// NewBranchTileBuilder returns an instance of BranchTileBuilder that allows
// creating tiles based on the given VCS or code review system based on
// querying db.
//
// TODO(stephana): The EventBus is used to update the internal cache as commits are updated.
func NewBranchTileBuilder(db DB, git *gitinfo.GitInfo, reviewURL string, evt *eventbus.EventBus) BranchTileBuilder {
	return &tileBuilder{
		db:        db,
		vcs:       git,
		review:    rietveld.New(reviewURL, util.NewTimeoutClient()),
		reviewURL: reviewURL,
		cache:     lru.New(MAX_ISSUE_CACHE_SIZE),
		tcache:    lru.New(MAX_TILE_CACHE_SIZE),
	}
}

func New(oncecap, twicecap int) *Cache {
	c := &Cache{
		once:  lru.New(oncecap),
		twice: lru.New(twicecap),
	}
	// make sure keys evicted from two make it to the head of one
	c.twice.OnEvicted = func(k lru.Key, v interface{}) {
		c.once.Add(k, v)
	}
	return c
}

// NewTraceServiceServer creates a new DB that stores the data in BoltDB format at
// the given filename location.
func NewTraceServiceServer(filename string) (*TraceServiceImpl, error) {
	d, err := bolt.Open(filename, 0600, &bolt.Options{Timeout: 1 * time.Second})
	if err != nil {
		return nil, fmt.Errorf("Failed to open BoltDB at %s: %s", filename, err)
	}
	createBuckets := func(tx *bolt.Tx) error {
		_, err := tx.CreateBucketIfNotExists([]byte(COMMIT_BUCKET_NAME))
		if err != nil {
			return fmt.Errorf("Failed to create bucket %s: %s", COMMIT_BUCKET_NAME, err)
		}
		_, err = tx.CreateBucketIfNotExists([]byte(TRACE_BUCKET_NAME))
		if err != nil {
			return fmt.Errorf("Failed to create bucket %s: %s", TRACE_BUCKET_NAME, err)
		}
		_, err = tx.CreateBucketIfNotExists([]byte(TRACEID_BUCKET_NAME))
		if err != nil {
			return fmt.Errorf("Failed to create bucket %s: %s", TRACEID_BUCKET_NAME, err)
		}
		return nil
	}
	if err := d.Update(createBuckets); err != nil {
		return nil, fmt.Errorf("Failed to create buckets: %s", err)
	}
	return &TraceServiceImpl{
		db:    d,
		cache: lru.New(MAX_INT64_ID_CACHED),
	}, nil
}

func newPeerStore(maxInfoHashes, maxInfoHashPeers int) *peerStore {
	return &peerStore{
		values:           lru.New(maxInfoHashes),
		maxInfoHashes:    maxInfoHashes,
		maxInfoHashPeers: maxInfoHashPeers,
	}
}

func BenchmarkSetGPLRU(b *testing.B) {
	plru := lru.New(lruSize)
	// run the Fib function b.N times
	for n := 0; n < b.N; n++ {
		plru.Add("A"+strconv.FormatInt(int64(n), 10), "A")
	}
}

func (ac *AdminController) SaveBlogEditCtr(c *gin.Context) {
	session := sessions.Default(c)
	username := session.Get("username")
	if username == nil {
		(&umsg{"You have no permission", "/"}).ShowMessage(c)
		return
	}
	var BI EditBlogItem
	c.BindWith(&BI, binding.Form)
	if BI.Aid == "" {
		(&umsg{"Can not find the blog been edit", "/"}).ShowMessage(c)
		return
	}
	if BI.Title == "" {
		(&umsg{"Title can not empty", "/"}).ShowMessage(c)
		return
	}
	if BI.Content == "" {
		(&umsg{"Content can not empty", "/"}).ShowMessage(c)
		return
	}
	_, err := DB.Exec("update top_article set title=?, content=? where aid = ?", BI.Title, BI.Content, BI.Aid)
	if err == nil {
		Cache = lru.New(8192)
		(&umsg{"Success", "/"}).ShowMessage(c)
	} else {
		(&umsg{"Failed to save blog", "/"}).ShowMessage(c)
	}

}

// NewTraceServiceDB creates a new DB that stores the data in the BoltDB backed
// gRPC accessible traceservice.
func NewTraceServiceDB(conn *grpc.ClientConn, traceBuilder tiling.TraceBuilder) (*TsDB, error) {
	ret := &TsDB{
		conn:         conn,
		traceService: traceservice.NewTraceServiceClient(conn),
		traceBuilder: traceBuilder,
		cache:        lru.New(MAX_ID_CACHED),
		ctx:          context.Background(),
	}

	// This ping causes the client to try and reach the backend. If the backend
	// is down, it will keep trying until it's up.
	if err := ret.ping(); err != nil {
		return nil, err
	}

	go func() {
		liveness := metrics.NewLiveness("tracedb-ping")
		for _ = range time.Tick(time.Minute) {
			if ret.ping() == nil {
				liveness.Update()
			}
		}
	}()
	return ret, nil
}

func (ac *AdminController) SaveBlogAddCtr(c *gin.Context) {
	session := sessions.Default(c)
	username := session.Get("username")
	if username == nil {
		(&umsg{"You have no permission", "/"}).ShowMessage(c)
		return
	}
	var BI BlogItem
	c.BindWith(&BI, binding.Form)
	if BI.Title == "" {
		(&umsg{"Title can not empty", "/"}).ShowMessage(c)
		return
	}
	if BI.Content == "" {
		(&umsg{"Content can not empty", "/"}).ShowMessage(c)
		return
	}
	_, err := DB.Exec(
		"insert into top_article (title, content, publish_time, publish_status) values (?, ?, ?, 1)",
		BI.Title, BI.Content, time.Now().Format("2006-01-02 15:04:05"))
	if err == nil {
		Cache = lru.New(8192)
		(&umsg{"Success", "/"}).ShowMessage(c)
	} else {
		(&umsg{"Failed to save blog", "/"}).ShowMessage(c)
	}

