func executeCommand(launcher launchers.Launcher, command string) (err error) {
	settings := launcher.GetSettings()

	switch command {
	case verbs.Serve:
		return verbs.DoServe()

	default:
		return verbs.DoRun(launcher, settings)
	}
}

func setupUserInterface(launcher launchers.Launcher, userInterface ui.UserInterface) {
	userInterface.SetApp(launcher.GetTitle())

	log.SetCallback(func(level logging.Level, message string) {
		if level <= logging.INFO {
			userInterface.SetStatus(message)
		}
	})

	userInterface.Show()
}

func (app *App) GetActualIconPath(launcher launchers.Launcher) string {
	referenceDescriptor, err := app.GetReferenceDescriptor()
	if err != nil {
		log.Warning("Error while retrieving the reference descriptor: %v", err)
		return launcher.GetIconPath()
	}

	referenceIconPath := referenceDescriptor.GetIconPath()

	if referenceIconPath != "" {
		return filepath.Join(app.filesDirectory, referenceIconPath)
	}

	return launcher.GetIconPath()
}

func (app *App) CreateDesktopShortcut(launcher launchers.Launcher, referenceDescriptor descriptors.AppDescriptor) (err error) {
	desktopDir, err := caravel.GetUserDesktop()
	if err != nil {
		return err
	}

	if !caravel.DirectoryExists(desktopDir) {
		return fmt.Errorf("Expected desktop dir '%v' not found", desktopDir)
	}

	shortcutFileName := caravel.FormatFileName(referenceDescriptor.GetName()) + ".desktop"
	log.Debug("Shortcut file name: '%v'", shortcutFileName)

	shortcutFilePath := filepath.Join(desktopDir, shortcutFileName)

	log.Info("Creating desktop shortcut: '%v'...", shortcutFilePath)

	shortcutFile, err := os.OpenFile(shortcutFilePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0700)
	if err != nil {
		return err
	}
	defer func() {
		shortcutFile.Close()
		if err != nil {
			os.Remove(shortcutFilePath)
		}
	}()

	actualIconPath := app.GetActualIconPath(launcher)

	shortcutContent := fmt.Sprintf(linuxShortcutContent,
		referenceDescriptor.GetName(),
		referenceDescriptor.GetDescription(),
		launcher.GetExecutable(),
		app.GetLocalDescriptorPath(),
		actualIconPath)

	_, err = shortcutFile.Write([]byte(shortcutContent))
	if err != nil {
		return err
	}

	log.Notice("Desktop shortcut created")

	return nil
}

func (app *App) CreateDesktopShortcut(launcher launchers.Launcher, referenceDescriptor descriptors.AppDescriptor) (err error) {
	desktopDir, err := caravel.GetUserDesktop()
	if err != nil {
		return err
	}

	if !caravel.DirectoryExists(desktopDir) {
		return fmt.Errorf("Expected desktop dir '%v' not found", desktopDir)
	}

	scriptFileName := caravel.FormatFileName(referenceDescriptor.GetName())
	log.Debug("Bash shortcut name: '%v'", scriptFileName)

	scriptFilePath := filepath.Join(desktopDir, scriptFileName)
	log.Info("Creating Bash shortcut: '%v'...", scriptFilePath)

	scriptFile, err := os.OpenFile(scriptFilePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0700)
	if err != nil {
		return err
	}
	defer func() {
		scriptFile.Close()

		if err != nil {
			os.Remove(scriptFilePath)
		}
	}()

	scriptContent := fmt.Sprintf(macScriptContentFormat,
		launcher.GetExecutable(),
		app.localDescriptorPath)

