ClickHouse/dbms/include/DB/Functions/FunctionsEmbeddedDictionaries.h

#pragma once

#include <DB/DataTypes/DataTypesNumber.h>
#include <DB/DataTypes/DataTypeArray.h>
#include <DB/DataTypes/DataTypeString.h>

#include <DB/Columns/ColumnsNumber.h>
#include <DB/Columns/ColumnConst.h>
#include <DB/Columns/ColumnArray.h>
#include <DB/Columns/ColumnString.h>

#include <DB/Interpreters/Context.h>
#include <DB/Interpreters/EmbeddedDictionaries.h>

#include <DB/Functions/IFunction.h>
#include <DB/Dictionaries/Embedded/RegionsHierarchy.h>
#include <DB/Dictionaries/Embedded/RegionsHierarchies.h>
#include <DB/Dictionaries/Embedded/RegionsNames.h>
#include <DB/Dictionaries/Embedded/TechDataHierarchy.h>


namespace DB
{

namespace ErrorCodes
{
	extern const int DICTIONARIES_WAS_NOT_LOADED;
	extern const int BAD_ARGUMENTS;
}

/** Функции, использующие словари Яндекс.Метрики
  * - словари регионов, операционных систем, поисковых систем.
  *
  * Подняться по дереву до определенного уровня.
  *  regionToCity, regionToArea, regionToCountry, ...
  *
  * Преобразовать значения в столбце
  *  regionToName
  *
  * Является ли первый идентификатор потомком второго.
  *  regionIn
  *
  * Получить массив идентификаторов регионов, состоящий из исходного и цепочки родителей. Порядок implementation defined.
  *  regionHierarchy
  */


struct RegionToCityImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toCity(x); }
};

struct RegionToAreaImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toArea(x); }
};

struct RegionToDistrictImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toDistrict(x); }
};

struct RegionToCountryImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toCountry(x); }
};

struct RegionToContinentImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toContinent(x); }
};

struct RegionToTopContinentImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toTopContinent(x); }
};

struct RegionToPopulationImpl
{
	static UInt32 apply(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.getPopulation(x); }
};

struct OSToRootImpl
{
	static UInt8 apply(UInt8 x, const TechDataHierarchy & hierarchy) { return hierarchy.OSToMostAncestor(x); }
};

struct SEToRootImpl
{
	static UInt8 apply(UInt8 x, const TechDataHierarchy & hierarchy) { return hierarchy.SEToMostAncestor(x); }
};

struct RegionInImpl
{
	static bool apply(UInt32 x, UInt32 y, const RegionsHierarchy & hierarchy) { return hierarchy.in(x, y); }
};

struct OSInImpl
{
	static bool apply(UInt32 x, UInt32 y, const TechDataHierarchy & hierarchy) { return hierarchy.isOSIn(x, y); }
};

struct SEInImpl
{
	static bool apply(UInt32 x, UInt32 y, const TechDataHierarchy & hierarchy) { return hierarchy.isSEIn(x, y); }
};

struct RegionHierarchyImpl
{
	static UInt32 toParent(UInt32 x, const RegionsHierarchy & hierarchy) { return hierarchy.toParent(x); }
};

struct OSHierarchyImpl
{
	static UInt8 toParent(UInt8 x, const TechDataHierarchy & hierarchy) { return hierarchy.OSToParent(x); }
};

struct SEHierarchyImpl
{
	static UInt8 toParent(UInt8 x, const TechDataHierarchy & hierarchy) { return hierarchy.SEToParent(x); }
};


/** Вспомогательная вещь, позволяющая достать из словаря конкретный словарь, соответствующий точке зрения
  *  (ключу словаря, передаваемому в аргументе функции).
  * Пример: при вызове regionToCountry(x, 'ua'), может быть использован словарь, в котором Крым относится к Украине.
  */
struct RegionsHierarchyGetter
{
	using Src = RegionsHierarchies;
	using Dst = RegionsHierarchy;

	static const Dst & get(const Src & src, const std::string & key)
	{
		return src.get(key);
	}
};

