using System;
using System.Data;
using System.Runtime.InteropServices;
using System.Text;

namespace IBM.Data.DB2
{
	/// <summary>
	/// DB2Prototypes class is a wrapper for the DB2.lib, IBM's Call Level Interface to DB2
	/// </summary>
	/// 

	internal class DB2CLIWrapper
	{
		static bool useLibCli;

		static public short Initialize(ref IntPtr pEnvHandle)
		{
			useLibCli = false;
			try
			{
				return DB2CLIWrapper.SQLAllocHandle(DB2Constants.SQL_HANDLE_ENV, IntPtr.Zero, out pEnvHandle);
			}
			catch {}
			useLibCli = false;
			return DB2CLIWrapper.SQLAllocHandle(DB2Constants.SQL_HANDLE_ENV, IntPtr.Zero, out pEnvHandle);
		}
    
		static public short SQLAllocHandle(short handleType, IntPtr inputHandle, out IntPtr outputHandle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLAllocHandle(handleType, inputHandle, out outputHandle);
			return StaticWrapper36.SQLAllocHandle(handleType, inputHandle, out outputHandle);
		}
		static public short SQLFreeHandle(short handleType, IntPtr inputHandle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLFreeHandle(handleType, inputHandle);
			return StaticWrapper36.SQLFreeHandle(handleType, inputHandle);
		}
		static public short SQLFreeStmt(IntPtr StatementHandle, short option)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLFreeStmt(StatementHandle, option);
			return StaticWrapper36.SQLFreeStmt(StatementHandle, option);
		}
		static public short SQLConnect(IntPtr sqlHdbc, string serverName, short serverNameLength, string userName, short userNameLength, string authentication, short authenticationLength)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLConnect(sqlHdbc, serverName, serverNameLength, userName, userNameLength, authentication, authenticationLength);
			return StaticWrapper36.SQLConnect(sqlHdbc, serverName, serverNameLength, userName, userNameLength, authentication, authenticationLength);
		}
		static public short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, StringBuilder CharacterAttribute, short BufferLength, out short StringLength, out int NumericAttribute)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLColAttribute(StatementHandle, ColumnNumber, FieldIdentifier, CharacterAttribute, BufferLength, out StringLength, out NumericAttribute);
			return StaticWrapper36.SQLColAttribute(StatementHandle, ColumnNumber, FieldIdentifier, CharacterAttribute, BufferLength, out StringLength, out NumericAttribute);
		}
		static public short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, IntPtr ValuePtr, int BufferLength, out int StringLengthPtr)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetConnectAttr(ConnectionHandle, Attribute, ValuePtr, BufferLength, out StringLengthPtr);
			return StaticWrapper36.SQLGetConnectAttr(ConnectionHandle, Attribute, ValuePtr, BufferLength, out StringLengthPtr);
		}
		static public short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, out int Value, int BufferLength, IntPtr Zero)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetConnectAttr(ConnectionHandle, Attribute, out Value, BufferLength, Zero);
			return StaticWrapper36.SQLGetConnectAttr(ConnectionHandle, Attribute, out Value, BufferLength, Zero);
		}
		static public short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, IntPtr CharacterAttribute, short BufferLength, ref short StringLength, ref int NumericAttribute)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLColAttribute(StatementHandle, ColumnNumber, FieldIdentifier, CharacterAttribute, BufferLength, ref StringLength, ref NumericAttribute);
			return StaticWrapper36.SQLColAttribute(StatementHandle, ColumnNumber, FieldIdentifier, CharacterAttribute, BufferLength, ref StringLength, ref NumericAttribute);
		}
		static public short SQLMoreResults(IntPtr StatementHandle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLMoreResults(StatementHandle);
			return StaticWrapper36.SQLMoreResults(StatementHandle);
		}
		static public short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, StringBuilder sb, int BufferLength, out int StrLen_or_Ind)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetData(StatementHandle, ColumnNumber, TargetType, sb, BufferLength, out StrLen_or_Ind);
			return StaticWrapper36.SQLGetData(StatementHandle, ColumnNumber, TargetType, sb, BufferLength, out StrLen_or_Ind);
		}
		static public short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, IntPtr TargetPtr, int BufferLength, out int StrLen_or_Ind)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetData(StatementHandle, ColumnNumber, TargetType, TargetPtr, BufferLength, out StrLen_or_Ind);
			return StaticWrapper36.SQLGetData(StatementHandle, ColumnNumber, TargetType, TargetPtr, BufferLength, out StrLen_or_Ind);
		}
