using System;
using System.Data;
using System.Data.OracleClient;

namespace Payroll.BO
{
	/// <summary>
	/// Summary description for ORACLEHelper.
	/// </summary>
	public class ORACLEHelper:DABase
	{
		public ORACLEHelper()
		{
			
		}
		private static bool IsTransaction=false;
		private static void PrepareOracleConnectiion()
		{
			if(OracleConnection==null) 
			{
				if(DABase.OracleStaticConnectionString !="")
				{
					OracleConnection=new System.Data.OracleClient.OracleConnection(DABase.OracleStaticConnectionString);
					if(OracleConnection ==null) throw new Exception("Cannot connect to ORACLE server");
				}
				else
					throw new Exception("Cannot connect to ORACLE server");
			}
			
			// If the provided connection is not open, we will open it
			
			if (OracleConnection.State!=ConnectionState.Open)
			{
				OracleConnection.Open();
			}
		}

		public static void BeginOracleTran()
		{
			PrepareOracleConnectiion();
			OracleTransaction=OracleConnection.BeginTransaction();
			IsTransaction=true;
		}

		public static void CommitOracleTran()
		{
			if(OracleTransaction!=null)
			{
				OracleTransaction.Commit();
				OracleTransaction=null;
				IsTransaction=false;
			}
			if(OracleConnection!=null)
			{
				if (OracleConnection.State==ConnectionState.Open)
				{
					OracleConnection.Close();
				}
			}
		}

		public static void RollbackOracleTran()
		{
			if(OracleTransaction!=null)
			{
				OracleTransaction.Rollback();
				OracleTransaction=null;
				IsTransaction=false;
			}
			if(OracleConnection!=null)
			{
				if (OracleConnection.State==ConnectionState.Open)
				{
					OracleConnection.Close();
				}
			}
		}

		public static IDataReader ExecuteReader(string CommandText, params object[] parameterValues)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=SQL.MakeSQL(CommandText,parameterValues);
				OracleCommand oCMD=new OracleCommand();
                
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				return (IDataReader)oCMD.ExecuteReader();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
//			finally
//			{
//				if(!IsTransaction && OracleConnection !=null)
//					OracleConnection.Close();
//					
//			}
		}

		public static void CloseConnection()
		{
			if(!IsTransaction && OracleConnection !=null)
				OracleConnection.Close();
		}
		public static int ExecuteNonQuery(string CommandText, params object[] parameterValues)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=SQL.MakeSQL(CommandText,parameterValues);
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				return oCMD.ExecuteNonQuery();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}
		public static int ExecuteNonQuery(string spname, OracleParameter[] OracleParameters)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=SQL.MakeSQL(DABase.DBUser + "." + spname);//GPSTSUSER
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}
				oCMD.CommandText=sSQL;
				oCMD.CommandType=CommandType.StoredProcedure;
				AttachParameters(oCMD,OracleParameters);
				return oCMD.ExecuteNonQuery();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}
		public static OracleParameter GetParameter(ParameterDirection pdirection,OracleType datatype,object pValue)
		{
			OracleParameter parameter=new OracleParameter();
			parameter.Direction=pdirection ;
			parameter.OracleType =datatype ;
			
			
//			if(datatype==OracleType.AnsiString) 
//			{parameter.Size=20; }
			parameter.Value=pValue ;
			return parameter;
		}

		public static OracleParameter GetParameter(string parametername,ParameterDirection pdirection,OracleType datatype,object pValue)
		{
			OracleParameter parameter=new OracleParameter();
			parameter.Direction=pdirection ;
			parameter.OracleType =datatype ;
			parameter.ParameterName=parametername;
			parameter.Value=pValue ;
			return parameter;
		}
		public static OracleParameter GetParameter(string parametername,ParameterDirection pdirection,OracleType datatype,int size,object pValue)
		{
			OracleParameter parameter=new OracleParameter();
			parameter.ParameterName=parametername;
			parameter.Direction=pdirection ;
			parameter.OracleType =datatype ;
			parameter.Size=size;
			parameter.Value=pValue ;
			return parameter;
		}

		public static OracleParameter GetParameter(ParameterDirection pdirection,OracleType datatype,int size,object pValue)
		{
			OracleParameter parameter=new OracleParameter();
			parameter.Direction=pdirection ;
			parameter.OracleType =datatype ;
			parameter.Size=size;
			parameter.Value=pValue ;
			return parameter;
		}
		private static void AttachParameters(OracleCommand  command, OracleParameter[] commandParameters)
		{
			if( command == null ) throw new ArgumentNullException( "command" );
			if( commandParameters != null )
			{
				foreach (OracleParameter p in commandParameters)
				{
					if( p != null )
					{
						// Check for derived output value with no value assigned
						if ( ( p.Direction == ParameterDirection.InputOutput || 
							p.Direction == ParameterDirection.Input ) && 
							(p.Value == null || p.Value.ToString()==""))
						{
							p.Value = DBNull.Value;
						}
						command.Parameters.Add(p);
					}
				}
			}
		}
		public static int ExecuteNonQuery(string CommandText)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=CommandText;
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				return oCMD.ExecuteNonQuery();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}
		public static object ExecuteScalar(string CommandText, params object[] parameterValues)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=SQL.MakeSQL(CommandText,parameterValues);
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				return oCMD.ExecuteScalar();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}

		public static object ExecuteScalar(string CommandText)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=CommandText;
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				return oCMD.ExecuteScalar();
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}
		public static int GenerateNewID(string TableName, string FieldName)
		{
			try
			{
				PrepareOracleConnectiion();

				string sSQL=SQL.MakeSQL("SELECT MAX(%q) FROM %q",FieldName,TableName);
				OracleCommand oCMD=new OracleCommand();
				if(IsTransaction)
				{
					oCMD.Connection=OracleConnection;
					oCMD.Transaction=OracleTransaction;
				}
				else
				{
					oCMD.Connection=OracleConnection;
				}

				oCMD.CommandText=sSQL;
				object obj= oCMD.ExecuteScalar();
				
				if(obj == DBNull.Value)return 1;
				else if(obj==null) return 1;
				else return Convert.ToInt32(obj) + 1;
			}
			catch(Exception ex)
			{
				throw new Exception("Framework Error : " + ex.Message);
			}
			finally
			{
				if(!IsTransaction && OracleConnection !=null)
					OracleConnection.Close();
					
			}
		}

		



	}
}