/*
 * This file is a part of morm
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/*
 * Copyright (c) 2018-2021, Tomasz Sowa
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef headerfile_morm_model
#define headerfile_morm_model

#include <string>
#include <list>
#include <vector>
#include <typeinfo>
#include <type_traits>

#include "textstream/textstream.h"
#include "modelconnector.h"
#include "dbexpression.h"
#include "flatexpression.h"
#include "modelenv.h"


namespace morm
{


class Model
{
public:

	enum SaveMode
	{
		DO_INSERT_ON_SAVE = 0,
		DO_UPDATE_ON_SAVE,
		DO_DELETE_ON_SAVE,
		DO_NOTHING_ON_SAVE,
	};

	virtual void     set_save_mode(SaveMode save_mode);
	virtual SaveMode get_save_mode();

	virtual void set_has_primary_key_set(bool has_primary_key);
	virtual bool get_has_primary_key_set();

	virtual void mark_to_delete();
	virtual void mark_to_remove();

	virtual void mark_to_insert();
	virtual void mark_to_update();

	virtual bool object_exists();
	virtual bool found();


	void set_connector(ModelConnector & connector);
	void set_connector(ModelConnector * connector);
	ModelConnector * get_connector();

	/*
	 * map fields to names
	 *
	 *
	 */
	virtual void map_fields() = 0;



	/*
	 *
	 * we can use the object for a different purpose than database (e.g. json)
	 * so let the table_name be non pure-virtual
	 *
	 */
	virtual void table_name(PT::TextStream & stream);

	virtual void to_text(PT::TextStream & stream, ModelData * model_data, bool clear_stream = true, bool dump_mode = false);
	virtual void to_text(PT::TextStream & stream, ModelData & model_data, bool clear_stream = true, bool dump_mode = false);
	virtual void to_text(PT::TextStream & stream, bool clear_stream = true, bool dump_mode = false);

	virtual void to_text(std::string & str, ModelData * model_data, bool clear_string = true, bool dump_mode = false);
	virtual void to_text(std::string & str, ModelData & model_data, bool clear_string = true, bool dump_mode = false);
	virtual void to_text(std::string & str, bool clear_string = true, bool dump_mode = false);

	virtual std::string to_text();
	virtual std::string to_string();

	virtual void generate_insert_query(PT::TextStream & stream, ModelData * model_data = nullptr);
	virtual bool insert(ModelData * model_data, bool insert_whole_tree = true);
	virtual bool insert(ModelData & model_data, bool insert_whole_tree = true);
	virtual bool insert(bool insert_whole_tree = true);

	virtual void generate_update_query(PT::TextStream & stream, ModelData * model_data = nullptr);
	virtual bool update(ModelData * model_data, bool update_whole_tree = true);
	virtual bool update(ModelData & model_data, bool update_whole_tree = true);
	virtual bool update(bool update_whole_tree = true);

	virtual void generate_remove_query(PT::TextStream & stream, ModelData * model_data = nullptr);
	virtual bool remove(ModelData * model_data, bool remove_whole_tree = true);
	virtual bool remove(ModelData & model_data, bool remove_whole_tree = true);
	virtual bool remove(bool remove_whole_tree = true);

	virtual bool save(ModelData * model_data, bool save_whole_tree = true);
	virtual bool save(ModelData & model_data, bool save_whole_tree = true);
	virtual bool save(bool save_whole_tree = true);


	virtual void generate_select_columns(PT::TextStream & stream);

	// set object to default values
	virtual void clear();

	// IMPROVE ME this will be protected
	// add set_field_value() functions for each POD type
	template<typename FieldValue>
	void set_field_value_generic(const wchar_t * db_field_name, const wchar_t * flat_field_name, const FieldValue & field_value)
	{
		ModelEnv model_env_local;
		model_env = &model_env_local;
		model_env->model_work_mode = MORM_MODEL_WORK_MODE_SET_FIELD_VALUE;
		model_env->field_index = 0;

