package web

import (
	"context"
	"embed"
	"github.com/BurntSushi/toml"
	"github.com/gin-contrib/sessions"
	"github.com/gin-contrib/sessions/cookie"
	"github.com/gin-gonic/gin"
	"github.com/nicksnyder/go-i18n/v2/i18n"
	"golang.org/x/text/language"
	"html/template"
	"io"
	"io/fs"
	"net"
	"net/http"
	"os"
	"runtime"
	"strconv"
	"time"
	"x-ui/config"
	"x-ui/logger"
	"x-ui/util/common"
	"x-ui/web/controller"
	"x-ui/web/service"
)

//go:embed assets/*
var assetsFS embed.FS

//go:embed html/*
var htmlFS embed.FS

//go:embed translation/*
var i18nFS embed.FS

type wrapAssetsFS struct {
	embed.FS
}

func (f *wrapAssetsFS) Open(name string) (fs.File, error) {
	return f.FS.Open("assets/" + name)
}

func stopServer(s *Server) {
	s.Stop()
}

type Server struct {
	*server
}

func NewServer() *Server {
	s := &Server{newServer()}
	runtime.SetFinalizer(s, stopServer)
	return s
}

type server struct {
	listener net.Listener

	index  *controller.IndexController
	server *controller.ServerController
	xui    *controller.XUIController

	xrayService    service.XrayService
	settingService service.SettingService

	ctx    context.Context
	cancel context.CancelFunc
}

func newServer() *server {
	ctx, cancel := context.WithCancel(context.Background())
	return &server{
		ctx:    ctx,
		cancel: cancel,
	}
}

func (s *server) initRouter() (*gin.Engine, error) {
	if config.IsDebug() {
		gin.SetMode(gin.DebugMode)
	} else {
		gin.DefaultWriter = io.Discard
		gin.DefaultErrorWriter = io.Discard
		gin.SetMode(gin.ReleaseMode)
	}

	engine := gin.Default()

	secret, err := s.settingService.GetSecret()
	if err != nil {
		return nil, err
	}

	basePath, err := s.settingService.GetBasePath()
	if err != nil {
		return nil, err
	}

	store := cookie.NewStore(secret)
	engine.Use(sessions.Sessions("session", store))
	engine.Use(func(c *gin.Context) {
		c.Set("base_path", basePath)
	})
	err = s.initI18n(engine)
	if err != nil {
		return nil, err
	}

	if config.IsDebug() {
		// for develop
		engine.LoadHTMLGlob("web/html/**/*.html")
		engine.StaticFS(basePath+"assets", http.FS(os.DirFS("web/assets")))
	} else {
		t := template.New("")
		t, err = t.ParseFS(htmlFS, "html/**/*.html")
		if err != nil {
			return nil, err
		}
		engine.SetHTMLTemplate(t)
		engine.StaticFS(basePath+"assets", http.FS(&wrapAssetsFS{FS: assetsFS}))
	}

	g := engine.Group(basePath)

	s.index = controller.NewIndexController(g)
	s.server = controller.NewServerController(g)
	s.xui = controller.NewXUIController(g)

	return engine, nil
}

func (s *server) initI18n(engine *gin.Engine) error {
	bundle := i18n.NewBundle(language.SimplifiedChinese)
	bundle.RegisterUnmarshalFunc("toml", toml.Unmarshal)
	err := fs.WalkDir(i18nFS, "translation", func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() {
			return nil
		}
		data, err := i18nFS.ReadFile(path)
		if err != nil {
			return err
		}
		_, err = bundle.ParseMessageFileBytes(data, path)
		return err
	})
	if err != nil {
		return err
	}

	findI18nParamNames := func(key string) []string {
		names := make([]string, 0)
		keyLen := len(key)
		for i := 0; i < keyLen-1; i++ {
			if key[i:i+2] == "{{" { // 判断开头 "{{"
				j := i + 2
				isFind := false
				for ; j < keyLen-1; j++ {
					if key[j:j+2] == "}}" { // 结尾 "}}"
						isFind = true
						break
					}
				}
				if isFind {
					names = append(names, key[i+3:j])
				}
			}
		}
		return names
	}

	var localizer *i18n.Localizer

	engine.FuncMap["i18n"] = func(key string, params ...string) (string, error) {
		names := findI18nParamNames(key)
		if len(names) != len(params) {
			return "", common.NewError("find names:", names, "---------- params:", params, "---------- num not equal")
		}
		templateData := map[string]interface{}{}
		for i := range names {
			templateData[names[i]] = params[i]
		}
		return localizer.Localize(&i18n.LocalizeConfig{
			MessageID:    key,
			TemplateData: templateData,
		})
	}

	engine.Use(func(c *gin.Context) {
		accept := c.GetHeader("Accept-Language")
		localizer = i18n.NewLocalizer(bundle, accept)
		c.Set("localizer", localizer)
		c.Next()
	})

	return nil
}

func (s *server) startTask() {
	go func() {
		err := s.xrayService.StartXray()
		if err != nil {
			logger.Warning("start xray failed:", err)
		}
		ticker := time.NewTicker(time.Second * 30)
		defer ticker.Stop()
		for {
			select {
			case <-s.ctx.Done():
				return
			case <-ticker.C:
			}
			if s.xrayService.IsXrayRunning() {
				continue
			}
			err := s.xrayService.StartXray()
			if err != nil {
				logger.Warning("start xray failed:", err)
			}
		}
	}()
}

func (s *server) Run() error {
	engine, err := s.initRouter()
	if err != nil {
		return err
	}

	s.startTask()

	certFile, err := s.settingService.GetCertFile()
	if err != nil {
		return err
	}
	keyFile, err := s.settingService.GetKeyFile()
	if err != nil {
		return err
	}
	listen, err := s.settingService.GetListen()
	if err != nil {
		return err
	}
	port, err := s.settingService.GetPort()
	if err != nil {
		return err
	}
	listenAddr := net.JoinHostPort(listen, strconv.Itoa(port))
	if certFile != "" || keyFile != "" {
		logger.Info("web server run https on", listenAddr)
		return engine.RunTLS(listenAddr, certFile, keyFile)
	} else {
		logger.Info("web server run http on", listenAddr)
		return engine.Run(listenAddr)
	}
}

func (s *Server) Stop() error {
	s.cancel()
	return s.listener.Close()
}