You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: watch.go
    path of file: ./repos/yao/share
    
    the code of the file until where you have to start completion: package share

import (
	"fmt"
	"io/fs"
	"log"
	"os"
	"path/filepath"
	"sync"

	"github.com/fatih/color"
	"github.com/fsnotify/fsnotify"
	"github.com/yaoapp/kun/exception"
)

var watchGroup sync.WaitGroup
var watchOp = map[fsnotify.Op]string{
	fsnotify.Create: "create",
	fsnotify.Write:  "write",
	fsnotify.Remove: "remove",
	fsnotify.Rename: "rename",
	fsnotify.Chmod:  "chmod",
}

// Watch 监听目录
func Watch(root string, cb func(op string, file string)) {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		watcher.Close()
		watchGroup.Done()
	}()

	watchGroup.Add(1)
	go func() {
		for {
			select {
			case event, ok := <-watcher.Events:
				if !ok {
					return
				}

				// 监听子目录
				if event.Op == fsnotify.Create {
					fil
    
func Watch(root string, cb func(op string, file string)) {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		watcher.Close()
		watchGroup.Done()
	}()

	watchGroup.Add(1)
	go func() {
		for {
			select {
			case event, ok := <-watcher.Events:
				if !ok {
					return
				}

				// 监听子目录
				if event.Op == fsnotify.Create {
					file, err := os.Open(event.Name)
					if err == nil {
						fi, err := file.Stat()
						file.Close()
						if err == nil && fi.IsDir() {
							Watch(event.Name, cb)
						}
					}
				}

				cb(watchOp[event.Op], event.Name)

			case err, ok := <-watcher.Errors:
				if !ok {
					return
				}
				log.Println("Error:", err)
			}
		}
	}()

	err = watcher.Add(root)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(color.GreenString("Watching: %s", root))

	// 监听子目录
	filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			exception.Err(err, 500).Throw()
			return err
		}

		if path == root {
			return nil
		}

		if d.IsDir() {
			go Watch(path, cb)
		}
		return nil
	})

	watchGroup.Wait()

}