		FieldValueHelper field_value_helper;
		field_value_helper.db_field_name   = db_field_name;
		field_value_helper.flat_field_name = flat_field_name;
		field_value_helper.value_object    = &field_value;
		field_value_helper.value_type_info = &typeid(field_value);

		std::vector<FieldValueHelper> helper_tab;
		helper_tab.push_back(field_value_helper);
		model_env->field_value_helper_tab = &helper_tab;

		map_fields();

		if( !helper_tab.back().found && model_connector )
		{
			PT::Log * plog = model_connector->get_logger();

			if( plog )
			{
				(*plog) << "Morm: I cannot find such a property: ";
				put_fields_to_log(*plog, db_field_name, flat_field_name);
				(*plog) << PT::Log::logend;
			}
		}

		// what if an exception was thrown?
		model_env = nullptr;
	}


protected:

	ModelConnector * model_connector;
	ModelEnv * model_env;
	SaveMode save_mode;
	bool has_primary_key_set;



	Model();
	Model(const Model & m);
	virtual ~Model();

	virtual void before_select();
	virtual void before_insert();
	virtual void before_update();
	virtual void before_remove();

	virtual void after_select();
	virtual void after_insert();
	virtual void after_update();
	virtual void after_remove();

	virtual void after_select_failure();
	virtual void after_insert_failure();
	virtual void after_update_failure();
	virtual void after_remove_failure();

	virtual int get_work_mode();

	virtual ModelData * get_model_data();

	virtual bool insert_tree(bool insert_whole_tree);
	virtual bool update_tree(bool update_whole_tree);
	virtual bool remove_tree(bool remove_whole_tree);
	virtual bool save_tree(bool save_whole_tree);

	virtual void map_values_from_query();


	/////////////////////////////////
	/*
	 * IMPLEMENT ME
	 * field methods for such field_values: signed char, wchar_t, char16_t, char32_t, std::u16string, std::u32string
	 *
	 */

	void field(const wchar_t * field_name, char & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, unsigned char & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, std::wstring & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * field_name, wchar_t * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * field_name, std::string & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * field_name, char * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * field_name, bool & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, short & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, unsigned short & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, int & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, unsigned int & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, unsigned long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, long long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, unsigned long long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, float & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, double & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, long double & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * field_name, void * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * field_name, PT::Date & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(field_name, field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * field_name, Model & field_value, bool insertable = true, bool updatable = true, bool has_foreign_key = true)
	{
		field_model(field_name, field_name, field_value, insertable, updatable, has_foreign_key);
	}

	template<typename ModelClass>
	void field(const wchar_t * field_name, std::list<ModelClass> & field_value, bool insertable = true, bool updatable = true)
	{
		ModelClass * list_model_null_pointer = nullptr;
		field_list(field_name, field_name, field_value, list_model_null_pointer, insertable, updatable);
	}

	template<typename ModelClass>
	void field(const wchar_t * field_name, std::vector<ModelClass> & field_value, bool insertable = true, bool updatable = true)
	{
		ModelClass * list_model_null_pointer = nullptr;
		field_list(field_name, field_name, field_value, list_model_null_pointer, insertable, updatable);
	}

//////////////////////

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, char & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, unsigned char & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, std::wstring & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, wchar_t * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, std::string & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, char * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, bool & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, short & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, unsigned short & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, int & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, unsigned int & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, unsigned long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, long long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, unsigned long long & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, float & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, double & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, long double & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}

//	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, void * field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
//	{
//		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
//	}

	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, PT::Date & field_value, bool insertable = true, bool updatable = true, bool is_primary_key = false)
	{
		field_generic(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
	}


	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_value, bool insertable = true, bool updatable = true, bool has_foreign_key = true)
	{
		field_model(db_field_name, flat_field_name, field_value, insertable, updatable, has_foreign_key);
	}

	template<typename ModelClass>
	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, std::list<ModelClass> & field_value, bool insertable = true, bool updatable = true)
	{
		ModelClass * list_model_null_pointer = nullptr;
		field_list(db_field_name, flat_field_name, field_value, list_model_null_pointer, insertable, updatable);
	}

	template<typename ModelClass>
	void field(const wchar_t * db_field_name, const wchar_t * flat_field_name, std::vector<ModelClass> & field_value, bool insertable = true, bool updatable = true)
	{
		ModelClass * list_model_null_pointer = nullptr;
		field_list(db_field_name, flat_field_name, field_value, list_model_null_pointer, insertable, updatable);
	}



protected:


	template<typename FieldValue>
	void field_generic_set_field_value(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		if( model_env->field_value_helper_tab )
		{
			if( model_env->field_index >= 0 && (size_t)model_env->field_index < model_env->field_value_helper_tab->size() )
			{
				FieldValueHelper & helper = (*model_env->field_value_helper_tab)[model_env->field_index];
				PT::Log * log = model_connector->get_logger();

