// random.cpp - Random number generation.
//
// (c) 2016-2017 Xestia Software Development.
//
// This file is part of Xestia Calendar.
//
// Xestia Calendar 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, version 3 of the license.
//
// Xestia Calendar 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 Xestia Calendar. If not, see <http://www.gnu.org/licenses/>

#include "random.h"

using namespace std;

int GenerateRandomNumber(int powerOf){
#if defined(WIN32)

	// Seed the randomiser!

	srand(time(0));

	int powerOfCalculation = (int)pow(2, (double)powerOf);
	int randomNumber = rand() % powerOfCalculation;

#else 
	// Get four bytes from /dev/urandom.
	
	int randomData = 0;
	
	ifstream randomFilehandle("/dev/urandom", ios::in|ios::binary);
	char *randomDataInput;
	
	randomDataInput = new char [4];
	randomFilehandle.read(randomDataInput, 4);
	
	// Seed the randomiser!
	
	srand(*randomDataInput);
	delete [] randomDataInput;
	
	randomFilehandle.close();
	
	int powerOfCalculation = (int)pow(2, (double)powerOf);
	int randomNumber = rand() % powerOfCalculation;
#endif
	
	return randomNumber;
}