package server

import (
	"context"
	"crypto/tls"
	"fmt"
	"log"
	"math/rand"
	"net"
	"net/http"
	"net/url"
	"os"
	"path"
	"regexp"
	"runtime"
	"strconv"
	"time"

	"github.com/influxdata/influxdb/v2/chronograf"
	"github.com/influxdata/influxdb/v2/chronograf/bolt"
	idgen "github.com/influxdata/influxdb/v2/chronograf/id"
	"github.com/influxdata/influxdb/v2/chronograf/influx"
	"github.com/influxdata/influxdb/v2/chronograf/oauth2"
	client "github.com/influxdata/usage-client/v1"
	flags "github.com/jessevdk/go-flags"
	"github.com/tylerb/graceful"
	bbolt "go.etcd.io/bbolt"
)

var (
	startTime time.Time
)

func init() {
	startTime = time.Now().UTC()
}

// Server for the chronograf API
type Server struct {
	Host string `long:"host" description:"The IP to listen on" default:"0.0.0.0" env:"HOST"`
	Port int    `long:"port" description:"The port to listen on for insecure connections, defaults to a random value" default:"8888" env:"PORT"`

	PprofEnabled bool `long:"pprof-enabled" description:"Enable the /debug/pprof/* HTTP routes" env:"PPROF_ENABLED"`

	Cert flags.Filename `long:"cert" description:"Path to PEM encoded public key certificate. " env:"TLS_CERTIFICATE"`
	Key  flags.Filename `long:"key" description:"Path to private key associated with given certificate. " env:"TLS_PRIVATE_KEY"`

	InfluxDBURL      string `long:"influxdb-url" description:"Location of your InfluxDB instance" env:"INFLUXDB_URL"`
	InfluxDBUsername string `long:"influxdb-username" description:"Username for your InfluxDB instance" env:"INFLUXDB_USERNAME"`
	InfluxDBPassword string `long:"influxdb-password" description:"Password for your InfluxDB instance" env:"INFLUXDB_PASSWORD"`

	KapacitorURL      string `long:"kapacitor-url" description:"Location of your Kapacitor instance" env:"KAPACITOR_URL"`
	KapacitorUsername string `long:"kapacitor-username" description:"Username of your Kapacitor instance" env:"KAPACITOR_USERNAME"`
	KapacitorPassword string `long:"kapacitor-password" description:"Password of your Kapacitor instance" env:"KAPACITOR_PASSWORD"`

	NewSources string `long:"new-sources" description:"Config for adding a new InfluxDB source and Kapacitor server, in JSON as an array of objects, and surrounded by single quotes. E.g. --new-sources='[{\"influxdb\":{\"name\":\"Influx 1\",\"username\":\"user1\",\"password\":\"pass1\",\"url\":\"http://localhost:8086\",\"metaUrl\":\"http://metaurl.com\",\"type\":\"influx-enterprise\",\"insecureSkipVerify\":false,\"default\":true,\"telegraf\":\"telegraf\",\"sharedSecret\":\"cubeapples\"},\"kapacitor\":{\"name\":\"Kapa 1\",\"url\":\"http://localhost:9092\",\"active\":true}}]'" env:"NEW_SOURCES" hidden:"true"`

	Develop       bool          `short:"d" long:"develop" description:"Run server in develop mode."`
	BoltPath      string        `short:"b" long:"bolt-path" description:"Full path to boltDB file (e.g. './chronograf-v1.db')" env:"BOLT_PATH" default:"chronograf-v1.db"`
	CannedPath    string        `short:"c" long:"canned-path" description:"Path to directory of pre-canned application layouts (/usr/share/chronograf/canned)" env:"CANNED_PATH" default:"canned"`
	ResourcesPath string        `long:"resources-path" description:"Path to directory of pre-canned dashboards, sources, kapacitors, and organizations (/usr/share/chronograf/resources)" env:"RESOURCES_PATH" default:"canned"`
	TokenSecret   string        `short:"t" long:"token-secret" description:"Secret to sign tokens" env:"TOKEN_SECRET"`
	JwksURL       string        `long:"jwks-url" description:"URL that returns OpenID Key Discovery JWKS document." env:"JWKS_URL"`
	UseIDToken    bool          `long:"use-id-token" description:"Enable id_token processing." env:"USE_ID_TOKEN"`
	AuthDuration  time.Duration `long:"auth-duration" default:"720h" description:"Total duration of cookie life for authentication (in hours). 0 means authentication expires on browser close." env:"AUTH_DURATION"`

