#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>

static void
wr2(Biobuf *bo, short n)
{
	Bwrite(bo, &n, 2);
}

static void
wrn(Biobuf *bo, void *buf, int len)
{
	Bwrite(bo, buf, len);
}

static void
str(Biobuf *bo, int r, int c, char *s)
{
	int len;

	len = strlen(s);
	wr2(bo, 0x0204);	/* string object */
	wr2(bo, len + 8);	/* bytes following */
	wr2(bo, r);
	wr2(bo, c);
	wr2(bo, 0);		/* format type - none  */
	wr2(bo, len);		/* string length */
	wrn(bo, s, len);
}

static void
num(Biobuf *bo, int r, int c, double n)
{
	wr2(bo, 0x0203);	/* number object */
	wr2(bo, 14);		/* bytes following */
	wr2(bo, r);
	wr2(bo, c);
	wr2(bo, 0);		/* format type - none */
	wrn(bo, &n, sizeof(double));
}

static void
cell(Biobuf *bo, int r, int c, char *s)
{
	char *t;
	double n;

	n = strtod(s, &t);
	if(*s == 0 || *t != 0)
		str(bo, r, c, s);
	else
		num(bo, r, c, n);
}

static void
usage(void)
{
	fprint(2, "usage: %s [-d c] [<input-file>]\n", argv0);
	fprint(2, "  -d  c   set field deliminator\n");
	exits("usage");
}

void
main(int argc, char *argv[])
{
	int n, r, c;
	char *delim, *line, *a[128];
	Biobuf bout, *bo = &bout;
	Biobuf binp, *bi = &binp;

	delim = "|";
	ARGBEGIN{
	case 'd':
		delim = EARGF(usage());
		break;
	default:
		usage();
		break;
	}ARGEND;

	switch(argc){
	case 1:
		bi = Bopen(argv[0], OREAD);
		if(bi == nil)
			sysfatal("%s cannot open - %r\n", argv[0]);
		break;
	case 0:
		Binit(bi, OREAD, 0);
		break;
	default:
		usage();
		break;
	}

	Binit(bo, OWRITE, 1);

	wr2(bo, 0x0809);	/* Start of file */
	wr2(bo, 4);		/* bytes following */
	wr2(bo, 0x500);		/* Biff V5 file */
	wr2(bo, 0x10);		/* is a worksheet */

	while((line = Brdline(bi, '\n')) != nil){
		line[Blinelen(bi) -1] = 0;

		n = getfields(line, a, nelem(a), 0, delim);
		if(n < 2)				/* blank lines */
			continue;
		if(a[0][0] == '#')			/* comments */
			continue;
		r = atoi(a[0]) -1;			/* -1 as excel ordinates start at zero */
		for(c = 1; c < n; c++)
			cell(bo, r, c-1, a[c]);		/* -1 as excel ordinates start at zero */
	}


	wr2(bo, 0xa);		/* End of file */
	wr2(bo, 0);		/* bytes following */

	Bterm(bi);
	Bterm(bo);
	exits(nil);
}