package cmd

import (
	"errors"
	"fmt"
	"net/http"
	_ "net/http/pprof" // pprof handler
	"os"
	"os/signal"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/evcc-io/evcc/cmd/shutdown"
	"github.com/evcc-io/evcc/core"
	"github.com/evcc-io/evcc/push"
	"github.com/evcc-io/evcc/server"
	"github.com/evcc-io/evcc/server/updater"
	"github.com/evcc-io/evcc/util"
	"github.com/evcc-io/evcc/util/pipe"
	"github.com/evcc-io/evcc/util/sponsor"
	"github.com/prometheus/client_golang/prometheus/promhttp"

	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var (
	log     = util.NewLogger("main")
	cfgFile string

	ignoreErrors = []string{"warn", "error"}        // don't add to cache
	ignoreMqtt   = []string{"auth", "releaseNotes"} // excessive size may crash certain brokers
)

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
	Use:     "evcc",
	Short:   "EV Charge Controller",
	Version: server.FormattedVersion(),
	Run:     runRoot,
}

func init() {
	cobra.OnInitialize(initConfig)

	// global options
	rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "Config file (default \"~/evcc.yaml\" or \"/etc/evcc.yaml\")")

	rootCmd.PersistentFlags().BoolP("help", "h", false, "Help")

	rootCmd.PersistentFlags().Bool(flagHeaders, false, flagHeadersDescription)

	// config file options
	rootCmd.PersistentFlags().StringP("log", "l", "info", "Log level (fatal, error, warn, info, debug, trace)")
	bindP(rootCmd, "log", "log")

	rootCmd.Flags().Bool("metrics", false, "Expose metrics")
	bind(rootCmd, "metrics", "metrics")

	rootCmd.Flags().Bool("profile", false, "Expose pprof profiles")
	bind(rootCmd, "profile", "profile")
}

// initConfig reads in config file and ENV variables if set
func initConfig() {
	if cfgFile != "" {
		// Use config file from the flag
		viper.SetConfigFile(cfgFile)
	} else {
		// Search for config in home directory if available
		if home, err := os.UserHomeDir(); err == nil {
			viper.AddConfigPath(home)
		}

		// Search config in home directory with name "mbmd" (without extension).
		viper.AddConfigPath(".")    // optionally look for config in the working directory
		viper.AddConfigPath("/etc") // path to look for the config file in

		viper.SetConfigName("evcc")
	}

	viper.AutomaticEnv() // read in environment variables that match
}

// Execute adds all child commands to the root command and sets flags appropriately.
func Execute() {
	if err := rootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

var valueChan chan util.Param

func publish(key string, val any) {
	valueChan <- util.Param{Key: key, Val: val}
}

func unwrap(err error) (res []string) {
	for err != nil {
		inner := errors.Unwrap(err)
		if inner == nil {
			res = append(res, err.Error())
		} else {
			cur := strings.TrimSuffix(err.Error(), ": "+inner.Error())
			cur = strings.TrimSuffix(cur, inner.Error())
			res = append(res, strings.TrimSpace(cur))
		}
		err = inner
	}
	return
}

func redact(src string) string {
	secrets := []string{
		"url", "uri", "host", "broker", "mac", // infrastructure
		"sponsortoken", "plant", // global settings
		"user", "password", "pin", // users
		"token", "access", "refresh", // tokens
		"ain", "id", "secret", "serial", "deviceid", "machineid", // devices
		"vin"} // vehicles
	return regexp.
		MustCompile(fmt.Sprintf(`\b(%s)\b.*?:.*`, strings.Join(secrets, "|"))).
		ReplaceAllString(src, "$1: *****")
}

func publishErrorInfo(cfgFile string, err error) {
	if cfgFile != "" {
		file, pathErr := filepath.Abs(cfgFile)
		if pathErr != nil {
			file = cfgFile
		}
		publish("file", file)

		if src, fileErr := os.ReadFile(cfgFile); fileErr != nil {
			log.ERROR.Println("could not open config file:", fileErr)
		} else {
			publish("config", redact(string(src)))

			// find line number
			if match := regexp.MustCompile(`yaml: line (\d+):`).FindStringSubmatch(err.Error()); len(match) == 2 {
				if line, err := strconv.Atoi(match[1]); err == nil {
					publish("line", line)
				}
			}
		}
	}

	publish("fatal", unwrap(err))
}

func runRoot(cmd *cobra.Command, args []string) {
	util.LogLevel(viper.GetString("log"), viper.GetStringMapString("levels"))
	log.INFO.Printf("evcc %s", server.FormattedVersion())

	// load config and re-configure logging after reading config file
	var err error
	if cfgErr := loadConfigFile(&conf); errors.As(cfgErr, &viper.ConfigFileNotFoundError{}) {
		log.INFO.Println("missing config file - switching into demo mode")
		demoConfig(&conf)
	} else {
		err = cfgErr
	}

	util.LogLevel(viper.GetString("log"), viper.GetStringMapString("levels"))

