func main() {
	// set GPIO25 to output mode
	pin, err := gpio.OpenPin(rpi.GPIO25, gpio.ModeOutput)
	if err != nil {
		fmt.Printf("Error opening pin! %s\n", err)
		return
	}

	// turn the led off on exit
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func() {
		for _ = range c {
			fmt.Printf("\nClearing and unexporting the pin.\n")
			pin.Clear()
			pin.Close()
			os.Exit(0)
		}
	}()

	go buttonHandler(pin)

	// http listen
	//http.Handle("/button", websocket.Handler(EchoServer))
	http.HandleFunc("/button", func(w http.ResponseWriter, req *http.Request) {
		s := websocket.Server{Handler: websocket.Handler(EchoServer)}
		s.ServeHTTP(w, req)
	})
	http.ListenAndServe(":8080", nil)
}

// Authenticate a websocket before servicing it.
func AuthWebSocketHandler(h websocket.Handler) http.HandlerFunc {
	hndler := func(w http.ResponseWriter, r *http.Request) {
		if auth.TLSserver != nil && auth.Enabled {
			clive, err := r.Cookie("clive")
			if err != nil {
				cmd.Warn("wax/auth: no cookie: %s", err)
				http.Error(w, "auth failed", 403)
				return
			}
			toks := strings.SplitN(string(clive.Value), ":", 2)
			if len(toks) < 2 {
				cmd.Warn("wax/auth: wrong cookie")
				http.Error(w, "auth failed", 403)
				return
			}
			ch, resp := toks[0], toks[1]
			u, ok := auth.ChallengeResponseOk("wax", ch, resp)
			if !ok {
				cmd.Warn("wax/auth: failed for %s", u)
				http.Error(w, "auth failed", 403)
				return
			}
		}
		s := websocket.Server{Handler: h, Handshake: checkOrigin}
		s.ServeHTTP(w, r)
	}
	return hndler
}

// ServeHTTP will serve up connections as a websocket for the
// debug-log API.
//
// Args for the HTTP request are as follows:
//   includeEntity -> []string - lists entity tags to include in the response
//      - tags may finish with a '*' to match a prefix e.g.: unit-mysql-*, machine-2
//      - if none are set, then all lines are considered included
//   includeModule -> []string - lists logging modules to include in the response
//      - if none are set, then all lines are considered included
//   excludeEntity -> []string - lists entity tags to exclude from the response
//      - as with include, it may finish with a '*'
//   excludeModule -> []string - lists logging modules to exclude from the response
//   limit -> uint - show *at most* this many lines
//   backlog -> uint
//      - go back this many lines from the end before starting to filter
//      - has no meaning if 'replay' is true
//   level -> string one of [TRACE, DEBUG, INFO, WARNING, ERROR]
//   replay -> string - one of [true, false], if true, start the file from the start
func (h *debugLogHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	server := websocket.Server{
		Handler: func(conn *websocket.Conn) {
			socket := &debugLogSocketImpl{conn}
			defer socket.Close()

			logger.Infof("debug log handler starting")
			// Validate before authenticate because the authentication is
			// dependent on the state connection that is determined during the
			// validation.
			st, _, err := h.ctxt.stateForRequestAuthenticatedUser(req)
			if err != nil {
				socket.sendError(err)
				return
			}
			params, err := readDebugLogParams(req.URL.Query())
			if err != nil {
				socket.sendError(err)
				return
			}

			if err := h.handle(st, params, socket, h.stop); err != nil {
				if isBrokenPipe(err) {
					logger.Tracef("debug-log handler stopped (client disconnected)")
				} else {
					logger.Errorf("debug-log handler error: %v", err)
				}
			}
		},
	}
	server.ServeHTTP(w, req)
}

func (s *Server) wsContainersAttach(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
	if err := parseForm(r); err != nil {
		return err
	}
	if vars == nil {
		return fmt.Errorf("Missing parameter")
	}

