_many_to_many(const char *id, object::collection<object::object_ptr<ForeignType>> &objects, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr) {
     if (id == nullptr || join_column == nullptr || inverse_join_column == nullptr) {
       return;
     }
-    if (current_entity_pk_ == 0ULL) {
-      // Without a local PK we cannot create relation rows
-      // (PK may be assigned later by Identity; that case needs a different mechanism than requested here)
+
+    if (!utils::is_cascade_type_set(attr.cascade(), utils::cascade_type::Insert)) {
       return;
     }
 
@@ -143,38 +143,92 @@ public:
     if (it == schema_.end()) {
       throw query_builder_exception(query_build_error::UnknownType);
     }
-    const table &relation_table = it->second.table();
 
-    for (auto &obj : container) {
+    using relation_value_type = object::many_to_many_relation<ObjectType, ForeignType>;
+
+    if (std::type_index(typeid(relation_value_type)) != it->second.node().info().type_index()) {
+      throw query_builder_exception(query_build_error::InvalidRelationType);
+    }
+
+    for (auto &obj : objects) {
       if (!obj) {
         continue;
       }
 
-      // Ensure target exists as dependency (deps first)
-      if (!obj.is_persistent()) {
-        using dep_t = std::remove_reference_t<decltype(*obj)>;
-        build_for<dep_t>(obj, steps_);
-      }
-
-      // Extract FK value from the foreign object
-      insert_step rel_step{};
-      const auto pk = rel_step.pk_accessor.get(*obj);
-      if (pk.is_valid()) {
+      if (obj.is_persistent()) {
         continue;
       }
 
-      // Build INSERT into relation table with the 2 FK columns
-      // rel_step.query = executable_query{
-        // insert()
-          // .into(relation_table, {table_column{&relation_table, join_column}, table_column{&relation_table, inverse_join_column}})
-          // .values({utils::database_type{current_entity_pk_}, utils::database_type{fk.value}})
-      // };
+      // Ensure target exists as dependency (deps first)
+      if (obj.is_transient()) {
+        build_for(obj, relation_steps_);
+      }
+
+      auto rel = object::make_object<relation_value_type>(join_column, inverse_join_column, ptr_, obj);
+
+      // Extract FK value from the foreign object
+      insert_step rel_step{};
+      // const auto pk = rel_step.pk_accessor.get(*obj);
+      // if (pk.is_valid()) {
+        // continue;
+      // }
+
       relation_steps_.push_back(std::move(rel_step));
     }
   }
-  template<class C>
-  static void on_has_many_to_many(const char * /*id*/, C &, const utils::foreign_attributes & ) {}
+  template<class ForeignType>
+  void on_has_many_to_many(const char *id, object::collection<object::object_ptr<ForeignType>> &objects, const utils::foreign_attributes &attr) {
+    if (!utils::is_cascade_type_set(attr.cascade(), utils::cascade_type::Insert)) {
+      return;
+    }
 
+    object::join_columns_collector collector;
+    auto join_columns = collector.collect<ForeignType>();
+
+    const auto it = schema_.find(std::string{id});
+    if (it == schema_.end()) {
+      throw query_builder_exception(query_build_error::UnknownType);
+    }
+
+    using relation_value_type = object::many_to_many_relation<ForeignType, ObjectType>;
+
+    if (std::type_index(typeid(relation_value_type)) != it->second.node().info().type_index()) {
+      throw query_builder_exception(query_build_error::InvalidRelationType);
+    }
+
+    for (auto &obj : objects) {
+      if (!obj) {
+        continue;
+      }
+
+      if (obj.is_persistent()) {
+        continue;
+      }
+
+      // Ensure target exists as dependency (deps first)
+      if (obj.is_transient()) {
+        build_for(obj, relation_steps_);
+      }
+
+      auto rel = object::make_object<relation_value_type>(join_columns.inverse_join_column, join_columns.join_column, obj, ptr_);
+
+      // Extract FK value from the foreign object
+      insert_step rel_step{};
+      // const auto pk = rel_step.pk_accessor.get(*obj);
+      // if (pk.is_valid()) {
+        // continue;
+      // }
+
+      relation_steps_.push_back(std::move(rel_step));
+    }
+  }
+
+  template<class CollectionType>
+  void process_has_many_to_many(const char *id, CollectionType &objects, const char *join_column, const char *inverse_join_column) {
+    if (id == nullptr || join_column == nullptr || inverse_join_column == nullptr) {
+      return;
+    }
+  }
 private:
   template<class EntityType>
   static std::pair<std::type_index, const void *> make_visit_key(const object::object_ptr<EntityType> &ptr) {
@@ -264,9 +318,6 @@ private:
   std::vector<insert_step> steps_;
   std::vector<insert_step> relation_steps_;
   std::unordered_set<std::pair<std::type_index, const void *>, visit_key_hash> visited_;
-
-
-  std::uint64_t current_entity_pk_{0};
 };
 }
 #endif //MATADOR_INSERT_QUERY_BUILDER_HPP

include/matador/query/query_builder_exception.hpp

@@ -13,7 +13,8 @@ enum class query_build_error : std::uint8_t {
   MissingPrimaryKey,
   MissingObject,
   UnexpectedError,
-  QueryError
+  QueryError,
+  InvalidRelationType
 };
 
 class query_builder_exception final : public std::exception {