	GithubClientID     string   `short:"i" long:"github-client-id" description:"Github Client ID for OAuth 2 support" env:"GH_CLIENT_ID"`
	GithubClientSecret string   `short:"s" long:"github-client-secret" description:"Github Client Secret for OAuth 2 support" env:"GH_CLIENT_SECRET"`
	GithubOrgs         []string `short:"o" long:"github-organization" description:"Github organization user is required to have active membership" env:"GH_ORGS" env-delim:","`

	GoogleClientID     string   `long:"google-client-id" description:"Google Client ID for OAuth 2 support" env:"GOOGLE_CLIENT_ID"`
	GoogleClientSecret string   `long:"google-client-secret" description:"Google Client Secret for OAuth 2 support" env:"GOOGLE_CLIENT_SECRET"`
	GoogleDomains      []string `long:"google-domains" description:"Google email domain user is required to have active membership" env:"GOOGLE_DOMAINS" env-delim:","`
	PublicURL          string   `long:"public-url" description:"Full public URL used to access Chronograf from a web browser. Used for OAuth2 authentication. (http://localhost:8888)" env:"PUBLIC_URL"`

	HerokuClientID      string   `long:"heroku-client-id" description:"Heroku Client ID for OAuth 2 support" env:"HEROKU_CLIENT_ID"`
	HerokuSecret        string   `long:"heroku-secret" description:"Heroku Secret for OAuth 2 support" env:"HEROKU_SECRET"`
	HerokuOrganizations []string `long:"heroku-organization" description:"Heroku Organization Memberships a user is required to have for access to Chronograf (comma separated)" env:"HEROKU_ORGS" env-delim:","`

	GenericName         string   `long:"generic-name" description:"Generic OAuth2 name presented on the login page"  env:"GENERIC_NAME"`
	GenericClientID     string   `long:"generic-client-id" description:"Generic OAuth2 Client ID. Can be used own OAuth2 service."  env:"GENERIC_CLIENT_ID"`
	GenericClientSecret string   `long:"generic-client-secret" description:"Generic OAuth2 Client Secret" env:"GENERIC_CLIENT_SECRET"`
	GenericScopes       []string `long:"generic-scopes" description:"Scopes requested by provider of web client." default:"user:email" env:"GENERIC_SCOPES" env-delim:","`
	GenericDomains      []string `long:"generic-domains" description:"Email domain users' email address to have (example.com)" env:"GENERIC_DOMAINS" env-delim:","`
	GenericAuthURL      string   `long:"generic-auth-url" description:"OAuth 2.0 provider's authorization endpoint URL" env:"GENERIC_AUTH_URL"`
	GenericTokenURL     string   `long:"generic-token-url" description:"OAuth 2.0 provider's token endpoint URL" env:"GENERIC_TOKEN_URL"`
	GenericAPIURL       string   `long:"generic-api-url" description:"URL that returns OpenID UserInfo compatible information." env:"GENERIC_API_URL"`
	GenericAPIKey       string   `long:"generic-api-key" description:"JSON lookup key into OpenID UserInfo. (Azure should be userPrincipalName)" default:"email" env:"GENERIC_API_KEY"`

