/*
 * Initializations
 */
func init() {
	flag.Parse()
	status.InputEventCount = expvar.NewInt("input_event_count")
	status.OutputEventCount = expvar.NewInt("output_event_count")
	status.ErrorCount = expvar.NewInt("error_count")

	expvar.Publish("connection_status",
		expvar.Func(func() interface{} {
			res := make(map[string]interface{}, 0)
			res["last_connect_time"] = status.LastConnectTime
			res["last_error_text"] = status.LastConnectError
			res["last_error_time"] = status.ErrorTime
			if status.IsConnected {
				res["connected"] = true
				res["uptime"] = time.Now().Sub(status.LastConnectTime).Seconds()
			} else {
				res["connected"] = false
				res["uptime"] = 0.0
			}

			return res
		}))
	expvar.Publish("uptime", expvar.Func(func() interface{} {
		return time.Now().Sub(status.StartTime).Seconds()
	}))
	expvar.Publish("subscribed_events", expvar.Func(func() interface{} {
		return config.EventTypes
	}))

	results = make(chan string, 100)
	output_errors = make(chan error)

	status.StartTime = time.Now()
}

func init() {
	expvar.Publish(kapacitor.ClusterIDVarName, cidVar)
	expvar.Publish(kapacitor.ServerIDVarName, sidVar)
	expvar.Publish(kapacitor.HostVarName, hostVar)
	expvar.Publish(kapacitor.ProductVarName, productVar)
	expvar.Publish(kapacitor.VersionVarName, versionVar)
}

func StartDebugServer(address string, sink *lager.ReconfigurableSink, metrics Metrics) (ifrit.Process, error) {
	expvar.Publish("numCPUS", expvar.Func(func() interface{} {
		return metrics.NumCPU()
	}))

	expvar.Publish("numGoRoutines", expvar.Func(func() interface{} {
		return metrics.NumGoroutine()
	}))

	expvar.Publish("loopDevices", expvar.Func(func() interface{} {
		return metrics.LoopDevices()
	}))

	expvar.Publish("backingStores", expvar.Func(func() interface{} {
		return metrics.BackingStores()
	}))

	expvar.Publish("depotDirs", expvar.Func(func() interface{} {
		return metrics.DepotDirs()
	}))

	server := http_server.New(address, handler(sink))
	p := ifrit.Invoke(server)
	select {
	case <-p.Ready():
	case err := <-p.Wait():
		return nil, err
	}
	return p, nil
}

func init() {
	besticon.SetCacheMaxSize(128)

	expvar.Publish("cacheBytes", expvar.Func(func() interface{} { return besticon.GetCacheStats().Bytes }))
	expvar.Publish("cacheItems", expvar.Func(func() interface{} { return besticon.GetCacheStats().Items }))
	expvar.Publish("cacheGets", expvar.Func(func() interface{} { return besticon.GetCacheStats().Gets }))
	expvar.Publish("cacheHits", expvar.Func(func() interface{} { return besticon.GetCacheStats().Hits }))
	expvar.Publish("cacheEvictions", expvar.Func(func() interface{} { return besticon.GetCacheStats().Evictions }))
}

func init() {

	expvar.Publish("now", expvar.Func(func() interface{} {
		return time.Now().Format("\"2006-01-02 15:04:05\"")
	}))

	stats = &Stats{}
	expvar.Publish("stats", stats)

	hits = expvar.NewMap("hits").Init()
}

func fanout(
	pubc chan Line,
	subc, unsubc chan Subscription,
	histc <-chan HistoryRequest,
	histSize int,
) {
	var (
		hist = NewHistory(histSize)
		reg  = registry{}

		publishs     = expvar.NewMap("publishs")
		subscribes   = expvar.NewMap("subscribes")
		unsubscribes = expvar.NewMap("unsubscribes")
	)

	expvar.Publish("history", hist)
	expvar.Publish("subscriptions", reg)
	for {
		select {
		case l := <-pubc:
			for _, s := range reg[l.Topic()] {
				s.In() <- l
			}
			hist.Store(l)

			publishs.Add(l.Topic(), 1)
		case s := <-subc:
			_, ok := reg[s.Topic()]
			if !ok {
				reg[s.Topic()] = map[string]Subscription{}
			}
			reg[s.Topic()][s.ID()] = s

			subscribes.Add(s.Topic(), 1)
			logf("fanout: subscribed %s\n", s.ID())
		case s := <-unsubc:
			subs, ok := reg[s.Topic()]
			if !ok {
				continue
			}
			_, ok = subs[s.ID()]
			if !ok {
				continue
			}
			delete(subs, s.ID())

			unsubscribes.Add(s.Topic(), 1)
			logf("fanout: unsubscribed %s\n", s.ID())
		case req := <-histc:
			req.Respond(hist.Get(req.Topic(), req.Size()))
		}
	}
}

func initDebug(mux *http.ServeMux) {
	stats.prev = time.Now()

	expvar.Publish("dcp", expvar.Func(dcp))
	expvar.Publish("goroutines", expvar.Func(goroutines))

