#ifndef _DATA_COLUMN_
#define _DATA_COLUMN_

#define INSENSETIVE
#include <iostream>
#include <QString>
#include <QDebug>
#include "UtilityGlobal.h"
#include <QDateTime>
using namespace std;

class DataTable;

/* 定义：表示 DataTable 或DataRow中的列的架构
DataColumn是用于创建 架构DataTable的基本构建基块。 通过将一个或多个 DataColumn 对象添加到 来 DataColumnCollection生成架构。 
可通过Value()获取值Value(param)设置值
也可通过=设置值 */
template <typename T>
class UTILITY_API TDataColumn
{
public:
	TDataColumn() : _column_name(QString()), _caption(QString()){};	
	TDataColumn(const QString& column_name) : _column_name(column_name), _caption(QString()){};
	TDataColumn(const QString& column_name, QVariant::Type column_type) : _column_name(column_name), _type(column_type){};
	virtual ~TDataColumn(){};

public:
	void 			Caption(const QString& caption) { _caption = caption; }					//设置列的标题
	QString 		Caption() const { return _caption.size() ? _caption : _column_name; }			//获取列的标题
	void 			ColumnName(const QString& column_name) { _column_name = column_name; }	//设置 DataColumnCollection 中的列的名称
	QString 		ColumnName() const { return _column_name; }									//获取 DataColumnCollection 中的列的名称
	void 			Value(const T& value) { _value = value; }								//获取值
	T 				Value() const { return _value; }										//设置值
	void 			Table(DataTable* p_table){ _table = p_table; }							//设置列所属的 DataTable
	DataTable*		Table() const { return _table; }												//获取列所属的 DataTable
	QVariant::Type  DataType() const { return _type;}											//获取存储在列中的数据的类型
	void 			DataType(QVariant::Type column_type) { _type = column_type;}				//设置存储在列中的数据的类型

protected:
	QString 		_column_name;															//列名 
	QString 		_caption;																//列的标题
	T 				_value = T();																	//值
	QVariant::Type  _type;																	//列的数据类型
	DataTable* 		_table = nullptr;																	//列所属DataTable
};

//template class UTILITY_API TDataColumn<QString>;
//template class UTILITY_API TDataColumn<std::string>;
template class UTILITY_API TDataColumn<QVariant>; // 经测试，QVariant没有精度问题

class UTILITY_API DataColumn : public TDataColumn<QVariant>
{
	friend class DataColumnCollection;
	friend class DataTable;

public:
	DataColumn() : TDataColumn<QVariant>(){};
	explicit DataColumn(const QString& column_name) : TDataColumn<QVariant>(column_name) {}
	DataColumn(const QString& column_name, QVariant::Type column_type) : TDataColumn<QVariant>(column_name, column_type) {}
	~DataColumn() { };

	QString toString()
	{
		if(this->Value().isNull())
		{
			return "";
		}

		if (this->DataType() == QVariant::DateTime) 
		{
			return this->Value().toDateTime().toString("yyyy-MM-dd");
		} 
		else 
		{
			return this->Value().toString();
		}

		
	}
	int toInt()
	{
		if(this->Value().isNull())
		{
			return 0;
		}
		return this->Value().toInt();
	}
	double toDouble()
	{
		if(this->Value().isNull())
		{
			return 0;
		}
		return this->Value().toDouble();
	}

	bool toBool()
	{
		if(this->Value().isNull())
		{
			return false;
		}
		return this->Value().toBool();
	}
	DataColumn(const DataColumn& data_column) { *this = data_column; }		
	DataColumn &operator=(const DataColumn& data_column)
	{
		_column_name = data_column._column_name;
		_caption = data_column._caption;
		_value = data_column._value;
		_table = data_column._table;
		_type = data_column._type;
		return *this;
	}
	DataColumn &operator=(const QVariant& value) { 											//可使用=给value赋值
		_value = value;  
		return *this;
	}
	
};

//备用代码： QString 版本
/* class UTILITY_API DataColumn : public TDataColumn<QString>
{
public:
	friend class DataColumnCollection;
	friend class DataTable;
	DataColumn() : TDataColumn<QString>(){};
	~DataColumn(){ qDebug() << "delete!"; };
	DataColumn(const DataColumn& data_column){ *this = data_column; }
	DataColumn &operator=(const DataColumn& data_column)
	{
		_column_name = data_column._column_name;
		_caption = data_column._caption;
		_value = data_column._value;
		_table = data_column._table;
		return *this;
	}
	DataColumn(const QString& column_name) : TDataColumn<QString>(column_name){}
	void Show()
	{
		qDebug() << "columnName:" << _column_name << ",caption:" << Caption() << ",value:" << _value ;
	}

};
 */

#endif