	cont, err := s.daemon.Get(vars["name"])
	if err != nil {
		return err
	}

	h := websocket.Handler(func(ws *websocket.Conn) {
		defer ws.Close()

		wsAttachWithLogsConfig := &daemon.ContainerWsAttachWithLogsConfig{
			InStream:  ws,
			OutStream: ws,
			ErrStream: ws,
			Logs:      boolValue(r, "logs"),
			Stream:    boolValue(r, "stream"),
		}

		if err := s.daemon.ContainerWsAttachWithLogs(cont, wsAttachWithLogsConfig); err != nil {
			logrus.Errorf("Error attaching websocket: %s", err)
		}
	})
	ws := websocket.Server{Handler: h, Handshake: nil}
	ws.ServeHTTP(w, r)

	return nil
}

func (srv *Server) apiHandler(w http.ResponseWriter, req *http.Request) {
	addCount := func(delta int64) {
		atomic.AddInt64(&srv.connCount, delta)
	}

	addCount(1)
	defer addCount(-1)

	connectionID := atomic.AddUint64(&srv.lastConnectionID, 1)

	apiObserver := srv.newObserver()
	apiObserver.Join(req, connectionID)
	defer apiObserver.Leave()

	wsServer := websocket.Server{
		Handler: func(conn *websocket.Conn) {
			modelUUID := req.URL.Query().Get(":modeluuid")
			logger.Tracef("got a request for model %q", modelUUID)
			if err := srv.serveConn(conn, modelUUID, apiObserver, req.Host); err != nil {
				logger.Errorf("error serving RPCs: %v", err)
			}
		},
	}
	wsServer.ServeHTTP(w, req)
}

func (s *router) wsContainersAttach(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
	if err := httputils.ParseForm(r); err != nil {
		return err
	}
	containerName := vars["name"]

	if !s.daemon.Exists(containerName) {
		return derr.ErrorCodeNoSuchContainer.WithArgs(containerName)
	}

	h := websocket.Handler(func(ws *websocket.Conn) {
		defer ws.Close()

		wsAttachWithLogsConfig := &daemon.ContainerWsAttachWithLogsConfig{
			InStream:  ws,
			OutStream: ws,
			ErrStream: ws,
			Logs:      httputils.BoolValue(r, "logs"),
			Stream:    httputils.BoolValue(r, "stream"),
		}

		if err := s.daemon.ContainerWsAttachWithLogs(containerName, wsAttachWithLogsConfig); err != nil {
			logrus.Errorf("Error attaching websocket: %s", err)
		}
	})
	ws := websocket.Server{Handler: h, Handshake: nil}
	ws.ServeHTTP(w, r)

	return nil
}

// WSHandler is websocket end point
func WSHandler(w http.ResponseWriter, r *http.Request) {
	s := websocket.Server{Handler: websocket.Handler(
		func(ws *websocket.Conn) {
			connection := &webSocketConnection{ws: ws}

			// add connection
			manager.AddConnection(connection)
			defer func() {
				// delete connection
				manager.DelConnection(connection)
			}()

			for {
				// receive message
				message := new(Message)
				err := websocket.JSON.Receive(ws, message)
				if err != nil {
					// close event
					if err == io.EOF {
						return
					}

					log.Println(err)
				}
				log.Printf("client: %#v\n", message)
			}
		}),
	}
	s.ServeHTTP(w, r)
}

// ServeHTTP implements the http.Handler interface.
func (h *logSinkHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	server := websocket.Server{
		Handler: func(socket *websocket.Conn) {
			defer socket.Close()

			st, entity, err := h.ctxt.stateForRequestAuthenticatedAgent(req)
			if err != nil {
				h.sendError(socket, req, err)
				return
			}
			tag := entity.Tag()

