#ifndef __SAFE_LIST__
#define __SAFE_LIST__

#include <list>
#include <locale.h>
#include "CritSection.h"
class CDatabase;
using namespace std;

extern void WriteTextLog(const TCHAR *format, ...);

template <class _Ty,class _Ax = allocator<_Ty>>
class SafeList: public std::list<_Ty, _Ax>
{
public:
	ThreadSection _critSection;
	void _push_back(const _Ty& _Val)
	{
		AutoThreadSection aSection(&_critSection);
		push_back(_Val);
	}

	void _push_front(const _Ty& _Val)
	{
		AutoThreadSection aSection(&_critSection);
		push_front(_Val);
	}

	void _pop_front()
	{
		AutoThreadSection aSection(&_critSection);
		pop_front();
	}

	CDatabase* _pop_front_()
	{
		AutoThreadSection aSection(&_critSection);
		CDatabase* it = front();
		pop_front();
		return it;
	}

	void _pop_back()
	{
		AutoThreadSection aSection(&_critSection);
		pop_back();
	}

	void _remove(const _Ty& _Val_arg)
	{
		AutoThreadSection aSection(&_critSection);
		remove(_Val_arg);
	}

	reference _front()
	{
		AutoThreadSection aSection(&_critSection);
		return (*begin());
	}

	const_reference _front() const
	{	
		AutoThreadSection aSection(&_critSection);
		return (*begin());
	}

	reference _back()
	{	
		AutoThreadSection aSection(&_critSection);
		return (*(--end()));
	}

	const_reference _back() const
	{	
		AutoThreadSection aSection(&_critSection);
		return (*(--end()));
	}

	size_type _size()
	{	
		//AutoThreadSection aSection(&_critSection);
		return (_Mysize);
	}
};

typedef SafeList<CDatabase*> ODBCConnectList;

class CODBCPool
{
	ThreadSection m_critSection;
	// 空闲数据库连接池;
	ODBCConnectList m_listIdleConnections;
	// 在使用的数据库连接池;
	ODBCConnectList m_listBusyConnections;

	// 可用的指标：最大、最小;
	INT m_nMaxCount;
	INT m_nMinCount;

	// 引入的指针变量;
	DWORD m_dwDBPort;
	CString m_strDBSource;
	CString m_strDBAccount;
	CString m_strPassWord;
	CString m_strDBName;

	BOOL m_bNeedExit;	// 退出数据池;
	BOOL m_bNeedStop;
	BOOL m_bNeedConnection;
public:
	CODBCPool(void) {
		m_nRef = 0;
		m_nObjRef = 0;

		m_nMaxCount = 0;
		m_nMinCount = 0;

		m_bNeedExit = FALSE;
		m_bNeedStop = FALSE;
		m_bNeedConnection = FALSE;
	};
	~CODBCPool(void) {DestroyAllDBConnections();};

	// 获取实例指针;
	static CODBCPool* GetInstance()
	{
		static CODBCPool* pInstance = NULL;
		if ( pInstance == NULL )
			pInstance = new CODBCPool;

		return pInstance;
	}

	// 初始化所有连接;
	DWORD InitializePool( IN LPCTSTR lpDBSource, IN CONST DWORD &dwDBPort, IN LPCTSTR lpDBAccount, IN LPCTSTR lpPassWord, IN LPCTSTR lpDBName, IN CONST INT &nMinConn = 1, IN CONST INT &nMaxConn = 5)
	{
		if ( !lpDBSource || lpDBSource[0] == _T('\0') || !lpDBName || lpDBName[0] == _T('\0') )
		{
			return 0;
		}

		m_strDBSource = lpDBSource;
		m_dwDBPort = dwDBPort;
		m_strDBAccount = lpDBAccount;
		m_strPassWord = lpPassWord;
		m_strDBName = lpDBName;

		m_nMinCount = nMinConn;
		m_nMaxCount = nMaxConn;

		return IntiAllConnections();
	}
	// 关闭所有连接;
	void ReleasePool(){DestroyAllDBConnections();}

	// 设置数据库信息;
	void SetDBConnectionInfo(IN LPCTSTR lpDBSource, IN CONST DWORD &dwDBPort, IN LPCTSTR lpDBAccount, IN LPCTSTR lpPassWord, IN LPCTSTR lpDBName);
	// 初始化所有连接;
	INT IntiAllConnections()
	{
		DestroyAllDBConnections();

		// 开始按照最小数量开始创建;
		int nCount = 0;
		CDatabase *pDatabase = NULL;
		for (int i = 0; i < m_nMinCount; i++)
		{
			pDatabase = InitAConnection();
			if ( pDatabase )
			{
				nCount++;
				m_listIdleConnections._push_back(pDatabase);
				InterlockedIncrement(&m_nObjRef);	//增加引用计数;
				pDatabase = NULL;
			}
		}

		return nCount;
	}
	// 断开所有连接;
	void DestroyAllDBConnections()
	{
		m_bNeedExit = TRUE;
		// 首先等待m_listBusyConnections.size() == 0;
		while(1)
		{
			if ( m_listBusyConnections.size() == 0 )
				break;
			Sleep(1000);
		}