		static public short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, byte[] TargetPtr, int BufferLength, out int StrLen_or_Ind)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetData(StatementHandle, ColumnNumber, TargetType, TargetPtr, BufferLength, out StrLen_or_Ind);
			return StaticWrapper36.SQLGetData(StatementHandle, ColumnNumber, TargetType, TargetPtr, BufferLength, out StrLen_or_Ind);
		}
		static public short SQLDisconnect(IntPtr sqlHdbc)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLDisconnect(sqlHdbc);
			return StaticWrapper36.SQLDisconnect(sqlHdbc);
		}
		static public short SQLGetDiagRec( short handleType, IntPtr handle, short recNum, StringBuilder sqlState, out int nativeError, StringBuilder errorMessage, int bufferLength, out short textLengthPtr)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetDiagRec( handleType, handle, recNum, sqlState, out nativeError, errorMessage, bufferLength, out textLengthPtr);
			return StaticWrapper36.SQLGetDiagRec( handleType, handle, recNum, sqlState, out nativeError, errorMessage, bufferLength, out textLengthPtr);
		}
		static public short SQLSetConnectAttr(IntPtr sqlHdbc, int sqlAttr, IntPtr sqlValuePtr, int sqlValueLength)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLSetConnectAttr(sqlHdbc, sqlAttr, sqlValuePtr, sqlValueLength);
			return StaticWrapper36.SQLSetConnectAttr(sqlHdbc, sqlAttr, sqlValuePtr, sqlValueLength);
		}
		static public short SQLSetStmtAttr(IntPtr sqlHdbc, int sqlAttr, IntPtr sqlValuePtr, int sqlValueLength)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLSetStmtAttr(sqlHdbc, sqlAttr, sqlValuePtr, sqlValueLength);
			return StaticWrapper36.SQLSetStmtAttr(sqlHdbc, sqlAttr, sqlValuePtr, sqlValueLength);
		}
		static public short SQLEndTran (short handleType, IntPtr handle, short fType)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLEndTran (handleType, handle, fType);
			return StaticWrapper36.SQLEndTran (handleType, handle, fType);
		}
		static public short SQLCancel(IntPtr handle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLCancel(handle);
			return StaticWrapper36.SQLCancel(handle);
		}
		static public short SQLNumResultCols(IntPtr handle, out short numCols)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLNumResultCols(handle, out numCols);
			return StaticWrapper36.SQLNumResultCols(handle, out numCols);
		}
		static public short SQLFetch(IntPtr handle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLFetch(handle);
			return StaticWrapper36.SQLFetch(handle);
		}
		static public short SQLRowCount(IntPtr stmtHandle, out int numRows)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLRowCount(stmtHandle, out numRows);
			return StaticWrapper36.SQLRowCount(stmtHandle, out numRows);
		}
		static public short SQLExecute(IntPtr handle)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLExecute(handle);
			return StaticWrapper36.SQLExecute(handle);
		}
		static public short SQLExecDirect(IntPtr stmtHandle, string stmt, int length)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLExecDirect(stmtHandle, stmt, length);
			return StaticWrapper36.SQLExecDirect(stmtHandle, stmt, length);
		}
		static public short SQLDriverConnect(IntPtr hdbc, IntPtr windowHandle, string inConnectStr, short inStrLength, StringBuilder outConnectStr, short outStrCapacity, out short outStrLengthReturned, int completion)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLDriverConnect(hdbc, windowHandle, inConnectStr, inStrLength, outConnectStr, outStrCapacity, out outStrLengthReturned, completion);
			return StaticWrapper36.SQLDriverConnect(hdbc, windowHandle, inConnectStr, inStrLength, outConnectStr, outStrCapacity, out outStrLengthReturned, completion);
		}
		static public short SQLPrepare(IntPtr stmtHandle, string stmt, int length)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLPrepare(stmtHandle, stmt, length);
			return StaticWrapper36.SQLPrepare(stmtHandle, stmt, length);
		}
		static public short SQLBindParameter(IntPtr stmtHandle, short paramNumber, short dataType, short valueType, short paramType, int colSize, short decDigits, IntPtr dataBufferPtr, int dataBufferLength, IntPtr StrLen_or_IndPtr)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLBindParameter(stmtHandle, paramNumber, dataType, valueType, paramType, colSize, decDigits, dataBufferPtr, dataBufferLength, StrLen_or_IndPtr);
			return StaticWrapper36.SQLBindParameter(stmtHandle, paramNumber, dataType, valueType, paramType, colSize, decDigits, dataBufferPtr, dataBufferLength, StrLen_or_IndPtr);
		}
		public static short SQLGetInfo(IntPtr sqlHdbc, short fInfoType, [Out] StringBuilder rgbInfoValue, short cbInfoValueMax, out short pcbInfoValue)
		{
			if(useLibCli)
				return StaticWrapperCli.SQLGetInfo(sqlHdbc, fInfoType, rgbInfoValue, cbInfoValueMax, out pcbInfoValue);
			return StaticWrapper36.SQLGetInfo(sqlHdbc, fInfoType, rgbInfoValue, cbInfoValueMax, out pcbInfoValue);
		}

