// Emit errors as `error.$event-name`
func EmitError(stats statsd.Statter, eventName string) (err error) {
	eventName = CleanStatsdComponent(eventName)
	if stats != nil {
		err = stats.Inc(StatsdEventName("error", eventName), 1, StatsSampleRate)
	}
	return
}

func timedHandler(fn func(w http.ResponseWriter, r *http.Request), stats statsd.Statter) func(w http.ResponseWriter, r *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		fn(w, r)
		stats.TimingDuration("request", time.Since(start), 1)
	}
}

// Emit stop signals as `stop.$signal`
func EmitStopSignal(stats statsd.Statter, signal string) (err error) {
	signal = CleanStatsdComponent(signal)
	if stats != nil {
		err = stats.Inc(StatsdEventName("stop", signal), 1, StatsSampleRate)
	}
	return
}

// Emit successful actions as `$action.success.$event-name`
func EmitActionSuccessTiming(stats statsd.Statter, action, eventName string, took time.Duration) (err error) {
	action = CleanStatsdComponent(action)
	eventName = CleanStatsdComponent(eventName)
	if stats != nil {
		err = stats.TimingDuration(StatsdEventName(action, eventName), took, StatsSampleRate)
	}
	return
}

// Emit successful actions as `$action.success.$event-name`
func EmitActionSuccess(stats statsd.Statter, action, eventName string) (err error) {
	action = CleanStatsdComponent(action)
	eventName = CleanStatsdComponent(eventName)
	if stats != nil {
		err = stats.Inc(StatsdEventName("success", action, eventName), 1, StatsSampleRate)
	}
	return
}

func send_gauge(client statsd.Statter, v []string, name string, position int64) {
	stat := fmt.Sprint(v[0], ".", name)
	value, _ := strconv.ParseInt(v[position], 10, 64)
	fmt.Println(fmt.Sprint(stat, ":", value, "|g"))
	err := client.Gauge(stat, value, 1.0)
	if err != nil {
		log.Printf("Error sending metric: %+v", err)
	}
}

func send_counter(previous int64, client statsd.Statter, v []string, name string, position int64) {
	stat := fmt.Sprint(v[0], ".", name)
	value_at_interval, _ := strconv.ParseInt(v[position], 10, 64)
	value := value_at_interval - previous
	fmt.Println(fmt.Sprint(stat, ":", value, "|c"))
	err := client.Inc(stat, value, 1)
	if err != nil {
		log.Printf("Error sending metric: %+v", err)
	}
}

func pushMem(client statsd.Statter, mem Mem) error {
	var err error

	err = client.Gauge("mem.resident", mem.Resident, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("mem.virtual", mem.Virtual, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("mem.mapped", mem.Mapped, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("mem.mapped_with_journal", mem.MappedWithJournal, 1.0)
	if err != nil {
		return err
	}

	return nil
}

func (r *requestContext) recordStats(statter statsd.Statter) {
	prefix := strings.Join([]string{
		r.Method,
		strings.Replace(r.Endpoint, ".", "_", -1),
		strconv.Itoa(r.Status),
	}, ".")
	for stat, duration := range r.Timers {
		statter.Timing(prefix+"."+stat, duration.Nanoseconds(), 0.1)
	}
	if r.BadClient {
		// We expect these to be infrequent. We may want to decreate this
		// if it turns out not to be the case
		statter.Inc("bad_client", 1, 1.0)
	}
}

func pushExtraInfo(client statsd.Statter, info ExtraInfo) error {
	var err error

	err = client.Gauge("extra.page_faults", info.PageFaults, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("extra.heap_usage", info.HeapUsageInBytes, 1.0)
	if err != nil {
		return err
	}

	return nil
}

func test(target string, s statsd.Statter, debug bool) {
	tuple := strings.Split(target, ":")
	host := tuple[0]
	port := tuple[1]
	subhost := strings.Replace(host, ".", "_", -1)
	pre := time.Now()
	conn, err := net.Dial("tcp", target)
	if err != nil {
		if debug {
			fmt.Println("connect error:", subhost, port)
		}
		s.Inc(fmt.Sprintf("%s.%s.dial_failed", subhost, port), 1, 1)
		return
	}
	conn.Close()
	duration := time.Since(pre)
	ms := int64(duration / time.Millisecond)
	if debug {
		fmt.Printf("%s.%s.duration %d\n", subhost, port, ms)
	}
	s.Timing(fmt.Sprintf("%s.%s", subhost, port), ms, 1)
}

func pushConnections(client statsd.Statter, connections Connections) error {
	var err error
	// Connections
	err = client.Gauge("connections.current", int64(connections.Current), 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("connections.available", int64(connections.Available), 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("connections.created", int64(connections.TotalCreated), 1.0)
	if err != nil {
		return err
	}

	return nil
}

// Emit reloads as `reload`
func EmitReload(stats statsd.Statter) (err error) {
	if stats != nil {
		err = stats.Inc(StatsdEventName("reload"), 1, StatsSampleRate)
	}
	return
}