	Auth0Domain        string   `long:"auth0-domain" description:"Subdomain of auth0.com used for Auth0 OAuth2 authentication" env:"AUTH0_DOMAIN"`
	Auth0ClientID      string   `long:"auth0-client-id" description:"Auth0 Client ID for OAuth2 support" env:"AUTH0_CLIENT_ID"`
	Auth0ClientSecret  string   `long:"auth0-client-secret" description:"Auth0 Client Secret for OAuth2 support" env:"AUTH0_CLIENT_SECRET"`
	Auth0Organizations []string `long:"auth0-organizations" description:"Auth0 organizations permitted to access Chronograf (comma separated)" env:"AUTH0_ORGS" env-delim:","`
	Auth0SuperAdminOrg string   `long:"auth0-superadmin-org" description:"Auth0 organization from which users are automatically granted SuperAdmin status" env:"AUTH0_SUPERADMIN_ORG"`

	StatusFeedURL          string            `long:"status-feed-url" description:"URL of a JSON Feed to display as a News Feed on the client Status page." default:"https://www.influxdata.com/feed/json" env:"STATUS_FEED_URL"`
	CustomLinks            map[string]string `long:"custom-link" description:"Custom link to be added to the client User menu. Multiple links can be added by using multiple of the same flag with different 'name:url' values, or as an environment variable with comma-separated 'name:url' values. E.g. via flags: '--custom-link=InfluxData:https://www.influxdata.com --custom-link=Chronograf:https://github.com/influxdata/influxdb/chronograf'. E.g. via environment variable: 'export CUSTOM_LINKS=InfluxData:https://www.influxdata.com,Chronograf:https://github.com/influxdata/influxdb/chronograf'" env:"CUSTOM_LINKS" env-delim:","`
	TelegrafSystemInterval time.Duration     `long:"telegraf-system-interval" default:"1m" description:"Duration used in the GROUP BY time interval for the hosts list" env:"TELEGRAF_SYSTEM_INTERVAL"`

	ReportingDisabled bool   `short:"r" long:"reporting-disabled" description:"Disable reporting of usage stats (os,arch,version,cluster_id,uptime) once every 24hr" env:"REPORTING_DISABLED"`
	LogLevel          string `short:"l" long:"log-level" value-name:"choice" choice:"debug" choice:"info" choice:"error" default:"info" description:"Set the logging level" env:"LOG_LEVEL"`
	Basepath          string `short:"p" long:"basepath" description:"A URL path prefix under which all chronograf routes will be mounted. (Note: PREFIX_ROUTES has been deprecated. Now, if basepath is set, all routes will be prefixed with it.)" env:"BASE_PATH"`
	ShowVersion       bool   `short:"v" long:"version" description:"Show Chronograf version info"`
	BuildInfo         chronograf.BuildInfo
	Listener          net.Listener
	handler           http.Handler
}

func provide(p oauth2.Provider, m oauth2.Mux, ok func() bool) func(func(oauth2.Provider, oauth2.Mux)) {
	return func(configure func(oauth2.Provider, oauth2.Mux)) {
		if ok() {
			configure(p, m)
		}
	}
}

// UseGithub validates the CLI parameters to enable github oauth support
func (s *Server) UseGithub() bool {
	return s.TokenSecret != "" && s.GithubClientID != "" && s.GithubClientSecret != ""
}

// UseGoogle validates the CLI parameters to enable google oauth support
func (s *Server) UseGoogle() bool {
	return s.TokenSecret != "" && s.GoogleClientID != "" && s.GoogleClientSecret != "" && s.PublicURL != ""
}

// UseHeroku validates the CLI parameters to enable heroku oauth support
func (s *Server) UseHeroku() bool {
	return s.TokenSecret != "" && s.HerokuClientID != "" && s.HerokuSecret != ""
}

// UseAuth0 validates the CLI parameters to enable Auth0 oauth support
func (s *Server) UseAuth0() bool {
	return s.Auth0ClientID != "" && s.Auth0ClientSecret != ""
}