	mux.Handle("/debug/vars/", http.HandlerFunc(expvarHandler))
	mux.Handle("/debug/pprof/", http.HandlerFunc(pprof.Index))
	mux.Handle("/debug/pprof/cmdline", http.HandlerFunc(pprof.Cmdline))
	mux.Handle("/debug/pprof/profile", http.HandlerFunc(pprof.Profile))
	mux.Handle("/debug/pprof/symbol", http.HandlerFunc(pprof.Symbol))
	mux.Handle("/debug/pprof/trace", http.HandlerFunc(pprof.Trace))
}

func main() {
	flag.Parse()

	if err := loadContext(); err != nil {
		panic(err)
	}

	ctx := context()
	expvar.Publish("config", &ctx.Config)

	expvar.Publish("codemanager", expvar.Func(func() interface{} {
		return context().InputManager
	}))
	expvar.Publish("queues", expvar.Func(func() interface{} {
		return context().QueueManager
	}))
	expvar.Publish("inflight_runs", expvar.Func(func() interface{} {
		return context().InflightMonitor
	}))
	cachePath := path.Join(ctx.Config.Grader.RuntimePath, "cache")
	go ctx.InputManager.PreloadInputs(
		cachePath,
		grader.NewGraderCachedInputFactory(cachePath),
		&sync.Mutex{},
	)

	// Database
	db, err := sql.Open(
		ctx.Config.Db.Driver,
		ctx.Config.Db.DataSourceName,
	)
	if err != nil {
		panic(err)
	}
	if err := db.Ping(); err != nil {
		panic(err)
	}

	setupMetrics(ctx)
	ctx.Log.Info("omegaUp grader started")

	mux := http.DefaultServeMux
	if ctx.Config.Grader.V1.Enabled {
		registerV1CompatHandlers(mux, db)
		go common.RunServer(&ctx.Config.TLS, mux, ctx.Config.Grader.V1.Port, *insecure)
		mux = http.NewServeMux()
	}

	registerHandlers(mux, db)
	common.RunServer(&ctx.Config.TLS, mux, ctx.Config.Grader.Port, *insecure)
}

func init() {
	expvar.Publish("snmp_request_cache", expvar.Func(func() interface{} {
		requests_mutex.Lock()
		size := requests_cache.Size()
		requests_mutex.Unlock()
		return size
	}))

	expvar.Publish("snmp_bytes_cache", expvar.Func(func() interface{} {
		bytes_mutex.Lock()
		size := bytes_cache.Size()
		bytes_mutex.Unlock()
		return size
	}))
}

// NewStatistics creates an expvar-based map. Within there "name" is the Measurement name, "tags" are the tags,
// and values are placed at the key "values".
// The "values" map is returned so that statistics can be set.
func NewStatistics(name string, tags map[string]string) *expvar.Map {
	expvarMu.Lock()
	defer expvarMu.Unlock()

	key := uuid.NewV4().String()

	m := &expvar.Map{}
	m.Init()
	expvar.Publish(key, m)

	// Set the name
	nameVar := &expvar.String{}
	nameVar.Set(name)
	m.Set("name", nameVar)

	// Set the tags
	tagsVar := &expvar.Map{}
	tagsVar.Init()
	for k, v := range tags {
		value := &expvar.String{}
		value.Set(v)
		tagsVar.Set(k, value)
	}
	m.Set("tags", tagsVar)

	// Create and set the values entry used for actual stats.
	statMap := &expvar.Map{}
	statMap.Init()
	m.Set("values", statMap)

	return statMap
}

func hook(m measurable.Measurable, event measurable.HookEvent) {
	switch m.MsType() {
	case measurable.CounterType, measurable.GaugeType:
		// ok
	default:
		return // not supported
	}

	name := m.MsName()

	switch event {
	case measurable.RegisterEvent, measurable.RegisterCatchupEvent:
		a := &adaptor{
			measurable: m,
		}

		measurablesMutex.Lock()
		defer measurablesMutex.Unlock()

		measurables[name] = a
		expvar.Publish(name, a)

	case measurable.UnregisterEvent:
		a := measurables[name]
		if a != nil { // this should always be the case, but whatever
			a.mutex.Lock()
			defer a.mutex.Unlock()

			a.measurable = nil
		}
	}
}

func NewCounters(name string) *Counters {
	c := &Counters{counts: make(map[string]int64)}
	if name != "" {
		expvar.Publish(name, c)
	}
	return c
}

