package main

import (
	"flag"
	"fmt"
	"os"
	"os/signal"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"syscall"
	"time"

	"github.com/metacubex/mihomo/config"
	C "github.com/metacubex/mihomo/constant"
	"github.com/metacubex/mihomo/constant/features"
	"github.com/metacubex/mihomo/hub"
	"github.com/metacubex/mihomo/hub/executor"
	"github.com/metacubex/mihomo/log"

	"go.uber.org/automaxprocs/maxprocs"
)

var (
	version            bool
	testConfig         bool
	geodataMode        bool
	homeDir            string
	configFile         string
	externalUI         string
	externalController string
	secret             string
	updateGeoMux       sync.Mutex
	updatingGeo        = false
)

func init() {
	flag.StringVar(&homeDir, "d", os.Getenv("CLASH_HOME_DIR"), "set configuration directory")
	flag.StringVar(&configFile, "f", os.Getenv("CLASH_CONFIG_FILE"), "specify configuration file")
	flag.StringVar(&externalUI, "ext-ui", os.Getenv("CLASH_OVERRIDE_EXTERNAL_UI_DIR"), "override external ui directory")
	flag.StringVar(&externalController, "ext-ctl", os.Getenv("CLASH_OVERRIDE_EXTERNAL_CONTROLLER"), "override external controller address")
	flag.StringVar(&secret, "secret", os.Getenv("CLASH_OVERRIDE_SECRET"), "override secret for RESTful API")
	flag.BoolVar(&geodataMode, "m", false, "set geodata mode")
	flag.BoolVar(&version, "v", false, "show current version of mihomo")
	flag.BoolVar(&testConfig, "t", false, "test configuration and exit")
	flag.Parse()
}

func main() {
	_, _ = maxprocs.Set(maxprocs.Logger(func(string, ...any) {}))
	if version {
		fmt.Printf("Mihomo Meta %s %s %s with %s %s\n",
			C.Version, runtime.GOOS, runtime.GOARCH, runtime.Version(), C.BuildTime)
		if tags := features.Tags(); len(tags) != 0 {
			fmt.Printf("Use tags: %s\n", strings.Join(tags, ", "))
		}

		return
	}

	if homeDir != "" {
		if !filepath.IsAbs(homeDir) {
			currentDir, _ := os.Getwd()
			homeDir = filepath.Join(currentDir, homeDir)
		}
		C.SetHomeDir(homeDir)
	}

	if configFile != "" {
		if !filepath.IsAbs(configFile) {
			currentDir, _ := os.Getwd()
			configFile = filepath.Join(currentDir, configFile)
		}
	} else {
		configFile = filepath.Join(C.Path.HomeDir(), C.Path.Config())
	}
	C.SetConfig(configFile)

	if geodataMode {
		C.GeodataMode = true
	}

	if err := config.Init(C.Path.HomeDir()); err != nil {
		log.Fatalln("Initial configuration directory error: %s", err.Error())
	}

	if testConfig {
		if _, err := executor.Parse(); err != nil {
			log.Errorln(err.Error())
			fmt.Printf("configuration file %s test failed\n", C.Path.Config())
			os.Exit(1)
		}
		fmt.Printf("configuration file %s test is successful\n", C.Path.Config())
		return
	}

	var options []hub.Option
	if externalUI != "" {
		options = append(options, hub.WithExternalUI(externalUI))
	}
	if externalController != "" {
		options = append(options, hub.WithExternalController(externalController))
	}
	if secret != "" {
		options = append(options, hub.WithSecret(secret))
	}

	if err := hub.Parse(options...); err != nil {
		log.Fatalln("Parse config error: %s", err.Error())
	}

	if C.GeoAutoUpdate {
		ticker := time.NewTicker(time.Duration(C.GeoUpdateInterval) * time.Hour)

		log.Infoln("[GEO] Start update GEO database every %d hours", C.GeoUpdateInterval)
		go func() {
			for range ticker.C {
				updateGeoDatabases()
			}
		}()
	}

	defer executor.Shutdown()

	termSign := make(chan os.Signal, 1)
	hupSign := make(chan os.Signal, 1)
	signal.Notify(termSign, syscall.SIGINT, syscall.SIGTERM)
	signal.Notify(hupSign, syscall.SIGHUP)
	for {
		select {
		case <-termSign:
			return
		case <-hupSign:
			if cfg, err := executor.ParseWithPath(C.Path.Config()); err == nil {
				executor.ApplyConfig(cfg, true)
			} else {
				log.Errorln("Parse config error: %s", err.Error())
			}
		}
	}
}

func updateGeoDatabases() {
	log.Infoln("[GEO] Start updating GEO database")
	updateGeoMux.Lock()

	if updatingGeo {
		updateGeoMux.Unlock()
		log.Infoln("[GEO] GEO database is updating, skip")
		return
	}

	updatingGeo = true
	updateGeoMux.Unlock()

	go func() {
		defer func() {
			updatingGeo = false
		}()

		log.Infoln("[GEO] Updating GEO database")

		if err := config.UpdateGeoDatabases(); err != nil {
			log.Errorln("[GEO] update GEO database error: %s", err.Error())
			return
		}

		cfg, err := executor.ParseWithPath(C.Path.Config())
		if err != nil {
			log.Errorln("[GEO] update GEO database failed: %s", err.Error())
			return
		}

		log.Infoln("[GEO] Update GEO database success, apply new config")
		executor.ApplyConfig(cfg, false)
	}()
}