// NewAmqpRPCClient constructs an RPC client using AMQP
func NewAmqpRPCClient(
	clientQueuePrefix string,
	amqpConf *cmd.AMQPConfig,
	rpcConf *cmd.RPCServerConfig,
	stats statsd.Statter,
) (rpc *AmqpRPCCLient, err error) {
	hostname, err := os.Hostname()
	if err != nil {
		return nil, err
	}

	randID := make([]byte, 3)
	_, err = rand.Read(randID)
	if err != nil {
		return nil, err
	}
	clientQueue := fmt.Sprintf("%s.%s.%x", clientQueuePrefix, hostname, randID)

	reconnectBase := amqpConf.ReconnectTimeouts.Base.Duration
	if reconnectBase == 0 {
		reconnectBase = 20 * time.Millisecond
	}
	reconnectMax := amqpConf.ReconnectTimeouts.Max.Duration
	if reconnectMax == 0 {
		reconnectMax = time.Minute
	}

	timeout := rpcConf.RPCTimeout.Duration
	if timeout == 0 {
		timeout = 10 * time.Second
	}

	rpc = &AmqpRPCCLient{
		serverQueue: rpcConf.Server,
		clientQueue: clientQueue,
		connection:  newAMQPConnector(clientQueue, reconnectBase, reconnectMax),
		pending:     make(map[string]chan []byte),
		timeout:     timeout,
		log:         blog.Get(),
		stats:       stats,
	}

	err = rpc.connection.connect(amqpConf)
	if err != nil {
		return nil, err
	}

	go func() {
		for {
			select {
			case msg, ok := <-rpc.connection.messages():
				if ok {
					corrID := msg.CorrelationId
					rpc.mu.RLock()
					responseChan, present := rpc.pending[corrID]
					rpc.mu.RUnlock()

					if !present {
						// occurs when a request is timed out and the arrives
						// afterwards
						stats.Inc("RPC.AfterTimeoutResponseArrivals."+clientQueuePrefix, 1, 1.0)
						continue
					}

					responseChan <- msg.Body
					rpc.mu.Lock()
					delete(rpc.pending, corrID)
					rpc.mu.Unlock()
				} else {
					// chan has been closed by rpc.connection.Cancel
					rpc.log.Info(fmt.Sprintf(" [!] Client reply channel closed: %s", rpc.clientQueue))
					continue
				}
			case err = <-rpc.connection.closeChannel():
				rpc.log.Info(fmt.Sprintf(" [!] Client reply channel closed : %s", rpc.clientQueue))
				rpc.connection.reconnect(amqpConf, rpc.log)
			}
		}
	}()

	return rpc, err
}

func sendGauges(client statsd.Statter, gauges map[string]int64) {
	for gauge, value := range gauges {
		client.Gauge(gauge, value, 1.0)
	}
}

func pushOpcounters(client statsd.Statter, opscounters Opcounters) error {
	var err error

	// Ops Counters (non-RS)
	err = client.Gauge("ops.inserts", opscounters.Insert, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("ops.queries", opscounters.Query, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("ops.updates", opscounters.Update, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("ops.deletes", opscounters.Delete, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("ops.getmores", opscounters.GetMore, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("ops.commands", opscounters.Command, 1.0)
	if err != nil {
		return err
	}

	return nil
}

func main() {

	// command line flags
	var opts struct {
		HostPort  string        `long:"host" default:"127.0.0.1:8125" description:"host:port of statsd server"`
		Prefix    string        `long:"prefix" default:"test-client" description:"Statsd prefix"`
		StatType  string        `long:"type" default:"count" description:"stat type to send. Can be timing, count, guage"`
		StatValue int64         `long:"value" default:"1" description:"Value to send"`
		Name      string        `short:"n" long:"name" default:"counter" description:"stat name"`
		Rate      float32       `short:"r" long:"rate" default:"1.0" description:"sample rate"`
		Volume    int           `short:"c" long:"count" default:"1000" description:"Number of stats to send. Volume."`
		Noop      bool          `long:"noop" default:"false" description:"Use noop client"`
		Duration  time.Duration `short:"d" long:"duration" default:"10s" description:"How long to spread the volume across. Each second of duration volume/seconds events will be sent."`
	}