// UseGenericOAuth2 validates the CLI parameters to enable generic oauth support
func (s *Server) UseGenericOAuth2() bool {
	return s.TokenSecret != "" && s.GenericClientID != "" &&
		s.GenericClientSecret != "" && s.GenericAuthURL != "" &&
		s.GenericTokenURL != ""
}

func (s *Server) githubOAuth(logger chronograf.Logger, auth oauth2.Authenticator) (oauth2.Provider, oauth2.Mux, func() bool) {
	gh := oauth2.Github{
		ClientID:     s.GithubClientID,
		ClientSecret: s.GithubClientSecret,
		Orgs:         s.GithubOrgs,
		Logger:       logger,
	}
	jwt := oauth2.NewJWT(s.TokenSecret, s.JwksURL)
	ghMux := oauth2.NewAuthMux(&gh, auth, jwt, s.Basepath, logger, s.UseIDToken)
	return &gh, ghMux, s.UseGithub
}

func (s *Server) googleOAuth(logger chronograf.Logger, auth oauth2.Authenticator) (oauth2.Provider, oauth2.Mux, func() bool) {
	redirectURL := s.PublicURL + s.Basepath + "/oauth/google/callback"
	google := oauth2.Google{
		ClientID:     s.GoogleClientID,
		ClientSecret: s.GoogleClientSecret,
		Domains:      s.GoogleDomains,
		RedirectURL:  redirectURL,
		Logger:       logger,
	}
	jwt := oauth2.NewJWT(s.TokenSecret, s.JwksURL)
	goMux := oauth2.NewAuthMux(&google, auth, jwt, s.Basepath, logger, s.UseIDToken)
	return &google, goMux, s.UseGoogle
}

func (s *Server) herokuOAuth(logger chronograf.Logger, auth oauth2.Authenticator) (oauth2.Provider, oauth2.Mux, func() bool) {
	heroku := oauth2.Heroku{
		ClientID:      s.HerokuClientID,
		ClientSecret:  s.HerokuSecret,
		Organizations: s.HerokuOrganizations,
		Logger:        logger,
	}
	jwt := oauth2.NewJWT(s.TokenSecret, s.JwksURL)
	hMux := oauth2.NewAuthMux(&heroku, auth, jwt, s.Basepath, logger, s.UseIDToken)
	return &heroku, hMux, s.UseHeroku
}

func (s *Server) genericOAuth(logger chronograf.Logger, auth oauth2.Authenticator) (oauth2.Provider, oauth2.Mux, func() bool) {
	gen := oauth2.Generic{
		PageName:       s.GenericName,
		ClientID:       s.GenericClientID,
		ClientSecret:   s.GenericClientSecret,
		RequiredScopes: s.GenericScopes,
		Domains:        s.GenericDomains,
		RedirectURL:    s.genericRedirectURL(),
		AuthURL:        s.GenericAuthURL,
		TokenURL:       s.GenericTokenURL,
		APIURL:         s.GenericAPIURL,
		APIKey:         s.GenericAPIKey,
		Logger:         logger,
	}
	jwt := oauth2.NewJWT(s.TokenSecret, s.JwksURL)
	genMux := oauth2.NewAuthMux(&gen, auth, jwt, s.Basepath, logger, s.UseIDToken)
	return &gen, genMux, s.UseGenericOAuth2
}

func (s *Server) auth0OAuth(logger chronograf.Logger, auth oauth2.Authenticator) (oauth2.Provider, oauth2.Mux, func() bool) {
	redirectPath := path.Join(s.Basepath, "oauth", "auth0", "callback")
	redirectURL, err := url.Parse(s.PublicURL)
	if err != nil {
		logger.Error("Error parsing public URL: err:", err)
		return &oauth2.Auth0{}, &oauth2.AuthMux{}, func() bool { return false }
	}
	redirectURL.Path = redirectPath

