/* 7 MAY 81 */
/* based on the formatter presented in Kernighan and Plauger's
SOFTWARE TOOLS, modified for BDS C */


#include "ROFF.H"

main(argc, argv)
int argc;
char **argv;
{
	char filename[20], line[ MAXLINE ];
	struct _buf iobuf;


	dioinit (&argc, argv);	/* directed I/O */
	fprintf(STDERR,"\nVersion 5.1\n");
	while (0) putchar('\7');

	debug = FALSE;
	if (argc == 1)
	{ fprintf(STDERR,"\nUSAGE:  format file1\n  more than one file OK ");
		exit();
	}

	argv++;
	while ( --argc > 0 )
	{ strcpy (filename, *argv++);		/* get next argument */
		fprintf(STDERR,"\nNow processing <%s>",filename );
		if (filename[0] == '-' && filename[1]=='D')
		{
			debug=TRUE;
			continue;
		}


		if (ERROR == fopen( filename, &iobuf ))
		{ fprintf(STDERR,"\ncan not open <%s>", filename );
			continue;
		}

		init_defaults();

		while ( fgets( line, &iobuf ) != 0 ) /*until EOF or CPMEOF */
		{ if (line[0] == COMMAND )
				comand (line);
			else
				text (line);

		}
		if (LINENO > 0  || OUTBUF[0] !='\0')
			space (HUGE);		/* flush last output */
		fprintf(STDERR,"\nDone processing <%s>", filename );

	} 	/* end while (--argc > 0 ) */
	dioflush();
}		/* end main()	       */


/********************************************************************
initializes the global variables governing the execution of the
 format commands.
********************************************************************/
init_defaults()
{

	FILL = FI_DEF;	/* yes we want filled lines */
	LSVAL = LS_DEF;	/* line spacing = 1 */
	INVAL = IN_DEF;	/* left margin indent  0 */
	RMVAL = RM_DEF;	/* right margin = page width  */
	TIVAL = TI_DEF;	/* left margin temporary indent    0 */
	CEVAL = CE_DEF;	/* next n lines to be centered -  0  */
	ULVAL = UL_DEF;	/* next n lines to be underlined -  0  */

	PAGESTOP = FALSE;
	PLVAL = PAGELEN;
	M1VAL = M1_DEF;		/* top and bottom margins */
	M2VAL = M2_DEF;
	M3VAL = M3_DEF;
	M4VAL = M4_DEF;
	CURPAG = 0;
	NEWPAG = 1;
	LINENO = 0;
	BOTTOM = PLVAL - M3VAL - M4VAL;

	OUTWRDS = 0;	/* no. of words in outbuf */
	OUTBUF [0] = '\0';
	DIR = 0;

	strcpy ( HEADER, "\n" );
	strcpy ( FOOTER, "\n" );
}


/*****************************************************************
this function decodes the command type, returning the type, or
	UNKNOWN.
*******************************************************************/
int comtyp (line)
char *line;
{
	char let1, let2;

	let1 = toupper( line[1] );
	let2 = toupper( line[2] );

	if ( let1=='F' && let2=='I')	return( FI );
	if ( let1=='F' && let2=='O')	return( FO );
	if ( let1=='T' && let2=='I')	return( TI );
	if ( let1=='B' && let2=='P')	return( BP );
	if ( let1=='B' && let2=='R')	return( BR );
	if ( let1=='C' && let2=='E')	return( CE );
	if ( let1=='H' && let2=='E')	return( HE );
	if ( let1=='I' && let2=='N')	return( IN );
	if ( let1=='L' && let2=='S')	return( LS );
	if ( let1=='N' && let2=='F')	return( NF );
	if ( let1=='P' && let2=='L')	return( PL );
	if ( let1=='R' && let2=='M')	return( RM );
	if ( let1=='S' && let2=='P')	return( SP );
	if ( let1=='U' && let2=='L')	return( UL );
	if ( let1=='M')
	{ if (let2=='1')		return( M1 );
		if (let2=='2')		return( M2 );
		if (let2=='3')		return( M3 );
		if (let2=='4')		return( M4 );
	}

	return( UNKNOWN );		/* no match */

}


/*********************************************************************
Skips white-space characters at the beginning of a string.
*********************************************************************/
skip_blanks ( string )
char *string;
{
	char local[ MAXLINE ];
	int i, j, k;



	strcpy ( local, string );

	for (i=0; local[i]==' ' || local[i]=='\t' || local[i]=='\n' ; i++);

	for (j=0; (string[j]=local[i]) != '\0' ; i++, j++ )	;

	return;
}


/*********************************************************************

Truncates white-space characters at the end of a string.