/** Для словарей без поддержки ключей. Ничего не делает.
  */
template <typename Dict>
struct IdentityDictionaryGetter
{
	using Src = Dict;
	using Dst = Dict;

	static const Dst & get(const Src & src, const std::string & key)
	{
		if (key.empty())
			return src;
		else
			throw Exception("Dictionary doesn't support 'point of view' keys.", ErrorCodes::BAD_ARGUMENTS);
	}
};


/// Преобразует идентификатор, используя словарь.
template <typename T, typename Transform, typename DictGetter, typename Name>
class FunctionTransformWithDictionary : public IFunction
{
public:
	static constexpr auto name = Name::name;
	using base_type = FunctionTransformWithDictionary;

private:
	const std::shared_ptr<typename DictGetter::Src> owned_dict;

public:
	FunctionTransformWithDictionary(const std::shared_ptr<typename DictGetter::Src> & owned_dict_)
		: owned_dict(owned_dict_)
	{
		if (!owned_dict)
			throw Exception("Dictionaries was not loaded. You need to check configuration file.", ErrorCodes::DICTIONARIES_WAS_NOT_LOADED);
	}

	String getName() const override
	{
		return name;
	}

	bool isVariadic() const override { return true; }
	size_t getNumberOfArguments() const override { return 0; }

	DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
	{
		if (arguments.size() != 1 && arguments.size() != 2)
			throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
				+ toString(arguments.size()) + ", should be 1 or 2.",
				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

		if (arguments[0]->getName() != TypeName<T>::get())
			throw Exception("Illegal type " + arguments[0]->getName() + " of argument of function " + getName()
				+ " (must be " + TypeName<T>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		if (arguments.size() == 2 && arguments[1]->getName() != TypeName<String>::get())
			throw Exception("Illegal type " + arguments[1]->getName() + " of the second ('point of view') argument of function " + getName()
				+ " (must be " + TypeName<String>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		return arguments[0];
	}

	void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
	{
		/// Ключ словаря, определяющий "точку зрения".
		std::string dict_key;

		if (arguments.size() == 2)
		{
			const ColumnConstString * key_col = typeid_cast<const ColumnConstString *>(block.safeGetByPosition(arguments[1]).column.get());

			if (!key_col)
				throw Exception("Illegal column " + block.safeGetByPosition(arguments[1]).column->getName()
					+ " of second ('point of view') argument of function " + name
					+ ". Must be constant string.",
					ErrorCodes::ILLEGAL_COLUMN);

			dict_key = key_col->getData();
		}

		const typename DictGetter::Dst & dict = DictGetter::get(*owned_dict, dict_key);

		if (const ColumnVector<T> * col_from = typeid_cast<const ColumnVector<T> *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			auto col_to = std::make_shared<ColumnVector<T>>();
			block.safeGetByPosition(result).column = col_to;

			const typename ColumnVector<T>::Container_t & vec_from = col_from->getData();
			typename ColumnVector<T>::Container_t & vec_to = col_to->getData();
			size_t size = vec_from.size();
			vec_to.resize(size);

			for (size_t i = 0; i < size; ++i)
				vec_to[i] = Transform::apply(vec_from[i], dict);
		}
		else if (const ColumnConst<T> * col_from = typeid_cast<const ColumnConst<T> *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			block.safeGetByPosition(result).column = std::make_shared<ColumnConst<T>>(
				col_from->size(), Transform::apply(col_from->getData(), dict));
		}
		else
			throw Exception("Illegal column " + block.safeGetByPosition(arguments[0]).column->getName()
					+ " of first argument of function " + name,
				ErrorCodes::ILLEGAL_COLUMN);
	}
};


/// Проверяет принадлежность, используя словарь.
template <typename T, typename Transform, typename DictGetter, typename Name>
class FunctionIsInWithDictionary : public IFunction
{
public:
	static constexpr auto name = Name::name;
	using base_type = FunctionIsInWithDictionary;

private:
	const std::shared_ptr<typename DictGetter::Src> owned_dict;

public:
	FunctionIsInWithDictionary(const std::shared_ptr<typename DictGetter::Src> & owned_dict_)
		: owned_dict(owned_dict_)
	{
		if (!owned_dict)
			throw Exception("Dictionaries was not loaded. You need to check configuration file.", ErrorCodes::DICTIONARIES_WAS_NOT_LOADED);
	}

