#include <u.h>
#include <libc.h>
#include <bio.h>
#include "feed.h"

#define MIN(a,b) ((a)<(b)?(a):(b))
#define MAX(a,b) ((a)>(b)?(a):(b))

#pragma varargck type "ß" char*
#pragma varargck type "ś" char*

int mainstacksize = 32768;
Tzone *tzone;

static char *datefmt = "YYYY-MM-DD hh:mm";

static void
printitem(Biobuf *b, Feed *f, Item *i)
{
	char *s;
	int n;

	s = i->author;
	if(s == nil){
		s = f->editor;
		if(s == nil)
			s = f->title;
	}

	Bprint(b, "\n%τ\t%s\n", tmfmt(&i->published, datefmt), s);
	Bprint(b, "    %ß\n", i->title);
	if(i->descr)
		Bprint(b, "%ś\n", i->descr);
	for(n = 0; n < i->nencls; n++)
		Bprint(b, "    %s\n", i->encls[n]);
	Bprint(b, "→ %s\n", i->link);
}

static int
cmpitem(void *a, void *b)
{
	return tmnorm(&((Item*)a)->published) - tmnorm(&((Item*)b)->published);
}

static void
freefeed(Feed *f)
{
	int i;

	free(f->items);
	for(i = 0; i < f->nitems; i++)
		free(f->items[i].encls);
	f->free(f);
	free(f);
}

int
sfmt(Fmt *f)
{
	char *s;

	s = va_arg(f->args, char*);
	for(; *s; s++){
		if(*s == '\n'){
			if(s[1] != 0 && s[1] != '\n')
				fmtrune(f, ' ');
		}else{
			fmtrune(f, *s);
		}
	}

	return 0;
}

static char *
readall(int f)
{
	int bufsz, sz, n;
	char *s;

	bufsz = 1023;
	s = nil;
	for(sz = 0;; sz += n){
		if(bufsz-sz < 1024){
			bufsz *= 2;
			s = realloc(s, bufsz);
		}
		if((n = readn(f, s+sz, bufsz-sz-1)) < 1)
			break;
	}
	if(n < 0 || sz < 1){
		free(s);
		return nil;
	}
	s[sz] = 0;

	return s;
}

static int
htmlfmt(Fmt *f)
{
	int p[4], pid;
	char *s;

	s = va_arg(f->args, char*);
	if(s == nil)
		return 0;

	pipe(p);
	pipe(p+2);
	if((pid = rfork(RFPROC|RFFDG)) == 0){
		dup(p[0], 0);
		dup(p[2], 1);
		close(p[0]);
		close(p[1]);
		close(p[2]);
		close(p[3]);
		close(2);
		execl("/bin/rc", "rc", "-c", "{echo .ll 9999i; echo .pl 1no; echo .po 4; cat | html2ms} | nroff -N", nil);
		sysfatal("execl: %r");
	}
	if(pid < 0)
		sysfatal("failed: %r");

	fprint(p[1], "%s", s);
	close(p[0]);
	close(p[1]);
	close(p[2]);
	s = readall(p[3]);
	close(p[3]);

	if(s != nil && *s){
		s[strlen(s)-1] = 0;
		fmtstrcpy(f, s);
		free(s);
	}

	return 0;
}

static void
usage(void)
{
	fprint(2, "usage: %s [-d DATEFMT]\n", argv0);
	exits("usage");
}

void
main(int argc, char **argv)
{
	Biobuf in, out;
	Feed *f;
	Item *i;

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

	quotefmtinstall();
	tmfmtinstall();
	fmtinstall(L'ß', sfmt);
	fmtinstall(L'ś', htmlfmt);

	if((tzone = tzload("local")) == nil)
		sysfatal("%r");

	Binit(&in, 0, OREAD);
	Binit(&out, 1, OWRITE);
	if((f = parserss(&in)) == nil)
		sysfatal("%r");
	f->ttl = MAX(1, MIN(60, f->ttl)); /* 1..60min */

	qsort(f->items, f->nitems, sizeof(Item), cmpitem);
	for(i = f->items; i != f->items+f->nitems; i++)
		printitem(&out, f, i);

	freefeed(f);

	exits(nil);
}