// Join copies data between local and remote connections.
// It reads from one connection and writes to the other.
// It's a building block for ProxyFunc implementations.
func Join(local, remote net.Conn, log logging.Logger) {
	var wg sync.WaitGroup
	wg.Add(2)

	transfer := func(side string, dst, src net.Conn) {
		log.Debug("proxing %s -> %s", src.RemoteAddr(), dst.RemoteAddr())

		n, err := io.Copy(dst, src)
		if err != nil {
			log.Error("%s: copy error: %s", side, err)
		}

		if err := src.Close(); err != nil {
			log.Debug("%s: close error: %s", side, err)
		}

		// not for yamux streams, but for client to local server connections
		if d, ok := dst.(*net.TCPConn); ok {
			if err := d.CloseWrite(); err != nil {
				log.Debug("%s: closeWrite error: %s", side, err)
			}

		}
		wg.Done()
		log.Debug("done proxing %s -> %s: %d bytes", src.RemoteAddr(), dst.RemoteAddr(), n)
	}

	go transfer("remote to local", local, remote)
	go transfer("local to remote", remote, local)

	wg.Wait()
}

// UninstallCommand configures the Uninstall struct and calls it based on the
// given codegangsta/cli context.
//
// TODO: remove all artifacts, ie bolt db, ssh keys, kd etc.
func UninstallCommand(c *cli.Context, log logging.Logger, _ string) (string, int) {
	warnings := []string{}

	// Ensure /etc/kite/kite.key is migrated to konfig.bolt before
	// old klient gets uninstalled. The endpoint/config package
	// performs lazy migrations, so it's enough to call any of
	// its methods and disregard the result.
	_ = configcli.List()

	s, err := newService(nil)
	if err != nil {
		log.Warning("Failed creating Service for uninstall. err:%s", err)
		warnings = append(warnings, FailedUninstallingKlientWarn)
	}

	uninstaller := &Uninstall{
		ServiceUninstaller: s,
		KlientName:         config.KlientName,
		KlientctlName:      config.Name,
		KlientctlPath:      filepath.Join(KlientctlDirectory, KlientctlBinName),
		// TODO: Store the klient directory structure(s) somewhere
		KlientParentDirectory: "/opt",
		KlientDirectory:       "kite/klient",
		KlientFilename:        "klient",
		KlientshFilename:      "klient.sh",
		remover:               os.Remove,
		warnings:              warnings,
		log:                   log,
	}

	return uninstaller.Uninstall()
}

// NewMachine initializes a new Machine struct with any internal vars created.
func NewMachine(meta MachineMeta, log logging.Logger, t Transport) (*Machine, error) {
	log = MachineLogger(meta, log)

	// Create our Pingers, to be used in the PingTrackers
	kitePinger := kitepinger.NewKitePinger(t)
	httpPinger, err := kitepinger.NewKiteHTTPPinger(meta.URL)
	if err != nil {
		log.Error(
			"Unable to create HTTPPinger from meta.URL. url:%s, err:%s", meta.URL, err,
		)
		return nil, err
	}

	m := &Machine{
		MachineMeta: meta,
		Log:         log,
		KiteTracker: kitepinger.NewPingTracker(kitePinger),
		HTTPTracker: kitepinger.NewPingTracker(httpPinger),
		Transport:   t,
		discover:    discover.NewClient(),
		mountLocker: util.NewMutexWithState(),
	}

	m.discover.Log = m.Log.New("discover")

	// Start our http pinger, to give online/offline statuses for all machines.
	m.HTTPTracker.Start()

	return m, nil
}

func NewStatus(log logging.Logger, mg MachineGetter) *Status {
	return &Status{
		Log:           log.New("status"),
		MachineGetter: mg,
		HTTPClient:    defaultHTTPClient,
	}
}

// NewAddresses fetches EC2 IP address list from each region.
//
// If log is nil, defaultLogger is used instead.
func NewAddresses(clients *amazon.Clients, log logging.Logger) *Addresses {
	if log == nil {
		log = defaultLogger
	}
	a := newAddresses()
	var wg sync.WaitGroup
	var mu sync.Mutex // protects a.m
	for region, client := range clients.Regions() {
		wg.Add(1)
		go func(region string, client *amazon.Client) {
			defer wg.Done()
			addresses, err := client.Addresses()
			if err != nil {
				log.Error("[%s] fetching IP addresses error: %s", region, err)
				return
			}
			log.Info("[%s] fetched %d addresses", region, len(addresses))
			var ok bool
			mu.Lock()
			if _, ok = a.m[client]; !ok {
				a.m[client] = addresses
			}
			mu.Unlock()
			if ok {
				panic(fmt.Errorf("[%s] duplicated client=%p: %+v", region, client, addresses))
			}
		}(region, client)
	}
	wg.Wait()
	return a
}

