#include <u.h>
#include <libc.h>
#include <thread.h>
#include <bio.h>
#include <ndb.h>
#include "collectd.h"

char *hostname;
char *server;
uint interval = 10;

QLock snoozelock;
Rendez snoozerendez;

void
snooze(void)
{
	qlock(&snoozelock);
	rsleep(&snoozerendez);
	qunlock(&snoozelock);
}

void
wakeupall(void)
{
	qlock(&snoozelock);
	rwakeupall(&snoozerendez);
	qunlock(&snoozelock);
}

static void
usage(void)
{
	fprint(2, "usage: %s [-h hostname] [-n interval] [net!]server[!service]\n", argv0);
	exits("usage");
}

static void
submitproc(void *arg)
{
	char *addr;
	int fd;
	Channel *c;
	Packet *pp;
	long n;
	static uchar buf[PACKETMAX];

	addr = netmkaddr(server, "udp", "collectd");
	fd = dial(addr, nil, nil, nil);
	if(fd < 0)
		sysfatal("couldn't dial %s: %r", addr);
	c = arg;
	for(;;){
		pp = recvp(c);
		if(pp == nil)
			sysfatal("bad packet");
		n = convS2P(pp, buf, sizeof buf);
		write(fd, buf, n);
		pfree(pp);
	}
}

static void (*proctab[])(void *) = {
	cpuproc,
	dfproc,
	interfaceproc,
	loadproc,
	memoryproc,
	swapproc,
	uptimeproc,
	usersproc,
	submitproc,
};

void
threadmain(int argc, char *argv[])
{
	Ndb *db;
	Channel *c;
	int i;

	ARGBEGIN{
	case 'h':
		hostname = EARGF(usage());
		break;
	case 'n':
		interval = atoi(EARGF(usage()));
		break;
	default:
		usage();
	}ARGEND

	if(argc == 0)
		usage();

	server = argv[0];

	/*
	 * By default, collectd prefers the FQDN for a given host.
	 * We attempt to honor this by first looking up the dom in the
	 * ndb(6) before falling back to sysname.
	 */
	if(hostname == nil){
		db = ndbopen(nil);
		if(db){
			hostname = ndbgetvalue(db, nil, "sys", sysname(), "dom", nil);
			ndbclose(db);
		}
		if(hostname == nil)
			hostname = sysname();
	}

	/*
	 * We create individual procs for each supported plugin; a shared
	 * channel is employed to serialize submission to the server.
	 */
	snoozerendez.l = &snoozelock;

	c = chancreate(sizeof(Packet *), 128);
	for(i = 0; i < nelem(proctab); ++i)
		proccreate(proctab[i], c, 8*1024);

	for(;;){
		sleep(interval*1000);
		wakeupall();
	}
}