				if( (!helper.compare_db_field_name || is_the_same_field(db_field_name, helper.db_field_name)) &&
					(!helper.compare_flat_field_name || is_the_same_field(flat_field_name, helper.flat_field_name)) )
				{
					if( helper.value_object && helper.value_type_info )
					{
						if( typeid(field_value) == *helper.value_type_info )
						{
							field_value = *(FieldValue*)helper.value_object;
						}
						else
						{
							table_name(model_env->table_name);

							if( log )
							{
								(*log) << PT::Log::log1 << "Morm: incorrect type of a field in " << model_env->table_name << ", ";
								put_fields_to_log(*log, db_field_name, flat_field_name);
								(*log) << ", type expected " << typeid(field_value).name()
									   << " got " << helper.value_type_info->name() << PT::Log::logend;
							}
						}
					}

					helper.found = true;
					model_env->field_index += 1;
				}
			}
		}
	}

	template<typename FieldValue>
	void field_generic_iterate_primary_key_values(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		if( is_primary_key )
		{
			if( model_env->field_value_helper_tab )
			{
				if( model_env->field_index >= 0 && (size_t)model_env->field_index < model_env->field_value_helper_tab->size() )
				{
					FieldValueHelper & helper = (*model_env->field_value_helper_tab)[model_env->field_index];
					helper.value_object = &field_value;
					helper.value_type_info = &typeid(field_value);
				}
			}

			model_env->field_index += 1;
		}
	}

	template<typename FieldValue>
	void field_generic_generate_flat_string(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		FlatConnector * flat_connector = model_connector->get_flat_connector();

		if( flat_connector )
		{
			FlatExpression * flat_expression = flat_connector->get_expression();

			if( flat_expression && !is_empty_field(flat_field_name) )
			{
				// insertable, updatable and is_primary_key are ignored here
				flat_expression->field(flat_field_name, field_value, insertable, updatable, is_primary_key, model_env);
			}
		}
	}

	template<typename FieldValue>
	void field_generic_generate_db_sql(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector )
		{
			DbExpression * db_expression = db_connector->get_expression();

			if( db_expression && !is_empty_field(db_field_name) )
			{
				db_expression->field(db_field_name, field_value, insertable, updatable, is_primary_key, model_env);
			}
		}
	}

	template<typename FieldValue>
	void field_generic_read_value_from_db_resultset(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector )
		{
			if( !is_empty_field(db_field_name) )
			{
				if( model_env->cursor_helper && model_env->cursor_helper->has_autogenerated_select )
				{
					get_value_by_field_index(model_env->cursor_helper->current_column, field_value, is_primary_key);
					model_env->cursor_helper->current_column += 1;
				}
				else
				{
					get_value_by_field_name(db_field_name, field_value, is_primary_key);
				}
			}
		}
	}

	template<typename FieldValue>
	void field_generic_clear_value(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		Clearer * clearer = model_connector->get_clearer();

		if( clearer )
		{
			clearer->clear_value(field_value);
		}
	}


	template<typename FieldValue>
	void field_generic(const wchar_t * db_field_name, const wchar_t * flat_field_name, FieldValue & field_value, bool insertable, bool updatable, bool is_primary_key)
	{
		if( model_connector && model_env )
		{
			if( is_primary_key )
			{
				model_env->was_primary_key_read = true;
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_SET_FIELD_VALUE )
			{
				field_generic_set_field_value(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_ITERATE_PRIMARY_KEY_VALUES )
			{
				field_generic_iterate_primary_key_values(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_FLAT_STRING )
			{
				field_generic_generate_flat_string(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_DB_SQL )
			{
				field_generic_generate_db_sql(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_READING_VALUE_FROM_DB_RESULTSET )
			{
				field_generic_read_value_from_db_resultset(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_CLEARING_VALUE )
			{
				field_generic_clear_value(db_field_name, flat_field_name, field_value, insertable, updatable, is_primary_key);
			}
		}
	}