*********************************************************************/
trunc_bl (string)
char *string;
{
	char *ptr;
	int k;

	k = strlen (string);
	ptr = &string[ k-1 ];	/* char before terminating nul */

	while (*ptr==BLANK || *ptr==TAB || *ptr==NEWLINE)	
		*ptr--  = '\0';
}


/*******************************************************************
performs the formatting command returned by comtyp - sets global
  variables ( indenting, underlining, etc. )
*******************************************************************/

comand ( line )
char *line;
{
	int c_type;	/* command type  */
	int arg_val;	/* argument value, if any */
	char arg_typ;	/* relative (+ or -) or absolute */
	int i;

	c_type = comtyp (line);
	if DEBUG fprintf(STDERR,"\n\nCOMAND %d",c_type);

	if (c_type == UNKNOWN)	/* IGNORE ALIEN ORDERS */
	{
		fprintf(STDERR, "UNKNOWN COMMAND: <%s>\n", line);
		return;
	}

	arg_val = get_val ( line, &arg_typ );
	if DEBUG fprintf(STDERR, " \n	get_val returned arg_val=%d, arg_typ= %c   ",
	  arg_val,    arg_typ   );
	if DEBUG fprintf(STDERR,"\n\n");

	switch (c_type)
	{
	case FI :	/* filled lines  */
		brk();	/* flush out last unfilled */
		FILL = YES;
		break;

	case NF :	/* non-filled lines */
		brk();	/* flush out */
		FILL = NO;
		break;	/* down and cry */

	case BR :	/* just cause a break */
		brk();
		break;

	case LS :	/* set line spacing value */
		set (&LSVAL, arg_val, arg_typ, LS_DEF, 1, HUGE );
		break;

	case TI :	/* set temporary left indent */
		brk();
		set ( &TIVAL, arg_val, arg_typ, TI_DEF, 0, RMVAL );
		break;

	case IN :	/* set left indent */
		set ( &INVAL, arg_val, arg_typ, IN_DEF, 0, RMVAL-1 );
		TIVAL = INVAL;
		break;

	case RM:	/* set right margin */
		set ( &RMVAL, arg_val, arg_typ, RM_DEF, TIVAL+1, HUGE );
		break;
	case M1:	/* set topmost margin */
		set ( &M1VAL, arg_val, arg_typ, M1_DEF, 0, HUGE);
		break;

	case M2:	/* set second top margin */
		set ( &M2VAL, arg_val, arg_typ, M2_DEF, 0, HUGE);
		break;

	case M3:	/* set first bottom margin */
		set ( &M3VAL, arg_val, arg_typ, M3_DEF, 0, HUGE);
		break;

	case M4:	/* set bottom-most margin */
		set ( &M4VAL, arg_val, arg_typ, M4_DEF, 0, HUGE);
		break;

	case CE :	/* center next arg_val lines */
		brk();
		set ( &CEVAL, arg_val, arg_typ, CE_DEF, 0, HUGE);
		break;

	case UL :	/* underline next arg_val lines */
		set ( &ULVAL, arg_val, arg_typ, UL_DEF, 1, HUGE );
		break;

	case HE :	/* get header title for pages */
		gettl ( line, HEADER );
		break;

	case FO :	/* get footer title for pages */
		gettl ( line, FOOTER );
		break;

	case SP :	/* space down arg_val blank lines */
		set (&SPVAL, arg_val, arg_typ, 1, 0, HUGE);
		space ( SPVAL );
		break;

	case BP :	/* set pageno arg_val - begin page */
		if ( LINENO > 0 )	space (HUGE);
		set ( &CURPAG, arg_val, arg_typ, CURPAG+1, -HUGE, HUGE);
		NEWPAG = CURPAG;
		break;

	case PL :	/* set page length */
		set (&PLVAL, arg_val, arg_typ, PAGELEN,
		  M1VAL+M2VAL+M3VAL+M4VAL+1, HUGE);
		BOTTOM = PLVAL - M3VAL - M4VAL;
		break;


