package files

import (
	"io/fs"
	"os"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"time"
	"velvettear/dedupe/log"
)

var subdirectories []string

// exported function(s)
func RemoveEmptyDirectories(directory string) {
	subdirectories = nil
	timestamp := time.Now()
	log.Info("deleting empty subdirectories...", "directory: "+directory)
	filepath.WalkDir(directory, collectSubdirectories)
	sort.Slice(subdirectories, func(i, j int) bool {
		return strings.Count(subdirectories[i], string(os.PathSeparator)) > strings.Count(subdirectories[j], string(os.PathSeparator))
	})
	count := 0
	for _, subdirectory := range subdirectories {
		files, error := os.ReadDir(subdirectory)
		if error != nil {
			log.Error("encountered an error checking the content of directory '" + subdirectory)
		}
		if len(files) > 0 {
			continue
		}
		error = os.Remove(subdirectory)
		if error != nil {
			log.Warning("encountered an error deleting directory '"+subdirectory+"'", error.Error())
			continue
		}
		count++
		log.Debug("deleted directory '" + subdirectory + "'")
	}
	log.InfoTimed("finished deleting "+strconv.Itoa(count)+" empty subdirectoies", timestamp.UnixMilli(), "directory: "+directory)
}

// unexported function(s)
func collectSubdirectories(path string, dir fs.DirEntry, err error) error {
	if err != nil {
		return err
	}
	if !dir.IsDir() {
		return nil
	}
	subdirectories = append(subdirectories, path)
	return nil
}