// NewMultiInstances fetches EC2 instance list from each region.
func NewMultiInstances(clients *amazon.Clients, log logging.Logger) *MultiInstances {
	if log == nil {
		log = defaultLogger
	}
	var m = newMultiInstances()
	var wg sync.WaitGroup
	var mu sync.Mutex // protects m.m
	for region, client := range clients.Regions() {
		wg.Add(1)
		go func(region string, client *amazon.Client) {
			defer wg.Done()
			instances, err := client.Instances()
			if err != nil {
				log.Error("[%s] fetching instances error: %s", region, err)
				return
			}
			log.Info("[%s] fetched %d instances", region, len(instances))
			i := make(Instances, len(instances))
			for _, instance := range instances {
				i[aws.StringValue(instance.InstanceId)] = instance
			}
			var ok bool
			mu.Lock()
			if _, ok = m.m[client]; !ok {
				m.m[client] = i
			}
			mu.Unlock()
			if ok {
				panic(fmt.Errorf("[%s] duplicated client=%p: %+v", region, client, i))
			}
		}(region, client)
	}
	wg.Wait()
	return m
}

func CreateMetrics(appName string, log logging.Logger, outputMetrics bool) (*kodingmetrics.Metrics, *kodingmetrics.DogStatsD) {
	metric := kodingmetrics.New(appName)

	// if outputMetrics, do print output to the console
	if outputMetrics {
		// change those loggers
		// https://github.com/rcrowley/go-metrics/blob/37df06ff62a7d8b4473b48d355008c838da87561/log.go
		// get those numbers from config
		// output metrics every 1 minutes
		go metrics.Log(metric.Registry, 6e10, slog.New(os.Stderr, "metrics: ", slog.Lmicroseconds))
	}

	// Left here for future reference

	// for Mac
	syslogPath := "/var/run/syslog"
	if runtime.GOOS != "darwin" {
		// for linux
		syslogPath = "/dev/log"
	}

	w, err := syslog.Dial("unixgram", syslogPath, syslog.LOG_INFO, "socialapi-metrics")
	if err != nil {
		log.Error("Err while initing syslog for metrics, metrics wont be in the syslog %s", err.Error())
	} else {
		go metrics.Syslog(metric.Registry, 30e10, w)
	}

	statsd, err := kodingmetrics.NewDogStatsD(appName)
	if err == nil {
		go kodingmetrics.Collect(metric.Registry, statsd, 24e10)
	}

	return metric, statsd
}

// MachineListCommand returns list of remote machines belonging to the user or
// that can be accessed by her.
func MachineListCommand(c *cli.Context, log logging.Logger, _ string) (int, error) {
	// List command doesn't support identifiers.
	idents, err := getIdentifiers(c)
	if err != nil {
		return 1, err
	}
	if err := identifiersLimit(idents, 0, 0); err != nil {
		return 1, err
	}

	opts := &machine.ListOptions{
		Log: log.New("machine:list"),
	}

	infos, err := machine.List(opts)
	if err != nil {
		return 1, err
	}

	if c.Bool("json") {
		enc := json.NewEncoder(os.Stdout)
		enc.SetIndent("", "\t")
		enc.Encode(infos)
		return 0, nil
	}

	tabFormatter(os.Stdout, infos)
	return 0, nil
}

func NewErrorCommand(stdout io.Writer, log logging.Logger, err error, msg string) *ErrorCommand {
	return &ErrorCommand{
		Stdout:  util.NewFprint(stdout),
		Log:     log.New("errorCommand"),
		Message: msg,
		Error:   err,
	}
}

// NewRecordManager creates a RecordManager
func NewRecordManager(session *session.Session, log logging.Logger, region string, hostedZoneConf HostedZone) *RecordManager {
	return &RecordManager{
		route53:        route53.New(session),
		log:            log.New("recordmanager"),
		region:         region,
		hostedZoneConf: hostedZoneConf,
	}
}

func NewPagerduty(pc *PagerdutyConfig, log logging.Logger) (*Pagerduty, error) {

	return &Pagerduty{
		publicURL:      pc.PublicURL,
		integrationURL: pc.IntegrationURL,
		log:            log.New(PAGERDUTY),
	}, nil
}

func NewDefaultHealthChecker(l kodinglogging.Logger) *HealthChecker {
	return &HealthChecker{
		Log:                  l.New("HealthChecker"),
		HTTPClient:           defaultClient,
		LocalKlientAddress:   config.Konfig.Endpoints.Klient.Private.String(),
		KontrolAddress:       config.Konfig.Endpoints.Kontrol().Public.String(),
		InternetCheckAddress: config.Konfig.Endpoints.KlientLatest.Public.String(),
		TunnelKiteAddress:    config.Konfig.Endpoints.Tunnel.Public.String(),
	}
}