	/*
	 * IMPROVE ME there can be more rows in the result set when there are more items on the left hand side of the join
	 * this is only in a case when has_foreign_key is false, may it can be ignored? we can use unique index in such a case
	 *
	 */
	void field_model_left_join(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable, bool has_foreign_key, DbExpression * db_expression)
	{
		if( model_env && field_model.model_env && model_env->finder_helper )
		{
			model_env->finder_helper->foreign_keys.clear();
			PT::TextStream & join_tables_str = model_env->finder_helper->join_tables_str;
			field_model.model_env->table_index = model_env->finder_helper->add_join_table(field_model.model_env->table_name_short);

			join_tables_str << "LEFT JOIN " << field_model.model_env->table_name << " AS ";
			field_model.put_table_name_with_index(join_tables_str);

			int expr_work_mode = db_expression->get_work_mode();
			int expr_output_type = db_expression->get_output_type();
			bool expr_allow_prefix = db_expression->get_allow_to_use_prefix();

			db_expression->set_work_mode(MORM_WORK_MODE_MODEL_SAVE_FIELDS);
			db_expression->set_output_type(MORM_OUTPUT_TYPE_JOIN_TABLES);
			db_expression->allow_to_use_prefix(false);

			if( has_foreign_key )
			{
				field_model.map_fields();

				join_tables_str << " ON ";
				put_table_name_with_index(join_tables_str);
				join_tables_str << '.' << db_field_name << " = ";
				field_model.put_table_name_with_index(join_tables_str);
				join_tables_str << '.';

				// IMPROVE ME at the moment support only for foreign keys consisting of only one column
				if( model_env->finder_helper->foreign_keys.size() == 1 )
				{
					join_tables_str << model_env->finder_helper->foreign_keys.front();
				}
			}
			else
			{
				ModelEnv * old_model_env = field_model.model_env;
				map_fields(); // map_fields() will set field_model.model_env to null
				field_model.model_env =  old_model_env;

				join_tables_str << " ON ";
				put_table_name_with_index(join_tables_str);
				join_tables_str << '.';

				// IMPROVE ME at the moment support only for foreign keys consisting of only one column
				if( model_env->finder_helper->foreign_keys.size() == 1 )
				{
					join_tables_str << model_env->finder_helper->foreign_keys.front();
				}

				join_tables_str << " = ";
				field_model.put_table_name_with_index(join_tables_str);
				join_tables_str << '.' << db_field_name;
			}

			join_tables_str << ' ';

			db_expression->set_work_mode(expr_work_mode);
			db_expression->set_output_type(expr_output_type);
			db_expression->allow_to_use_prefix(expr_allow_prefix);
		}
	}


	/*
	 * first we iterate through fields and save primary key values to helper_tab
	 */
	void field_model_save_key(const wchar_t * db_field_name)
	{
		DbConnector * db_connector = model_connector->get_db_connector();
		PT::Log * plog = model_connector->get_logger();

		if( db_connector )
		{
			DbExpression * db_expression = db_connector->get_expression();

			if( db_expression && !is_empty_field(db_field_name) && model_env->field_value_helper_tab )
			{
				int old_work_mode = model_env->model_work_mode;
				model_env->model_work_mode = MORM_MODEL_WORK_MODE_ITERATE_PRIMARY_KEY_VALUES;
				model_env->field_index = 0;
				map_fields();
				model_env->model_work_mode = old_work_mode;

				if( model_env->field_value_helper_tab->empty() && plog )
				{
					(*plog) << "Morm: I cannot find a primary key in " << model_env->table_name << PT::Log::logend;
				}
			}
		}
	}


	/*
	 * now we iterate through fields in field_model and save primary key values from *this object to the specified fields in field_model
	 */
	void field_model_set_parent_key_in_child(const wchar_t * db_field_name, Model & field_model)
	{
		DbConnector * db_connector = model_connector->get_db_connector();
		PT::Log * log = model_connector->get_logger();

		if( db_connector )
		{
			DbExpression * db_expression = db_connector->get_expression();

			if( db_expression && !is_empty_field(db_field_name) && model_env->field_value_helper_tab )
			{
				std::vector<FieldValueHelper> & helper_tab = *model_env->field_value_helper_tab;

				if( (size_t)model_env->field_index == helper_tab.size() )
				{
					ModelEnv model_env_local;
					model_env_local.copy_global_objects(*model_env);
					model_env_local.has_primary_key_set = field_model.has_primary_key_set;
					model_env_local.model_work_mode = MORM_MODEL_WORK_MODE_SET_FIELD_VALUE;
					model_env_local.field_value_helper_tab = &helper_tab;
					model_env_local.field_index = 0;
					field_model.model_env = &model_env_local;

					field_model.map_fields();

					if( (size_t)field_model.model_env->field_index != helper_tab.size() && log )
					{
						if( model_env->table_name.empty() )
							table_name(model_env->table_name);

						if( field_model.model_env->table_name.empty() )
							field_model.table_name(field_model.model_env->table_name);

