func mustWait(s *store.Store, n int64) <-chan store.Event {
	c, err := s.Wait(store.Any, n)
	if err != nil {
		panic(err)
	}
	return c
}

func Clean(c chan string, st *store.Store, p consensus.Proposer) {
	for addr := range c {
		_, g := st.Snap()
		name := getName(addr, g)
		if name != "" {
			go func() {
				clearSlot(p, g, name)
				removeInfo(p, g, name)
			}()
		}
	}
}

func walk(path string, st *store.Store, ch chan store.Event) {
	for path != "/" && strings.HasSuffix(path, "/") {
		// TODO generalize and factor this into pkg store.
		path = path[0 : len(path)-1]
	}
	v, rev := st.Get(path)
	if rev != store.Dir {
		ch <- store.Event{0, path, v[0], rev, "", nil, nil}
		return
	}
	if path == "/" {
		path = ""
	}
	for _, ent := range v {
		walk(path+"/"+ent, st, ch)
	}
}

func sendLearn(out chan<- Packet, p *packet, st *store.Store) {
	if p.msg.Cmd != nil && *p.msg.Cmd == msg_INVITE {
		ch, err := st.Wait(store.Any, *p.Seqn)

		if err == store.ErrTooLate {
			log.Println(err)
		} else {
			e := <-ch
			m := msg{
				Seqn:  &e.Seqn,
				Cmd:   learn,
				Value: []byte(e.Mut),
			}
			buf, _ := proto.Marshal(&m)
			out <- Packet{p.Addr, buf}
		}
	}
}

func activate(st *store.Store, self string, c *doozer.Conn) int64 {
	rev, _ := st.Snap()

	for _, base := range store.Getdir(st, calDir) {
		p := calDir + "/" + base
		v, rev := st.Get(p)
		if rev != store.Dir && v[0] == "" {
			seqn, err := c.Set(p, rev, []byte(self))
			if err != nil {
				log.Println(err)
				continue
			}

			return seqn
		}
	}

	for {
		ch, err := st.Wait(calGlob, rev+1)
		if err != nil {
			panic(err)
		}
		ev, ok := <-ch
		if !ok {
			panic(io.EOF)
		}
		rev = ev.Rev
		// TODO ev.IsEmpty()
		if ev.IsSet() && ev.Body == "" {
			seqn, err := c.Set(ev.Path, ev.Rev, []byte(self))
			if err != nil {
				log.Println(err)
				continue
			}
			return seqn
		} else if ev.IsSet() && ev.Body == self {
			return ev.Seqn
		}
	}

	return 0
}

func Clean(st *store.Store, keep int64, ticker <-chan time.Time) {
	for _ = range ticker {
		last := (<-st.Seqns) - keep
		st.Clean(last)
	}
}