// Copyright (c) 2006-2010 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 <e32debug.h>

#include <hal.h>

#include <sqldb.h>

#include "sqlite3.h"

#include "SqlSrvStatementUtil.h"

#include "SqlSrvUtil.h"

#include "SqlUtil.h"

#include "SqliteSymbian.h"		//sqlite3SymbianLastOsError()

#include "SqlSrvResourceProfiler.h"

//The database names in all statements are quoted to avoid the "sql injection" threat.

_LIT8(KPageCountPragma, "PRAGMA \"%S\".page_count\x0");

_LIT8(KPageSizePragma,  "PRAGMA \"%S\".page_size\x0");

_LIT8(KCacheSizePragma,  "PRAGMA \"%S\".cache_size\x0");

_LIT8(KEncodingPragma,  "PRAGMA \"%S\".encoding\x0");

_LIT8(KFreePageCountPragma, "PRAGMA \"%S\".freelist_count\x0");

_LIT8(KVacuumModePragma, "PRAGMA \"%S\".auto_vacuum\x0");

_LIT8(KIncrementalVacuumPragma, "PRAGMA \"%S\".incremental_vacuum(%d)\x0");

///////////////////////////////////////////////////////////////////////////////////////////////////////////////

//Calls sqlite3_open16() to create or open database file with aFileNameZ.

//aFileNameZ is UTF16 encoded, zero-terminated.

//The function returns system-wide errors or database specific errors.

//The function may panic with code 7 in _DEBUG mode - internal error: the created database handle is NULL.

TInt CreateDbHandle16(const TDesC& aFileNameZ, sqlite3*& aDbHandle)

	{

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TInt err = sqlite3_open16(aFileNameZ.Ptr(), &aDbHandle);

	if(err == SQLITE_OK)

		{

		(void)sqlite3_extended_result_codes(aDbHandle, 0);

		}

	//Get the return error code now, because the next "if" may destroy it.

	TInt rc = ::Sql2OsErrCode(err, sqlite3SymbianLastOsError());

	if(err != SQLITE_OK)

		{//Yes, it is possible error code != SQLITE_OK and aDbHandle != NULL.

		CloseDbHandle(aDbHandle);

		aDbHandle = NULL;

		}

	return rc;

	}

//Calls sqlite3_open() to create or open database file with aFileNameZ.

//aFileNameZ is UTF8 encoded, zero-terminated.

//The function returns system-wide errors or database specific errors.

//The function may panic with code 7 in _DEBUG mode - internal error: the created database handle is NULL.

TInt CreateDbHandle8(const TDesC8& aFileNameZ, sqlite3*& aDbHandle)

	{

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TInt err = sqlite3_open((const char *) aFileNameZ.Ptr(), &aDbHandle);

	if(err == SQLITE_OK)

		{

		(void)sqlite3_extended_result_codes(aDbHandle, 0);

		}

	//Get the return error code now, because the next "if" may destroy it.

	TInt rc = ::Sql2OsErrCode(err, sqlite3SymbianLastOsError());

	if(err != SQLITE_OK)

		{//Yes, it is possible error code != SQLITE_OK and aDbHandle != NULL.

		CloseDbHandle(aDbHandle);

		aDbHandle = NULL;

		}

	return rc;

	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////

/////                     16-bit and 8-bit SQL statements execution upon completion                        ////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////

//16-bit SQL statement execution.

//

//aSql - zero-terminated string

//

//Prepares the supplied as an argument (aSql) 16-bit SQL statement and executes it.

//If aSql argument contains more than one SQL statements, separated with ';', then

//the function panics in _DEBUG mode (panic code 7).

//

//The function panics in debug mode (panic code 2) if aDbHandle is NULL.

//

//If the function completes successfully, it returns SQLITE_ROW or SQLITE_DONE.

//If the function fails then it returns one of the SQLITE error codes.

static TInt DoSingleStmtExec16(sqlite3 *aDbHandle, const TDesC16& aSql)

	{

	sqlite3_stmt* stmtHandle = NULL;

	const void* stmtTail = NULL;

    //sqlite3_prepare16_v2() expects parameter #3 to be one of the following:

    // - byte length of the sql statement (parameter #2), excluding terminating zero;

    // - negative value - the sql statement (parameter #2) is zero-terminated;

	TInt err = sqlite3_prepare16_v2(aDbHandle, aSql.Ptr(), aSql.Length() * sizeof(TUint16) - sizeof(TUint16), &stmtHandle, &stmtTail);

	if(stmtHandle)	//stmtHandle can be NULL for statements like this: ";".