}

func initStmtsLRU(max int) {
	if stmtsLRU.lru != nil {
		stmtsLRU.Max(max)
	} else {
		stmtsLRU.lru = lru.New(max)
	}
}

// Start initializes the limiter for execution.
func (il *intervalVaryByLimiter) Start() {
	if il.bursts < 0 {
		il.bursts = 0
	}
	il.keys = lru.New(il.maxKeys)
	il.keys.OnEvicted = il.stopProcess
}

func New(rdb *gorocksdb.DB) *DB {
	db := &DB{rdb: rdb}
	db.wo = gorocksdb.NewDefaultWriteOptions()
	db.ro = gorocksdb.NewDefaultReadOptions()
	db.caches = lru.New(1000)
	db.RawSet([]byte{MAXBYTE}, nil) // for Enumerator seek to last
	return db
}

func newPeerStore(maxInfoHashes, maxInfoHashPeers int) *peerStore {
	return &peerStore{
		infoHashPeers:        lru.New(maxInfoHashes),
		localActiveDownloads: make(map[InfoHash]bool),
		maxInfoHashes:        maxInfoHashes,
		maxInfoHashPeers:     maxInfoHashPeers,
	}
}

// NewSession wraps an existing Node.
func NewSession(p ConnectionPool, c ClusterConfig) *Session {
	session := &Session{Pool: p, cons: c.Consistency, prefetch: 0.25, cfg: c}

	// create the query info cache
	session.routingKeyInfoCache.lru = lru.New(c.MaxRoutingKeyInfo)

	return session
}

func newStore() *Store {
	return &Store{
		Created:   time.Now().UnixNano(),
		Streams:   lru.New(maxStreams),
		Updates:   make(chan *Object, 100),
		streams:   make(map[string]int64),
		metadatas: make(map[string]*Metadata),
	}
}

func NewFileHandler(notFound http.Handler) *FileHandler {
	reaper := &Reaper{make(chan Life)}
	go reaper.Run()
	lockChan := make(chan bool, 1)
	lockChan <- true

	return &FileHandler{
		make(chan string), notFound, reaper, lru.New(32), lockChan}
}

// NewSession wraps an existing Node.
func NewSession(cfg ClusterConfig) (*Session, error) {
	//Check that hosts in the ClusterConfig is not empty
	if len(cfg.Hosts) < 1 {
		return nil, ErrNoHosts
	}

	maxStreams := 128
	if cfg.ProtoVersion > protoVersion2 {
		maxStreams = 32768
	}

	if cfg.NumStreams <= 0 || cfg.NumStreams > maxStreams {
		cfg.NumStreams = maxStreams
	}

	pool, err := cfg.ConnPoolType(&cfg)
	if err != nil {
		return nil, err
	}

	//Adjust the size of the prepared statements cache to match the latest configuration
	stmtsLRU.Lock()
	initStmtsLRU(cfg.MaxPreparedStmts)
	stmtsLRU.Unlock()

	s := &Session{
		Pool:     pool,
		cons:     cfg.Consistency,
		prefetch: 0.25,
		cfg:      cfg,
	}

	//See if there are any connections in the pool
	if pool.Size() > 0 {
		s.routingKeyInfoCache.lru = lru.New(cfg.MaxRoutingKeyInfo)

		s.SetConsistency(cfg.Consistency)
		s.SetPageSize(cfg.PageSize)

		if cfg.DiscoverHosts {
			s.hostSource = &ringDescriber{
				session:    s,
				dcFilter:   cfg.Discovery.DcFilter,
				rackFilter: cfg.Discovery.RackFilter,
				closeChan:  make(chan bool),
			}

			go s.hostSource.run(cfg.Discovery.Sleep)
		}

		return s, nil
	}

	s.Close()

	return nil, ErrNoConnectionsStarted
}

func NewHandler() *GODNSHandler {

	var (
		resolver *Resolver
		Cache    *MemoryCache
	)
	resolver = &Resolver{}
	Cache = &MemoryCache{lru.New(MAX_CACHES), time.Duration(EXPIRE_SECONDS) * time.Second, MAX_CACHES}
	return &GODNSHandler{resolver, Cache}
}

func BenchmarkNotSequentialGPLRU(b *testing.B) {
	plru := lru.New(lruSize)
	for i := 0; i < lruSize; i++ {
		plru.Add("A"+strconv.FormatInt(int64(i), 10), "A")
	}
	// run the Fib function b.N times
	for n := 1; n <= b.N; n++ {
		plru.Get("A" + strconv.FormatInt(int64(lruSize%n), 10))
	}
}

func NewHandler() *GODNSHandler {

	var (
		resolver *Resolver
		Cache    *lru.Cache
	)
	resolver = &Resolver{}
	Cache = lru.New(MAX_CACHES)
	return &GODNSHandler{resolver, Cache}
}

// NewEventAggregator returns a new instance of an EventAggregator
func NewEventAggregator(lruCacheSize int, keyFunc EventAggregatorKeyFunc, messageFunc EventAggregatorMessageFunc,
	maxEvents int, maxIntervalInSeconds int, clock clock.Clock) *EventAggregator {
	return &EventAggregator{
		cache:                lru.New(lruCacheSize),
		keyFunc:              keyFunc,
		messageFunc:          messageFunc,
		maxEvents:            maxEvents,
		maxIntervalInSeconds: maxIntervalInSeconds,
		clock:                clock,
	}
}