// RestartCommand stops and starts klient. If Klient is not running to begin
// with, it *just* starts klient.
func RestartCommand(c *cli.Context, log logging.Logger, _ string) int {
	if len(c.Args()) != 0 {
		cli.ShowCommandHelp(c, "restart")
		return 1
	}

	log = log.New("cmd:restart")

	s, err := newService(nil)
	if err != nil {
		log.Error("Error creating Service. err:%s", err)
		fmt.Println(GenericInternalNewCodeError)
		return 1
	}

	fmt.Printf("Restarting the %s, this may take a moment...\n", config.KlientName)

	klientWasRunning := IsKlientRunning(config.Konfig.Endpoints.Klient.Private.String())

	if klientWasRunning {
		// If klient is running, stop it, and tell the user if we fail
		if err := s.Stop(); err != nil {
			log.Error("Error stopping Service. err:%s", err)
			fmt.Println(FailedStopKlient)
			return 1
		}
	} else {
		// If klient appears to not be running, try to stop it anyway. However,
		// because it may not actually be running, don't inform the user if we fail here.
		s.Stop()
	}

	err = WaitUntilStopped(config.Konfig.Endpoints.Klient.Private.String(), CommandAttempts, CommandWaitTime)
	if err != nil {
		log.Error(
			"Timed out while waiting for Klient to start. attempts:%d, err:%s",
			5, err,
		)
		fmt.Println(FailedStopKlient)
		return 1
	}

	if klientWasRunning {
		fmt.Println("Stopped successfully.")
	}

	// No UX message needed, startKlient will do that itself.
	if err := startKlient(log, s); err != nil {
		log.Error("failed to start klient: %s", err)
		return 1
	}

	fmt.Printf("Successfully restarted %s\n", config.KlientName)
	return 0
}

func newCommand(cwd string, log logging.Logger) *command {
	cmd := &command{
		cwd: cwd,
	}

	if log != nil {
		cmd.log = log.New(cwd)
	}

	return cmd
}

func NewPivotal(pc *PivotalConfig, log logging.Logger) (*Pivotal, error) {
	if pc.ServerURL == "" {
		pc.ServerURL = PivotalServerURL
	}

	return &Pivotal{
		serverURL:      pc.ServerURL,
		publicURL:      pc.PublicURL,
		integrationURL: pc.IntegrationURL,
		log:            log.New(PIVOTAL),
	}, nil
}

// NewLifeCycle creates a new lifecycle management system, everything begins
// with an autoscaling resource, we are listening to any change on that
// resource, to be able to listen them we are attaching a notification
// configuration to given autoscaling resource, notification configuration works
// with a TopicARN, which is basically a SNS Topic, to be able to listen from a
// Topic ARN we need a SQS, SQS is attached to Notification Topic and configured
// to pass events as soon as they occur, it also has re- try mechanism. One
// event only be handled by one manager, there wont be any race condition on
// processing that particular message. Manager is idempotent, if any given
// resource doesnt exist in the given AWS system, it will create or re-use the
// previous ones
func NewLifeCycle(session *session.Session, log logging.Logger, asgName string) *LifeCycle {
	return &LifeCycle{
		closed:      false,
		closeChan:   make(chan chan struct{}),
		ec2:         ec2.New(session),
		sqs:         sqs.New(session),
		sns:         sns.New(session),
		autoscaling: autoscaling.New(session),
		asgName:     &asgName,
		log:         log.New("lifecycle"),
	}
}

// fetchHostedZone fetches all hosted zones from account and iterates over them
// until it finds the respective one
func (r *RecordManager) fetchHostedZone(hostedZoneLogger logging.Logger) error {
	const maxIterationCount = 100
	iteration := 0