	auth0, err := oauth2.NewAuth0(s.Auth0Domain, s.Auth0ClientID, s.Auth0ClientSecret, redirectURL.String(), s.Auth0Organizations, logger)

	jwt := oauth2.NewJWT(s.TokenSecret, s.JwksURL)
	genMux := oauth2.NewAuthMux(&auth0, auth, jwt, s.Basepath, logger, s.UseIDToken)

	if err != nil {
		logger.Error("Error parsing Auth0 domain: err:", err)
		return &auth0, genMux, func() bool { return false }
	}
	return &auth0, genMux, s.UseAuth0
}

func (s *Server) genericRedirectURL() string {
	if s.PublicURL == "" {
		return ""
	}

	genericName := "generic"
	if s.GenericName != "" {
		genericName = s.GenericName
	}

	publicURL, err := url.Parse(s.PublicURL)
	if err != nil {
		return ""
	}

	publicURL.Path = path.Join(publicURL.Path, s.Basepath, "oauth", genericName, "callback")
	return publicURL.String()
}

func (s *Server) useAuth() bool {
	return s.UseGithub() || s.UseGoogle() || s.UseHeroku() || s.UseGenericOAuth2() || s.UseAuth0()
}

func (s *Server) useTLS() bool {
	return s.Cert != ""
}

// NewListener will an http or https listener depending useTLS()
func (s *Server) NewListener() (net.Listener, error) {
	addr := net.JoinHostPort(s.Host, strconv.Itoa(s.Port))
	if !s.useTLS() {
		listener, err := net.Listen("tcp", addr)
		if err != nil {
			return nil, err
		}
		return listener, nil
	}

	// If no key specified, therefore, we assume it is in the cert
	if s.Key == "" {
		s.Key = s.Cert
	}

	cert, err := tls.LoadX509KeyPair(string(s.Cert), string(s.Key))
	if err != nil {
		return nil, err
	}

	listener, err := tls.Listen("tcp", addr, &tls.Config{
		Certificates: []tls.Certificate{cert},
	})

	if err != nil {
		return nil, err
	}
	return listener, nil
}

type builders struct {
	Layouts       LayoutBuilder
	Sources       SourcesBuilder
	Kapacitors    KapacitorBuilder
	Dashboards    DashboardBuilder
	Organizations OrganizationBuilder
}

func (s *Server) newBuilders(logger chronograf.Logger) builders {
	return builders{
		Layouts: &MultiLayoutBuilder{
			Logger:     logger,
			UUID:       &idgen.UUID{},
			CannedPath: s.CannedPath,
		},
		Dashboards: &MultiDashboardBuilder{
			Logger: logger,
			ID:     idgen.NewTime(),
			Path:   s.ResourcesPath,
		},
		Sources: &MultiSourceBuilder{
			InfluxDBURL:      s.InfluxDBURL,
			InfluxDBUsername: s.InfluxDBUsername,
			InfluxDBPassword: s.InfluxDBPassword,
			Logger:           logger,
			ID:               idgen.NewTime(),
			Path:             s.ResourcesPath,
		},
		Kapacitors: &MultiKapacitorBuilder{
			KapacitorURL:      s.KapacitorURL,
			KapacitorUsername: s.KapacitorUsername,
			KapacitorPassword: s.KapacitorPassword,
			Logger:            logger,
			ID:                idgen.NewTime(),
			Path:              s.ResourcesPath,
		},
		Organizations: &MultiOrganizationBuilder{
			Logger: logger,
			Path:   s.ResourcesPath,
		},
	}
}