						(*log) << PT::Log::log1 << "Morm: primary key in " << model_env->table_name << " consists of " << model_env->field_index << " column(s)"
							   << " but in " << field_model.model_env->table_name << " there are only "
							   << field_model.model_env->field_index << " matching column(s)" << PT::Log::logend;
					}

					field_model.model_env = nullptr;
				}
				else
				if( log )
				{
					table_name(model_env->table_name);

					(*log) << PT::Log::log1 << "Morm: primary key in " << model_env->table_name << " consists of incorrect number of columns"
						   << ", expected " << helper_tab.size() << " column(s) but got " << model_env->field_index << PT::Log::logend;
				}
			}
		}
	}


	void field_model_set_parent_key(const wchar_t * db_field_name, Model & field_model)
	{
		FieldValueHelper helper;
		helper.db_field_name = db_field_name;
		helper.flat_field_name = nullptr;
		helper.compare_flat_field_name = false;

		std::vector<FieldValueHelper> helper_tab;
		helper_tab.push_back(helper);
		// only one column at the moment, in the future we can have a primary key from more than one column

		model_env->field_value_helper_tab = &helper_tab;

		field_model_save_key(db_field_name);
		field_model_set_parent_key_in_child(db_field_name, field_model);

		model_env->field_value_helper_tab = nullptr;
	}


	void field_model_iterate_through_childs(const wchar_t * db_field_name, Model & field_model)
	{
		if( !is_empty_field(db_field_name) )
		{
			if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_INSERT )
			{
				field_model.insert_tree(true);
			}

			if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_UPDATE )
			{
				field_model.update_tree(true);
			}

			if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_REMOVE )
			{
				field_model.remove_tree(true);
			}

			if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_SAVE )
			{
				field_model.save_tree(true);
			}
		}
	}



	void field_model_generate_flat_string(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable)
	{
		FlatConnector * flat_connector = model_connector->get_flat_connector();

		if( flat_connector )
		{
			FlatExpression * flat_expression = flat_connector->get_expression();

			if( flat_expression && !is_empty_field(flat_field_name) )
			{
				if( model_env->dump_mode || field_model.save_mode == DO_INSERT_ON_SAVE || field_model.save_mode == DO_UPDATE_ON_SAVE )
				{
					field_model.model_env->model_work_mode = MORM_MODEL_WORK_MODE_GENERATING_FLAT_STRING;
					flat_expression->field_model(flat_field_name, field_model, insertable, updatable, false, model_env);
				}
			}
		}
	}


	void field_model_generate_db_sql(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable, bool has_foreign_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector )
		{
			DbExpression * db_expression = db_connector->get_expression();

			if( db_expression && !is_empty_field(db_field_name) )
			{
				field_model.model_env->model_work_mode = MORM_MODEL_WORK_MODE_GENERATING_DB_SQL;

				field_model.table_name(field_model.model_env->table_name);
				db_expression->prepare_short_table_name(field_model.model_env->table_name, field_model.model_env->table_name_short);

				if( db_expression->get_output_type() == MORM_OUTPUT_TYPE_SELECT_COLUMNS )
				{
					field_model_left_join(db_field_name, flat_field_name, field_model, insertable, updatable, has_foreign_key, db_expression);
				}

				if( has_foreign_key )
				{
					if( db_expression->get_work_mode() == MORM_WORK_MODE_MODEL_FIELDS && db_expression->get_output_type() == MORM_OUTPUT_TYPE_DB_INSERT )
					{
						if( insertable )
						{
							int not_used_object = 0;
							db_expression->field(db_field_name, not_used_object, insertable, updatable, false, model_env);
						}
					}

