/*
 *  M_APM  -  mapmutil.c
 *
 *  Copyright (C) 1999 - 2007   Michael C. Ring
 *
 *  Permission to use, copy, and distribute this software and its
 *  documentation for any purpose with or without fee is hereby granted,
 *  provided that the above copyright notice appear in all copies and
 *  that both that copyright notice and this permission notice appear
 *  in supporting documentation.
 *
 *  Permission to modify the software is granted. Permission to distribute
 *  the modified code is granted. Modifications are to be distributed by
 *  using the file 'license.txt' as a template to modify the file header.
 *  'license.txt' is available in the official MAPM distribution.
 *
 *  This software is provided "as is" without express or implied warranty.
 */

/*
 *
 *      This file contains various utility functions needed by the
 *	library in addition to some basic user callable functions.
 */

#include "pgAdmin3.h"
#include "pgscript/utilities/mapm-lib/m_apm_lc.h"

static  UCHAR	*M_mul_div = NULL;
static  UCHAR   *M_mul_rem = NULL;

static  UCHAR   M_mul_div_10[100];
static	UCHAR   M_mul_rem_10[100];

static	int	M_util_firsttime = TRUE;
static	int     M_firsttime3 = TRUE;

static	M_APM	M_work_0_5;

static  const char    *M_init_error_msg = "\'m_apm_init\', Out of memory";

/****************************************************************************/
M_APM	m_apm_init()
{
	M_APM	atmp;

	if (M_firsttime3)
	{
		M_firsttime3 = FALSE;
		M_init_util_data();
		M_init_trig_globals();
	}

	if ((atmp = (M_APM)MAPM_MALLOC(sizeof(M_APM_struct))) == NULL)
	{
		/* fatal, this does not return */

		M_apm_log_error_msg(M_APM_FATAL, M_init_error_msg);
	}

	atmp->m_apm_id           = M_APM_IDENT;
	atmp->m_apm_malloclength = 80;
	atmp->m_apm_datalength   = 1;
	atmp->m_apm_refcount     = 1;           /* not for us, for MAPM C++ class */
	atmp->m_apm_exponent     = 0;
	atmp->m_apm_sign         = 0;

	if ((atmp->m_apm_data = (UCHAR *)MAPM_MALLOC(84)) == NULL)
	{
		/* fatal, this does not return */

		M_apm_log_error_msg(M_APM_FATAL, M_init_error_msg);
	}

	atmp->m_apm_data[0] = 0;
	return(atmp);
}
/****************************************************************************/
void	m_apm_free(M_APM atmp)
{
	if (atmp->m_apm_id == M_APM_IDENT)
	{
		atmp->m_apm_id = 0x0FFFFFF0L;
		MAPM_FREE(atmp->m_apm_data);
		MAPM_FREE(atmp);
	}
	else
	{
		M_apm_log_error_msg(M_APM_RETURN, "\'m_apm_free\', Invalid M_APM variable");
	}
}
/****************************************************************************/
void	M_free_all_util()
{
	if (M_util_firsttime == FALSE)
	{
		m_apm_free(M_work_0_5);
		M_util_firsttime = TRUE;
	}

	if (M_firsttime3 == FALSE)
	{
		MAPM_FREE(M_mul_div);
		MAPM_FREE(M_mul_rem);

		M_mul_div    = NULL;
		M_mul_rem    = NULL;
		M_firsttime3 = TRUE;
	}
}
/****************************************************************************/
/*
 *      just a dummy wrapper to keep some compilers from complaining
 */
int 	M_get_sizeof_int()
{
	return(sizeof(int));
}
/****************************************************************************/
void	M_init_util_data()
{
	int	k;
	UCHAR   ndiv, nrem;

	if (M_mul_div != NULL)
		return;

	M_mul_div = (UCHAR *)MAPM_MALLOC(10000 * sizeof(UCHAR));
	M_mul_rem = (UCHAR *)MAPM_MALLOC(10000 * sizeof(UCHAR));

	if (M_mul_div == NULL || M_mul_rem == NULL)
	{
		/* fatal, this does not return */

