package main

import (
	"embed"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/google/uuid"
	"github.com/gorilla/csrf"
	"imuslab.com/zoraxy/mod/access"
	"imuslab.com/zoraxy/mod/acme"
	"imuslab.com/zoraxy/mod/auth"
	"imuslab.com/zoraxy/mod/auth/sso"
	"imuslab.com/zoraxy/mod/database"
	"imuslab.com/zoraxy/mod/dockerux"
	"imuslab.com/zoraxy/mod/dynamicproxy/loadbalance"
	"imuslab.com/zoraxy/mod/dynamicproxy/redirection"
	"imuslab.com/zoraxy/mod/email"
	"imuslab.com/zoraxy/mod/forwardproxy"
	"imuslab.com/zoraxy/mod/ganserv"
	"imuslab.com/zoraxy/mod/geodb"
	"imuslab.com/zoraxy/mod/info/logger"
	"imuslab.com/zoraxy/mod/info/logviewer"
	"imuslab.com/zoraxy/mod/mdns"
	"imuslab.com/zoraxy/mod/netstat"
	"imuslab.com/zoraxy/mod/pathrule"
	"imuslab.com/zoraxy/mod/sshprox"
	"imuslab.com/zoraxy/mod/statistic"
	"imuslab.com/zoraxy/mod/statistic/analytic"
	"imuslab.com/zoraxy/mod/streamproxy"
	"imuslab.com/zoraxy/mod/tlscert"
	"imuslab.com/zoraxy/mod/update"
	"imuslab.com/zoraxy/mod/uptime"
	"imuslab.com/zoraxy/mod/utils"
	"imuslab.com/zoraxy/mod/webserv"
)

// General flags
var webUIPort = flag.String("port", ":8000", "Management web interface listening port")
var noauth = flag.Bool("noauth", false, "Disable authentication for management interface")
var showver = flag.Bool("version", false, "Show version of this server")
var allowSshLoopback = flag.Bool("sshlb", false, "Allow loopback web ssh connection (DANGER)")
var allowMdnsScanning = flag.Bool("mdns", true, "Enable mDNS scanner and transponder")
var mdnsName = flag.String("mdnsname", "", "mDNS name, leave empty to use default (zoraxy_{node-uuid}.local)")
var ztAuthToken = flag.String("ztauth", "", "ZeroTier authtoken for the local node")
var ztAPIPort = flag.Int("ztport", 9993, "ZeroTier controller API port")
var runningInDocker = flag.Bool("docker", false, "Run Zoraxy in docker compatibility mode")
var acmeAutoRenewInterval = flag.Int("autorenew", 86400, "ACME auto TLS/SSL certificate renew check interval (seconds)")
var acmeCertAutoRenewDays = flag.Int("earlyrenew", 30, "Number of days to early renew a soon expiring certificate (days)")
var enableHighSpeedGeoIPLookup = flag.Bool("fastgeoip", false, "Enable high speed geoip lookup, require 1GB extra memory (Not recommend for low end devices)")
var staticWebServerRoot = flag.String("webroot", "./www", "Static web server root folder. Only allow chnage in start paramters")
var allowWebFileManager = flag.Bool("webfm", true, "Enable web file manager for static web server root folder")
var enableAutoUpdate = flag.Bool("cfgupgrade", true, "Enable auto config upgrade if breaking change is detected")

var (
	name        = "Zoraxy"
	version     = "3.1.2"
	nodeUUID    = "generic" //System uuid, in uuidv4 format
	development = true      //Set this to false to use embedded web fs
	bootTime    = time.Now().Unix()

	/*
		Binary Embedding File System
	*/
	//go:embed web/*
	webres embed.FS

	/*
		Handler Modules
	*/
	sysdb          *database.Database              //System database
	authAgent      *auth.AuthAgent                 //Authentication agent
	tlsCertManager *tlscert.Manager                //TLS / SSL management
	redirectTable  *redirection.RuleTable          //Handle special redirection rule sets
	webminPanelMux *http.ServeMux                  //Server mux for handling webmin panel APIs
	csrfMiddleware func(http.Handler) http.Handler //CSRF protection middleware