					if( db_expression->get_work_mode() == MORM_WORK_MODE_MODEL_VALUES && db_expression->get_output_type() == MORM_OUTPUT_TYPE_DB_INSERT )
					{
						if( insertable )
						{
							db_expression->set_output_type(MORM_OUTPUT_TYPE_DB_INSERT_PRIMARY_KEY);
							field_model.map_fields();
							db_expression->set_output_type(MORM_OUTPUT_TYPE_DB_INSERT);
						}
					}

					if( db_expression->get_work_mode() == MORM_WORK_MODE_MODEL_FIELDS_VALUES && db_expression->get_output_type() == MORM_OUTPUT_TYPE_DB_UPDATE )
					{
						if( updatable )
						{
							std::vector<const wchar_t *> key_fields;
							key_fields.push_back(db_field_name); // at the moment only one key

							db_expression->set_output_type(MORM_OUTPUT_TYPE_DB_UPDATE_PRIMARY_KEY);
							field_model.model_env->field_index = 0;
							field_model.model_env->set_field_name_helper = &key_fields;
							field_model.map_fields();
							db_expression->set_output_type(MORM_OUTPUT_TYPE_DB_UPDATE);

							if( (size_t)field_model.model_env->field_index != key_fields.size() )
							{
								// IMPROVEME
								// number of keys are different
								// put error log here
							}
						}
					}
				}

				if( db_expression->get_output_type() != MORM_OUTPUT_TYPE_JOIN_TABLES &&
					db_expression->get_output_type() != MORM_OUTPUT_TYPE_DB_PRIMARY_KEY &&
					db_expression->get_output_type() != MORM_OUTPUT_TYPE_DB_INSERT &&
					db_expression->get_output_type() != MORM_OUTPUT_TYPE_DB_UPDATE )
				{
					field_model.map_fields();
				}

				field_model.model_env->model_work_mode = MORM_MODEL_WORK_MODE_NONE;
			}
		}
	}


	void field_model_clear_values(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable, bool has_foreign_key)
	{
		Clearer * clearer = model_connector->get_clearer();

		if( clearer )
		{
			clearer->clear_model(field_model);
		}
	}


	void field_model_read_values_from_queryresult(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable, bool has_foreign_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector )
		{
			if( !is_empty_field(db_field_name) )
			{
				DbExpression * db_expression = db_connector->get_expression();

				if( db_expression )
				{
					if( model_env->cursor_helper &&
						!model_env->cursor_helper->has_autogenerated_select &&
						model_env->cursor_helper->use_table_prefix_for_fetching_values )
					{
						field_model.prepare_table_names();
					}

					field_model.before_select();
					field_model.map_values_from_query();

					if( field_model.found() )
					{
						field_model.after_select();
					}
				}
			}
		}
	}

	void field_model(const wchar_t * db_field_name, const wchar_t * flat_field_name, Model & field_model, bool insertable, bool updatable, bool has_foreign_key)
	{
		if( model_connector && model_env )
		{
			ModelEnv model_env_local;
			model_env_local.copy_global_objects(*model_env);

			field_model.model_env = &model_env_local;
			field_model.model_env->has_primary_key_set = field_model.has_primary_key_set;
			field_model.set_connector(model_connector);

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_SET_PARENT_ID )
			{
				if( !has_foreign_key )
				{
					field_model_set_parent_key(db_field_name, field_model);
				}
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_ITERATE_THROUGH_CHILDS_WITH_FOREIGN_KEY )
			{
				if( has_foreign_key )
				{
					field_model_iterate_through_childs(db_field_name, field_model);
				}
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_ITERATE_THROUGH_CHILDS_WITHOUT_FOREIGN_KEY )
			{
				if( !has_foreign_key )
				{
					field_model_iterate_through_childs(db_field_name, field_model);
				}
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_FLAT_STRING )
			{
				field_model_generate_flat_string(db_field_name, flat_field_name, field_model, insertable, updatable);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_DB_SQL )
			{
				field_model_generate_db_sql(db_field_name, flat_field_name, field_model, insertable, updatable, has_foreign_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_CLEARING_VALUE )
			{
				field_model_clear_values(db_field_name, flat_field_name, field_model, insertable, updatable, has_foreign_key);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_READING_VALUE_FROM_DB_RESULTSET )
			{
				field_model_read_values_from_queryresult(db_field_name, flat_field_name, field_model, insertable, updatable, has_foreign_key);
			}

