using System;
using System.Data;
using System.Data.SqlClient;

using MonitorSystem.LogFileModule;

namespace MonitorSystem.MonitorCenter
{
	/// <summary>
	/// 
	/// </summary>
	public class DBConnectionPool
	{
		/// <summary>
		/// 數據庫連接相關信息
		/// </summary>
		private string ConnString="";

		private MonitorSystem.BasicClass.SystemLog m_SysLog = new MonitorSystem.BasicClass.SystemLog();
		
		public DBConnectionPool()
		{
			// 
			// TODO: Add constructor logic here
			//
		}
		public DBConnectionPool(string iConnStr)
		{
			ConnString = iConnStr;
		}		
		/// <summary>
		/// 從配置文件中讀取數據庫相關的配置項
		/// </summary>
		public int InitDBString(string iConnStr)
		{			
			ConnString = iConnStr;
			if (ConnString == null)
				return -1;
			return 0;
		}		
		
		/// <summary>
		/// 從連接池中獲得一個連接
		/// </summary>		
		public SqlConnection GetDBConnect()
		{
			System.Data.SqlClient.SqlConnection curr_Connect = new SqlConnection();
						
			if (ConnString == null)
				return null;			
			curr_Connect.ConnectionString = ConnString;
			try
			{
				curr_Connect.Open();
			}
			catch(Exception e)
			{
				m_SysLog.WriteToSysLog(0,e.ToString());
				return null;  
			}
			return curr_Connect;
		}

		public int ReleaseDBConnect(SqlConnection iDBConnect)
		{//將指定連接放回連接池
			try
			{
				iDBConnect.Close();
			}
			catch(Exception e)
			{
				m_SysLog.WriteToSysLog(0,e.ToString());
				return -1;
			}
			return 0;
		}		
	}
}