	// parse said flags
	_, err := flags.Parse(&opts)
	if err != nil {
		if e, ok := err.(*flags.Error); ok {
			if e.Type == flags.ErrHelp {
				os.Exit(0)
			}
		}
		fmt.Printf("Error: %+v\n", err)
		os.Exit(1)
	}

	var client statsd.Statter
	if !opts.Noop {
		client, err = statsd.New(opts.HostPort, opts.Prefix)
		if err != nil {
			log.Fatal(err)
		}
		defer client.Close()
	} else {
		client, err = statsd.NewNoop(opts.HostPort, opts.Prefix)
	}

	var stat func(stat string, value int64, rate float32) error
	switch opts.StatType {
	case "count":
		stat = func(stat string, value int64, rate float32) error {
			return client.Inc(stat, value, rate)
		}
	case "gauge":
		stat = func(stat string, value int64, rate float32) error {
			return client.Gauge(stat, value, rate)
		}
	case "timing":
		stat = func(stat string, value int64, rate float32) error {
			return client.Timing(stat, value, rate)
		}
	default:
		log.Fatal("Unsupported state type")
	}

	pertick := opts.Volume / int(opts.Duration.Seconds()) / 10
	// add some extra tiem, because the first tick takes a while
	ender := time.After(opts.Duration + 100*time.Millisecond)
	c := time.Tick(time.Second / 10)
	count := 0
	for {
		select {
		case <-c:
			for x := 0; x < pertick; x++ {
				err := stat(opts.Name, opts.StatValue, opts.Rate)
				if err != nil {
					log.Printf("Got Error: %+v", err)
					break
				}
				count += 1
			}
		case <-ender:
			log.Printf("%d events called", count)
			os.Exit(0)
			return
		}
	}
}

func pushGlobalLocks(client statsd.Statter, glob GlobalLock) error {
	var err error

	err = client.Gauge("global_lock.total_time", glob.TotalTime, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.lock_time", glob.LockTime, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.active_readers", glob.ActiveClients.Readers, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.active_writers", glob.ActiveClients.Writers, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.active_total", glob.ActiveClients.Total, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.queued_readers", glob.CurrentQueue.Readers, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.queued_writers", glob.CurrentQueue.Writers, 1.0)
	if err != nil {
		return err
	}

	err = client.Gauge("global_lock.queued_total", glob.CurrentQueue.Total, 1.0)
	if err != nil {
		return err
	}

	return nil
}

func sendCounters(client statsd.Statter, counters map[string]int64) {
	for counter, value := range counters {
		client.Inc(counter, value, 1.0)
	}
}

// ProfileCmd runs forever, sending Go runtime statistics to StatsD.
func ProfileCmd(stats statsd.Statter) {
	c := time.Tick(1 * time.Second)
	for range c {
		var memoryStats runtime.MemStats
		runtime.ReadMemStats(&memoryStats)

		stats.Gauge("Gostats.Goroutines", int64(runtime.NumGoroutine()), 1.0)

		stats.Gauge("Gostats.Heap.Alloc", int64(memoryStats.HeapAlloc), 1.0)
		stats.Gauge("Gostats.Heap.Objects", int64(memoryStats.HeapObjects), 1.0)
		stats.Gauge("Gostats.Heap.Idle", int64(memoryStats.HeapIdle), 1.0)
		stats.Gauge("Gostats.Heap.InUse", int64(memoryStats.HeapInuse), 1.0)
		stats.Gauge("Gostats.Heap.Released", int64(memoryStats.HeapReleased), 1.0)

		// Calculate average and last and convert from nanoseconds to milliseconds
		gcPauseAvg := (int64(memoryStats.PauseTotalNs) / int64(len(memoryStats.PauseNs))) / 1000000
		lastGC := int64(memoryStats.PauseNs[(memoryStats.NumGC+255)%256]) / 1000000
		stats.Timing("Gostats.Gc.PauseAvg", gcPauseAvg, 1.0)
		stats.Gauge("Gostats.Gc.LastPauseTook", lastGC, 1.0)
		stats.Gauge("Gostats.Gc.NextAt", int64(memoryStats.NextGC), 1.0)
	}
}