		M_apm_log_error_msg(M_APM_FATAL, "\'M_init_util_data\', Out of memory");
	}

	ndiv = 0;
	nrem = 0;

	for (k = 0; k < 100; k++)
	{
		M_mul_div_10[k] = ndiv;
		M_mul_rem_10[k] = nrem;

		if (++nrem == 10)
		{
			nrem = 0;
			ndiv++;
		}
	}

	ndiv = 0;
	nrem = 0;

	for (k = 0; k < 10000; k++)
	{
		M_mul_div[k] = ndiv;
		M_mul_rem[k] = nrem;

		if (++nrem == 100)
		{
			nrem = 0;
			ndiv++;
		}
	}
}
/****************************************************************************/
void	M_get_div_rem_addr(UCHAR **ndivp, UCHAR **nremp)
{
	*ndivp = M_mul_div;
	*nremp = M_mul_rem;
}
/****************************************************************************/
void	M_get_div_rem(int tbl_lookup, UCHAR *ndiv, UCHAR *nrem)
{
	*ndiv = M_mul_div[tbl_lookup];
	*nrem = M_mul_rem[tbl_lookup];
}
/****************************************************************************/
void	M_get_div_rem_10(int tbl_lookup, UCHAR *ndiv, UCHAR *nrem)
{
	*ndiv = M_mul_div_10[tbl_lookup];
	*nrem = M_mul_rem_10[tbl_lookup];
}
/****************************************************************************/
void	m_apm_round(M_APM btmp, int places, M_APM atmp)
{
	int	ii;

	if (M_util_firsttime)
	{
		M_util_firsttime = FALSE;

		M_work_0_5 = m_apm_init();
		m_apm_set_string(M_work_0_5, "5");
	}

	ii = places + 1;

	if (atmp->m_apm_datalength <= ii)
	{
		m_apm_copy(btmp, atmp);
		return;
	}

	M_work_0_5->m_apm_exponent = atmp->m_apm_exponent - ii;

	if (atmp->m_apm_sign > 0)
		m_apm_add(btmp, atmp, M_work_0_5);
	else
		m_apm_subtract(btmp, atmp, M_work_0_5);

	btmp->m_apm_datalength = ii;
	M_apm_normalize(btmp);
}
/****************************************************************************/
void	M_apm_normalize(M_APM atmp)
{
	int	i, index, datalength, exponent;
	UCHAR   *ucp, numdiv, numrem, numrem2;

	if (atmp->m_apm_sign == 0)
		return;

	datalength = atmp->m_apm_datalength;
	exponent   = atmp->m_apm_exponent;

	/* make sure trailing bytes/chars are 0                */
	/* the following function will adjust the 'datalength' */
	/* we want the original value and will fix it later    */

	M_apm_pad(atmp, (datalength + 3));

	while (TRUE)			/* remove lead-in '0' if any */
	{
		M_get_div_rem_10((int)atmp->m_apm_data[0], &numdiv, &numrem);

		if (numdiv >= 1)      /* number is normalized, done here */
			break;

		index = (datalength + 1) >> 1;

		if (numrem == 0)      /* both nibbles are 0, we can move full bytes */
		{
			i = 0;
			ucp = atmp->m_apm_data;

			while (TRUE)	 /* find out how many '00' bytes we can move */
			{
				if (*ucp != 0)
					break;

				ucp++;
				i++;
			}

			memmove(atmp->m_apm_data, ucp, (index + 1 - i));
			datalength -= 2 * i;
			exponent -= 2 * i;
		}
		else
		{
			for (i = 0; i < index; i++)
			{
				M_get_div_rem_10((int)atmp->m_apm_data[i + 1], &numdiv, &numrem2);
				atmp->m_apm_data[i] = 10 * numrem + numdiv;
				numrem = numrem2;
			}

			datalength--;
			exponent--;
		}
	}

	while (TRUE)			/* remove trailing '0' if any */
	{
		index = ((datalength + 1) >> 1) - 1;

		if ((datalength & 1) == 0)   /* back-up full bytes at a time if the */
		{
			/* current length is an even number    */
			ucp = atmp->m_apm_data + index;
			if (*ucp == 0)
			{
				while (TRUE)
				{
					datalength -= 2;
					index--;
					ucp--;

					if (*ucp != 0)
						break;
				}
			}
		}

		M_get_div_rem_10((int)atmp->m_apm_data[index], &numdiv, &numrem);

		if (numrem != 0)		/* last digit non-zero, all done */
			break;

		if ((datalength & 1) != 0)   /* if odd, then first char must be non-zero */
		{
			if (numdiv != 0)
				break;
		}

