#pragma once
#include <string>
#include <vector>
#include "sqldatetime.h"

class CSqlVariant
{
	public:
	enum Type
	{
		Invalid = 0,
		Bool,
		Char,
		UChar,
		Short,
		UShort,
		Int,
		UInt,
		LongLong,
		ULongLong,
		Float,
		Double,
		Date,
		Time,
		DateTime,
		String,
		ByteArray
	};
	public:
		CSqlVariant();
		CSqlVariant(Type type);
		CSqlVariant(char v);
		CSqlVariant(bool v);
		CSqlVariant(int v);
		CSqlVariant(unsigned int v);
		CSqlVariant(long long v);
		CSqlVariant(unsigned long long v);
		CSqlVariant(float v);
		CSqlVariant(double v);
		CSqlVariant(short v);
		CSqlVariant(unsigned short v);
		CSqlVariant(unsigned char v);
		CSqlVariant(const CSqlDate &v);
		CSqlVariant(const CSqlTime &v);
		CSqlVariant(const CSqlDateTime &v);
		CSqlVariant(const char *v);
		CSqlVariant(const char* v,unsigned int len,bool bIsByteArray);
		CSqlVariant(const std::string &v ,bool bIsByteArray= false);
		CSqlVariant(const CSqlVariant &O);
		CSqlVariant &operator=(const CSqlVariant &o);
		~CSqlVariant();
		
		bool  operator==(const CSqlVariant &o) const;
		bool  operator!=(const CSqlVariant &o) const;
		
		template<typename T> T ToValue() const { T v; ToValue(v); return v; }
		int ToValue(int &v)const;
		unsigned int ToValue(unsigned int &v) const;
		long long ToValue(long long &v) const;
		unsigned long long ToValue(unsigned long long &v) const;
		bool ToValue(bool &v)const;
		float ToValue(float &v) const;
		double ToValue(double &v)const;
		std::string & ToValue(std::string &v) const;
		char ToValue(char &v) const;
		unsigned char ToValue(unsigned char &v) const;
		short ToValue(short &v)const;
		unsigned short ToValue(unsigned short &v) const;
		CSqlDate & ToValue(CSqlDate &v)const;
		CSqlTime & ToValue(CSqlTime &v)const;
		CSqlDateTime & ToValue(CSqlDateTime &v)const;
		const void *GetData()const;
		unsigned int GetDataLen()const;
		void* GetBuffer();
		int GetBufferLen()const;
		void SetDataLen(int nlen);
		void SetBufferLen(int nlen);
		void ReleaseBuffer();
		void SetType(Type type);
		Type GetType()const;
		const char*GetTypeName()const;
		bool CanConvertTo(Type t)const;
		bool IsNull()const;
		void SetNull(bool bNull);
private:
	void CopyFrom(const CSqlVariant &o);
	void InitBuffer(unsigned int len);
	void InitData(const char*v,unsigned int len);
	void FreeBuffer();
	union
	{
		bool b;
		char c;
		unsigned char uc;
		short s;
		unsigned short us;
		int i;
		unsigned int ui; //also store the time,date
		long long ll;
		unsigned long long ull; //also store the datetime
		float f;
		double d;
		int *p; //format :[ref_count][buf_len][data_len][data][....]  ,这个内存数据可以共享使用。线程不安全
						//         p[0]       p[1]      p[2]     [p3]  
	} m_data;
	Type m_type;
	unsigned int m_is_null;
};

#define VARINTARR  std::vector<CSqlVariant>