// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#include <e32std.h>

#include "SqlSrvStrings.h"

_LIT(KCreateSql, "CREATE");

_LIT(KIndexSql,  "INDEX");

_LIT(KIfSql,     "IF");

_LIT(KNotSql,    "NOT");

_LIT(KExistsSql, "EXISTS");

_LIT(KDotSql,    ".");

/**

Determines whether the specified string is an SQL statement that is supported as a config operation.

Currently only 'CREATE INDEX' SQL statements are supported. If necessary adds qualifyed DB name  to index name.

@param aStatementIn The string to be checked to determine if it is a supported SQL statement

@param aDbName Logical database name: "main" for the main database or attached database name

@param aStatementOut Output parameter. Buffer for the constructed statement (if the statement is supported).

@return True if the aStatementIn statement is supported, aStatementOut will contain the zero-terminated

		aStatementIn statement with the database name in it, if aDbName is a name of an attached database

*/	

TBool IsStatementSupported(const TDesC& aStatementIn, const TDesC& aDbName, TDes& aStatementOut)

	{	

	//'CREATE INDEX' is the only statement currently supported.

	//We must allow for whitespace between the 'CREATE' and the 'INDEX'

	TLex stmtParser(aStatementIn);

	TPtrC firstToken = stmtParser.NextToken(); // extract the first token of the statement

	if(firstToken.CompareF(KCreateSql()) != 0)

		{

		return EFalse;	

		}

	//The first token is 'CREATE', now skip any whitespace between 

	//it and the next token and ensure that the next token is 'INDEX'

	TPtrC secondToken = stmtParser.NextToken(); // skip any whitespace and extract the next token

	if(secondToken.CompareF(KIndexSql()) != 0)

		{

		return EFalse;	

		}

	//The second token is 'INDEX'

	TPtrC curToken = stmtParser.NextToken();

	// skip optional [IF NOT EXISTS]

	if(curToken.CompareF(KIfSql()) == 0)

		{

		curToken.Set(stmtParser.NextToken());

		if(curToken.CompareF(KNotSql()) != 0)

			{

			return EFalse;	

			}

		curToken.Set(stmtParser.NextToken());

		if(curToken.CompareF(KExistsSql()) != 0)

			{

			return EFalse;	

			}

		curToken.Set(stmtParser.NextToken());

		}

	// we got '[database-name.]index-name'

	if(curToken.Find(KDotSql)==KErrNotFound && aDbName.CompareF(KMainDb16) != 0) // just index-name

		{

		// Add DB name prefix before table name in the case of CREATE INDEX

		aStatementOut.Copy(aStatementIn.Ptr(), curToken.Ptr()-aStatementIn.Ptr());

		aStatementOut.Append(aDbName);

		aStatementOut.Append(KDotSql);

		aStatementOut.Append(curToken);

		aStatementOut.Append(stmtParser.Remainder());

		}

	else

		{

		aStatementOut.Copy(aStatementIn);

		}

	aStatementOut.Append(TChar(0)); // SQLite requires statements to be zero-terminated

	return ETrue;

	}