// Serve starts and runs the chronograf server
func (s *Server) Serve(ctx context.Context) error {
	logger := &chronograf.NoopLogger{}
	_, err := NewCustomLinks(s.CustomLinks)
	if err != nil {
		logger.
			WithField("component", "server").
			WithField("CustomLink", "invalid").
			Error(err)
		return err
	}
	service := openService(ctx, s.BuildInfo, s.BoltPath, s.newBuilders(logger), logger, s.useAuth())
	service.SuperAdminProviderGroups = superAdminProviderGroups{
		auth0: s.Auth0SuperAdminOrg,
	}
	service.Env = chronograf.Environment{
		TelegrafSystemInterval: s.TelegrafSystemInterval,
	}

	if !validBasepath(s.Basepath) {
		err := fmt.Errorf("invalid basepath, must follow format \"/mybasepath\"")
		logger.
			WithField("component", "server").
			WithField("basepath", "invalid").
			Error(err)
		return err
	}

	providerFuncs := []func(func(oauth2.Provider, oauth2.Mux)){}

	auth := oauth2.NewCookieJWT(s.TokenSecret, s.AuthDuration)
	providerFuncs = append(providerFuncs, provide(s.githubOAuth(logger, auth)))
	providerFuncs = append(providerFuncs, provide(s.googleOAuth(logger, auth)))
	providerFuncs = append(providerFuncs, provide(s.herokuOAuth(logger, auth)))
	providerFuncs = append(providerFuncs, provide(s.genericOAuth(logger, auth)))
	providerFuncs = append(providerFuncs, provide(s.auth0OAuth(logger, auth)))

	s.handler = NewMux(MuxOpts{
		Develop:       s.Develop,
		Auth:          auth,
		Logger:        logger,
		UseAuth:       s.useAuth(),
		ProviderFuncs: providerFuncs,
		Basepath:      s.Basepath,
		StatusFeedURL: s.StatusFeedURL,
		CustomLinks:   s.CustomLinks,
	}, service)

	// Add chronograf's version header to all requests
	s.handler = Version(s.BuildInfo.Version, s.handler)

	if s.useTLS() {
		// Add HSTS to instruct all browsers to change from http to https
		s.handler = HSTS(s.handler)
	}

	listener, err := s.NewListener()
	if err != nil {
		logger.
			WithField("component", "server").
			Error(err)
		return err
	}
	s.Listener = listener

	// Using a log writer for http server logging
	w := logger.Writer()
	defer w.Close()
	stdLog := log.New(w, "", 0)

	// TODO: Remove graceful when changing to go 1.8
	httpServer := &graceful.Server{
		Server: &http.Server{
			ErrorLog: stdLog,
			Handler:  s.handler,
		},
		Logger:       stdLog,
		TCPKeepAlive: 5 * time.Second,
	}
	httpServer.SetKeepAlivesEnabled(true)

	if !s.ReportingDisabled {
		go reportUsageStats(s.BuildInfo, logger)
	}
	scheme := "http"
	if s.useTLS() {
		scheme = "https"
	}
	logger.
		WithField("component", "server").
		Info("Serving chronograf at ", scheme, "://", s.Listener.Addr())

	if err := httpServer.Serve(s.Listener); err != nil {
		logger.
			WithField("component", "server").
			Error(err)
		return err
	}

	logger.
		WithField("component", "server").
		Info("Stopped serving chronograf at ", scheme, "://", s.Listener.Addr())

	return nil
}

func NewServiceV2(ctx context.Context, d *bbolt.DB) (*Service, error) {
	db := bolt.NewClient()
	db.WithDB(d)

	if err := db.Open(ctx, nil, chronograf.BuildInfo{}); err != nil {
		return nil, err
	}

	logger := &chronograf.NoopLogger{}

	return &Service{
		TimeSeriesClient: &InfluxClient{},
		Store: &DirectStore{
			LayoutsStore:            db.LayoutsStore,
			DashboardsStore:         db.DashboardsStore,
			SourcesStore:            db.SourcesStore,
			ServersStore:            db.ServersStore,
			OrganizationsStore:      db.OrganizationsStore,
			UsersStore:              db.UsersStore,
			ConfigStore:             db.ConfigStore,
			MappingsStore:           db.MappingsStore,
			OrganizationConfigStore: db.OrganizationConfigStore,
		},
		// TODO(desa): what to do about logger
		Logger: logger,
		Databases: &influx.Client{
			Logger: logger,
		},
	}, nil
}