		/// <summary>
		/// db2Prototypes class is a wrapper for the db2.lib, IBM's Call Level Interface to Db2
		/// </summary>
		public class StaticWrapperCli
		{
			private const string libname = "db2cli";
		
			[DllImport(libname, EntryPoint = "SQLAllocHandle")]
			public static extern short SQLAllocHandle(short handleType, IntPtr inputHandle,  out IntPtr outputHandle);
			[DllImport(libname, EntryPoint = "SQLFreeHandle")]
			public static extern short SQLFreeHandle(short handleType, IntPtr inputHandle);

			[DllImport(libname, EntryPoint = "SQLFreeStmt")]
			public static extern short SQLFreeStmt(IntPtr StatementHandle, short option);

			[DllImport(libname, EntryPoint = "SQLConnectW", CharSet=CharSet.Unicode)]

			public static extern short SQLConnect(IntPtr sqlHdbc, string serverName, short serverNameLength, string userName, short userNameLength, string authentication, short authenticationLength);
			[DllImport(libname, EntryPoint = "SQLColAttributeW", CharSet=CharSet.Unicode)]
			public static extern short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, [Out] StringBuilder CharacterAttribute, short BufferLength,  out short StringLength, out int NumericAttribute);

			[DllImport(libname, EntryPoint = "SQLGetConnectAttrW", CharSet=CharSet.Unicode)]
			public static extern short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, [Out] IntPtr ValuePtr, int BufferLength, out int StringLengthPtr);

			[DllImport(libname, EntryPoint = "SQLGetConnectAttrW", CharSet=CharSet.Unicode)]
			public static extern short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, out int Value, int BufferLength, IntPtr Zero);

			[DllImport(libname, EntryPoint = "SQLColAttributeW", CharSet=CharSet.Unicode)]
			public static extern short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, IntPtr CharacterAttribute, short BufferLength,  ref short StringLength,  ref int NumericAttribute);
			[DllImport(libname, EntryPoint="SQLMoreResults")]
			public static extern short SQLMoreResults(IntPtr StatementHandle);

			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, [Out] StringBuilder sb, int BufferLength, out int StrLen_or_Ind);

			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, IntPtr TargetPtr, int BufferLength, out int StrLen_or_Ind);
		
			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, [Out] byte[] TargetPtr, int BufferLength, out int StrLen_or_Ind);

			[DllImport(libname,  EntryPoint = "SQLDisconnect")]
			public static extern short SQLDisconnect(IntPtr sqlHdbc);

			[DllImport(libname, EntryPoint = "SQLGetDiagRec")]
			public static extern short SQLGetDiagRec( short handleType, IntPtr handle, short recNum, [Out] StringBuilder sqlState, out int nativeError, [Out] StringBuilder errorMessage, int bufferLength, out short textLengthPtr);