		{

		if(err == SQLITE_OK)

			{

			while((err = sqlite3_step(stmtHandle)) == SQLITE_ROW)

				{

				}

			if(err == SQLITE_ERROR)	//It may be "out of memory" problem

				{

				err = sqlite3_reset(stmtHandle);

				}

			}

		(void)sqlite3_finalize(stmtHandle);//sqlite3_finalize() fails only if an invalid statement handle is passed.

		}

	return err;

	}

/**

This function searches aString argument for ';' occurences.

Every time when it finds a ';' character, the function places a zero character right after the ';' and

tests the just created, zero-terminated substring if it is a comlpete SQL statement.

If it is a SQL statement, the function replaces the found ';' character with zero and returns the just created

zero-terminated substring.Also the function modifies aString argument to point right after the found

SQL string. If it is not SQL statement, the function will continue the searching.

If there is no ';' inside aString argument, the function returns the same string as a return result and

modifies aString argument - sets it to TPtr(NULL, 0, 0).

The function expects aString argument to be zero-terminated.

@internalComponent

*/

TPtrC GetFirstSqlStmt(TPtr& aString)

	{

	const TChar KDelimitier(';');

	TPtr originalStr(aString);

	TPtr str(const_cast <TUint16*> (aString.Ptr()), aString.Length(), aString.Length());

	TInt afterDelimitierPos = 0;

	TInt pos;

	while((pos = str.Locate(KDelimitier) + 1) > 0 && pos < str.Length())

		{

		//There is a possibility that the string, which terminates with the found ';' character, is a SQL statement.

		//Zero terminate the string placing a zero right after the ';' character and test it using sqlite3_complete16().

		//If it is not a SQL string, restore the original character and continue searching.

		afterDelimitierPos += pos;

		TChar ch = aString[afterDelimitierPos];

		aString[afterDelimitierPos] = 0;

		TInt res = sqlite3_complete16(aString.Ptr());

		aString[afterDelimitierPos] = ch;

		if(res)

			{

			str.Set(const_cast <TUint16*> (aString.Ptr()), afterDelimitierPos, afterDelimitierPos);	

			//Replace the found ';' character with 0.

			str[afterDelimitierPos - 1] = 0;

			aString.Set(const_cast <TUint16*> (aString.Ptr()) + afterDelimitierPos, aString.Length() - afterDelimitierPos, aString.Length() - afterDelimitierPos);

			return str;

			}

		str.Set(const_cast <TUint16*> (str.Ptr()) + pos, str.Length() - pos, str.Length() - pos);	

		}

	//aString argument does not contain valid SQL statement or there is no ';' character inside aString.

	//Set aString to TPtr(NULL, 0, 0) and return the original string.

	aString.Set(NULL, 0, 0);

	str.Set(originalStr);

	return str;

	}

/**

Executes one or more 16-bit SQL statements. SQL statements of any kind can be executed, but the 

method won't return any record(s) if the SQL statement type is "SELECT".

If the SQL statement(s) contains one or more parameters, the method will execute it giving the parameters

default NULL values.

@param aDbHandle Database handle. Not NULL.

@param aSqlStmt String containing one or more 16-bit SQL statements, separated with ';'. Zero-terminated string.

				Note: The ExecL() call can modify the content of aSqlStmt argument.

@return KErrNone, Operation completed successfully;

		KErrNoMemory, Out of memory;

		KSqlErrGeneral, Syntax error. A text message describing the problem can be obtained calling

						RSqlDatabase::LastErrorMessage();

						Other system-wide error codes or SQL errors of ESqlDbError type.

@panic SqlDb 4 In _DEBUG mode if aSqlStmt is not zero-terminated string

@panic SqlDb 7 In _DEBUG mode if aDbHandle is NULL

@internalComponent

*/

	{

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TInt err = SQLITE_DONE;

	//Execute SQL statement(s)

	//16-bit SQL string - no sqlite3_exec16() function, so the execution is made with 

	//sqlite3_prepare16_v2() and sqlite3_step() functions.

