/*
 * dbObject.cc
 *
 *  Created on: July 27, 2014
 *      Author: Hovanes Egiyan
 */

#include "dbObject.hh"

//QSqlDatabase 	dbObject::db;			// Static variable for accessing databases

dbObject::dbObject( string uri ) : dbURI(uri) {
	db = openDB( uri );
}

dbObject::~dbObject() {
//	db.close();
}

QSqlDatabase dbObject::openDB(string uri) {
	// Parse the URI
	string::size_type pos = uri.find("://");
	string protocol = uri.substr(0, pos);

	transform(protocol.begin(), protocol.end(), protocol.begin(), ::tolower);

	string resource = uri.substr(pos + 3);
//	qDebug() << "uri = " << uri.c_str() << " protocol = " << protocol.c_str()
//			<< " resource = " << resource.c_str() << endl;

	QSqlDatabase newDB;
	// Open appropriate DB if the connection does not already exist
	if (protocol.compare("sqlite") == 0) {
//		cout << "The DB protocol is SQLite - " << protocol << endl;
		if ( QSqlDatabase::contains(resource.c_str()) ) {
//			cout << "There was an existing DB " << resource << endl;
			newDB = QSqlDatabase::database(resource.c_str());
			if (!newDB.isOpen()) {
				cout << "The existing DB " << resource << " was not open, will open." ;
				if (!newDB.open()) {
					cerr << "Can't open existing database: " << uri << endl;
					cerr << newDB.lastError().text().toStdString() << endl;
					exit(1);
				}
			}
		} else {
			cout << "There was no existing DB " << resource << endl;
			newDB = QSqlDatabase::addDatabase("QSQLITE", resource.c_str());
			newDB.setDatabaseName(resource.c_str());

			if (!newDB.open()) {
				cerr << "Can't open database: " << uri << endl;
				cerr << newDB.lastError().text().toStdString() << endl;
				exit(1);
			}
		}
	} else if (protocol.compare("mysql") == 0) {
		cout << "The DB protocol is MySQL -  " << protocol << endl;
		// Still need to implement MySQL part
	} else {
		cerr << "Unsupported DB protocol - " << protocol << endl;
		exit(1); // FIXME::Might be a status should be risen and program should continue without this part
	}
	return newDB;
}


// Checks if a DB is open. If not, throws an exception. Returns  otherwise
void dbObject::checkDB() {
	// When reached the end of the branch find the crate corresponding to this leaf
	if( ! db.isOpen() ) {
		// Raise an exception if the DB has not been opened first
		stringstream errMsg;
		errMsg << "Error: Database has not been opened. Use dbSubsystem::OpenDB first!" ;
		qWarning() << errMsg.str().c_str() << endl;
		throw StringException(errMsg.str());
	}
	return;
}

int dbObject::sqlSize(QSqlQuery& query) {
    int initialPos = query.at();
    // Very strange but for no records .at() returns -2
    int pos = 0;
    if (query.last())
        pos = query.at() + 1;
    else
        pos = 0;
    // Important to restore initial pos
    query.seek(initialPos);
    return pos;
}