	pathRuleHandler    *pathrule.Handler         //Handle specific path blocking or custom headers
	geodbStore         *geodb.Store              //GeoIP database, for resolving IP into country code
	accessController   *access.Controller        //Access controller, handle black list and white list
	netstatBuffers     *netstat.NetStatBuffers   //Realtime graph buffers
	statisticCollector *statistic.Collector      //Collecting statistic from visitors
	uptimeMonitor      *uptime.Monitor           //Uptime monitor service worker
	mdnsScanner        *mdns.MDNSHost            //mDNS discovery services
	ganManager         *ganserv.NetworkManager   //Global Area Network Manager
	webSshManager      *sshprox.Manager          //Web SSH connection service
	streamProxyManager *streamproxy.Manager      //Stream Proxy Manager for TCP / UDP forwarding
	acmeHandler        *acme.ACMEHandler         //Handler for ACME Certificate renew
	acmeAutoRenewer    *acme.AutoRenewer         //Handler for ACME auto renew ticking
	staticWebServer    *webserv.WebServer        //Static web server for hosting simple stuffs
	forwardProxy       *forwardproxy.Handler     //HTTP Forward proxy, basically VPN for web browser
	loadBalancer       *loadbalance.RouteManager //Global scope loadbalancer, store the state of the lb routing
	ssoHandler         *sso.SSOHandler           //Single Sign On handler

	//Helper modules
	EmailSender       *email.Sender         //Email sender that handle email sending
	AnalyticLoader    *analytic.DataLoader  //Data loader for Zoraxy Analytic
	DockerUXOptimizer *dockerux.UXOptimizer //Docker user experience optimizer, community contribution only
	SystemWideLogger  *logger.Logger        //Logger for Zoraxy
	LogViewer         *logviewer.Viewer
)

// Kill signal handler. Do something before the system the core terminate.
func SetupCloseHandler() {
	c := make(chan os.Signal, 2)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
	go func() {
		<-c
		ShutdownSeq()
		os.Exit(0)
	}()
}

func ShutdownSeq() {
	SystemWideLogger.Println("Shutting down " + name)
	//SystemWideLogger.Println("Closing GeoDB")
	//geodbStore.Close()
	SystemWideLogger.Println("Closing Netstats Listener")
	netstatBuffers.Close()
	SystemWideLogger.Println("Closing Statistic Collector")
	statisticCollector.Close()
	if mdnsTickerStop != nil {
		SystemWideLogger.Println("Stopping mDNS Discoverer (might take a few minutes)")
		// Stop the mdns service
		mdnsTickerStop <- true
	}
	mdnsScanner.Close()
	SystemWideLogger.Println("Shutting down load balancer")
	loadBalancer.Close()
	SystemWideLogger.Println("Closing Certificates Auto Renewer")
	acmeAutoRenewer.Close()
	//Remove the tmp folder
	SystemWideLogger.Println("Cleaning up tmp files")
	os.RemoveAll("./tmp")

	//Close database
	SystemWideLogger.Println("Stopping system database")
	sysdb.Close()

	//Close logger
	SystemWideLogger.Println("Closing system wide logger")
	SystemWideLogger.Close()
}

func main() {
	//Parse startup flags
	flag.Parse()
	if *showver {
		fmt.Println(name + " - Version " + version)
		os.Exit(0)
	}

	if !utils.ValidateListeningAddress(*webUIPort) {
		fmt.Println("Malformed -port (listening address) paramter. Do you mean -port=:" + *webUIPort + "?")
		os.Exit(0)
	}

	if *enableAutoUpdate {
		fmt.Println("Checking required config update")
		update.RunConfigUpdate(0, update.GetVersionIntFromVersionNumber(version))
	}

	SetupCloseHandler()

	//Read or create the system uuid
	uuidRecord := "./sys.uuid"
	if !utils.FileExists(uuidRecord) {
		newSystemUUID := uuid.New().String()
		os.WriteFile(uuidRecord, []byte(newSystemUUID), 0775)
	}
	uuidBytes, err := os.ReadFile(uuidRecord)
	if err != nil {
		SystemWideLogger.PrintAndLog("ZeroTier", "Unable to read system uuid from file system", nil)
		panic(err)
	}
	nodeUUID = string(uuidBytes)

	//Create a new webmin mux and csrf middleware layer
	webminPanelMux = http.NewServeMux()
	csrfMiddleware = csrf.Protect(
		[]byte(nodeUUID),
		csrf.CookieName("zoraxy-csrf"),
		csrf.Secure(false),
		csrf.Path("/"),
		csrf.SameSite(csrf.SameSiteLaxMode),
	)

	//Startup all modules
	startupSequence()

	//Initiate management interface APIs
	requireAuth = !(*noauth)
	initAPIs(webminPanelMux)

	//Start the reverse proxy server in go routine
	go func() {
		ReverseProxtInit()
	}()

	time.Sleep(500 * time.Millisecond)

	//Start the finalize sequences
	finalSequence()

	SystemWideLogger.Println("Zoraxy started. Visit control panel at http://localhost" + *webUIPort)
	err = http.ListenAndServe(*webUIPort, csrfMiddleware(webminPanelMux))

	if err != nil {
		log.Fatal(err)
	}

}