	String getName() const override
	{
		return name;
	}

	bool isVariadic() const override { return true; }
	size_t getNumberOfArguments() const override { return 0; }

	DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
	{
		if (arguments.size() != 2 && arguments.size() != 3)
			throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
				+ toString(arguments.size()) + ", should be 2 or 3.",
				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

		if (arguments[0]->getName() != TypeName<T>::get())
			throw Exception("Illegal type " + arguments[0]->getName() + " of first argument of function " + getName()
				+ " (must be " + TypeName<T>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		if (arguments[1]->getName() != TypeName<T>::get())
			throw Exception("Illegal type " + arguments[1]->getName() + " of second argument of function " + getName()
				+ " (must be " + TypeName<T>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		if (arguments.size() == 3 && arguments[2]->getName() != TypeName<String>::get())
			throw Exception("Illegal type " + arguments[2]->getName() + " of the third ('point of view') argument of function " + getName()
				+ " (must be " + TypeName<String>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		return std::make_shared<DataTypeUInt8>();
	}

	void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
	{
		/// Ключ словаря, определяющий "точку зрения".
		std::string dict_key;

		if (arguments.size() == 3)
		{
			const ColumnConstString * key_col = typeid_cast<const ColumnConstString *>(block.safeGetByPosition(arguments[2]).column.get());

			if (!key_col)
				throw Exception("Illegal column " + block.safeGetByPosition(arguments[2]).column->getName()
				+ " of third ('point of view') argument of function " + name
				+ ". Must be constant string.",
				ErrorCodes::ILLEGAL_COLUMN);

			dict_key = key_col->getData();
		}

		const typename DictGetter::Dst & dict = DictGetter::get(*owned_dict, dict_key);

		const ColumnVector<T> * col_vec1 = typeid_cast<const ColumnVector<T> *>(block.safeGetByPosition(arguments[0]).column.get());
		const ColumnVector<T> * col_vec2 = typeid_cast<const ColumnVector<T> *>(block.safeGetByPosition(arguments[1]).column.get());
		const ColumnConst<T> * col_const1 = typeid_cast<const ColumnConst<T> *>(block.safeGetByPosition(arguments[0]).column.get());
		const ColumnConst<T> * col_const2 = typeid_cast<const ColumnConst<T> *>(block.safeGetByPosition(arguments[1]).column.get());

		if (col_vec1 && col_vec2)
		{
			auto col_to = std::make_shared<ColumnUInt8>();
			block.safeGetByPosition(result).column = col_to;

			const typename ColumnVector<T>::Container_t & vec_from1 = col_vec1->getData();
			const typename ColumnVector<T>::Container_t & vec_from2 = col_vec2->getData();
			typename ColumnUInt8::Container_t & vec_to = col_to->getData();
			size_t size = vec_from1.size();
			vec_to.resize(size);

			for (size_t i = 0; i < size; ++i)
				vec_to[i] = Transform::apply(vec_from1[i], vec_from2[i], dict);
		}
		else if (col_vec1 && col_const2)
		{
			auto col_to = std::make_shared<ColumnUInt8>();
			block.safeGetByPosition(result).column = col_to;

			const typename ColumnVector<T>::Container_t & vec_from1 = col_vec1->getData();
			const T const_from2 = col_const2->getData();
			typename ColumnUInt8::Container_t & vec_to = col_to->getData();
			size_t size = vec_from1.size();
			vec_to.resize(size);

			for (size_t i = 0; i < size; ++i)
				vec_to[i] = Transform::apply(vec_from1[i], const_from2, dict);
		}
		else if (col_const1 && col_vec2)
		{
			auto col_to = std::make_shared<ColumnUInt8>();
			block.safeGetByPosition(result).column = col_to;