			// Note that this endpoint is agent-only. Thus the only
			// callers will necessarily provide their Juju version.
			//
			// This would be a problem if non-Juju clients (e.g. the
			// GUI) could use this endpoint since we require that the
			// *Juju* version be provided as part of the request. Any
			// attempt to open this endpoint to broader access must
			// address this caveat appropriately.
			ver, err := jujuClientVersionFromReq(req)
			if err != nil {
				h.sendError(socket, req, err)
				return
			}

			filePrefix := st.ModelUUID() + " " + tag.String() + ":"
			dbLogger := state.NewDbLogger(st, tag, ver)
			defer dbLogger.Close()

			// If we get to here, no more errors to report, so we report a nil
			// error.  This way the first line of the socket is always a json
			// formatted simple error.
			h.sendError(socket, req, nil)

			logCh := h.receiveLogs(socket)
			for {
				select {
				case <-h.ctxt.stop():
					return
				case m := <-logCh:
					fileErr := h.logToFile(filePrefix, m)
					if fileErr != nil {
						logger.Errorf("logging to logsink.log failed: %v", fileErr)
					}
					level, _ := loggo.ParseLevel(m.Level)
					dbErr := dbLogger.Log(m.Time, m.Module, m.Location, level, m.Message)
					if dbErr != nil {
						logger.Errorf("logging to DB failed: %v", err)
					}
					if fileErr != nil || dbErr != nil {
						return
					}
				}
			}
		},
	}
	server.ServeHTTP(w, req)
}

func (srv *Server) serveAPI(w http.ResponseWriter, req *http.Request) {
	wsServer := websocket.Server{
		Handler: func(conn *websocket.Conn) {
			srv.serveConn(conn, req.URL.Query().Get(":modeluuid"))
		},
	}
	wsServer.ServeHTTP(w, req)
}

func (s *containerRouter) wsContainersAttach(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
	if err := httputils.ParseForm(r); err != nil {
		return err
	}
	containerName := vars["name"]

	var keys []byte
	var err error
	detachKeys := r.FormValue("detachKeys")
	if detachKeys != "" {
		keys, err = term.ToBytes(detachKeys)
		if err != nil {
			logrus.Warnf("Invalid escape keys provided (%s) using default : ctrl-p ctrl-q", detachKeys)
		}
	}

	done := make(chan struct{})
	started := make(chan struct{})

	setupStreams := func() (io.ReadCloser, io.Writer, io.Writer, error) {
		wsChan := make(chan *websocket.Conn)
		h := func(conn *websocket.Conn) {
			wsChan <- conn
			<-done
		}

		srv := websocket.Server{Handler: h, Handshake: nil}
		go func() {
			close(started)
			srv.ServeHTTP(w, r)
		}()

		conn := <-wsChan
		return conn, conn, conn, nil
	}

	attachConfig := &backend.ContainerAttachConfig{
		GetStreams: setupStreams,
		Logs:       httputils.BoolValue(r, "logs"),
		Stream:     httputils.BoolValue(r, "stream"),
		DetachKeys: keys,
		UseStdin:   true,
		UseStdout:  true,
		UseStderr:  true,
		MuxStreams: false, // TODO: this should be true since it's a single stream for both stdout and stderr
	}

	err = s.backend.ContainerAttach(containerName, attachConfig)
	close(done)
	select {
	case <-started:
		logrus.Errorf("Error attaching websocket: %s", err)
		return nil
	default:
	}
	return err
}

func (this *webScoketAdapter) webScoketHandlerAdapter(request *http.Request, pathFragments map[string]string, reply *Reply) {
	reply.startWebSocket()
	server := websocket.Server{Handler: func(conn *websocket.Conn) {
		defer func() {
			conn.Close()
		}()
		this.handler(request, pathFragments, &WebSocketReply{conn})
	}, Handshake: checkOrigin}
	server.ServeHTTP(reply.w, request)
}

