package main

import (
	"testing"
)

type Type int

const (
	TypeChild Type = iota
	TypeChildren
	TypeAllChildren
)

type Node struct {
	Prev *Node
	Next *Node
	Name []rune
	Type Type
}

// func extractPath(cur *Node) string {
// 	var path []byte

// 	if cur.Next.Next == nil {
// 		return "/"
// 	}

// 	for ; cur != nil; cur = cur.Next {
// 		path = append(path, cur.Name...)
// 		if cur.Next.Next == nil {
// 			break
// 		}
// 		path = append(path, '/')
// 	}
// 	return string(path)
// }

func toString(root *Node) string {
	var content string

	for root != nil {

		content += string(root.Name)
		if root.Type == TypeAllChildren {
			content += "//"
		} else {
			content += "/"
		}
		root = root.Next
	}

	return content
}

func xPath(spath string) string {

	var path []rune = []rune(spath)
	path = append(path, ' ')

	root := &Node{}
	cur := root

	for i := 0; i < len(spath); i++ {
		c := path[i]
		switch c {
		case '/':
			if path[i+1] == '/' {
				cur.Type = TypeAllChildren
				i++
			} else {
				cur.Type = TypeChild
			}

			if len(cur.Name) == 0 {
				continue
			}

			cur.Next = &Node{Prev: cur}
			cur = cur.Next
		// case '(': 先拿括号

		default:
			cur.Name = append(cur.Name, c)
		}
	}

	return toString(root)
}

func TestMain(t *testing.T) {
	// t.Error(xPath("/a/../../b/../c//.//"))
	// 	t.Error(xPath("/a/./b/../../c/"))
	// 	t.Error(xPath("/"))
	t.Error(xPath("/a/./b/../../c/"))
	// t.Error(xPath("/a//b////c/d//././/.."))
}