			field_model.model_env = nullptr;
		}
	}


	template<typename ModelContainer, typename ModelContainerType>
	void field_list_set_parent_key(const wchar_t * db_field_name, ModelContainer & field_container, ModelContainerType * model_container_type)
	{
		FieldValueHelper helper;
		helper.db_field_name = db_field_name;
		helper.flat_field_name = nullptr;
		helper.compare_flat_field_name = false;

		std::vector<FieldValueHelper> helper_tab;
		helper_tab.push_back(helper);
		// only one column at the moment, in the future we can have a primary key from more than one column

		model_env->field_value_helper_tab = &helper_tab;
		field_model_save_key(db_field_name);

		for(ModelContainerType & child_model : field_container)
		{
			child_model.set_connector(model_connector);
			field_model_set_parent_key_in_child(db_field_name, child_model);
		}

		model_env->field_value_helper_tab = nullptr;
	}


	template<typename ModelContainer, typename ModelContainerType>
	void field_list_iterate_through_childs(const wchar_t * db_field_name, ModelContainer & field_container, ModelContainerType * model_container_type)
	{
		if( !is_empty_field(db_field_name) )
		{
			for(ModelContainerType & child_model : field_container)
			{
				ModelEnv model_env_local;
				model_env_local.copy_global_objects(*model_env);

				child_model.model_env = &model_env_local;
				child_model.model_env->has_primary_key_set = child_model.has_primary_key_set;
				child_model.set_connector(model_connector);

				if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_INSERT )
				{
					child_model.insert_tree(true);
				}

				if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_UPDATE )
				{
					child_model.update_tree(true);
				}

				if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_REMOVE )
				{
					child_model.remove_tree(true);
				}

				if( model_env->model_work_submode == MORM_MODEL_WORK_SUBMODE_SAVE )
				{
					child_model.save_tree(true);
				}

				child_model.model_env = nullptr;
			}
		}

	}


	template<typename ModelContainer>
	void field_list_generate_flat_string(const wchar_t * flat_field_name, ModelContainer & field_container, bool insertable, bool updatable)
	{
		FlatConnector * flat_connector = model_connector->get_flat_connector();

		if( flat_connector )
		{
			FlatExpression * flat_expression = flat_connector->get_expression();

			if( flat_expression && !is_empty_field(flat_field_name) )
			{
				// insertable and updatable will be ignored there
				flat_expression->field_list(flat_field_name, field_container, insertable, updatable, false, model_connector, model_env);
			}
		}
	}


	template<typename ModelContainer>
	void field_list_clearing_values(ModelContainer & field_container)
	{
		Clearer * clearer = model_connector->get_clearer();

		if( clearer )
		{
			clearer->clear_container(field_container);
		}
	}


	template<typename ModelContainer, typename ModelContainerType>
	void field_list(const wchar_t * db_field_name, const wchar_t * flat_field_name, ModelContainer & field_container, ModelContainerType * model_container_type, bool insertable, bool updatable)
	{
		if( model_connector && model_env )
		{
			if( !is_empty_field(db_field_name) )
			{
				if constexpr (std::is_base_of<Model, ModelContainerType>())
				{
					if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_SET_PARENT_ID )
					{
						field_list_set_parent_key(db_field_name, field_container, model_container_type);
					}

					if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_ITERATE_THROUGH_CHILDS_WITHOUT_FOREIGN_KEY )
					{
						field_list_iterate_through_childs(db_field_name, field_container, model_container_type);
					}
				}
				else
				{
					PT::Log * plog = model_connector->get_logger();

					if( plog )
					{
						(*plog) << "Morm: ignoring " << db_field_name << " as this is not a container with Model objects" << PT::Log::logend;
					}
				}
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_FLAT_STRING )
			{
				field_list_generate_flat_string(flat_field_name, field_container, insertable, updatable);
			}

			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_CLEARING_VALUE )
			{
				field_list_clearing_values(field_container);
			}
		}
	}


	template<typename FieldValue>
	void get_value_by_field_index(int field_index, FieldValue & field_value, bool is_primary_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector && model_env->cursor_helper && model_env->cursor_helper->query_result )
		{
			if( !model_env->cursor_helper->query_result->is_null(field_index) )
			{
				const char * val_str = model_env->cursor_helper->query_result->get_field_string_value(field_index);

				if( val_str )
				{
					db_connector->get_value(val_str, field_value);
				}
			}
			else
			{
				if( is_primary_key )
				{
					model_env->has_primary_key_set = false;
				}
			}
		}
	}


	template<typename FieldValue>
	void get_value_by_field_name(const wchar_t * field_name, FieldValue & field_value, bool is_primary_key)
	{
		DbConnector * db_connector = model_connector->get_db_connector();

		if( db_connector && model_env->cursor_helper && model_env->cursor_helper->query_result )
		{
			int column_index = -1;

			if( model_env->cursor_helper->use_table_prefix_for_fetching_values && model_env->finder_helper )
			{
				// CHECK what about escaping field names here?