			[DllImport(libname, EntryPoint = "SQLSetConnectAttr")]
			public static extern short SQLSetConnectAttr(IntPtr sqlHdbc, int sqlAttr, [In] IntPtr sqlValuePtr, int sqlValueLength);
			[DllImport(libname, EntryPoint = "SQLSetStmtAttr")]
			public static extern short SQLSetStmtAttr(IntPtr sqlHdbc, int sqlAttr, [In] IntPtr sqlValuePtr, int sqlValueLength);
			[DllImport(libname, EntryPoint = "SQLEndTran")]
			public static extern short SQLEndTran (short handleType, IntPtr handle, short fType);
			[DllImport(libname, EntryPoint = "SQLCancel")]
			public static extern short SQLCancel(IntPtr handle);
			[DllImport(libname, EntryPoint = "SQLNumResultCols")]
			public static extern short SQLNumResultCols(IntPtr handle, out short numCols);
			[DllImport(libname, EntryPoint = "SQLFetch")]
			public static extern short SQLFetch(IntPtr handle);
			[DllImport(libname, EntryPoint = "SQLRowCount")]
			public static extern short SQLRowCount(IntPtr stmtHandle, out int numRows);
			[DllImport(libname, EntryPoint = "SQLExecute")]
			public static extern short SQLExecute(IntPtr handle);
			[DllImport (libname, EntryPoint = "SQLExecDirectW", CharSet=CharSet.Unicode)]
			public static extern short SQLExecDirect(IntPtr stmtHandle, string stmt, int length);
			[DllImport(libname, EntryPoint = "SQLDriverConnectW", CharSet=CharSet.Unicode)]
			public static extern short SQLDriverConnect(IntPtr hdbc, IntPtr windowHandle, [In] string inConnectStr, [In] short inStrLength, [Out] StringBuilder outConnectStr, [Out] short outStrCapacity, out short outStrLengthReturned, [In] int completion);
			[DllImport(libname, EntryPoint = "SQLPrepareW", CharSet=CharSet.Unicode)]
			public static extern short SQLPrepare(IntPtr stmtHandle, string stmt, int length);
			[DllImport(libname)]
			public static extern short SQLBindParameter(IntPtr stmtHandle, short paramNumber, 
				short dataType, short valueType, short paramType, int colSize, short decDigits, 
				IntPtr dataBufferPtr, int dataBufferLength, IntPtr StrLen_or_IndPtr);
			[DllImport(libname, EntryPoint = "SQLGetInfoW", CharSet=CharSet.Unicode)]
			public static extern short SQLGetInfo(IntPtr sqlHdbc, short fInfoType, [Out] StringBuilder rgbInfoValue, short cbInfoValueMax, out short pcbInfoValue);
		}

		public class StaticWrapper36
		{
			private const string libname = "db2_36";
		
			[DllImport(libname, EntryPoint = "SQLAllocHandle")]
			public static extern short SQLAllocHandle(short handleType, IntPtr inputHandle,  out IntPtr outputHandle);
			[DllImport(libname, EntryPoint = "SQLFreeHandle")]
			public static extern short SQLFreeHandle(short handleType, IntPtr inputHandle);

			[DllImport(libname, EntryPoint = "SQLFreeStmt")]
			public static extern short SQLFreeStmt(IntPtr StatementHandle, short option);

			[DllImport(libname, EntryPoint = "SQLConnect")]

			public static extern short SQLConnect(IntPtr sqlHdbc, string serverName, short serverNameLength, string userName, short userNameLength, string authentication, short authenticationLength);
			[DllImport(libname, EntryPoint = "SQLColAttributeW", CharSet=CharSet.Unicode)]
			public static extern short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, [Out] StringBuilder CharacterAttribute, short BufferLength,  out short StringLength, out int NumericAttribute);

			[DllImport(libname, EntryPoint = "SQLGetConnectAttrW", CharSet=CharSet.Unicode)]
			public static extern short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, [Out] IntPtr ValuePtr, int BufferLength, out int StringLengthPtr);

			[DllImport(libname, EntryPoint = "SQLGetConnectAttrW", CharSet=CharSet.Unicode)]
			public static extern short SQLGetConnectAttr(IntPtr ConnectionHandle, int Attribute, out int Value, int BufferLength, IntPtr Zero);