	}

	return;
}

/******************************************************************

gets the number ( if any ) associated with any command 

*******************************************************************/
int get_val ( line, typ )
char *line, *typ;
{
	int i;
	char local[ MAXLINE ];

	strcpy (local, line);	/* local copy */

/* skip over the command line */
	for (i=1; local[i]!=' ' && local[i]!='\t' && local[i]!='\n' ; i++ )
		;

	skip_blanks (&local[i]);	/* find the number */
	*typ = local[i];	/* relative or absolute */

	if ( *typ=='+' || *typ=='-' )	i++;
	else if ( !isdigit( *typ ) )	return( NO_VAL );

	return ( atoi( &local[i] ));

}


/*****************************************************************
 sets a global parameter like line-spacing, underlining, etc.
 Also checks that the new value is within the range of that 
 parameter.  Assigns the default for that parameter if no value
  is specified.
******************************************************************/

set ( param, val, arg_typ, defval, minval, maxval )
int *param, val, defval, minval, maxval;
char arg_typ;
{
	if (val == NO_VAL )		/* defaulted */
		*param = defval;
	else if (arg_typ == '+')	/* relative + */
		*param += val;
	else if (arg_typ == '-')	/* relative - */
		*param -= val;
	else	*param = val;		/* absolute */

	*param = min (*param,maxval);
	*param = max (*param, minval);

	if DEBUG fprintf(STDERR,"\n	SET *param = %d", *param);
	return;
}



/**********************************************************
		centers a line of text
**********************************************************/
center (line)
char *line;
{
	TIVAL = max(( RMVAL+TIVAL-strlen(line))/2, 0 );
	return;
}


/**************************************************************
	get next word from input line
***************************************************************/
int getwrd (in,  out )
char *in, *out;
{
	int i, j, n;

/* find first non-blank */
	skip_blanks (in);
	replace_char ( in, TAB, BLANK); /* replace tabs w/space */

/* scan off a word */
	if ( 1 == (n = sscanf( in, "%s ", out)))	
	{ if DEBUG fprintf(STDERR,"\nafter sscanf out = <%s>",out);
		j = strlen (out);
		replace_char (out, NEWLINE, BLANK);
		for (i=0; i<j; i++ )	in[i] = BLANK;	/* blank out word in input */
	}
	if DEBUG fprintf(STDERR,"\ngetwrd will return %d", n);
	return(n);	/* WE_HAVE_A_WORD = 1 */
}




/*****************************************************************
	distibute words evenly across a line
*****************************************************************/
spread ( line, nextra, no_words)
char *line;
int nextra;	/* no. extra places left in line */
int no_words;   /* no. words in the line         */
{
	int i, j, nblanks, nholes;

	if DEBUG fprintf(STDERR,"\n\nspread:line=<%s>, nextra=%d, no_words=%d",
	  line,      nextra,    no_words   );
	if (nextra <= 0 || no_words <= 1)	return;

	DIR = !(DIR);
	nholes = no_words - 1;
	trunc_bl (line);
	i = strlen(line) - 1 ; /* last character of string */
	j = min (MAXLINE - 2,  i + nextra);	/* last  position in output */
	line[j+1] = '\0';
	if DEBUG fprintf(STDERR,"\nDIR=%d, nholes=%d, i=%d, j=%d",
	  DIR,    nholes,    i,    j   );

	for ( ; i<j ; i--, j-- )
	{ line[j] = line[i];
		if DEBUG fprintf(STDERR,"[%c i=%d j=%d] ", line[j], i, j);
		if ( line[i] == BLANK)
		{ if (DIR == 0)
				nblanks = (nextra - 1)/nholes   +   1;
			else
				nblanks = nextra/nholes;
			nextra = nextra - nblanks;
			nholes = nholes - 1;

			if DEBUG fprintf(STDERR,"\nnblanks=%d, nextra=%d",
			  nblanks,    nextra   );
			for ( ; nblanks > 0;  nblanks-- )
				line[--j] = BLANK;
		}
	}
	if DEBUG fprintf(STDERR,"\nafter spreading, line is:\n<%s>", line);
	return;
}


/****************************************************************
	end current filled line 
*****************************************************************/
brk()
{
	int l;
	if DEBUG fprintf(STDERR,"\nbrk: OUTBUF=<%s>", OUTBUF);

	if ( 0!= ( l = strlen (OUTBUF)))
	{ OUTBUF[l] = NEWLINE;
		OUTBUF[l+1] = '\0';
		put (OUTBUF);
	}

	OUTWRDS = 0;
	OUTBUF[0] = '\0';
	return;

}