			const T const_from1 = col_const1->getData();
			const typename ColumnVector<T>::Container_t & vec_from2 = col_vec2->getData();
			typename ColumnUInt8::Container_t & vec_to = col_to->getData();
			size_t size = vec_from2.size();
			vec_to.resize(size);

			for (size_t i = 0; i < size; ++i)
				vec_to[i] = Transform::apply(const_from1, vec_from2[i], dict);
		}
		else if (col_const1 && col_const2)
		{
			block.safeGetByPosition(result).column = std::make_shared<ColumnConst<UInt8>>(col_const1->size(),
				Transform::apply(col_const1->getData(), col_const2->getData(), dict));
		}
		else
			throw Exception("Illegal columns " + block.safeGetByPosition(arguments[0]).column->getName()
					+ " and " + block.safeGetByPosition(arguments[1]).column->getName()
					+ " of arguments of function " + name,
				ErrorCodes::ILLEGAL_COLUMN);
	}
};


/// Получает массив идентификаторов, состоящий из исходного и цепочки родителей.
template <typename T, typename Transform, typename DictGetter, typename Name>
class FunctionHierarchyWithDictionary : public IFunction
{
public:
	static constexpr auto name = Name::name;
	using base_type = FunctionHierarchyWithDictionary;

private:
	const std::shared_ptr<typename DictGetter::Src> owned_dict;

public:
	FunctionHierarchyWithDictionary(const std::shared_ptr<typename DictGetter::Src> & owned_dict_)
	: owned_dict(owned_dict_)
	{
		if (!owned_dict)
			throw Exception("Dictionaries was not loaded. You need to check configuration file.", ErrorCodes::DICTIONARIES_WAS_NOT_LOADED);
	}

	String getName() const override
	{
		return name;
	}

	bool isVariadic() const override { return true; }
	size_t getNumberOfArguments() const override { return 0; }

	DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
	{
		if (arguments.size() != 1 && arguments.size() != 2)
			throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
				+ toString(arguments.size()) + ", should be 1 or 2.",
				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

		if (arguments[0]->getName() != TypeName<T>::get())
			throw Exception("Illegal type " + arguments[0]->getName() + " of argument of function " + getName()
			+ " (must be " + TypeName<T>::get() + ")",
			ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		if (arguments.size() == 2 && arguments[1]->getName() != TypeName<String>::get())
			throw Exception("Illegal type " + arguments[1]->getName() + " of the second ('point of view') argument of function " + getName()
				+ " (must be " + TypeName<String>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		return std::make_shared<DataTypeArray>(arguments[0]);
	}

	void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
	{
		/// Ключ словаря, определяющий "точку зрения".
		std::string dict_key;

		if (arguments.size() == 2)
		{
			const ColumnConstString * key_col = typeid_cast<const ColumnConstString *>(block.safeGetByPosition(arguments[1]).column.get());

			if (!key_col)
				throw Exception("Illegal column " + block.safeGetByPosition(arguments[1]).column->getName()
				+ " of second ('point of view') argument of function " + name
				+ ". Must be constant string.",
				ErrorCodes::ILLEGAL_COLUMN);

			dict_key = key_col->getData();
		}

		const typename DictGetter::Dst & dict = DictGetter::get(*owned_dict, dict_key);

		if (const ColumnVector<T> * col_from = typeid_cast<const ColumnVector<T> *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			auto col_values = std::make_shared<ColumnVector<T>>();
			auto col_array = std::make_shared<ColumnArray>(col_values);
			block.safeGetByPosition(result).column = col_array;

			ColumnArray::Offsets_t & res_offsets = col_array->getOffsets();
			typename ColumnVector<T>::Container_t & res_values = col_values->getData();

			const typename ColumnVector<T>::Container_t & vec_from = col_from->getData();
			size_t size = vec_from.size();
			res_offsets.resize(size);
			res_values.reserve(size * 4);

			for (size_t i = 0; i < size; ++i)
			{
				T cur = vec_from[i];
				while (cur)
				{
					res_values.push_back(cur);
					cur = Transform::toParent(cur, dict);
				}
				res_offsets[i] = res_values.size();
			}
		}
		else if (const ColumnConst<T> * col_from = typeid_cast<const ColumnConst<T> *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			Array res;

