// GetStoreList returns a storeList that contains all active stores that
// contain the required attributes and their associated stats. It also returns
// the number of total alive stores.
// TODO(embark, spencer): consider using a reverse index map from
// Attr->stores, for efficiency. Ensure that entries in this map still
// have an opportunity to be garbage collected.
func (sp *StorePool) getStoreList(required roachpb.Attributes, deterministic bool) (StoreList, int) {
	sp.mu.RLock()
	defer sp.mu.RUnlock()

	var storeIDs roachpb.StoreIDSlice
	for storeID := range sp.stores {
		storeIDs = append(storeIDs, storeID)
	}
	// Sort the stores by key if deterministic is requested. This is only for
	// unit testing.
	if deterministic {
		sort.Sort(storeIDs)
	}
	sl := StoreList{}
	var aliveStoreCount int
	for _, storeID := range storeIDs {
		detail := sp.stores[roachpb.StoreID(storeID)]
		if !detail.dead && detail.desc != nil {
			aliveStoreCount++
			if required.IsSubset(*detail.desc.CombinedAttrs()) {
				sl.add(detail.desc)
			}
		}
	}
	return sl, aliveStoreCount
}

// GetStoreList returns a storeList that contains all active stores that
// contain the required attributes and their associated stats.
// TODO(embark, spencer): consider using a reverse index map from
// Attr->stores, for efficiency. Ensure that entries in this map still
// have an opportunity to be garbage collected.
func (sp *StorePool) getStoreList(required roachpb.Attributes, excludeNodes []roachpb.NodeID, deterministic bool) StoreList {
	sp.mu.RLock()
	defer sp.mu.RUnlock()

	// Convert list of excluded nodes to a map for quick lookup.
	excludeMap := map[roachpb.NodeID]struct{}{}
	for _, nodeID := range excludeNodes {
		excludeMap[nodeID] = struct{}{}
	}

	var storeIDs roachpb.StoreIDSlice
	for storeID := range sp.stores {
		storeIDs = append(storeIDs, storeID)
	}
	// Sort the stores by key if deterministic is requested. This is only for
	// unit testing.
	if deterministic {
		sort.Sort(storeIDs)
	}
	sl := StoreList{}
	for _, storeID := range storeIDs {
		detail := sp.stores[roachpb.StoreID(storeID)]
		if _, ok := excludeMap[detail.desc.Node.NodeID]; ok {
			continue
		}
		if !detail.dead && required.IsSubset(*detail.desc.CombinedAttrs()) {
			desc := detail.desc
			sl.add(&desc)
		}
	}
	return sl
}

// match returns if the store is alive, and if the store is available and it's
// attributes contain the required ones respectively.
func (sd *storeDetail) match(now time.Time, required roachpb.Attributes) storeMatch {
	// The store must be alive and it must have a descriptor to be considered
	// alive.
	if sd.dead || sd.desc == nil {
		return storeMatchDead
	}
	// The store must not have a recent declined reservation to be considered
	// available for matching.
	if sd.unavailableUntil.After(now) || !required.IsSubset(*sd.desc.CombinedAttrs()) {
		return storeMatchAlive
	}
	return storeMatchMatched
}

// match checks the store against the attributes and returns a storeMatch.
func (sd *storeDetail) match(now time.Time, required roachpb.Attributes) storeMatch {
	// The store must be alive and it must have a descriptor to be considered
	// alive.
	if sd.dead || sd.desc == nil {
		return storeMatchDead
	}

	// Does the store match the attributes?
	if !required.IsSubset(*sd.desc.CombinedAttrs()) {
		return storeMatchAlive
	}

	// The store must not have a recent declined reservation to be available.
	if sd.throttledUntil.After(now) {
		return storeMatchThrottled
	}

	return storeMatchAvailable
}

// GetStoreList returns a storeList that contains all active stores that
// contain the required attributes and their associated stats.
// TODO(embark, spencer): consider using a reverse index map from
// Attr->stores, for efficiency. Ensure that entries in this map still
// have an opportunity to be garbage collected.
func (sp *StorePool) getStoreList(required roachpb.Attributes, deterministic bool) *StoreList {
	sp.mu.RLock()
	defer sp.mu.RUnlock()

	var storeIDs roachpb.StoreIDSlice
	for storeID := range sp.stores {
		storeIDs = append(storeIDs, storeID)
	}
	// Sort the stores by key if deterministic is requested. This is only for
	// unit testing.
	if deterministic {
		sort.Sort(storeIDs)
	}
	sl := new(StoreList)
	for _, storeID := range storeIDs {
		detail := sp.stores[roachpb.StoreID(storeID)]
		if !detail.dead && required.IsSubset(*detail.desc.CombinedAttrs()) {
			desc := detail.desc
			sl.add(&desc)
		}
	}
	return sl
}