/**
*	@file		WDouble.h
*	@brief		double型变量封装，可以设置精度
*	@author		沙漠乌鸦
*	@date		2009-09-07
*	@warning	WDouble类暂时需要实现的功能
*				1) 设置全局的默认精度和单独的精度
*				2) 返回原始double值或运用精度计算后的值
*				3) 同时支持正、负数的格式化
*				3) 大小比较符<、>、<=、>=
*				4) ==、!=操作符
*				5) +、-、*、/、+=、-=、*=、/=操作符
*				6) <<、>>操作符
*/

#pragma once
#include <iostream>
using std::ostream;
using std::istream;

namespace wuya
{

class AFX_EXT_CLASS WDouble
{
public:
	WDouble(void);
	WDouble(double dVal,size_t nPrecision = GetPrecisionDef());
	WDouble(const WDouble& dVal);
	~WDouble(void) throw();

	WDouble& operator = (const WDouble& dVal);
	WDouble& operator = (double dVal);

	// operator
	friend inline bool operator == (const WDouble& dVal1,const WDouble& dVal2);
	friend inline bool operator != (const WDouble& dVal1,const WDouble& dVal2);
	friend inline bool operator < (const WDouble& dVal1,const WDouble& dVal2);
	friend inline bool operator > (const WDouble& dVal1,const WDouble& dVal2);
	friend inline bool operator <= (const WDouble& dVal1,const WDouble& dVal2);
	friend inline bool operator >= (const WDouble& dVal1,const WDouble& dVal2);
	friend inline void operator += (WDouble& dVal1,const WDouble& dVal2);			///< 精度以第一个操作数为准
	friend inline void operator -= (WDouble& dVal1,const WDouble& dVal2);
	friend inline void operator *= (WDouble& dVal1,const WDouble& dVal2);
	friend inline void operator /= (WDouble& dVal1,const WDouble& dVal2);
	friend inline WDouble operator + (const WDouble& dVal1,const WDouble& dVal2);	///< 精度以精度较大的为准
	friend inline WDouble operator - (const WDouble& dVal1,const WDouble& dVal2);
	friend inline WDouble operator * (const WDouble& dVal1,const WDouble& dVal2);
	friend inline WDouble operator / (const WDouble& dVal1,const WDouble& dVal2);
	friend inline ostream& operator << (ostream& os,const WDouble& object);
	friend inline istream& operator >> (istream& is,WDouble& object);

	/**
	*	@brief	设置WDouble精度
	*	@param	[in]nPrecision 由于double型精度最大支持10位，该值范围为0-10，若非该范围值，则保留原精度
	*/
	void	SetPrecision(size_t nPrecision);
	/** @brief	返回WDoule精度 */
	size_t	GetPrecision() const;

	/**
	*	@brief	返回double值，精度为WDouble保存精度
	*/
	double	Get() const;
	/**
	*	@brief	返回double值，精度为nPrecision
	*/
	double	Get(size_t nPrecision) const;
	/**
	*	@brief	返回输入的double值、未进行四舍五入
	*/
	double	GetEnter() const;

	static	void	SetPrecisionDef(size_t nPrecision);
	static	size_t	GetPrecisionDef();

private:
	/** @brief	对原始数据进行四舍五入计算 */
	double	Round(size_t nPrecision) const;

	void	Round();

private:
	double	m_dDbl;				///< 按照精度四舍五入后的double值
	double	m_dDblEnter;		///< 原始double值
	size_t	m_nPrecision;		///< double精度

	static	size_t	m_nPrecisionDef;	///< 默认精度、值为1，即可以精确到0.1
};

//operator
inline bool operator == (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl == dVal2.m_dDbl;
}
inline bool operator != (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl != dVal2.m_dDbl;
}
inline bool operator < (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl < dVal2.m_dDbl;
}
inline bool operator > (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl > dVal2.m_dDbl;
}
inline bool operator <= (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl <= dVal2.m_dDbl;
}
inline bool operator >= (const WDouble& dVal1,const WDouble& dVal2)
{
	return dVal1.m_dDbl >= dVal2.m_dDbl;
}
inline void operator += (WDouble& dVal1,const WDouble& dVal2)
{
	dVal1.m_dDblEnter += dVal2.m_dDblEnter;

	// 以dVal1的精度为准
	dVal1.Round();
}
inline void operator -= (WDouble& dVal1,const WDouble& dVal2)
{
	dVal1.m_dDblEnter -= dVal2.m_dDblEnter;

	// 以dVal1的精度为准
	dVal1.Round();
}
inline void operator *= (WDouble& dVal1,const WDouble& dVal2)
{
	dVal1.m_dDblEnter *= dVal2.m_dDblEnter;

	// 以dVal1的精度为准
	dVal1.Round();
}
inline void operator /= (WDouble& dVal1,const WDouble& dVal2)
{
	dVal1.m_dDblEnter /= dVal2.m_dDblEnter;

	// 以dVal1的精度为准
	dVal1.Round();
	dVal1.m_dDblEnter = dVal1.m_dDbl;
}
inline WDouble operator + (const WDouble& dVal1,const WDouble& dVal2)
{	
	size_t nPrecision;
	if(dVal1.m_nPrecision > dVal2.m_nPrecision)
		nPrecision = dVal1.m_nPrecision;
	else
		nPrecision = dVal2.m_nPrecision;

	WDouble dVal(dVal1.m_dDbl + dVal2.m_dDbl,nPrecision);
	return dVal;
}
inline WDouble operator - (const WDouble& dVal1,const WDouble& dVal2)
{	
	size_t nPrecision;
	if(dVal1.m_nPrecision > dVal2.m_nPrecision)
		nPrecision = dVal1.m_nPrecision;
	else
		nPrecision = dVal2.m_nPrecision;

	WDouble dVal(dVal1.m_dDbl - dVal2.m_dDbl,nPrecision);
	return dVal;
}
inline WDouble operator * (const WDouble& dVal1,const WDouble& dVal2)
{	
	size_t nPrecision;
	if(dVal1.m_nPrecision > dVal2.m_nPrecision)
		nPrecision = dVal1.m_nPrecision;
	else
		nPrecision = dVal2.m_nPrecision;

	WDouble dVal(dVal1.m_dDbl * dVal2.m_dDbl,nPrecision);
	return dVal;
}
inline WDouble operator / (const WDouble& dVal1,const WDouble& dVal2)
{	
	size_t nPrecision;
	if(dVal1.m_nPrecision > dVal2.m_nPrecision)
		nPrecision = dVal1.m_nPrecision;
	else
		nPrecision = dVal2.m_nPrecision;

	WDouble dVal(dVal1.m_dDbl / dVal2.m_dDbl,nPrecision);
	return dVal;
}
inline ostream& operator << (ostream& os,const WDouble& object)
{
	os << object.m_dDbl;

	return os;
}
inline istream& operator >> (istream& is,WDouble& object)
{
	double dVal;
	is >> dVal;

	if(is)
	{
		object.m_dDblEnter = dVal;
		object.Round();
	}
	else
		object = WDouble();

	return is;
}

};