	_, err = scriptFile.Write([]byte(scriptContent))
	if err != nil {
		return err
	}

	log.Notice("Bash shortcut script created")

	return nil
}

func NewGtkUserInterface(launcher launchers.Launcher) (userInterface *GtkUserInterface, err error) {
	userInterface = &GtkUserInterface{
		launcher: launcher,
	}

	gladeDescriptorPath := filepath.Join(
		filepath.Dir(launcher.GetExecutable()),
		"moondeploy.glade")

	runOnUIThreadAndWait(func() interface{} {
		builder, err := gtk.BuilderNew()
		if err != nil {
			panic(err)
		}

		err = builder.AddFromFile(gladeDescriptorPath)
		if err != nil {
			panic(err)
		}

		windowObject, err := builder.GetObject("mainWindow")
		if err != nil {
			panic(err)
		}
		window := windowObject.(*gtk.Window)
		userInterface.window = window

		launcher := userInterface.launcher

		window.SetTitle(launcher.GetTitle())
		window.SetIconFromFile(launcher.GetIconPathAsPng())

		window.Connect("destroy", func() {
			window.Destroy()
			userInterface.window = nil
			gtk.MainQuit()
			userInterface.closedByUser = true
		})

		appLabelObject, err := builder.GetObject("appLabel")
		if err != nil {
			panic(err)
		}
		userInterface.appLabel = appLabelObject.(*gtk.Label)

		headerLabelObject, err := builder.GetObject("headerLabel")
		if err != nil {
			panic(err)
		}
		userInterface.headerLabel = headerLabelObject.(*gtk.Label)

		statusLabelObject, err := builder.GetObject("statusLabel")
		if err != nil {
			panic(err)
		}
		userInterface.statusLabel = statusLabelObject.(*gtk.Label)

		progressBarObject, err := builder.GetObject("progressBar")
		if err != nil {
			panic(err)
		}
		userInterface.progressBar = progressBarObject.(*gtk.ProgressBar)

		return nil
	})

	return userInterface, nil
}

/*
Run is the entry point you must employ to create a custom installer, for example to
employ custom settings or a brand-new user interface, based on any technology
*/
func Run(
	launcher launchers.Launcher,
	userInterface ui.UserInterface,
	bootDescriptor descriptors.AppDescriptor) (err error) {

	settings := launcher.GetSettings()

	//----------------------------------------------------------------------------

	setupUserInterface(launcher, userInterface)
	defer dismissUserInterface(userInterface)

	//----------------------------------------------------------------------------

	userInterface.SetHeader("Performing startup operations")

	log.Debug("The boot descriptor is: %#v", bootDescriptor)

	//----------------------------------------------------------------------------

	userInterface.SetApp(bootDescriptor.GetName())

	//----------------------------------------------------------------------------

	appGallery := apps.NewAppGallery(settings.GetGalleryDirectory())
	log.Debug("The app gallery is: %#v", appGallery)

	//----------------------------------------------------------------------------

	log.Info("Resolving the app...")
	app, err := appGallery.GetApp(bootDescriptor)
	if err != nil {
		return err
	}
	log.Notice("The app directory is: '%v'", app.Directory)

	log.Debug("App is: %#v", app)

	firstRun := !app.DirectoryExists()
	log.Debug("Is this a first run for the app? %v", firstRun)

	//----------------------------------------------------------------------------

	if firstRun {
		log.Info("Now asking the user if the app can run...")

		canRun := app.CanPerformFirstRun(userInterface)
		if !canRun {
			return &ExecutionCanceled{}
		}

		log.Debug("The user agreed to proceed")

		log.Info("Ensuring the app dir is available...")
		err = app.EnsureDirectory()
		if err != nil {
			return err
		}
		log.Notice("App dir available")
	}

	//----------------------------------------------------------------------------

	log.Info("Locking the app dir...")
	err = app.LockDirectory()
	if err != nil {
		return err
	}
	defer func() {
		unlockErr := app.UnlockDirectory()
		if unlockErr != nil {
			log.Warning(unlockErr.Error())
		}
	}()

	log.Notice("App dir locked")

	//----------------------------------------------------------------------------

	log.Info("Checking for conflicting local descriptors...")
	err = app.CheckForConflictingLocalDescriptors()
	if err != nil {
		return err
	}
	log.Notice("No conflicting local descriptors found")

	//----------------------------------------------------------------------------

	log.Info("Resolving the local descriptor...")
	localDescriptor := app.GetLocalDescriptor()

	startedWithLocalDescriptor := localDescriptor != nil
	log.Debug("Started with local descriptor? %v", startedWithLocalDescriptor)

	if startedWithLocalDescriptor {
		log.Info("Checking that local descriptor and boot descriptor actually match...")
//.........这里部分代码省略.........