			[DllImport(libname, EntryPoint = "SQLColAttributeW", CharSet=CharSet.Unicode)]
			public static extern short SQLColAttribute(IntPtr StatementHandle, short ColumnNumber, short FieldIdentifier, IntPtr CharacterAttribute, short BufferLength,  ref short StringLength,  ref int NumericAttribute);
			[DllImport(libname, EntryPoint="SQLMoreResults")]
			public static extern short SQLMoreResults(IntPtr StatementHandle);

			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, [Out] StringBuilder sb, int BufferLength, out int StrLen_or_Ind);

			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, IntPtr TargetPtr, int BufferLength, out int StrLen_or_Ind);
		
			[DllImport(libname, EntryPoint = "SQLGetData")]
			public static extern short SQLGetData(IntPtr StatementHandle, short ColumnNumber, short TargetType, [Out] byte[] TargetPtr, int BufferLength, out int StrLen_or_Ind);

			[DllImport(libname,  EntryPoint = "SQLDisconnect")]
			public static extern short SQLDisconnect(IntPtr sqlHdbc);

			[DllImport(libname, EntryPoint = "SQLGetDiagRec")]
			public static extern short SQLGetDiagRec( short handleType, IntPtr handle, short recNum, [Out] StringBuilder sqlState, out int nativeError, [Out] StringBuilder errorMessage, int bufferLength, out short textLengthPtr);

			[DllImport(libname, EntryPoint = "SQLSetConnectAttr")]
			public static extern short SQLSetConnectAttr(IntPtr sqlHdbc, int sqlAttr, [In] IntPtr sqlValuePtr, int sqlValueLength);
			[DllImport(libname, EntryPoint = "SQLSetStmtAttr")]
			public static extern short SQLSetStmtAttr(IntPtr sqlHdbc, int sqlAttr, [In] IntPtr sqlValuePtr, int sqlValueLength);
			[DllImport(libname, EntryPoint = "SQLEndTran")]
			public static extern short SQLEndTran (short handleType, IntPtr handle, short fType);
			[DllImport(libname, EntryPoint = "SQLCancel")]
			public static extern short SQLCancel(IntPtr handle);
			[DllImport(libname, EntryPoint = "SQLNumResultCols")]
			public static extern short SQLNumResultCols(IntPtr handle, out short numCols);
			[DllImport(libname, EntryPoint = "SQLFetch")]
			public static extern short SQLFetch(IntPtr handle);
			[DllImport(libname, EntryPoint = "SQLRowCount")]
			public static extern short SQLRowCount(IntPtr stmtHandle, out int numRows);
			[DllImport(libname, EntryPoint = "SQLExecute")]
			public static extern short SQLExecute(IntPtr handle);
			[DllImport (libname, EntryPoint = "SQLExecDirectW", CharSet=CharSet.Unicode)]
			public static extern short SQLExecDirect(IntPtr stmtHandle, string stmt, int length);
			[DllImport(libname, EntryPoint = "SQLDriverConnectW", CharSet=CharSet.Unicode)]
			public static extern short SQLDriverConnect(IntPtr hdbc, IntPtr windowHandle, [In] string inConnectStr, [In] short inStrLength, [Out] StringBuilder outConnectStr, [Out] short outStrCapacity, out short outStrLengthReturned, [In] int completion);
			[DllImport(libname, EntryPoint = "SQLPrepareW", CharSet=CharSet.Unicode)]
			public static extern short SQLPrepare(IntPtr stmtHandle, string stmt, int length);
			[DllImport(libname)]
			public static extern short SQLBindParameter(IntPtr stmtHandle, short paramNumber, 
				short dataType, short valueType, short paramType, int colSize, short decDigits, 
				IntPtr dataBufferPtr, int dataBufferLength, IntPtr StrLen_or_IndPtr);
			[DllImport(libname, EntryPoint = "SQLGetInfo")]
			public static extern short SQLGetInfo(IntPtr sqlHdbc, short fInfoType, [Out] StringBuilder rgbInfoValue, short cbInfoValueMax, out short pcbInfoValue);

		}
	}
}