#include "CipresCommlib/util_rand.h"

#ifdef __cplusplus

#include <cstdlib>
#include <ctime>
#include <climits>

using std::time;
using std::srand;
using std::rand;

namespace cipres {
extern "C" 
{
#else /*__cplusplus*/

#include <stdlib.h>
#include <time.h>
#include <limits.h>

#endif /*__cplusplus*/


/** 
 * Returns a random number in the range [0,upperRange).
 */
unsigned randInt(unsigned upperRange)
{
#ifdef NOTDEF	
	/*assert(upperRange > 0);*/
	if (upperRange < 2)
		return 0;
	const double prob = 1.0/((double) upperRange);
	double x = randDouble();
	unsigned toReturn = upperRange - 1;

	tl - microsoft C compiler requires that declarations 
	preceed executable statements.
#endif	

	double prob;
	double x;
	unsigned toReturn;
	if (upperRange < 2)
		return 0;
	
	prob = 1.0/((double) upperRange);
	x = randDouble();
	toReturn = upperRange - 1;

	for (; toReturn > 0; --toReturn) {
		x -= prob;
		if (x < 0.0)
			return toReturn;
	}
	return 0;
}

/** sets seed to s (or time if s is 0 or UINT_MAX)*/
unsigned setRandSeed(unsigned s)
{
	if (s == 0 || s == UINT_MAX)
		s = time(NULL);
	srand(s);
	return s;
}

/** Returns a double from the distribution Uniform[0,1.0) */
double randDouble()
{
	return ((double)rand())/((double) RAND_MAX);
}

#ifdef __cplusplus
} /* end extern "C" */
} /* end namespace cipres */
#endif /*__cplusplus*/