// Update when zk updates
func (d *Dispatcher) Update(group map[int][]string,
	store map[string]*meta.Store, volume map[int32]*meta.VolumeState,
	storeVolume map[string][]int32) (err error) {
	var (
		gid                        int
		i                          int
		vid                        int32
		gids                       []int
		sid                        string
		stores                     []string
		restSpace, minScore, score int
		totalAdd, totalAddDelay    uint64
		write, ok                  bool
		storeMeta                  *meta.Store
		volumeState                *meta.VolumeState
	)
	gids = []int{}
	for gid, stores = range group {
		write = true
		// check all stores can writeable by the group.
		for _, sid = range stores {
			if storeMeta, ok = store[sid]; !ok {
				log.Errorf("idStore cannot match store: %s", sid)
				break
			}
			if !storeMeta.CanWrite() {
				write = false
				break
			}
		}
		if !write {
			continue
		}
		// calc score
		for _, sid = range stores {
			totalAdd, totalAddDelay, restSpace, minScore = 0, 0, 0, 0
			// get all volumes by the store.
			for _, vid = range storeVolume[sid] {
				volumeState = volume[vid]
				totalAdd = totalAdd + volumeState.TotalWriteProcessed
				restSpace = restSpace + int(volumeState.FreeSpace)
				totalAddDelay = totalAddDelay + volumeState.TotalWriteDelay
			}
			score = d.calScore(int(totalAdd), int(totalAddDelay), restSpace)
			if score < minScore || minScore == 0 {
				minScore = score
			}
		}
		for i = 0; i < minScore; i++ {
			gids = append(gids, gid)
		}
	}
	d.gids = gids
	return
}

// checkNeedles check the store health.
func (p *Pitchfork) checkNeedles(store *meta.Store, stop chan struct{}) (err error) {
	var (
		status, i int
		needle    *meta.Needle
		volume    *meta.Volume
		volumes   []*meta.Volume
	)
	log.Infof("checkNeedles job start")
	for {
		select {
		case <-stop:
			log.Infof("checkNeedles job stop")
			return
		case <-time.After(p.config.HeadInterval):
			break
		}
		if volumes, err = store.Info(); err != nil {
			log.Errorf("get store info failed, retry host:%s", store.Stat)
			continue
		}
		status = store.Status
		for _, volume = range volumes {
			if volume.Block.LastErr != nil {
				break
			} else {
				for _, needle = range volume.CheckNeedles {
					for i = 0; i < retryCount; i++ {
						if err = store.Head(needle, volume.Id); err == nil {
							break
						}
					}
					if err != nil {
						log.Errorf("head store failed, needle:%d host:%s", needle.Key, store.Stat)
						store.Status = meta.StoreStatusFail
						goto feedback
					}
				}
			}
		}
	feedback:
		if status != store.Status {
			if err = p.zk.SetStore(store); err != nil {
				log.Errorf("update store zk status failed, retry")
				continue
			}
			if err = p.zk.setRoot(); err != nil {
				log.Errorf("setRoot zk failed")
			}
		}
	}
	return
}

// checkHealth check the store health.
func (p *Pitchfork) checkHealth(store *meta.Store, stop chan struct{}) (err error) {
	var (
		status, i int
		volume    *meta.Volume
		volumes   []*meta.Volume
	)
	log.Infof("check_health job start")
	for {
		select {
		case <-stop:
			log.Infof("check_health job stop")
			return
		case <-time.After(p.config.GetInterval):
			break
		}
		status = store.Status
		for i = 0; i < retryCount; i++ {
			if volumes, err = store.Info(); err == nil {
				break
			}
		}
		if err == nil {
			for _, volume = range volumes {
				if volume.Block.LastErr != nil {
					log.Infof("get store block.lastErr:%s   host:%s", volume.Block.LastErr, store.Stat)
					store.Status = meta.StoreStatusFail
					break
				} else if volume.Block.Full() {
					log.Infof("block: %s, offset: %d", volume.Block.File, volume.Block.Offset)
					store.Status = meta.StoreStatusRead
				}
			}
		} else {
			log.Errorf("get store info failed, retry host:%s", store.Stat)
			store.Status = meta.StoreStatusFail
		}

		if status != store.Status {
			if err = p.zk.SetStore(store); err != nil {
				log.Errorf("update store zk status failed, retry")
				continue
			}
			if err = p.zk.setRoot(); err != nil {
				log.Errorf("setRoot zk failed")
			}
		}
	}
	return
}

// DelStores get delable stores for http del
func (d *Directory) DelStores(key int64, cookie int32) (vid int32, stores []string, err error) {
	var (
		n         *meta.Needle
		ok        bool
		store     string
		svrs      []string
		storeMeta *meta.Store
	)
	if n, err = d.hbase.Get(key); err != nil {
		log.Errorf("hbase.Get error(%v)", err)
		err = errors.ErrHbase
		return
	}
	if n == nil {
		err = errors.ErrNeedleNotExist
		return
	}
	if n.Cookie != cookie {
		err = errors.ErrNeedleCookie
		return
	}
	vid = n.Vid
	if svrs, ok = d.volumeStore[n.Vid]; !ok {
		err = errors.ErrZookeeperDataError
		return
	}
	stores = make([]string, 0, len(svrs))
	for _, store = range svrs {
		if storeMeta, ok = d.store[store]; !ok {
			err = errors.ErrZookeeperDataError
			return
		}
		if !storeMeta.CanWrite() {
			err = errors.ErrStoreNotAvailable
			return
		}
		stores = append(stores, storeMeta.Api)
	}
	if err = d.hbase.Del(key); err != nil {
		log.Errorf("hbase.Del error(%v)", err)
		err = errors.ErrHbase
	}
	return
}