				std::wstring table_field_name;
				PT::TextStream table_field_name_str;

				put_table_name_with_index(table_field_name_str);
				table_field_name_str << '.';
				table_field_name_str << field_name;
				table_field_name_str.to_string(table_field_name);
				column_index = model_env->cursor_helper->query_result->get_column_index(table_field_name.c_str());
			}
			else
			{
				column_index = model_env->cursor_helper->query_result->get_column_index(field_name);
			}

			if( column_index != -1 && !model_env->cursor_helper->query_result->is_null(column_index) )
			{
				const char * val_str = model_env->cursor_helper->query_result->get_field_string_value(column_index);

				if( val_str )
				{
					db_connector->get_value(val_str, field_value);
				}
			}
			else
			{
				if( is_primary_key )
				{
					model_env->has_primary_key_set = false;
				}
			}
		}
	}


	virtual void set_parent_key_in_childs()
	{
		if( model_env )
		{
			model_env->model_work_mode = MORM_MODEL_WORK_MODE_SET_PARENT_ID;
			map_fields();
		}
	}


public:


	template<typename FieldValue>
	bool get_last_sequence(const wchar_t * sequence_table_name, FieldValue & field_value)
	{
		if( model_connector )
		{
			DbConnector * db_connector = model_connector->get_db_connector();

			if( db_connector && !is_empty_field(sequence_table_name) )
			{
				return db_connector->get_last_sequence(sequence_table_name, field_value);
			}
		}

		return false;
	}


	template<typename FieldValue>
	bool get_last_sequence_for_primary_key(const wchar_t * sequence_table_name, FieldValue & field_value)
	{
		has_primary_key_set = get_last_sequence(sequence_table_name, field_value);
		return has_primary_key_set;
	}


	template<typename FieldValue>
	void add_field_for_select(const wchar_t * new_column_expression, const wchar_t * new_column_name, const wchar_t * flat_field_name, FieldValue & field_value)
	{
		if( model_connector && model_env )
		{
			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_DB_SQL )
			{
				DbConnector * db_connector = model_connector->get_db_connector();

				if( db_connector )
				{
					DbExpression * db_expression = db_connector->get_expression();

					if( db_expression && !is_empty_field(new_column_expression) )
					{
						db_expression->add_field_for_select(new_column_expression, new_column_name, field_value);
					}
				}
			}
			else
			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_GENERATING_FLAT_STRING )
			{
				field_generic(L"", flat_field_name, field_value, false, false, false);
			}
			else
			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_READING_VALUE_FROM_DB_RESULTSET )
			{
				field_generic(new_column_name, L"", field_value, false, false, false);
			}
			else
			if( model_env->model_work_mode == MORM_MODEL_WORK_MODE_CLEARING_VALUE )
			{
				field_generic(L"", L"", field_value, false, false, false); // the names don't matter here
			}
		}
	}

	// RENAME ME to something like select_field() or field_select()
	template<typename FieldValue>
	void add_field_for_select(const wchar_t * new_column_expression, const wchar_t * new_column_name, FieldValue & field_value)
	{
		add_field_for_select(new_column_expression, new_column_name, new_column_name, field_value);
	}



protected:

	virtual bool is_empty_field(const wchar_t * value);
	virtual bool is_the_same_field(const wchar_t * field1, const wchar_t * field2);
	virtual void prepare_table_names(bool prepare_table_index = true);
	virtual void put_table_name_with_index(PT::TextStream & str);


	virtual void put_to_log(const wchar_t * str);
	virtual void put_fields_to_log(PT::Log & log, const wchar_t * db_field_name, const wchar_t * flat_field_name);

	template<typename ModelClass> friend class Finder;
	template<typename ModelClass> friend class Cursor;
	friend class BaseExpression;

};

} // namespace

#endif