#pragma once

#include <DataTypes/IDataType.h>

#include <optional>

namespace DB

{

/** Tuple data type.

* Used as an intermediate result when evaluating expressions.

* Also can be used as a column - the result of the query execution.

*

* Tuple elements can have names.

* If an element is unnamed, it will have automatically assigned name like '1', '2', '3' corresponding to its position.

* Manually assigned names must not begin with digit. Names must be unique.

*

* All tuples with same size and types of elements are equivalent for expressions, regardless to names of elements.

*/

class DataTypeTuple final : public IDataType

{

private:

DataTypes elems;

Strings names;

bool has_explicit_names;

public:

static constexpr bool is_parametric = true;

explicit DataTypeTuple(const DataTypes & elems);

DataTypeTuple(const DataTypes & elems, const Strings & names);

TypeIndex getTypeId() const override { return TypeIndex::Tuple; }

std::string doGetName() const override;

std::string doGetPrettyName(size_t indent) const override;

const char * getFamilyName() const override { return "Tuple"; }

bool canBeInsideNullable() const override { return true; }

bool supportsSparseSerialization() const override { return true; }

bool canBeInsideSparseColumns() const override { return false; }

MutableColumnPtr createColumn() const override;

MutableColumnPtr createColumn(const ISerialization & serialization) const override;

Field getDefault() const override;

void insertDefaultInto(IColumn & column) const override;

bool equals(const IDataType & rhs) const override;

bool isParametric() const override { return true; }

bool haveSubtypes() const override { return !elems.empty(); }

bool isComparable() const override;

bool textCanContainOnlyValidUTF8() const override;

bool hasDynamicStructure() const override;

bool haveMaximumSizeOfValue() const override;

size_t getMaximumSizeOfValueInMemory() const override;

size_t getSizeOfValueInMemory() const override;

SerializationPtr doGetSerialization(const SerializationInfoSettings & settings) const override;

SerializationPtr getSerialization(const SerializationInfo & info) const override;

MutableSerializationInfoPtr createSerializationInfo(const SerializationInfoSettings & settings) const override;

SerializationInfoPtr getSerializationInfo(const IColumn & column) const override;

DataTypePtr getNormalizedType() const override;

const DataTypePtr & getElement(size_t i) const { return elems[i]; }

const DataTypes & getElements() const { return elems; }

const Strings & getElementNames() const { return names; }

size_t getPositionByName(std::string_view name, bool case_insensitive = false) const;

std::optional<size_t> tryGetPositionByName(std::string_view name, bool case_insensitive = false) const;

String getNameByPosition(size_t i) const;

bool hasExplicitNames() const { return has_explicit_names; }

void updateHashImpl(SipHash & hash) const override;

void forEachChild(const ChildCallback & callback) const override;

private:

SerializationInfoMutablePtr getSerializationInfoImpl(const IColumn & column) const;

};

}