	TPtr16 sql(const_cast <TUint16*> (aSqlStmt.Ptr()), aSqlStmt.Length(), aSqlStmt.Length());

	TPtrC firstSqlStmt(KNullDesC);

	while(err == SQLITE_DONE && sql.Length() > 1) //"> 1" because it is a zero terminated string

		{

		firstSqlStmt.Set(GetFirstSqlStmt(sql));

        SQLPROFILER_SQL16_PRINT((TUint)aDbHandle, firstSqlStmt.Left(firstSqlStmt.Length() - 1), EFalse);

		err = ::DoSingleStmtExec16(aDbHandle, firstSqlStmt);

		}

	err = ::Sql2OsErrCode(err, sqlite3SymbianLastOsError());

	if(err == KSqlAtEnd)

		{

		err = KErrNone;	

		}

	return err;

	}

/**

Executes one or more 8-bit SQL statements. SQL statements of any kind can be executed, but the 

method won't return any record(s) if the SQL statement type is "SELECT".

If the SQL statement(s) contains one or more parameters, the method will execute it giving the parameters

default NULL values.

@param aDbHandle Database handle. Not NULL.

@param aSqlStmt String containing one or more 8-bit SQL statements, separated with ';'. Zero-terminated string.

@return KErrNone, Operation completed successfully;

		KErrNoMemory, Out of memory;

		KSqlErrGeneral, Syntax error. A text message describing the problem can be obtained calling

						RSqlDatabase::LastErrorMessage();

		Other system-wide error codes or SQL errors of ESqlDbError type.

@panic SqlDb 4 In _DEBUG mode if aSqlStmt is not zero-terminated string

@panic SqlDb 7 In _DEBUG mode if aDbHandle is NULL

@internalComponent

*/

	{

    SQLPROFILER_SQL8_PRINT((TUint)aDbHandle, aSqlStmt.Left(aSqlStmt.Length() - 1), EFalse);

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TInt err = sqlite3_exec(aDbHandle, reinterpret_cast <const char*> (aSqlStmt.Ptr()), NULL, NULL, NULL);

	err = ::Sql2OsErrCode(err, sqlite3SymbianLastOsError());

	if(err == KSqlAtEnd)

		{

		err = KErrNone;	

		}

	return err;

	}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////

/////                     16-bit and 8-bit SQL statement preparation                                      /////

///////////////////////////////////////////////////////////////////////////////////////////////////////////////

//Prepares 16-bit SQL statement, returning in aStmtHandle the statement handle and

//setting aHasTail to true, if aStmt contains more than one sql statements.

//aStmt - zero-terminated string.

//Returns one of SQLITE error codes.

static TInt DoPrepareStmt16(sqlite3* aDbHandle, const TDesC& aStmt, sqlite3_stmt** aStmtHandle, TBool& aHasTail)

	{

	const void* stmtTail = NULL;

    //sqlite3_prepare16_v2() expects parameter #3 to be one of the following:

    // - byte length of the sql statement (parameter #2), excluding terminating zero;

    // - negative value - the sql statement (parameter #2) is zero-terminated;

	TInt err = sqlite3_prepare16_v2(aDbHandle, aStmt.Ptr(), aStmt.Length() * sizeof(TUint16) - sizeof(TUint16), aStmtHandle, &stmtTail);

	aHasTail = stmtTail && static_cast <const TUint16*> (stmtTail)[0] != 0;

	//(*aStmtHandle) is NULL for ";" statements, when err == SQLITE_OK. Since the server should not panic

	//that situation is handled later (not inside the assert above)

	return err;

	}

//Prepares 8-bit SQL statement, returning in aStmtHandle the statement handle and

//setting aHasTail to true, if aStmt contains more than one sql statements.

//aStmt - zero-terminated string.

