package main

import (
	"log"
	"path"
	"strconv"
	"strings"
)

func IsDir(s string) bool {
	return s[len(s)-1] == '/'
}

type ByName [][]string

func (a ByName) Len() int {
	return len(a)
}

func (a ByName) Swap(i, j int) {
	a[i], a[j] = a[j], a[i]
}

func (a ByName) Less(i, j int) bool {
	return namesCmp(a[i], a[j]) < 0
}

func nameSplit(name string) []string {
	cols := strings.Split(name, "/")
	if IsDir(name) {
		cols = cols[:len(cols)-1]
		cols[len(cols)-1] += "/"
	}
	return cols
}

func nameJoin(name []string) (s string) {
	s = path.Join(name...)
	if IsDir(name[len(name)-1]) {
		s += "/"
	}
	return
}

func namesCmp(n1, n2 []string) int {
	min := len(n1)
	if len(n2) < min {
		min = len(n2)
	}
	var t1, t2 string
	for i := 0; i < min; i++ {
		t1 = strings.TrimSuffix(n1[i], "/")
		t2 = strings.TrimSuffix(n2[i], "/")
		if t1 < t2 {
			return -1
		}
		if t1 > t2 {
			return +1
		}
	}
	if len(n1) > len(n2) {
		return +1
	}
	if len(n1) < len(n2) {
		return -1
	}
	return 0
}

func hasPrefix(name, prefix []string) bool {
	if len(name) < len(prefix) {
		return false
	}
	return namesCmp(name[:len(prefix)], prefix) == 0
}

func deoctalize(s string) string {
	chars := make([]byte, 0, len(s))
	for i := 0; i < len(s); i++ {
		if s[i] == '\\' {
			b, err := strconv.ParseUint("0"+s[i+1:i+1+3], 0, 8)
			if err != nil {
				log.Fatalln(err)
			}
			chars = append(chars, byte(b))
			i += 3
		} else {
			chars = append(chars, s[i])
		}
	}
	return string(chars)
}