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

#include <paper.h>

static void fdgc(Pointer*);

static Metatable fdmeta = {
.gc = fdgc,
};

static void
fdgc(Pointer *p)
{
	int fd;

	assert(p->meta == &fdmeta);

	fd = (uintptr)p->v;

	assert(close(fd) == 0);
}

static void
ppopen(Node *r, Node **av, int na)
{
	int fd, omode;
	Node nodpath, nodmode;

	if(na != 2)
		pperror("open(path, mode): arg count");

	ppexpr(av[0], &nodpath);
	ppexpr(av[1], &nodmode);

	if(nodpath.store.type != TSTRING || nodmode.store.type != TINT)
		pperror("open(path, mode): arg type");

	omode = nodmode.store.ival;

	fd = open(nodpath.store.string->string, omode);
	if(fd < 0)
		pperror("open: %r");

	r->op = OCONST;
	r->store.type = TPOINTER;
	r->store.pval = pppointernode((void*)(uintptr)fd, &fdmeta);
}

static void
ppread(Node *r, Node **av, int na)
{
	int fd, n;
	char buf[8192];
	Node nodfd;

	if(na != 1)
		pperror("read(fd): arg count");

	ppexpr(av[0], &nodfd);

	if(nodfd.store.type != TPOINTER)
		pperror("read(fd): arg type");

	fd = (uintptr)nodfd.store.pval->v;
	n = read(fd, buf, sizeof(buf));
	if(n < 0)
		pperror("read: %r");

	if(n == 0)
		return;

	ppsetstringlen(r, buf, n);
}

static void
usage(void)
{
	fprint(2, "usage: %s\n", argv0);
	exits("usage");
}

#ifdef __unix__
#define TESTFILE "/etc/services"
#else
#define TESTFILE "/lib/glass"
#endif

void
main(int argc, char *argv[])
{
	ARGBEGIN{
	default:
		usage();
	}ARGEND

	static char ppscript[] = "\
OREAD = 0; \
OWRITE = 1; \
fd = open(\"" TESTFILE "\", OREAD); \
s = read(fd); \
while s != nil do { \
//	print(s); \n\
	s = read(fd); \
}; \
fd = {};";

	ppsetup();

	ppbind("open", ppopen);
	ppbind("read", ppread);
	ppcall("interpret", ppstring(ppscript), nil);

	gc(1);

	exits(nil);
}