		if (datalength == 1)
		{
			atmp->m_apm_sign = 0;
			exponent = 0;
			break;
		}

		datalength--;
	}

	atmp->m_apm_datalength = datalength;
	atmp->m_apm_exponent   = exponent;
}
/****************************************************************************/
void	M_apm_scale(M_APM ctmp, int count)
{
	int	ii, numb, ct;
	UCHAR	*chp, numdiv, numdiv2, numrem;
	void	*vp;

	ct = count;

	ii = (ctmp->m_apm_datalength + ct + 1) >> 1;
	if (ii > ctmp->m_apm_malloclength)
	{
		if ((vp = MAPM_REALLOC(ctmp->m_apm_data, (ii + 32))) == NULL)
		{
			/* fatal, this does not return */

			M_apm_log_error_msg(M_APM_FATAL, "\'M_apm_scale\', Out of memory");
		}

		ctmp->m_apm_malloclength = ii + 28;
		ctmp->m_apm_data = (UCHAR *)vp;
	}

	if ((ct & 1) != 0)          /* move odd number first */
	{
		ct--;
		chp = ctmp->m_apm_data;
		ii  = ((ctmp->m_apm_datalength + 1) >> 1) - 1;

		if ((ctmp->m_apm_datalength & 1) == 0)
		{
			/*
			 *   original datalength is even:
			 *
			 *   uv  wx  yz   becomes  -->   0u  vw  xy  z0
			 */

			numdiv = 0;

			while (TRUE)
			{
				M_get_div_rem_10((int)chp[ii], &numdiv2, &numrem);

				chp[ii + 1] = 10 * numrem + numdiv;
				numdiv = numdiv2;

				if (ii == 0)
					break;

				ii--;
			}

			chp[0] = numdiv2;
		}
		else
		{
			/*
			 *   original datalength is odd:
			 *
			 *   uv  wx  y0   becomes  -->   0u  vw  xy
			 */

			M_get_div_rem_10((int)chp[ii], &numdiv2, &numrem);

			if (ii == 0)
			{
				chp[0] = numdiv2;
			}
			else
			{
				while (TRUE)
				{
					M_get_div_rem_10((int)chp[ii - 1], &numdiv, &numrem);

					chp[ii] = 10 * numrem + numdiv2;
					numdiv2 = numdiv;

					if (--ii == 0)
						break;
				}

				chp[0] = numdiv;
			}
		}

		ctmp->m_apm_exponent++;
		ctmp->m_apm_datalength++;
	}

	/* ct is even here */

	if (ct > 0)
	{
		numb = (ctmp->m_apm_datalength + 1) >> 1;
		ii   = ct >> 1;

		memmove((ctmp->m_apm_data + ii), ctmp->m_apm_data, numb);
		memset(ctmp->m_apm_data, 0, ii);

		ctmp->m_apm_datalength += ct;
		ctmp->m_apm_exponent += ct;
	}
}
/****************************************************************************/
void	M_apm_pad(M_APM ctmp, int new_length)
{
	int	num1, numb, ct;
	UCHAR	numdiv, numrem;
	void	*vp;

	ct = new_length;
	if (ctmp->m_apm_datalength >= ct)
		return;

	numb = (ct + 1) >> 1;
	if (numb > ctmp->m_apm_malloclength)
	{
		if ((vp = MAPM_REALLOC(ctmp->m_apm_data, (numb + 32))) == NULL)
		{
			/* fatal, this does not return */

			M_apm_log_error_msg(M_APM_FATAL, "\'M_apm_pad\', Out of memory");
		}

		ctmp->m_apm_malloclength = numb + 28;
		ctmp->m_apm_data = (UCHAR *)vp;
	}

	num1 = (ctmp->m_apm_datalength + 1) >> 1;

	if ((ctmp->m_apm_datalength & 1) != 0)
	{
		M_get_div_rem_10((int)ctmp->m_apm_data[num1 - 1], &numdiv, &numrem);
		ctmp->m_apm_data[num1 - 1] = 10 * numdiv;
	}

	memset((ctmp->m_apm_data + num1), 0, (numb - num1));
	ctmp->m_apm_datalength = ct;
}
/****************************************************************************/

/*
      debug_dsp(cc)
      M_APM cc;
      {
static char buffer[8192];

m_apm_to_string(buffer, -1, cc);
printf("(dsp func) = [%s]\n",buffer);

      }
*/