/******************************************************************************
* Bzr-Read.c - Bezier curves handling routines - read from file.	      *
*******************************************************************************
* Written by Gershon Elber, Mar. 90.					      *
******************************************************************************/

#ifdef __MSDOS__
#include <stdlib.h>
#endif /* __MSDOS__ */

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include "cagd_loc.h"

#define  UNGET_STACK_SIZE	3

int _CagdGlblLineCount = 1;	     /* Used to locate errors in input file. */

static int GlblTknStackSize = 0;          /* Used by parser, to unget token. */
static char GlblStringToken[UNGET_STACK_SIZE][LINE_LEN];/* Save unget tokens.*/

static void GetStringToken(FILE *f, char *StringToken);

/*****************************************************************************
* Routine to read from input file f the	following [ATTR ...] [ATTR ...].     *
* Note the '[' was allready read.					     *
* Current supported attributes: None.					     *
* Returns NULL if O.k., otherwise string describing the error.		     *
*****************************************************************************/
char *_CagdGetCurveAttributes(FILE *f)
{
    TokenNumType i;
    char StringToken[LINE_LEN];

    do {
	switch (_CagdGetToken(f, StringToken)) {
	    default:
		while ((i = _CagdGetToken(f, StringToken)) !=
							TOKEN_CLOSE_PAREN &&
		       i != TOKEN_EOF);
		if (i == TOKEN_EOF)
		    return "EOF detected in middle of attribute.";
		break;
	}
    }
    while (_CagdGetToken(f, StringToken) == TOKEN_OPEN_PAREN);

    _CagdUnGetToken(StringToken);

    return NULL;
}

/*****************************************************************************
* Routine to read from input file f the	following [ATTR ...] [ATTR ...].     *
* Note the '[' was allready read.					     *
* Current supported attributes: None.					     *
* Returns NULL if O.k., otherwise string describing the error.		     *
*****************************************************************************/
char *_CagdGetSurfaceAttributes(FILE *f)
{
    TokenNumType i;
    char StringToken[LINE_LEN];

    do {
	switch (_CagdGetToken(f, StringToken)) {
	    default:
		while ((i = _CagdGetToken(f, StringToken)) !=
							TOKEN_CLOSE_PAREN &&
		       i != TOKEN_EOF);
		if (i == TOKEN_EOF)
		    return "EOF detected in middle of attribute.";
		break;
	}
    }
    while (_CagdGetToken(f, StringToken) == TOKEN_OPEN_PAREN);

    _CagdUnGetToken(StringToken);

    return NULL;
}

/******************************************************************************
*   Routine to unget one token (on stack of UNGET_STACK_SIZE levels!)	      *
******************************************************************************/
void _CagdUnGetToken(char *StringToken)
{
    if (GlblTknStackSize >= UNGET_STACK_SIZE)
	FATAL_ERROR(CAGD_ERR_PARSER_STACK_OV);

    strcpy(GlblStringToken[GlblTknStackSize++], StringToken);
}

/******************************************************************************
*   Routine to get the next token out of the input file	f.		      *
* Returns the next token found,	as StringToken.				      *
* Note:	StringToken must be allocated before calling this routine!	      *
******************************************************************************/
static void GetStringToken(FILE *f, char *StringToken)
{
    int	Len;
    char c, *LocalStringToken;

    if (GlblTknStackSize) {		       /* Get first the unget token. */
	strcpy(StringToken, GlblStringToken[--GlblTknStackSize]);
	return;
    }

    /* skip white spaces and comments: */
    while (!feof(f) && ((c = getc(f)) == ' ' || c == '\t' || c == '\n') ||
    							     c == '#') {
        /* Skip a comment if encounter one. */
	if (c == '#') while (!feof(f) && c != '\n') c = getc(f);
	if (c == '\n') _CagdGlblLineCount++;		 /* Count the lines. */
    }

    LocalStringToken = StringToken;
    if (c == '[')		      /* Its a token by itself so return it. */
	*LocalStringToken++ = c;	      /* Copy the token into string. */
    else {
	if (!feof(f))
	    do *LocalStringToken++ = c;       /* Copy the token into string. */
	    while ((!feof(f)) &&
		   ((c = getc(f)) != ' ') && (c != '\t') && (c != '\n'));
	if (c == '\n') ungetc(c, f);	 /* Save it to be counted next time. */
    }
    *LocalStringToken =	0;					 /* Put eos. */

    /* The following handles the spacial case were we have XXXX] - we must   */
    /* split it	into two token XXXX and	], UnGetToken(']') and return XXXX:  */
    if ((StringToken[Len = strlen(StringToken)-1] == ']') && (Len > 0))	{
	/* Return CloseParen */
	_CagdUnGetToken(&StringToken[Len]);	         /* Save next token. */
	StringToken[Len] = 0;			/* Set end of string on "]". */
    }
}

/******************************************************************************
*   Routine to get the next token out of the input file	f as token number.    *
* Returns the next token number	found, with numeric result in NumericToken    *
* if TokenType is TOKEN_NUMBER.						      *
* Note:	StringToken must be allocated before calling this routine!	      *
******************************************************************************/
TokenNumType _CagdGetToken(FILE *f, char *StringToken)
{
    GetStringToken(f, StringToken);

    if (feof(f))			     return TOKEN_EOF;

    if (!strcmp(StringToken, "["))	     return TOKEN_OPEN_PAREN;
    if (!strcmp(StringToken, "]"))	     return TOKEN_CLOSE_PAREN;

    if (!strcmp(StringToken, "BEZIER"))      return TOKEN_BEZIER;
    if (!strcmp(StringToken, "BSPLINE"))     return TOKEN_BSPLINE;
    if (!strcmp(StringToken, "POWER"))       return TOKEN_POWER;

    if (!strcmp(StringToken, "CURVE"))	     return TOKEN_CURVE;
    if (!strcmp(StringToken, "SURFACE"))     return TOKEN_SURFACE;

    if (!strcmp(StringToken, "PTYPE"))       return TOKEN_PTYPE;
    if (!strcmp(StringToken, "NUMPTS"))	     return TOKEN_NUM_PTS;
    if (!strcmp(StringToken, "ORDER"))	     return TOKEN_ORDER;

    if (!strcmp(StringToken, "KV"))	     return TOKEN_KV;

    return TOKEN_OTHER;				  /* Must be number or name. */
}

/*****************************************************************************
* Convert a real number into a string.					     *
*****************************************************************************/
char *_CagdReal2Str(double R)
{
    static char Buffer[LINE_LEN];
    int j;

    if (ABS(R) < EPSILON) R = 0.0;

    sprintf(Buffer, "%-8.6lg", R);

    for (j = strlen(Buffer) - 1; Buffer[j] == ' ' && j > 0; j--);
    if (strchr(Buffer, '.') != NULL)
	for (; Buffer[j] == '0' && j > 0; j--);
    Buffer[j+1] = 0;

    return Buffer;
}