// ============================================================================
//  Copyright (C) 2001-2013 by Jozef Starosczyk
//  ixen@copyhandler.com
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Library General Public License
//  (version 2) as published by the Free Software Foundation;
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU Library General Public
//  License along with this program; if not, write to the
//  Free Software Foundation, Inc.,
//  59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
// ============================================================================
#include "stdafx.h"
#include "TSerializerVersion.h"
#include "TSQLiteTransaction.h"
#include "ErrorCodes.h"
#include "TSerializerException.h"
#include "TSQLiteStatement.h"
#include "TSQLiteException.h"
#include "sqlite3\sqlite3.h"

BEGIN_CHCORE_NAMESPACE

using namespace sqlite;

TSerializerVersion::TSerializerVersion(const TSQLiteDatabasePtr& spDatabase) :
	m_spDatabase(spDatabase)
{
	if(!spDatabase)
		THROW_SERIALIZER_EXCEPTION(eErr_InvalidArgument, _T("No database provided"));
}

TSerializerVersion::~TSerializerVersion()
{
}

void TSerializerVersion::Setup()
{
	TSQLiteTransaction tTransaction(m_spDatabase);
	TSQLiteStatement tStatement(m_spDatabase);

	tStatement.Prepare(_T("SELECT count(*) FROM sqlite_master WHERE type=?1 AND name=?2"));
	tStatement.BindValue(1, _T("table"));
	tStatement.BindValue(2, _T("version"));
	if(tStatement.Step() != TSQLiteStatement::eStep_HasRow)
		THROW_SQLITE_EXCEPTION(eErr_InternalProblem, SQLITE_ERROR, _T("Problem accessing sqlite_master table"));
	
	int iVersionCount = tStatement.GetInt(0);
	if(iVersionCount == 0)
	{
		// create table
		tStatement.Prepare(_T("CREATE TABLE IF NOT EXISTS version(db_version INT NOT NULL)"));
		tStatement.Step();

		tStatement.Prepare(_T("INSERT INTO version(db_version) VALUES(?1)"));
		tStatement.BindValue(1, 0);
		tStatement.Step();
	}

	tTransaction.Commit();
}

int TSerializerVersion::GetVersion()
{
	TSQLiteTransaction tTransaction(m_spDatabase);
	TSQLiteStatement tStatement(m_spDatabase);

	// when table does not exist the sqlite error is just SQLITE_ERROR when preparing statement
	tStatement.Prepare(_T("SELECT db_version FROM version"));
	if(tStatement.Step() == TSQLiteStatement::eStep_HasRow)
	{
		tTransaction.Commit();
		return tStatement.GetInt(0);
	}

	tTransaction.Commit();
	return 0;
}

void TSerializerVersion::SetVersion(int iNewVersion)
{
	TSQLiteTransaction tTransaction(m_spDatabase);
	TSQLiteStatement tStatement(m_spDatabase);

	// create table
	tStatement.Prepare(_T("UPDATE version SET db_version=?1"));
	tStatement.BindValue(1, iNewVersion);
	tStatement.Step();

	tTransaction.Commit();
}

END_CHCORE_NAMESPACE