stratux/main/managementinterface.go

/*
	Copyright (c) 2015-2016 Christopher Young
	Distributable under the terms of The "BSD New"" License
	that can be found in the LICENSE file, herein included
	as part of this header.

	managementinterface.go: Web interfaces (JSON and websocket), web server for web interface HTML.
*/

package main

import (
	"encoding/hex"
	"encoding/json"
	"fmt"
	"golang.org/x/net/websocket"
	"io"
	"log"
	"net/http"
	"strings"
	"syscall"
	"time"
)

type SettingMessage struct {
	Setting string `json:"setting"`
	Value   bool   `json:"state"`
}

// Weather updates channel.
var weatherUpdate *uibroadcaster
var trafficUpdate *uibroadcaster

/*
	The /weather websocket starts off by sending the current buffer of weather messages, then sends updates as they are received.
*/

func handleWeatherWS(conn *websocket.Conn) {
	// Subscribe the socket to receive updates.
	weatherUpdate.AddSocket(conn)

	// Connection closes when function returns. Since uibroadcast is writing and we don't need to read anything (for now), just keep it busy.
	for {
		buf := make([]byte, 1024)
		_, err := conn.Read(buf)
		if err != nil {
			break
		}
		if buf[0] != 0 { // Dummy.
			continue
		}
		time.Sleep(1 * time.Second)
	}
}

// Works just as weather updates do.

func handleTrafficWS(conn *websocket.Conn) {
	trafficMutex.Lock()
	for _, traf := range traffic {
		if !traf.Position_valid { // Don't send unless a valid position exists.
			continue
		}
		trafficJSON, _ := json.Marshal(&traf)
		conn.Write(trafficJSON)
	}
	// Subscribe the socket to receive updates.
	trafficUpdate.AddSocket(conn)
	trafficMutex.Unlock()

	// Connection closes when function returns. Since uibroadcast is writing and we don't need to read anything (for now), just keep it busy.
	for {
		buf := make([]byte, 1024)
		_, err := conn.Read(buf)
		if err != nil {
			break
		}
		if buf[0] != 0 { // Dummy.
			continue
		}
		time.Sleep(1 * time.Second)
	}
}

func handleStatusWS(conn *websocket.Conn) {
	//	log.Printf("Web client connected.\n")

	timer := time.NewTicker(1 * time.Second)
	for {
		// The below is not used, but should be if something needs to be streamed from the web client ever in the future.
		/*		var msg SettingMessage
				err := websocket.JSON.Receive(conn, &msg)
				if err == io.EOF {
					break
				} else if err != nil {
					log.Printf("handleStatusWS: %s\n", err.Error())
				} else {
					// Use 'msg'.
				}
		*/

		// Send status.
		<-timer.C
		update, _ := json.Marshal(&globalStatus)
		_, err := conn.Write(update)

		if err != nil {
			//			log.Printf("Web client disconnected.\n")
			break
		}
	}
}

func handleSituationWS(conn *websocket.Conn) {
	timer := time.NewTicker(100 * time.Millisecond)
	for {
		<-timer.C
		situationJSON, _ := json.Marshal(&mySituation)
		_, err := conn.Write(situationJSON)

		if err != nil {
			break
		}

	}

}

// AJAX call - /getStatus. Responds with current global status
// a webservice call for the same data available on the websocket but when only a single update is needed
func handleStatusRequest(w http.ResponseWriter, r *http.Request) {
	setNoCache(w)
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Content-Type", "application/json")
	statusJSON, _ := json.Marshal(&globalStatus)
	fmt.Fprintf(w, "%s\n", statusJSON)
}

// AJAX call - /getSituation. Responds with current situation (lat/lon/gdspeed/track/pitch/roll/heading/etc.)
func handleSituationRequest(w http.ResponseWriter, r *http.Request) {
	setNoCache(w)
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Content-Type", "application/json")
	situationJSON, _ := json.Marshal(&mySituation)
	fmt.Fprintf(w, "%s\n", situationJSON)
}

// AJAX call - /getTowers. Responds with all ADS-B ground towers that have sent messages that we were able to parse, along with its stats.
func handleTowersRequest(w http.ResponseWriter, r *http.Request) {
	setNoCache(w)
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Content-Type", "application/json")
	towersJSON, _ := json.Marshal(&ADSBTowers)
	// for testing purposes, we can return a fixed reply
	// towersJSON = []byte(`{"(38.490880,-76.135554)":{"Lat":38.49087953567505,"Lng":-76.13555431365967,"Signal_strength_last_minute":100,"Signal_strength_max":67,"Messages_last_minute":1,"Messages_total":1059},"(38.978698,-76.309276)":{"Lat":38.97869825363159,"Lng":-76.30927562713623,"Signal_strength_last_minute":495,"Signal_strength_max":32,"Messages_last_minute":45,"Messages_total":83},"(39.179285,-76.668413)":{"Lat":39.17928457260132,"Lng":-76.66841268539429,"Signal_strength_last_minute":50,"Signal_strength_max":24,"Messages_last_minute":1,"Messages_total":16},"(39.666309,-74.315300)":{"Lat":39.66630935668945,"Lng":-74.31529998779297,"Signal_strength_last_minute":9884,"Signal_strength_max":35,"Messages_last_minute":4,"Messages_total":134}}`)
	fmt.Fprintf(w, "%s\n", towersJSON)
}

// AJAX call - /getSettings. Responds with all stratux.conf data.
func handleSettingsGetRequest(w http.ResponseWriter, r *http.Request) {
	setNoCache(w)
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Content-Type", "application/json")
	settingsJSON, _ := json.Marshal(&globalSettings)
	fmt.Fprintf(w, "%s\n", settingsJSON)
}