		ODBCConnectList::iterator itIdle = m_listIdleConnections.begin();
		while (itIdle != m_listIdleConnections.end())
		{
			if (NULL != (*itIdle))
			{
				(*itIdle)->Close();
				delete (*itIdle);
			}
			itIdle = m_listIdleConnections.erase(itIdle);
		}

		m_bNeedExit = FALSE;
	}

	// 获取一个空闲连接;
	CDatabase* GetAConnection( IN CONST DWORD &dwTimeOut = 1000 )
	{
		if ( m_bNeedExit )// 停止获取;
			return NULL;

		// 1.首先到池中查找有无空闲对象;
		BOOL bGetIdl = FALSE;
		DWORD dwTime = GetTickCount();
		CDatabase* pDBEngine = NULL;
		do 
		{
			if ( m_listIdleConnections._size() > 0){
				//AutoThreadSection aSection(&m_critSection);
				pDBEngine = m_listIdleConnections._pop_front_();
				if (pDBEngine)
				{
					m_listBusyConnections._push_back(pDBEngine);
					bGetIdl = TRUE;
				}
			}
			else 
			{
				if (m_nObjRef < m_nMaxCount)
				{
					//AutoThreadSection aSection(&m_critSection);
					pDBEngine = InitAConnection();
					if (pDBEngine){
						//bGetIdl = TRUE;
						m_listBusyConnections._push_back(pDBEngine);
						InterlockedIncrement(&m_nObjRef);	//增加引用计数;
						WriteTextLog(_T("创建连接对象：共有 %d 个"), m_nObjRef);
						break;
					}
				}
			}

			if ( !bGetIdl )	{
				// 未找到,小憩一会,防止CPU爆满;
				Sleep(0);
				// 超时,则结束返回NULL;
				if ( (GetTickCount() - dwTime) >= dwTimeOut){
					WriteTextLog(_T("获取连接对象超时"));
					break;
				}
			}
		} while ( !bGetIdl );

		return pDBEngine;
	}
	// 交还连接给空闲队列;
	void RestoreAConnection(IN CDatabase *pDBEngine)
	{
		if ( pDBEngine != NULL ){
			m_listBusyConnections._remove(pDBEngine);
			m_listIdleConnections._push_back(pDBEngine);
		}
	}

private:
	volatile LONG m_nRef;
	volatile LONG m_nObjRef;
	// 创建一个连接;
	CDatabase* InitAConnection()
	{
		if ( m_nObjRef == m_nMaxCount )
			return NULL;

		CDatabase * pDBEngine = new CDatabase;
		TCHAR szConnString[MAX_PATH] = {0};
		if (m_dwDBPort != 0)
		{
			if ( m_strDBAccount.IsEmpty() )
				_stprintf_s(szConnString, MAX_PATH, DB_SW_CONN_WITH_PORT, m_strDBSource.GetString(), m_dwDBPort, m_strDBName.GetString());
			else
				_stprintf_s(szConnString, MAX_PATH, DB_SS_CONN_WITH_PORT, m_strDBSource.GetString(), m_dwDBPort, m_strDBName.GetString(), m_strDBAccount.GetString(), m_strPassWord.GetString());
		}
		else
		{
			if ( m_strDBAccount.IsEmpty() )
				_stprintf_s(szConnString, MAX_PATH, DB_SW_CONN_WITHOUT_PORT, m_strDBSource.GetString(), m_strDBName.GetString());
			else
				_stprintf_s(szConnString, MAX_PATH, DB_SS_CONN_WITHOUT_PORT, m_strDBSource.GetString(), m_strDBName.GetString(), m_strDBAccount.GetString(), m_strPassWord.GetString());
		}

		try
		{
			pDBEngine->OpenEx(szConnString, CDatabase::noOdbcDialog);
		}
		catch (CDBException* e)
		{
			if ( pDBEngine )
				delete pDBEngine;
			pDBEngine = NULL;
			WriteTextLog(_T("SQL连接串：%s, 返回错误：%s"), szConnString, e->m_strError);
		}

		return pDBEngine;
	}

	// 关闭一个连接;
	void CloseAConnection(CDatabase* pDBEngine)
	{
		m_listIdleConnections._remove(pDBEngine);
		InterlockedDecrement(&m_nObjRef);	// 减少计数;
		if ( pDBEngine )
			delete pDBEngine;
	}

	// 将守卫类友元化;
	friend class ODBCConnGuard;
public:
	//////////////////////////////////////////////////////////////////////////
	// 数据库接口;
	BOOL ExecuteSQL( IN LPCTSTR lpExcuteSQL, IN CONST DWORD &dwTimeOut = 30000 );
};


#endif // __SAFE_LIST__