//Returns one of SQLITE error codes.

static TInt DoPrepareStmt8(sqlite3* aDbHandle, const TUint8* aStmt, sqlite3_stmt** aStmtHandle, TBool& aHasTail)

	{

	const char* stmtTail = NULL;

    //sqlite3_prepare_v2() expects parameter #3 to be one of the following:

    // - byte length of the sql statement (parameter #2), excluding terminating zero;

    // - negative value - the sql statement (parameter #2) is zero-terminated;

	TInt err = sqlite3_prepare_v2(aDbHandle, reinterpret_cast <const char*> (aStmt), -1, aStmtHandle, &stmtTail);

	aHasTail = stmtTail && stmtTail[0] != 0;

	//(*aStmtHandle) is NULL for ";" statements, when err == SQLITE_OK. Since the server should not panic

	//that situation is handled later (not inside the assert above)

	return err;

	}

//This function accepts as arguments the SQLITE error code, 

//"aHasTail" boolean flag set to true if the SQL string contains more than one SQL statement 

//and the statement handle.

//

//It checks the arguments and returns an error if:

// - aSqliteError != SQLITE_OK;

// - aHasTail is true (possibly more than one SQL statement, separated with ";");

// - aStmtHandle is NULL;

//

static TInt ProcessPrepareError(TInt aSqliteError, TBool aHasTail, sqlite3_stmt*& aStmtHandle)

	{

	if(aSqliteError != SQLITE_OK)

		{

		return ::Sql2OsErrCode(aSqliteError, sqlite3SymbianLastOsError());

		}

	else if(aHasTail || !aStmtHandle)

		{//Case 1:

		 // More than one SQL statement or the SQL string is "" or ";;;" or ";   ;; ;". 

		 // Report it as an error, because there is no statement handle.

		 //Case 2:

		 // Non-null aHasTail. In this case the SQL string contains more than one SQL statement.

		 // The statement handle is not null. The statement has to be finialized before reporting the error.

		(void)FinalizeStmtHandle(aStmtHandle);

		aStmtHandle = NULL;

		return KErrArgument;

		}

	return KErrNone;

	}

//This function accepts as arguments the SQLITE error code, 

//"aHasTail" boolean flag set to true if the SQL string contains more than one SQL statement 

//and the statement handle.

//

//It checks the arguments and leaves if:

// - aSqliteError != SQLITE_OK;

// - aHasTail is true (possibly more than one SQL statement, separated with ";");

// - aStmtHandle is NULL;

//

static void LeaveIfPrepareErrorL(TInt aSqliteError, TBool aHasTail, sqlite3_stmt* aStmtHandle)

	{

	}

/**

Prepares 16-bit aSqlStmt SQL statement.

@param aSqlStmt - zero-terminated string.

@leave KErrNoMemory, if there is no memory;

	   KErrArgument, if the SQL string contains more than one SQL statements;

	   One of the error codes in [KSqlErrGeneral..KSqlErrNotDb] range.

@return The prepared SQL statement handle.

@internalComponent

*/

sqlite3_stmt* StmtPrepare16L(sqlite3* aDbHandle, const TDesC16& aSqlStmt)

	{

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TBool hasTail = EFalse;

	sqlite3_stmt* stmtHandle = NULL;

	TInt err = DoPrepareStmt16(aDbHandle, aSqlStmt, &stmtHandle, hasTail);

	LeaveIfPrepareErrorL(err, hasTail, stmtHandle);

	return stmtHandle;

	}

/**

Prepares 8-bit aSqlStmt SQL statement.

@param aSqlStmt - zero-terminated string.

@leave KErrNoMemory, if there is no memory;

	   KErrArgument, if the SQL string contains more than one SQL statements;

	   One of the error codes in [KSqlErrGeneral..KSqlErrNotDb] range.

@return The prepared SQL statement handle.

@internalComponent

*/

TInt StmtPrepare8(sqlite3* aDbHandle, const TDesC8& aSqlStmt, sqlite3_stmt*& aStmtHandle)

	{

	(void)sqlite3SymbianLastOsError();//clear last OS error

	TBool hasTail = EFalse;

	TInt err = DoPrepareStmt8(aDbHandle, aSqlStmt.Ptr(), &aStmtHandle, hasTail);

	}

/**

Prepares 8-bit aSqlStmt SQL statement.

@param aSqlStmt - zero-terminated string.

@leave KErrNoMemory, if there is no memory;

	   KErrArgument, if the SQL string contains more than one SQL statements;

	   One of the error codes in [KSqlErrGeneral..KSqlErrNotDb] range.

@return The prepared SQL statement handle.