// ServeHTTP implements the http.Handler interface.
func (h *logSinkHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	server := websocket.Server{
		Handler: func(socket *websocket.Conn) {
			defer socket.Close()
			// Validate before authenticate because the authentication is
			// dependent on the state connection that is determined during the
			// validation.
			stateWrapper, err := h.validateEnvironUUID(req)
			if err != nil {
				if errErr := h.sendError(socket, err); errErr != nil {
					// Log at DEBUG so that in a standard environment
					// logs cant't fill up with auth errors for
					// unauthenticated connections.
					logger.Debugf("error sending logsink error: %v", errErr)
				}
				return
			}
			defer stateWrapper.cleanup()

			tag, err := stateWrapper.authenticateAgent(req)
			if err != nil {
				if errErr := h.sendError(socket, errors.Errorf("auth failed: %v", err)); errErr != nil {
					// DEBUG used as above.
					logger.Debugf("error sending logsink error: %v", errErr)
				}
				return
			}

			// If we get to here, no more errors to report, so we report a nil
			// error.  This way the first line of the socket is always a json
			// formatted simple error.
			if err := h.sendError(socket, nil); err != nil {
				logger.Errorf("failed to send nil error at start of connection")
				return
			}

			dbLogger := state.NewDbLogger(stateWrapper.state, tag)
			defer dbLogger.Close()
			var m LogMessage
			for {
				if err := websocket.JSON.Receive(socket, &m); err != nil {
					if err != io.EOF {
						logger.Errorf("error while receiving logs: %v", err)
					}
					break
				}
				if err := dbLogger.Log(m.Time, m.Module, m.Location, m.Level, m.Message); err != nil {
					logger.Errorf("logging to DB failed: %v", err)
					break
				}
			}
		}}
	server.ServeHTTP(w, req)
}

func (this *Transport) Listen(ch drs.ConnectionHandler) error {
	http.HandleFunc("/socket", func(w http.ResponseWriter, req *http.Request) {
		s := websocket.Server{
			Handler: websocket.Handler(func(ws *websocket.Conn) {
				ch(ws)
			}),
		}
		s.ServeHTTP(w, req)
	})
	return http.ListenAndServe(":12000", nil)
}

// WEBSOCKET adds a WebSocket route > handler to the router. Use the helper
// function FromContextWebsocket() to extract the websocket.Conn in your HandlerFunc
// from the context.
func (r *Router) WEBSOCKET(path string, h ctxhttp.HandlerFunc) {
	r.GET(path, func(ctx context.Context, w http.ResponseWriter, r *http.Request) (err error) {
		wss := websocket.Server{
			Handler: func(ws *websocket.Conn) {
				w.WriteHeader(http.StatusSwitchingProtocols)
				err = h(withContextWebsocket(ctx, ws), w, r)
			},
		}
		wss.ServeHTTP(w, r)
		return err
	})
}

// This example demonstrates a trivial echo server.
func main() {
	fmt.Println("before")
	ws := websocket.Server{}
	ws.Handshake = hs
	ws.Handler = echoServer
	http.Handle("/images/", http.StripPrefix("/images/", http.FileServer(http.Dir("./static"))))
	http.Handle("/websockets/v3", ws)
	fmt.Println("assigned")
	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		panic("ListenAndServe: " + err.Error())
	}
}

// WebSocket adds a WebSocket route > handler to the router.
func (e *Echo) WebSocket(path string, h HandlerFunc) {
	e.Get(path, func(c *Context) (err error) {
		wss := websocket.Server{
			Handler: func(ws *websocket.Conn) {
				c.socket = ws
				c.response.status = http.StatusSwitchingProtocols
				err = h(c)
			},
		}
		wss.ServeHTTP(c.response, c.request)
		return err
	})
}

func main() {
	seed := time.Now().UTC().UnixNano()
	rand.Seed(seed)

	Config = load("config.json")