			T cur = col_from->getData();
			while (cur)
			{
				res.push_back(static_cast<typename NearestFieldType<T>::Type>(cur));
				cur = Transform::toParent(cur, dict);
			}

			block.safeGetByPosition(result).column = std::make_shared<ColumnConstArray>(
				col_from->size(),
				res,
				std::make_shared<DataTypeArray>(std::make_shared<DataTypeNumber<T>>()));
		}
		else
			throw Exception("Illegal column " + block.safeGetByPosition(arguments[0]).column->getName()
			+ " of first argument of function " + name,
							ErrorCodes::ILLEGAL_COLUMN);
	}
};


struct NameRegionToCity				{ static constexpr auto name = "regionToCity"; };
struct NameRegionToArea				{ static constexpr auto name = "regionToArea"; };
struct NameRegionToDistrict			{ static constexpr auto name = "regionToDistrict"; };
struct NameRegionToCountry			{ static constexpr auto name = "regionToCountry"; };
struct NameRegionToContinent		{ static constexpr auto name = "regionToContinent"; };
struct NameRegionToTopContinent		{ static constexpr auto name = "regionToTopContinent"; };
struct NameRegionToPopulation		{ static constexpr auto name = "regionToPopulation"; };
struct NameOSToRoot					{ static constexpr auto name = "OSToRoot"; };
struct NameSEToRoot					{ static constexpr auto name = "SEToRoot"; };

struct NameRegionIn					{ static constexpr auto name = "regionIn"; };
struct NameOSIn						{ static constexpr auto name = "OSIn"; };
struct NameSEIn						{ static constexpr auto name = "SEIn"; };

struct NameRegionHierarchy			{ static constexpr auto name = "regionHierarchy"; };
struct NameOSHierarchy				{ static constexpr auto name = "OSHierarchy"; };
struct NameSEHierarchy				{ static constexpr auto name = "SEHierarchy"; };


struct FunctionRegionToCity :
	public FunctionTransformWithDictionary<UInt32, RegionToCityImpl,	RegionsHierarchyGetter,	NameRegionToCity>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToArea :
	public FunctionTransformWithDictionary<UInt32, RegionToAreaImpl,	RegionsHierarchyGetter,	NameRegionToArea>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToDistrict :
	public FunctionTransformWithDictionary<UInt32, RegionToDistrictImpl, RegionsHierarchyGetter, NameRegionToDistrict>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToCountry :
	public FunctionTransformWithDictionary<UInt32, RegionToCountryImpl, RegionsHierarchyGetter, NameRegionToCountry>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToContinent :
	public FunctionTransformWithDictionary<UInt32, RegionToContinentImpl, RegionsHierarchyGetter, NameRegionToContinent>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToTopContinent :
	public FunctionTransformWithDictionary<UInt32, RegionToTopContinentImpl, RegionsHierarchyGetter, NameRegionToTopContinent>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionRegionToPopulation :
	public FunctionTransformWithDictionary<UInt32, RegionToPopulationImpl, RegionsHierarchyGetter, NameRegionToPopulation>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionOSToRoot :
	public FunctionTransformWithDictionary<UInt8, OSToRootImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameOSToRoot>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};

struct FunctionSEToRoot :
	public FunctionTransformWithDictionary<UInt8, SEToRootImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameSEToRoot>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};

struct FunctionRegionIn :
	public FunctionIsInWithDictionary<UInt32, RegionInImpl, RegionsHierarchyGetter,	NameRegionIn>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionOSIn :
	public FunctionIsInWithDictionary<UInt8,	OSInImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameOSIn>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};

struct FunctionSEIn :
	public FunctionIsInWithDictionary<UInt8,	SEInImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameSEIn>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};

struct FunctionRegionHierarchy :
	public FunctionHierarchyWithDictionary<UInt32, RegionHierarchyImpl, RegionsHierarchyGetter, NameRegionHierarchy>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getRegionsHierarchies());
	}
};

struct FunctionOSHierarchy :
	public FunctionHierarchyWithDictionary<UInt8, OSHierarchyImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameOSHierarchy>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};

struct FunctionSEHierarchy :
	public FunctionHierarchyWithDictionary<UInt8, SEHierarchyImpl, IdentityDictionaryGetter<TechDataHierarchy>, NameSEHierarchy>
{
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<base_type>(context.getEmbeddedDictionaries().getTechDataHierarchy());
	}
};


