//go:build windows

package main

import (
	"fmt"
	"log"
	"os"
	"path/filepath"
	"runtime"
	"time"
	"unsafe"

	"github.com/jchv/go-webview2"
	"golang.org/x/sys/windows"

	"vpnclient/internal/apphost"
	"vpnclient/internal/appui"
	"vpnclient/internal/config"
	"vpnclient/internal/core"
	"vpnclient/internal/logbuf"
	"vpnclient/internal/trayhost"
	"vpnclient/internal/update"
)

func main() {
	if update.MaybeFinishUpdate(os.Args[1:]) {
		return
	}
	update.CleanupStaleDownloads()

	log.SetFlags(log.LstdFlags | log.Lshortfile)
	log.Printf("Navis %s · GOMAXPROCS=%d NumCPU=%d", update.DisplayVersion(), runtime.GOMAXPROCS(0), runtime.NumCPU())

	cfgPath, err := config.LocateConfig()
	if err != nil {
		fatalDialog("Не удалось найти путь конфига: %v", err)
	}
	if _, err := os.Stat(cfgPath); os.IsNotExist(err) {
		if err := config.WriteExample(cfgPath); err != nil {
			fatalDialog("Не удалось создать конфиг: %v", err)
		}
	}

	cfg, err := config.Load(cfgPath)
	if err != nil {
		fatalDialog("Ошибка конфига %s: %v", cfgPath, err)
	}

	logBuf := logbuf.New(0)
	mgr, err := core.NewManager(cfgPath, cfg, logBuf)
	if err != nil {
		fatalDialog("%v", err)
	}

	a := apphost.New(mgr, cfgPath, logBuf)
	a.OpenURL = shellOpen
	a.OnAfterUpdate = func() {
		// Hard-exit so Windows unlocks Navis.exe; do not wait on webview.Terminate.
		go func() {
			time.Sleep(300 * time.Millisecond)
			_ = a.Disconnect()
			os.Exit(0)
		}()
	}

	dataPath := filepath.Join(filepath.Dir(cfgPath), ".navis-webview")
	_ = os.MkdirAll(dataPath, 0o755)

	w := webview2.NewWithOptions(webview2.WebViewOptions{
		Debug:     false,
		AutoFocus: true,
		DataPath:  dataPath,
		WindowOptions: webview2.WindowOptions{
			Title:  "Navis",
			Width:  500,
			Height: 900,
			Center: true,
			IconId: 1,
		},
	})
	if w == nil {
		fatalDialog("Не удалось создать окно WebView2.\nУстановите Microsoft Edge WebView2 Runtime.")
	}
	defer func() {
		_ = mgr.Disconnect()
		w.Destroy()
	}()

	applyWindowIcon(w.Window())
	w.SetSize(500, 900, webview2.HintNone)

	mustBind(w, "getState", a.GetState)
	mustBind(w, "getEditState", a.GetEditState)
	mustBind(w, "connect", a.Connect)
	mustBind(w, "disconnect", a.Disconnect)
	mustBind(w, "connectProfile", a.ConnectProfile)
	mustBind(w, "saveProfile", a.SaveProfile)
	mustBind(w, "createProfile", a.CreateProfile)
	mustBind(w, "selectProfile", a.SelectProfile)
	mustBind(w, "deleteProfile", a.DeleteProfile)
	mustBind(w, "installCore", a.InstallCore)
	mustBind(w, "openURL", a.OpenShopURL)
	mustBind(w, "pingServers", a.PingServers)
	mustBind(w, "pingBest", a.PingBest)
	mustBind(w, "checkUpdate", a.CheckUpdate)
	mustBind(w, "applyUpdate", a.ApplyUpdate)
	mustBind(w, "saveHy2", a.SaveHy2)
	mustBind(w, "importSubscription", a.ImportSubscription)
	mustBind(w, "getLogs", a.GetLogs)
	mustBind(w, "probeTunnel", a.ProbeTunnel)
	mustBind(w, "savePrefs", a.SavePrefs)

	a.StartBackground()
	trayhost.Start("Navis", trayhost.Hooks{
		Connect:    func() { _ = a.Connect() },
		Disconnect: func() { _ = a.Disconnect() },
		Quit: func() {
			_ = a.Disconnect()
			os.Exit(0)
		},
		IsUp: func() bool { return a.Mgr.Status().Connected },
	})

	go a.AutoCheckUpdate()

	w.SetHtml(appui.IndexHTML)
	w.Run()
}

func mustBind(w webview2.WebView, name string, fn interface{}) {
	if err := w.Bind(name, fn); err != nil {
		fatalDialog("bind %s: %v", name, err)
	}
}

func shellOpen(raw string) error {
	verb, err := windows.UTF16PtrFromString("open")
	if err != nil {
		return err
	}
	file, err := windows.UTF16PtrFromString(raw)
	if err != nil {
		return err
	}
	return windows.ShellExecute(0, verb, file, nil, nil, windows.SW_SHOWNORMAL)
}

func applyWindowIcon(hwnd unsafe.Pointer) {
	ico := findIconPath()
	if ico == "" || hwnd == nil {
		return
	}
	pathPtr, err := windows.UTF16PtrFromString(ico)
	if err != nil {
		return
	}
	user32 := windows.NewLazySystemDLL("user32.dll")
	loadImage := user32.NewProc("LoadImageW")
	sendMessage := user32.NewProc("SendMessageW")
	const (
		imageIcon      = 1
		lrLoadFromFile = 0x0010
		lrDefaultSize  = 0x0040
		wmSetIcon      = 0x0080
		iconSmall      = 0
		iconBig        = 1
	)
	h, _, _ := loadImage.Call(0, uintptr(unsafe.Pointer(pathPtr)), imageIcon, 0, 0, lrLoadFromFile|lrDefaultSize)
	if h == 0 {
		return
	}
	sendMessage.Call(uintptr(hwnd), wmSetIcon, iconSmall, h)
	sendMessage.Call(uintptr(hwnd), wmSetIcon, iconBig, h)
}

func findIconPath() string {
	candidates := []string{}
	if exe, err := os.Executable(); err == nil {
		dir := filepath.Dir(exe)
		candidates = append(candidates,
			filepath.Join(dir, "assets", "navis.ico"),
			filepath.Join(dir, "navis.ico"),
		)
	}
	if cwd, err := os.Getwd(); err == nil {
		candidates = append(candidates, filepath.Join(cwd, "assets", "navis.ico"))
	}
	for _, c := range candidates {
		if st, err := os.Stat(c); err == nil && !st.IsDir() {
			return c
		}
	}
	return ""
}

func fatalDialog(format string, args ...interface{}) {
	msg := fmt.Sprintf(format, args...)
	log.Println(msg)
	messageBox(msg)
	os.Exit(1)
}