/* 
*
*  ProLinga-Data
*
*  Copyright (C) 2002-2008 Xobas Software.
*  All rights reserved.
*  
*  This file is part of ProLinga-Data.
*
*  ProLinga-Data is free software: you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation, either version 3 of the License, or
*  (at your option) any later version.
*
*  ProLinga-Data 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 General Public License
*  along with ProLinga-Data.  If not, see <http://www.gnu.org/licenses/>.
*
*  More information is available at the following addresses:
*
*  Website     : http://www.prolinga.org
*
*  Email       : prolinga-list@prolinga.org
*
*
*/

#include "DatCommon.h"
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
#include <libgda/libgda.h>
#include "DatMain.hpp"
#include "DCTransaction.hpp"
#include "DCSession.hpp"
#include "DatConfig.hpp"

extern DCSessionPtr sesPtr;

int DCTransaction(const xmlDocPtr docObj, const char *sessionId, char **externalError, xmlDocPtr *docReturn)
{
	xmlNodePtr curReturn;
	xmlXPathContextPtr ctxObj;
	xmlXPathObjectPtr resObj;
	GdaConnection *connection;
	char *objDataSource, *transMode, *transId, *isolationLevel;
	int dbStatus = 0;

	/* Create XPath Environment */
	ctxObj = xmlXPathNewContext(docObj);

	/* Get DataSource name */
	resObj = xmlXPathEval((const xmlChar *)"/ProLinga/Object/@DataSource", ctxObj);
	objDataSource = (char *)xmlXPathCastToString(resObj);

	/* Get Connection Object to Data Source */
	connection = sesPtr->getGdaConnection(sesPtr, sessionId, objDataSource);
	if (connection == NULL)
		return 70002;

	/* Get Transaction Mode */
	resObj = xmlXPathEval((const xmlChar *)"/ProLinga/Object/Transaction/@Mode", ctxObj);
	transMode = (char *)xmlXPathCastToString(resObj);

	if (strcmp(transMode, "Begin") == 0)
	{
		/* Check if there is no transaction in progress */
		transId = sesPtr->getTransactionId(sesPtr, sessionId);
		if (transId != NULL)
			return 70006;

		/* Create new transaction */
		//trans = gda_transaction_status_new(sessionId);

		/* Get Isolation Level */
		resObj = xmlXPathEval((const xmlChar *)"/ProLinga/Object/Transaction/IsolationLevel", ctxObj);
		isolationLevel = (char *)xmlXPathCastToString(resObj);

		/* Begin transaction */
		if (strcmp(isolationLevel, "Unknown") == 0)
			gda_connection_begin_transaction(connection, sessionId, GDA_TRANSACTION_ISOLATION_UNKNOWN, NULL);
		else if (strcmp(isolationLevel, "ReadCommitted") == 0)
			gda_connection_begin_transaction(connection, sessionId, GDA_TRANSACTION_ISOLATION_READ_COMMITTED, NULL);
		else if (strcmp(isolationLevel, "ReadUncommitted") == 0)
			gda_connection_begin_transaction(connection, sessionId, GDA_TRANSACTION_ISOLATION_READ_UNCOMMITTED, NULL);
		else if (strcmp(isolationLevel, "RepeatableRead") == 0)
			gda_connection_begin_transaction(connection, sessionId, GDA_TRANSACTION_ISOLATION_REPEATABLE_READ, NULL);
		else if (strcmp(isolationLevel, "Serializable") == 0)
			gda_connection_begin_transaction(connection, sessionId, GDA_TRANSACTION_ISOLATION_SERIALIZABLE, NULL);

		/* Begin transaction */
		//gda_connection_begin_transaction(connection, trans);

		/* Store transaction */
		sesPtr->putTransactionId(sesPtr, sessionId, sessionId);
	}
	else if (strcmp(transMode, "Commit") == 0)
	{
		/* Get Transaction */
		transId = sesPtr->getTransactionId(sesPtr, sessionId);
		if (transId == NULL)
			return 70007;

		/* Commit */
		gda_connection_commit_transaction(connection, sessionId, NULL);

		/* Clear memory */
		sesPtr->clearTransactionId(sesPtr, sessionId);
	}
	else if (strcmp(transMode, "Rollback") == 0)
	{
		/* Get Transaction */
		transId = sesPtr->getTransactionId(sesPtr, sessionId);

		if (transId == NULL)
			return 70007;

		/* Rollback */
		gda_connection_rollback_transaction(connection, sessionId, NULL);

		/* Clear memory */
		sesPtr->clearTransactionId(sesPtr, sessionId);
	}

	/* Create return document */
	*docReturn = xmlNewDoc((const xmlChar *)XML_VERSION);
	(*docReturn)->children = xmlNewDocNode(*docReturn, NULL, (const xmlChar *)ROOT_ELEM, NULL);
	curReturn = xmlDocGetRootElement(*docReturn);
	curReturn = xmlNewTextChild(curReturn, NULL, (const xmlChar *)"Object", (const xmlChar *)"");
	xmlNewProp(curReturn, (const xmlChar *)"DataSource", (const xmlChar *)objDataSource);

	/* Return */	
	return dbStatus;
}