	// network config
	if viper.GetString("uri") != "" {
		log.WARN.Println("`uri` is deprecated and will be ignored. Use `network` instead.")
	}

	log.INFO.Printf("listening at :%d", conf.Network.Port)

	// start broadcasting values
	tee := new(util.Tee)

	// value cache
	cache := util.NewCache()
	go cache.Run(pipe.NewDropper(ignoreErrors...).Pipe(tee.Attach()))

	// create web server
	socketHub := server.NewSocketHub()
	httpd := server.NewHTTPd(fmt.Sprintf(":%d", conf.Network.Port), socketHub)

	// metrics
	if viper.GetBool("metrics") {
		httpd.Router().Handle("/metrics", promhttp.Handler())
	}

	// pprof
	if viper.GetBool("profile") {
		httpd.Router().PathPrefix("/debug/").Handler(http.DefaultServeMux)
	}

	// publish to UI
	go socketHub.Run(tee.Attach(), cache)

	// setup values channel
	valueChan = make(chan util.Param)
	go tee.Run(valueChan)

	// setup environment
	if err == nil {
		err = configureEnvironment(cmd, conf)
	}

	// setup session log
	if err == nil && conf.Database.Dsn != "" {
		err = configureDatabase(conf.Database)
	}

	// setup site and loadpoints
	var site *core.Site
	if err == nil {
		cp.TrackVisitors() // track duplicate usage
		site, err = configureSiteAndLoadpoints(conf)
	}

	// setup database
	if err == nil && conf.Influx.URL != "" {
		configureInflux(conf.Influx, site.LoadPoints(), tee.Attach())
	}

	// setup mqtt publisher
	if err == nil && conf.Mqtt.Broker != "" {
		publisher := server.NewMQTT(strings.Trim(conf.Mqtt.Topic, "/"))
		go publisher.Run(site, pipe.NewDropper(ignoreMqtt...).Pipe(tee.Attach()))
	}

	// announce on mDNS
	if err == nil && strings.HasSuffix(conf.Network.Host, ".local") {
		err = configureMDNS(conf.Network)
	}

	// start HEMS server
	if err == nil && conf.HEMS.Type != "" {
		err = configureHEMS(conf.HEMS, site, httpd)
	}

	// setup messaging
	var pushChan chan push.Event
	if err == nil {
		pushChan, err = configureMessengers(conf.Messaging, cache)
	}

	stopC := make(chan struct{})
	go shutdown.Run(stopC)

	siteC := make(chan struct{})

	// show main ui
	if err == nil {
		httpd.RegisterSiteHandlers(site, cache)

		// set channels
		site.DumpConfig()
		site.Prepare(valueChan, pushChan)

		// version check
		go updater.Run(log, httpd, tee, valueChan)

		// capture log messages for UI
		util.CaptureLogs(valueChan)

		// expose sponsor to UI
		if sponsor.Subject != "" {
			publish("sponsor", sponsor.Subject)
		}

		// allow web access for vehicles
		cp.webControl(conf.Network, httpd.Router(), valueChan)

		go func() {
			site.Run(stopC, conf.Interval)
			close(siteC)
		}()
	} else {
		var once sync.Once
		httpd.RegisterShutdownHandler(func() {
			once.Do(func() {
				log.FATAL.Println("evcc was stopped. OS should restart the service. Or restart manually.")
				close(siteC)
			})
		})

		// delayed reboot on error
		const rebootDelay = 5 * time.Minute

		log.FATAL.Println(err)
		log.FATAL.Printf("will attempt restart in: %v", rebootDelay)

		publishErrorInfo(cfgFile, err)

		go func() {
			select {
			case <-time.After(rebootDelay):
			case <-siteC:
			}
			os.Exit(1)
		}()
	}

	// uds health check listener
	go server.HealthListener(site, siteC)

	// catch signals
	go func() {
		signalC := make(chan os.Signal, 1)
		signal.Notify(signalC, os.Interrupt, syscall.SIGTERM)

		<-signalC    // wait for signal
		close(stopC) // signal loop to end

		exitC := make(chan struct{})
		wg := new(sync.WaitGroup)
		wg.Add(2)

		// wait for main loop and shutdown functions to finish
		go func() { <-shutdown.Done(); wg.Done() }()
		go func() { <-siteC; wg.Done() }()
		go func() { wg.Wait(); close(exitC) }()

		select {
		case <-exitC: // wait for loop to end
		case <-time.NewTimer(conf.Interval).C: // wait max 1 period
		}

		os.Exit(1)
	}()

	log.FATAL.Println(httpd.ListenAndServe())
}