// Create a new simple moving percentile expvar.Var. It will be
// published under `name` and maintain `size` values for
// calculating the percentile.
//
// percentile must be between 0 and 1
//
// An empty name will cause it to not be published
func NewSimpleMovingPercentile(name string, percentile float64, size int) *SimpleMovingStat {
	sm := new(SimpleMovingStat)
	sm.size = size
	sm.mutex = new(sync.Mutex)
	sm.values = ring.New(size)

	sm.calculate = func(s *SimpleMovingStat) float64 {
		ary := make([]float64, 0)
		s.values.Do(func(val interface{}) {
			if val != nil {
				ary = append(ary, val.(float64))
			}
		})
		length := len(ary)
		if length == 0 {
			return 0.0
		}
		sort.Float64s(ary)
		mid := int(float64(len(ary)) * percentile)
		return ary[mid]
	}

	if name != "" {
		expvar.Publish(name, sm)
	}
	return sm

}

func NewTimings(name string) *Timings {
	t := &Timings{Histograms: make(map[string]*Histogram)}
	if name != "" {
		expvar.Publish(name, t)
	}
	return t
}

func main() {
	// Initialise our configuration from flags

	var nodeName = flag.String("name", REQUIRED, "Node network name and port, e.g. localhost:3000")
	var gobName = flag.String("gob", "", "Alternative gob network name and port for clients, allowing clients to connect over a different physical interface to nodes.")
	var httpName = flag.String("http", "", "Network name and port for the http ExpVar to listen on.")
	var cborName = flag.String("cbor", "", "Network name and port for the CBOR RPC interface to listen on.")
	var nodePath = flag.String("path", REQUIRED, "Node root path for configuration and log files")
	var clusterID = flag.String("id", "", "Cluster ID that this node is part of")

	flag.Parse()

	if flag.Lookup("help") != nil || flag.Lookup("h") != nil {
		flag.PrintDefaults()
		return
	}

	if *nodeName == REQUIRED {
		log.Printf("name missing.\n")
		flag.PrintDefaults()
		return
	}

	if *nodePath == REQUIRED {
		log.Printf("path missing.\n")
		flag.PrintDefaults()
		return
	}

	// Create our server
	serverNode, err := server.NewServerNode(*nodeName, *gobName, *httpName, *cborName, *nodePath, *clusterID)

	if err != nil {
		log.Fatalf("Unable to start server due to errors.\n")
	}

	expvar.Publish("node", expvar.Func(serverNode.ExpVar))

	//dataLog := &memlog.MemoryLog{}

	// Start a listener to handle incoming requests from other peers
	err = serverNode.ListenConnections()
	if err != nil {
		log.Fatalf("Error starting listener: %v\n", err)
	}

	// Setup signal handling to catch interrupts.
	sigc := make(chan os.Signal, 1)
	signal.Notify(sigc,
		os.Interrupt,
		os.Kill)
	go func() {
		<-sigc
		serverNode.RequestShutdown("Request to terminate process detected.")
	}()

	serverNode.WaitForShutdown()

}

func init() {
	raft.SetLogger(capnslog.NewPackageLogger("github.com/coreos/etcd", "raft"))
	expvar.Publish("raft.status", expvar.Func(func() interface{} {
		raftStatusMu.Lock()
		defer raftStatusMu.Unlock()
		return raftStatus()
	}))
}

func init() {
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, "Usage of inbucket [options] <conf file>:")
		flag.PrintDefaults()
	}

	expvar.Publish("uptime", expvar.Func(uptime))
}

// StartSelfMonitor starts http server on random port and exports expvars.
//
// It tries 1024 ports, starting from startPort and registers some expvars if ok.
func StartSelfMonitor() (string, error) {
	for port := startPort; port < startPort+1024; port++ {
		bind := fmt.Sprintf("localhost:%d", port)
		l, err := net.Listen("tcp", bind)
		if err != nil {
			continue
		}
		l.Close()

		expvar.Publish("Goroutines", expvar.Func(goroutines))
		expvar.Publish("Uptime", expvar.Func(uptime))
		go http.ListenAndServe(bind, nil)
		return bind, nil
	}

	return "", fmt.Errorf("no free ports found")
}

func init() {
	expvar.NewString("goVersion").Set(runtime.Version())
	expvar.NewString("iconVersion").Set(besticon.VersionString)

	expvar.NewString("timeLastDeploy").Set(parseUnixTimeStamp(os.Getenv("DEPLOYED_AT")).String())
	expvar.NewString("timeStartup").Set(time.Now().String())
	expvar.Publish("timeCurrent", expvar.Func(func() interface{} { return time.Now() }))
}

func initExpvars() {
	expvar.Publish("__binary_path", expvar.Func(func() interface{} { return &binaryPath }))
	expvar.Publish("__config_path", expvar.Func(func() interface{} { return &configPath }))
	expvar.Publish("_command_line", expvar.Func(func() interface{} { return &commandLine }))
	expvar.Publish("_version", expvar.Func(func() interface{} { return VersionInfo }))
	expvar.Publish("_hostname", expvar.Func(func() interface{} { return hostname }))

	expvar.Publish("_config", expvar.Func(func() interface{} {
		cf, err := structs.BadooStripSecretFields(config) // makes a copy of `config`
		if err != nil {
			return struct {
				Error string `json:"error"`
			}{err.Error()}
		}
		return cf
	}))

	expvar.Publish("_service-stats", expvar.Func(func() interface{} {
		stats, err := GatherServiceStats()
		if err != nil {
			return struct {
				Error string `json:"error"`
			}{err.Error()}
		}
		return stats
	}))
}