/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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.
 *
 * 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 General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "bagel/hodjnpodj/hnplibs/stdafx.h"
#include "bagel/hodjnpodj/mankala/bgenut.h"
#include "bagel/hodjnpodj/hodjnpodj.h"

namespace Bagel {
namespace HodjNPodj {
namespace Mankala {

///DEFS bgenut.h


//* CGenUtil::RandomInteger -- find random integer in specified range
int CGenUtil::RandomInteger(int iLow, int iHigh)
// iLow, iHigh -- range
// returns: integer which is ge iLow and le iHigh.
{
	JXENTER(CGenUtil::RandomInteger) ;
	int iRetval = 0;        // integer return value

	// for first call, initialize the random number generator
	if (!m_bRandomInit) {
		//srand((unsigned) time(&tTime)), m_bRandomInit = true ;

		// Note: since brand() returns a value uniform in [0, 2^15-1], the
		// following method, though simple, gives a slight preference
		// to lower numbers.  Might be worth fixing sometime.
		if (iLow < iHigh)       // if there's a valid range
			iRetval = iLow + (brand() % (iHigh - iLow + 1)) ;  // compute value
		else        // invalid args
			iRetval = iLow ;
	}
	JXELEAVE(CGenUtil::RandomInteger) ;
	return iRetval;
}

//* CGenUtil::RandomEvent -- return true with specified probability
bool CGenUtil::RandomEvent(int iNum, int iDenom)
// iNum / iDenom -- numerator and denominator of probability
// returns: true with probability iNum / iDenom, false otherwise
{
	JXENTER(CGenUtil::RandomEvent) ;
	//int iError = 0 ;
	bool bRetval ;      // return value

	bRetval = (iNum >= 1 + (brand() % iDenom)) ;
	JXELEAVE(CGenUtil::RandomEvent) ;
	return bRetval;
}


//* CGenUtil::RandomPermutation -- generate a random permutation
//	Generates a permutation of size iSize of the
//	integers from 0 to (iNum-1)
void CGenUtil::RandomPermutation(int iNum,
                                 int iSize, int *xpIntOut)
// iNum -- number of numbers in permutation
// iSize -- size of output array
// xpIntOut -- pointer to output array (size is iSize)
{
	//int iError = 0 ;
	int *xpInt ;    // array pointer variable
	int iI, iJ, iK ;    // loop variables
	int iRanVal ;   // random value to make a choice
	bool bDup ;     // duplicate found flag

	JXENTER(CGenUtil::RandomPermutation) ;
	if (iSize > iNum)   // can't handle more array than # of numbers
		iSize = iNum ;

	for (iI = 0 ; iI < iSize ; ++iI) {      // count numbers
		iRanVal = RandomInteger(0, iNum - iI - 1) ;
		// get random number in interval
		for (iJ = 0 ; iJ < iNum && iRanVal >= 0 ; ++iJ) {
			bDup = false ;      // not a duplicate yet
			for (xpInt = xpIntOut, iK = 0 ; iK < iI ; ++iK, ++xpInt)
				if (*xpInt == iJ)
					bDup = true ;
			if (!bDup && iRanVal-- == 0)    // if not a duplicate
				// and we've counted down the random integer
				*xpInt = iJ ;       // store into array
		}
	}
	JXELEAVE(CGenUtil::RandomPermutation) ;
}

//* CGenUtil::NormalizeCRect --
bool CGenUtil::NormalizeCRect(CRect& cRect)
// cRect -- rectangle to be normalized
// returns: true if error, false otherwise
{
	JXENTER(CGenUtil::NormalizeCRect) ;
	int iError = 0 ;        // error code
	int iSwap ;

	if ((iSwap = cRect.left) > cRect.right)
		cRect.left = cRect.right, cRect.right = iSwap ;
	if ((iSwap = cRect.top) > cRect.bottom)
		cRect.top = cRect.bottom, cRect.bottom = iSwap ;

// cleanup:

	JXELEAVE(CGenUtil::NormalizeCRect) ;
	RETURN(iError != 0) ;
}


//* CGenUtil::RandomSelection -- random selection of integer array
void CGenUtil::RandomSelection(int *xpiArray, int iNum,
                               int iSize)
// xpiArray (input/output) -- array of integers to make selection from
// iNum -- number of numbers in array
// iSize -- number of integers in desired selection
{
	JXENTER(CGenUtil::RandomSelection) ;
	int *xpiPermutation = new int[iSize] ;
	int iK ;

	RandomPermutation(iNum, iSize, xpiPermutation) ;

	for (iK = 0 ; iK < iSize ; ++iK)
		xpiPermutation[iK] = xpiArray[xpiPermutation[iK]] ;

	for (iK = 0 ; iK < iSize ; ++iK)
		xpiArray[iK] = xpiPermutation[iK] ;

	if (xpiPermutation)
		delete [] xpiPermutation ;

	JXELEAVE(CGenUtil::RandomSelection) ;
}

} // namespace Mankala
} // namespace HodjNPodj
} // namespace Bagel