package main

import (
	"context"
	"path/filepath"
	"time"

	"os"
	"strings"

	log "github.com/sirupsen/logrus"

	"sort"
)

var lstat = os.Lstat // for testing
func walk(path string, info os.FileInfo, walkFn filepath.WalkFunc) error {
	if !info.IsDir() {
		return walkFn(path, info, nil)
	}
	err1 := walkFn(path, info, nil)
	if err1 != nil {
		return err1
	}
	names, err := readDirNames(path)
	log.Info("names",names)
	if err != nil {
		return err
	}
	for _, name := range names {
		filename := filepath.Join(path, name)
		fileInfo, err := lstat(filename)
		if err != nil {
			if err := walkFn(filename, fileInfo, err); err != nil && err != filepath.SkipDir {
				return err
			}
		} else {
			err = walk(filename, fileInfo, walkFn)
			if err != nil {
				if !fileInfo.IsDir() || err != filepath.SkipDir {
					return err
				}
			}
		}
	}
	return nil
}
func CustomWalk(root string, walkFn filepath.WalkFunc) error {
	info, err := os.Lstat(root)
	if err != nil {
		err = walkFn(root, nil, err)
	} else {
		err = walk(root, info, walkFn)
	}
	if err == filepath.SkipDir {
		return nil
	}
	return err
}
func readDirNames(dirname string) ([]string, error) {
	f, err := os.Open(dirname)
	if err != nil {
		return nil, err
	}
	names, err := f.Readdirnames(-1)
	f.Close()
	if err != nil {
		return nil, err
	}
	sort.Strings(names)
	return names, nil
}

func walkLarge(rootpath string) {
	ctx, cancel := context.WithTimeout(context.Background(), 7200*time.Second)
	defer cancel()
	err := CustomWalk(rootpath, func(path string, info os.FileInfo, err error) error {
		time.Sleep(1 * time.Second)
		log.Info(path)
		if err != nil {
			return nil
		}
		select {
		case <-ctx.Done():
			log.Warn("Timeout", rootpath)
			return ctx.Err()
		default:
		}

		rel, err := filepath.Rel(rootpath, path)
		if err != nil {
			return err
		}
		if uint(len(strings.Split(rel, "/"))) > 4 {
			return filepath.SkipDir
		}

		if info.IsDir() {
			if info.Name() == ".git" {
				return filepath.SkipDir
			}
			f, err := os.Open(path)
			defer f.Close()
			if err != nil {
				return filepath.SkipDir
			}
			files, err := f.Readdir(1000)
			if err != nil {
				return filepath.SkipDir
			}
			if len(files) > 999 {
				log.Warn("Skip dir ", path)
				return filepath.SkipDir
			}

		} else {
			if !info.Mode().IsRegular() {
				return nil
			}
		}
		return nil
	})
	if err != nil {
		log.Errorf("walk error [%v]\n", err)
	}
}

func main() {
	walkLarge("/")
}

        err1 := walkFn(path, info, nil)
	if err1 != nil {
		return err1
	}
	names, err := readDirNames(path)
	log.Info("names",names)
	if err != nil {
		return err
	}

                         files, err := f.Readdir(1000)
			if err != nil {
				return filepath.SkipDir
			}
			if len(files) > 999 {
				log.Warn("Skip dir ", path)
				return filepath.SkipDir
			}