/* int	DecimalPercentage(pDst,src,opt);
 *
 * ARGUMENT
 *	DEC	*pDst;	dest
 *	DEC	*src;	source
 *	int	opt;	option
 *
 * DESCRIPTION
 *	According to the option	opt,
 *  opt	= 1		dst = src * 100
 *  opt	= 2		dst = src / 100
 *  opt	= 3		dst = src / 1200
 *
 * SIDE	EFFECTS
 *   None.
 *
 * RETURNS
 *	Returns	ptr to pDst if successful, else	GM_NULL.
 *
 * POSSIBLE ERROR CODES:
 *
 *	GM_NULLPOINTER
 *	GM_OVERFLOW
 *	GM_UNDERFLOW
 *	GM_ARGVAL
 *
 * AUTHOR
 *  Andy Anderson   20-Feb-87	16:35
 *   Copyright (C) 1987-1990 Greenleaf Software	Inc.  All rights reserved.
 *
 * MODIFICATIONS
 *
 */

#include <stdio.h>
#include "gm.h"
#include "gmsystem.h"

DEC	*DecimalPercentage(pDst,src,opt)
DEC	*pDst, *src;
int	opt;
{

	DEC	dcons, *cons=&dcons;

	_MacStart(GM_DPCT);
	_MacInVarD(src);
	_MacOutVarD(pDst);

	if ((opt<1)||(opt>3))  {
		_MacErr(GM_ARGVAL);
		_MacRet(GM_NULL);
	}

	_MacOutVar(pDst,GM_NULL);

	if (_MacIsDecZ(src))  {
		_MacDCopy(pDst,src);
		_MacRet(pDst);
	}

	if (opt==1)  {
		/*  try	to _MacRet the per cent	*/
		if(src->dc.id >= 2) {
			_MacDCopy(pDst,src);
			pDst->dc.id -= 2;
		}
		else {
			(void) ConvLongToDecimal(cons, 100L);
			if (!MultiplyDecimal(pDst,src,cons))  {
				_MacRet(GM_NULL);
			}
		}
	}

	if (opt	== 2)  {
		_MacDCopy(pDst,src);
		if (src->dc.id <= GM_MAXID-2)  {
			pDst->dc.id += 2;
		}
		else  {
			if (pDst->dc.id	== GM_MAXID-1)	{
				pDst->dc.id++;
				_DivUnsArrByUns( pDst->dc.sl,
					10, 5);
			}
			else
				_DivUnsArrByUns( pDst->dc.sl,
					100, 5);
			if (_MacIsDecZ(pDst))
				_MacErr(GM_UNDERFLOW);
		}
	}

	if (opt	== 3)  {
		(void) ConvLongToDecimal(cons, 1200L);
		(void) DivideDecimal(pDst, src,	cons);
	}

	_MacRet(pDst);
}