	// for pagination
	var nextMarker *string

	// try to get our hosted zone
	for {
		// just be paranoid about remove api calls, dont harden too much
		if iteration == maxIterationCount {
			return errors.New("iteration terminated")
		}

		log := hostedZoneLogger.New("iteration", iteration)

		iteration++

		log.Debug("Fetching hosted zone")
		listHostedZonesResp, err := r.route53.ListHostedZones(
			&route53.ListHostedZonesInput{
				Marker: nextMarker,
			}, // we dont have anything to filter
		)
		if err != nil {
			return err
		}

		if listHostedZonesResp == nil || listHostedZonesResp.HostedZones == nil {
			return errors.New("malformed response - reponse or hosted zone is nil")
		}

		for _, hostedZone := range listHostedZonesResp.HostedZones {
			if hostedZone == nil || hostedZone.CallerReference == nil {
				continue
			}

			if *hostedZone.CallerReference == r.hostedZoneConf.CallerReference {
				r.hostedZone = hostedZone
				return nil
			}
		}

		// if our result set is truncated we can try to fetch again, but if we
		// reach to end, nothing to do left
		if listHostedZonesResp.IsTruncated == nil || !*listHostedZonesResp.IsTruncated {
			return errHostedZoneNotFound
		}

		// assign next marker
		nextMarker = listHostedZonesResp.NextMarker
	}
}

func New(log logging.Logger, client algoliasearch.Client, indexSuffix string) *Controller {
	// TODO later on listen channel_participant_added event and remove this koding channel fetch
	c := models.NewChannel()
	q := request.NewQuery()
	q.GroupName = "koding"
	q.Name = "public"
	q.Type = models.Channel_TYPE_GROUP

	channel, err := c.ByName(q)
	if err != nil {
		log.Error("Could not fetch koding channel: %s:", err)
	}
	var channelId string
	if channel.Id != 0 {
		channelId = strconv.FormatInt(channel.Id, 10)
	}

	controller := &Controller{
		log:    log,
		client: client,
		indexes: &IndexSet{
			IndexTopics: &IndexSetItem{
				Index: client.InitIndex(IndexTopics + indexSuffix),
				Settings: &Settings{
					// empty slice means all properties will be searchable
					AttributesToIndex: []string{},
				},
			},
			IndexAccounts: &IndexSetItem{
				Index: client.InitIndex(IndexAccounts + indexSuffix),
				Settings: &Settings{
					AttributesToIndex: []string{
						"nick",
						"email",
						"firstName",
						"lastName",
						"_tags",
					},
					UnretrievableAttributes: []string{"email"},
				},
			},
			IndexMessages: &IndexSetItem{
				Index: client.InitIndex(IndexMessages + indexSuffix),
				Settings: &Settings{
					AttributesToIndex: []string{},
				},
			},
		},
		kodingChannelId: channelId,
	}

	return controller
}

// New creates a new terraformer
func New(conf *Config, log logging.Logger) (*Terraformer, error) {
	ls, err := storage.NewFile(conf.LocalStorePath, log)
	if err != nil {
		return nil, fmt.Errorf("error while creating local store: %s", err)
	}

	var rs storage.Interface
	if conf.AWS.Key != "" && conf.AWS.Secret != "" && conf.AWS.Bucket != "" {
		s3, err := storage.NewS3(conf.AWS.Key, conf.AWS.Secret, conf.AWS.Bucket, log)
		if err != nil {
			return nil, fmt.Errorf("error while creating remote store: %s", err)
		}

		rs = s3
	} else {
		remotePath := filepath.Dir(conf.LocalStorePath)
		if conf.AWS.Bucket != "" {
			remotePath = filepath.Join(remotePath, conf.AWS.Bucket)
		} else {
			remotePath = filepath.Join(remotePath, filepath.Base(conf.LocalStorePath)+".remote")
		}

		local, err := storage.NewFile(remotePath, log)
		if err != nil {
			return nil, fmt.Errorf("error while creating remote store on local: %s", err)
		}

		log.Info("no S3 credentials, using local storage: %s", remotePath)

		rs = local
	}

	c, err := kodingcontext.New(ls, rs, log, conf.Debug)
	if err != nil {
		return nil, err
	}

	t := &Terraformer{
		Log:       log,
		Metrics:   common.MustInitMetrics(Name),
		Debug:     conf.Debug,
		Context:   c,
		Config:    conf,
		closeChan: make(chan struct{}),
	}

	t.handleSignals()

	return t, nil
}

// FactoryCompletion implements codeganstas cli.Command's bash completion field
func FactoryCompletion(factory CommandFactory, log logging.Logger, cmdName string) cli.BashCompleteFunc {
	return func(c *cli.Context) {
		cmd := factory(c, log, cmdName)

		// If the command implements AutocompleteCommand, run the autocomplete.
		if aCmd, ok := cmd.(AutocompleteCommand); ok {
			if err := aCmd.Autocomplete(c.Args()...); err != nil {
				log.Error(
					"Autocompletion of a command encountered error. command:%s, err:%s",
					cmdName, err,
				)
			}
		}
	}
}