/// Преобразует числовой идентификатор региона в имя на заданном языке, используя словарь.
class FunctionRegionToName : public IFunction
{
public:
	static constexpr auto name = "regionToName";
	static FunctionPtr create(const Context & context)
	{
		return std::make_shared<FunctionRegionToName>(context.getEmbeddedDictionaries().getRegionsNames());
	}

private:
	const std::shared_ptr<RegionsNames> owned_dict;

public:
	FunctionRegionToName(const std::shared_ptr<RegionsNames> & owned_dict_)
		: owned_dict(owned_dict_)
	{
		if (!owned_dict)
			throw Exception("Dictionaries was not loaded. You need to check configuration file.", ErrorCodes::DICTIONARIES_WAS_NOT_LOADED);
	}

	String getName() const override
	{
		return name;
	}

	bool isVariadic() const override { return true; }
	size_t getNumberOfArguments() const override { return 0; }

	/// For the purpose of query optimization, we assume this function to be injective
	///  even in face of fact that there are many different cities named Moscow.
	bool isInjective(const Block &) override { return true; }

	DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
	{
		if (arguments.size() != 1 && arguments.size() != 2)
			throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
				+ toString(arguments.size()) + ", should be 1 or 2.",
				ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

		if (arguments[0]->getName() != TypeName<UInt32>::get())
			throw Exception("Illegal type " + arguments[0]->getName() + " of the first argument of function " + getName()
				+ " (must be " + TypeName<UInt32>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		if (arguments.size() == 2 && arguments[1]->getName() != TypeName<String>::get())
			throw Exception("Illegal type " + arguments[0]->getName() + " of the second argument of function " + getName()
				+ " (must be " + TypeName<String>::get() + ")",
				ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

		return std::make_shared<DataTypeString>();
	}

	void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
	{
		RegionsNames::Language language = RegionsNames::Language::RU;

		/// Если указан язык результата
		if (arguments.size() == 2)
		{
			if (const ColumnConstString * col_language = typeid_cast<const ColumnConstString *>(block.safeGetByPosition(arguments[1]).column.get()))
				language = RegionsNames::getLanguageEnum(col_language->getData());
			else
				throw Exception("Illegal column " + block.safeGetByPosition(arguments[1]).column->getName()
						+ " of the second argument of function " + getName(),
					ErrorCodes::ILLEGAL_COLUMN);
		}

		const RegionsNames & dict = *owned_dict;

		if (const ColumnUInt32 * col_from = typeid_cast<const ColumnUInt32 *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			auto col_to = std::make_shared<ColumnString>();
			block.safeGetByPosition(result).column = col_to;

			const ColumnUInt32::Container_t & region_ids = col_from->getData();

			for (size_t i = 0; i < region_ids.size(); ++i)
			{
				const StringRef & name_ref = dict.getRegionName(region_ids[i], language);
				col_to->insertDataWithTerminatingZero(name_ref.data, name_ref.size + 1);
			}
		}
		else if (const ColumnConst<UInt32> * col_from = typeid_cast<const ColumnConst<UInt32> *>(block.safeGetByPosition(arguments[0]).column.get()))
		{
			UInt32 region_id = col_from->getData();
			const StringRef & name_ref = dict.getRegionName(region_id, language);

			block.safeGetByPosition(result).column = std::make_shared<ColumnConstString>(col_from->size(), name_ref.toString());
		}
		else
			throw Exception("Illegal column " + block.safeGetByPosition(arguments[0]).column->getName()
					+ " of the first argument of function " + getName(),
				ErrorCodes::ILLEGAL_COLUMN);
	}
};

};