func openService(ctx context.Context, buildInfo chronograf.BuildInfo, boltPath string, builder builders, logger chronograf.Logger, useAuth bool) Service {
	db := bolt.NewClient()
	db.Path = boltPath

	if err := db.Open(ctx, logger, buildInfo, bolt.WithBackup()); err != nil {
		logger.
			WithField("component", "boltstore").
			Error(err)
		os.Exit(1)
	}

	layouts, err := builder.Layouts.Build(db.LayoutsStore)
	if err != nil {
		logger.
			WithField("component", "LayoutsStore").
			Error("Unable to construct a MultiLayoutsStore", err)
		os.Exit(1)
	}

	dashboards, err := builder.Dashboards.Build(db.DashboardsStore)
	if err != nil {
		logger.
			WithField("component", "DashboardsStore").
			Error("Unable to construct a MultiDashboardsStore", err)
		os.Exit(1)
	}
	sources, err := builder.Sources.Build(db.SourcesStore)
	if err != nil {
		logger.
			WithField("component", "SourcesStore").
			Error("Unable to construct a MultiSourcesStore", err)
		os.Exit(1)
	}

	kapacitors, err := builder.Kapacitors.Build(db.ServersStore)
	if err != nil {
		logger.
			WithField("component", "KapacitorStore").
			Error("Unable to construct a MultiKapacitorStore", err)
		os.Exit(1)
	}

	organizations, err := builder.Organizations.Build(db.OrganizationsStore)
	if err != nil {
		logger.
			WithField("component", "OrganizationsStore").
			Error("Unable to construct a MultiOrganizationStore", err)
		os.Exit(1)
	}

	return Service{
		TimeSeriesClient: &InfluxClient{},
		Store: &Store{
			LayoutsStore:            layouts,
			DashboardsStore:         dashboards,
			SourcesStore:            sources,
			ServersStore:            kapacitors,
			OrganizationsStore:      organizations,
			UsersStore:              db.UsersStore,
			ConfigStore:             db.ConfigStore,
			MappingsStore:           db.MappingsStore,
			OrganizationConfigStore: db.OrganizationConfigStore,
		},
		Logger:    logger,
		UseAuth:   useAuth,
		Databases: &influx.Client{Logger: logger},
	}
}

// reportUsageStats starts periodic server reporting.
func reportUsageStats(bi chronograf.BuildInfo, logger chronograf.Logger) {
	rand.Seed(time.Now().UTC().UnixNano())
	serverID := strconv.FormatUint(uint64(rand.Int63()), 10)
	reporter := client.New("")
	values := client.Values{
		"os":         runtime.GOOS,
		"arch":       runtime.GOARCH,
		"version":    bi.Version,
		"cluster_id": serverID,
		"uptime":     time.Since(startTime).Seconds(),
	}
	l := logger.WithField("component", "usage").
		WithField("reporting_addr", reporter.URL).
		WithField("freq", "24h").
		WithField("stats", "os,arch,version,cluster_id,uptime")
	l.Info("Reporting usage stats")
	_, _ = reporter.Save(clientUsage(values))

	ticker := time.NewTicker(24 * time.Hour)
	defer ticker.Stop()
	for {
		<-ticker.C
		values["uptime"] = time.Since(startTime).Seconds()
		l.Debug("Reporting usage stats")
		go reporter.Save(clientUsage(values))
	}
}

func clientUsage(values client.Values) *client.Usage {
	return &client.Usage{
		Product: "chronograf-ng",
		Data: []client.UsageData{
			{
				Values: values,
			},
		},
	}
}

func validBasepath(basepath string) bool {
	re := regexp.MustCompile(`(\/{1}[\w-]+)+`)
	return re.ReplaceAllLiteralString(basepath, "") == ""
}