// AJAX call - /setSettings. receives via POST command, any/all stratux.conf data.
func handleSettingsSetRequest(w http.ResponseWriter, r *http.Request) {
	// define header in support of cross-domain AJAX
	setNoCache(w)
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Method", "GET, POST, OPTIONS")
	w.Header().Set("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept")
	w.Header().Set("Content-Type", "application/json")

	// for an OPTION method request, we return header without processing.
	// this insures we are recognized as supporting cross-domain AJAX REST calls
	if r.Method == "POST" {
		// raw, _ := httputil.DumpRequest(r, true)
		// log.Printf("handleSettingsSetRequest:raw: %s\n", raw)

		decoder := json.NewDecoder(r.Body)
		for {
			var msg map[string]interface{} // support arbitrary JSON

			err := decoder.Decode(&msg)
			if err == io.EOF {
				break
			} else if err != nil {
				log.Printf("handleSettingsSetRequest:error: %s\n", err.Error())
			} else {
				for key, val := range msg {
					// log.Printf("handleSettingsSetRequest:json: testing for key:%s of type %s\n", key, reflect.TypeOf(val))
					switch key {
					case "UAT_Enabled":
						globalSettings.UAT_Enabled = val.(bool)
					case "ES_Enabled":
						globalSettings.ES_Enabled = val.(bool)
					case "GPS_Enabled":
						globalSettings.GPS_Enabled = val.(bool)
					case "AHRS_Enabled":
						globalSettings.AHRS_Enabled = val.(bool)
					case "DEBUG":
						globalSettings.DEBUG = val.(bool)
					case "ReplayLog":
						v := val.(bool)
						if v != globalSettings.ReplayLog { // Don't mark the files unless there is a change.
							globalSettings.ReplayLog = v
							replayMark(v)
						}
					case "PPM":
						globalSettings.PPM = int(val.(float64))
					case "WatchList":
						globalSettings.WatchList = val.(string)
					case "OwnshipModeS":
						// Expecting a hex string less than 6 characters (24 bits) long.
						if len(val.(string)) > 6 { // Too long.
							continue
						}
						// Pad string, must be 6 characters long.
						vals := strings.ToUpper(val.(string))
						for len(vals) < 6 {
							vals = "0" + vals
						}
						hexn, err := hex.DecodeString(vals)
						if err != nil { // Number not valid.
							log.Printf("handleSettingsSetRequest:OwnshipModeS: %s\n", err.Error())
							continue
						}
						globalSettings.OwnshipModeS = fmt.Sprintf("%02X%02X%02X", hexn[0], hexn[1], hexn[2])
					default:
						log.Printf("handleSettingsSetRequest:json: unrecognized key:%s\n", key)
					}
				}
				saveSettings()
			}
		}

		// while it may be redundent, we return the latest settings
		settingsJSON, _ := json.Marshal(&globalSettings)
		fmt.Fprintf(w, "%s\n", settingsJSON)
	}
}

func handleShutdownRequest(w http.ResponseWriter, r *http.Request) {
	syscall.Sync()
	syscall.Reboot(syscall.LINUX_REBOOT_CMD_POWER_OFF)
}

func handleRebootRequest(w http.ResponseWriter, r *http.Request) {
	syscall.Sync()
	syscall.Reboot(syscall.LINUX_REBOOT_CMD_RESTART)
}

func setNoCache(w http.ResponseWriter) {
	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
	w.Header().Set("Pragma", "no-cache")
	w.Header().Set("Expires", "0")
}

func defaultServer(w http.ResponseWriter, r *http.Request) {
	setNoCache(w)

	http.FileServer(http.Dir("/var/www")).ServeHTTP(w, r)
}

func managementInterface() {
	weatherUpdate = NewUIBroadcaster()
	trafficUpdate = NewUIBroadcaster()

	http.HandleFunc("/", defaultServer)
	http.Handle("/logs/", http.StripPrefix("/logs/", http.FileServer(http.Dir("/var/log"))))
	http.HandleFunc("/status",
		func(w http.ResponseWriter, req *http.Request) {
			s := websocket.Server{
				Handler: websocket.Handler(handleStatusWS)}
			s.ServeHTTP(w, req)
		})
	http.HandleFunc("/situation",
		func(w http.ResponseWriter, req *http.Request) {
			s := websocket.Server{
				Handler: websocket.Handler(handleSituationWS)}
			s.ServeHTTP(w, req)
		})
	http.HandleFunc("/weather",
		func(w http.ResponseWriter, req *http.Request) {
			s := websocket.Server{
				Handler: websocket.Handler(handleWeatherWS)}
			s.ServeHTTP(w, req)
		})
	http.HandleFunc("/traffic",
		func(w http.ResponseWriter, req *http.Request) {
			s := websocket.Server{
				Handler: websocket.Handler(handleTrafficWS)}
			s.ServeHTTP(w, req)
		})

	http.HandleFunc("/getStatus", handleStatusRequest)
	http.HandleFunc("/getSituation", handleSituationRequest)
	http.HandleFunc("/getTowers", handleTowersRequest)
	http.HandleFunc("/getSettings", handleSettingsGetRequest)
	http.HandleFunc("/setSettings", handleSettingsSetRequest)
	http.HandleFunc("/shutdown", handleShutdownRequest)
	http.HandleFunc("/reboot", handleRebootRequest)

	err := http.ListenAndServe(managementAddr, nil)

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