/*
	(void)	reopen()
		reopen (rewind) input file

	(int) getline(Line *m) 
		obtain next line from input, store in Line *m.
		Returns EndOfFile or !EndOfFile.
		If global !eof_okay and EndOfFile, exit()s.

	(int) getnbline(Line *m) 
		Same as getline(), only skips blank lines.
		
	(int) getndtaline(Line *m) 
		Same as getline(), only skips blank lines if global 
		options.skipblnks.

	(int) input_line_no()
		returns current line number of input line.  Before reading any
		lines, line number is 0.  When first line has been read, line
		is 1, and so on.

	During all input:
		1)	tabs are expanded to multiple blanks
		2)	trailing blanks are trimimed

	Copyright (c) 1992 by CRC
*/

#include "creatdct.h"

				/* Forward references		*/
static int check_eof() ;
static void trimline() ;
static void detabline() ;

static int line_no = 0 ; 

int input_line_no()
{
	return(line_no) ;
}

void reopen() 
{
	Line 	ttl ; 

	rewind(inf) ; 
	end_of_file = 0 ; 
	line_no = 0 ; 

	if (!options.notitle) (void) getnbline(&ttl) ; 
}

int getline(m)
register Line *m ; 
{
	if (end_of_file) {
		initline(m) ; 
		return(check_eof()) ;
	}
	line_no++ ;
	if (fgets(m->s, MAXWIDTH, inf)==NULL) {
		end_of_file = 1 ; 
		initline(m) ; 
		return(check_eof()) ; 
	}
	m->n = strlen(m->s) - 1 ; 
	if (m->n == -1) {		/* can`t happen		*/
		initline(m) ; 
		return(!EndOfFile) ; 
	}
	if (m->s[m->n] == '\n') { 	/* normal case		*/
		m->s[m->n] = '\0' ; 
		detabline(m) ; 
		trimline(m) ;
		return(!EndOfFile) ; 
	}
	fprintf(stderr,"%s: line longer than %d characters\n",
			progname, MAXWIDTH) ; 
	exit(TOOLONG_ERROR) ; 
	/*NOTREACHED*/
}

int getnbline(m)
register Line *m ; 
{
	while(getline(m)==0) { 
		if (m->n) return(0) ; 
	}
	return(check_eof()) ;
}

int getdtaline(m)
register Line *m ;
{
	if (options.skip_blanks) return(getnbline(m)) ;
	return(getline(m)) ;
}


/* ----------------------------------------------------------------------- */
					/* Internal utilities		*/

static int check_eof() { 
	if (eof_okay) return(EndOfFile) ; 
	fprintf(stderr,"%s: unexpected end-of-file\n",progname) ; 
	exit(UEOF_ERROR) ; 
	/*NOTREACHED*/
}



/*
	(void) trimline(Line *m) 

	remove trailing blanks from line
*/


static void trimline(m)
register Line *m ; 
{
	int	i ; 

	for (i=m->n - 1;i>=0 && m->s[i]==' ';i--) m->s[i] = '\0' ; 
	m->n = i + 1 ; 
}

/*
	(void) detabline(lask *m) 

	expand tabs in line.  The following may help in understanding
	the logic below:  Typically, TABPOS=8 and thus:

		0123456789012345678901234567890
			T	T	T

	Ergo, if at position i in string, the new position is 
	newi = (i/8+1)*8.  The strength is then extended by 
	newi-i characters.

*/

static void detabline(m)
register Line *m ; 
{
	int	i ; 
	int	newi ;
	char 	s2[MAXWIDTH] ; 

	for (i=0;i<(m->n);i++) { 
		if (m->s[i]=='\t') {
			newi = (i/TABPOS + 1)*TABPOS ;
			m->n = m->n + (newi-i) - 1 ;
			if (m->n >= MAXWIDTH) {
				fprintf(stderr,
		"%s: line longer than %d characters after detabbing\n",
				progname,MAXWIDTH) ; 
				exit(TOOLONG_ERROR) ; 
				/*NOTREACHED*/
			}
			strcpy(s2,&(m->s[i+1])) ; 
			for (;i<newi;i++) m->s[i] = ' ' ;
			strcpy(&(m->s[i]), s2) ; 
			i-- ;
		}
	}
}