	//http.Handle("/", websocket.Handler(wsHandler))
	http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
		s := websocket.Server{Handler: websocket.Handler(wsHandler)}
		s.ServeHTTP(w, req)
	})

	delay, _ := time.ParseDuration(Config.Delay)
	interval, _ := time.ParseDuration(Config.Interval)
	timer := time.NewTimer(delay)
	if !Config.OnlyTestConnect {
		go func() {
			for {
				<-timer.C
				timer.Reset(interval)
				totalLen := 0
				for i := 0; i < n; i++ {
					totalLen += wsList[i].Len()
				}
				if totalLen >= Config.TotalSize {
					fmt.Println("send timestamp to all")
					for i := 0; i < n; i++ {
						for e := wsList[i].Front(); e != nil; e = e.Next() {
							var ws = e.Value.(*websocket.Conn)
							now := time.Now().UnixNano() / int64(time.Millisecond)
							err := websocket.Message.Send(ws, strconv.FormatInt(now, 10))
							if err != nil {
								panic("Error: " + err.Error())
							}
						}
					}
				} else {
					fmt.Println("current websockets: " + strconv.Itoa(totalLen))
				}

			}
		}()
	}

	err := http.ListenAndServe(":"+strconv.Itoa(Config.Port), nil)
	if err != nil {
		panic("Error: " + err.Error())
	}
}

func (srv *Server) apiHandler(w http.ResponseWriter, req *http.Request) {
	reqNotifier := newRequestNotifier(&srv.connections)
	reqNotifier.join(req)
	defer reqNotifier.leave()
	wsServer := websocket.Server{
		Handler: func(conn *websocket.Conn) {
			modelUUID := req.URL.Query().Get(":modeluuid")
			logger.Tracef("got a request for model %q", modelUUID)
			if err := srv.serveConn(conn, reqNotifier, modelUUID); err != nil {
				logger.Errorf("error serving RPCs: %v", err)
			}
		},
	}
	wsServer.ServeHTTP(w, req)
}

func managementInterface() {
	http.Handle("/", http.FileServer(http.Dir("/var/www")))
	http.HandleFunc("/control",
		func(w http.ResponseWriter, req *http.Request) {
			s := websocket.Server{
				Handler: websocket.Handler(handleManagementConnection)}
			s.ServeHTTP(w, req)
		})

	err := http.ListenAndServe(managementAddr, nil)

	if err != nil {
		log.Printf("managementInterface ListenAndServe: %s\n", err.Error())
	}
}

func (h *handler) sendContinuousChangesByWebSocket(inChannels base.Set, options db.ChangesOptions) error {
	handler := func(conn *websocket.Conn) {
		h.logStatus(101, "Upgraded to WebSocket protocol")
		defer func() {
			conn.Close()
			base.LogTo("HTTP+", "#%03d:     --> WebSocket closed", h.serialNumber)
		}()

		// Read changes-feed options from an initial incoming WebSocket message in JSON format:
		if msg, err := readWebSocketMessage(conn); err != nil {
			return
		} else {
			var channelNames []string
			var err error
			if _, options, _, channelNames, err = h.readChangesOptionsFromJSON(msg); err != nil {
				return
			}
			if channelNames != nil {
				inChannels, _ = channels.SetFromArray(channelNames, channels.ExpandStar)
			}
		}

		options.Terminator = make(chan bool)
		defer close(options.Terminator)

		caughtUp := false
		h.generateContinuousChanges(inChannels, options, func(changes []*db.ChangeEntry) error {
			var data []byte
			if changes != nil {
				data, _ = json.Marshal(changes)
			} else if !caughtUp {
				caughtUp = true
				data, _ = json.Marshal([]*db.ChangeEntry{})
			} else {
				data = []byte{}
			}
			_, err := conn.Write(data)
			return err
		})
	}
	server := websocket.Server{
		Handshake: func(*websocket.Config, *http.Request) error { return nil },
		Handler:   handler,
	}
	server.ServeHTTP(h.response, h.rq)
	return nil
}