/* roff.c, conditional processing */
#include "nroff.h"
/* conditional processing */

/* if processing */

#define	MAXCOND	10	/* place to save last condition */
char	curcond[MAXCOND];
int	curcptr;

cond(buf, cmd)
char	*buf;
{
	int	val = 0;
	int	condi = TRUE;

	if(*buf == '!'){
		buf++;
		condi = FALSE;
	}
	if(*buf == '\"' || *buf == '\'')
		val = stricmp(&buf);
	else switch(*buf){
	case 'o':
		if(curpage & ODD)
			val = 1;
		buf++;
		break;
	case 'e':
		if( (curpage & ODD) == 0)
			val = 1;
		buf++;
		break;
	case 't':
	case 'n':	/* neither leave as zero always */
		buf++;
		break;
	default:
		val = eval(&buf);
		break;
	}
	val = (val > 0);	/* get condition right */
	if(!condi)
		val = !val;
	while(*buf == ' ')
		buf++;
	if(*buf == '\0')
		return;
	if(cmd == EI){
		if(curcptr >= MAXCOND){
			fprintf(stderr, "Condition stack overflow\n");
			exit(5);
		}
		curcond[curcptr++] = val;
	}
	iskip(buf, val);
}

iskip(buf, val)
char	*buf;
{
	int	level;
	int	c;

	while(*buf == ' ')
		buf++;
	if(*buf == '\0')
		return;
	if(val){		/* condition is true */
		if(*buf == echar && buf[1] == '{'){
			/* multipart text here */
			/*
			 * must shove this stuff into a diversion
			 * until it gets to the current point
			 */
			redirect(buf+2);
			return;
		}
		/* shame this can't be redirected !! */
		strcpy(inbuf, buf);	/* cheat badly !!!!! */
		if(CMD(inbuf[0]))
			command(inbuf);
		else
			text(inbuf);
		return;
	}
	/* condition fails */

	if(*buf == echar && buf[1] == '{'){
		buf += 2;	/* multi line stuff !! */
		level = 0;
		while(*buf){
			if(*buf == echar){
				buf++;
				if(*buf == '{')
					level++;
				else if(*buf == '}')
					if(--level < 0)
						return;
			}
			buf++;
		}
		while( (c = getm()) != EOF)
			if(c == echar){
				if((c = getm()) == EOF)
					return;
				if(c == '{')
					level++;
				else if(c == '}')
					if(--level < 0)
						return;
			}
	}
}

/*
 * read input and put onto a diversion so that it can then be put 
 * back onto the input !! it works !!
 */

redirect(buf)
char	*buf;
{
	int	level = 0;
	int	c;
	struct	source	*mp;

	/* going for a redirect !! */

	mp = (struct source *)mymalloc(sizeof(struct source), TRUE);
	mp->m_val = mymalloc(LINESIZE+1, FALSE);
	mp->m_eptr = mp->m_val + LINESIZE;
	mp->m_curp = mp->m_val;
	mp->m_last = curdiv;
	curdiv = mp;
	for(;c = *buf++;){
		if(c == echar){
			c = *buf++;
			if(c == '\0'){
				PUT(echar);
				break;
			}
			if(c == '{')
				level++;
			else if(c == '}')
				if(--level < 0)
					goto got;
			PUT(echar);
		}
		PUT(c);
	}
	/* must force out a NL here otherwise we get problems */
	PUTNL();
	while( (c = getm()) != EOF){
		if(c == echar){
			if((c = getm()) == EOF){
				PUT(echar);
				break;
			}
			if(c == '{')
				level++;
			else if(c == '}')
				if(--level < 0)
					break;
			PUT(echar);
		}
		PUT(c);
	}
	/* now have text read for reinput */
got:;
	curdiv = mp->m_last;
	*mp->m_curp = '\0';
			/* take off output, put back onto input */
	mp->m_last = curmacro;
	curmacro = mp;
	mp->m_curp = mp->m_val;
}

/* else processing */

econd(buf)
char	*buf;
{
	if(curcptr <= 0)	/* .if stack empty */
		return;
	iskip(buf, !curcond[--curcptr]);	/* reverse the sense */
}

/* if string1 == string2 !! */

stricmp(ptr)
char	**ptr;
{

}