package main

import (
	"io/fs"
	"log"
	"os"
	"path"
)

var (
	WalkerFiles int64
	WalkerDirs  int64
)

func walker(sink chan Ent, root []string) error {
	files, err := os.ReadDir(path.Join(root...)) // it is already sorted
	if err != nil {
		return err
	}
	var info fs.FileInfo
	ents := make([]Ent, 0, len(files))
	for _, file := range files {
		ent := Ent{name: append([]string{}, append(root, file.Name())...)}
		info, err = file.Info()
		if err == nil {
			if info.IsDir() {
				ent.name[len(ent.name)-1] += "/"
			} else if info.Mode().IsRegular() {
				ent.size = info.Size()
			}
			ent.mtime = info.ModTime().Unix()
		} else {
			log.Println("can not stat:", path.Join(ent.name...), ":", err)
		}
		ents = append(ents, ent)
	}
	for _, ent := range ents {
		sink <- ent
		if ent.IsDir() {
			WalkerDirs++
		} else {
			WalkerFiles++
			continue
		}
		err = walker(sink, ent.name)
		if err != nil {
			log.Println("can not stat:", path.Join(ent.name...), ":", err)
			continue
		}
	}
	return nil
}