package main

import (
	_ "bytes"
	_ "container/list"
	_ "encoding/binary"
	"encoding/hex"
	"fmt"
	"github.com/astaxie/beego"
	_ "math"
	"strconv"
	"strings"
)

type MainController struct {
	beego.Controller
}

func (this *MainController) Encode() {
	text := this.GetString("text")
	this.Ctx.WriteString(encodeText(text))
}

func (this *MainController) Decode() {
	text := this.GetString("text")
	this.Ctx.WriteString(decodeText(text))
}

func main() {
	// beego.SetStaticPath("/views", "views")
	// beego.SetStaticPath("/", "views/index.html")
	// beego.AutoRouter(&MainController{})
	// beego.Run()
	bData := encodeText("我去你妈的b")
	fmt.Println(bData)
	fmt.Println(decodeText(bData))
}

//加密
func encodeText(text string) (resultStr string) {
	strs := strings.Split(text, "") //分割字符串
	for _, element := range strs {
		str := []byte(element)
		hexStr := hex.EncodeToString(str)
		length := len(hexStr)
		lengthB := strconv.FormatInt(int64(length), 2)
		bLen := len(lengthB)
		if bLen < 3 {
			for i := 0; i < (3 - bLen); i++ {
				lengthB = "0" + lengthB
			}
		}
		resultStr += lengthB
		hexChars := strings.Split(hexStr, "") //分割字符串
		for _, element := range hexChars {
			resultStr += hexToBinary(element)
		}
	}
	return resultStr
}

//十进制转换成十六进制
func numToChar(num int64) (result string) {
	switch num {
	case 10:
		result = "A"
	case 11:
		result = "B"
	case 12:
		result = "C"
	case 13:
		result = "D"
	case 14:
		result = "E"
	case 15:
		result = "F"
	default:
		result = strconv.Itoa(int(num))
	}
	return result
}

//十六进制转换成十进制
func charToNum(char string) (result int64) {
	char = strings.ToUpper(char)
	var num string
	switch char {
	case "A":
		num = "10"
	case "B":
		num = "11"
	case "C":
		num = "12"
	case "D":
		num = "13"
	case "E":
		num = "14"
	case "F":
		num = "15"
	default:
		num = char
	}
	result, _ = strconv.ParseInt(num, 10, 64)
	return result
}

//十六进制转换成二进制
func hexToBinary(text string) (data string) {
	strs := strings.Split(text, "")
	for _, element := range strs {
		num := charToNum(element)
		bData := strconv.FormatInt(num, 2)
		length := len(bData)
		if length < 4 {
			//不够四位就补全四位
			for i := 0; i < (4 - length); i++ {
				bData = "0" + bData
			}

		}
		data += bData
	}
	return data
}

func checkErr(err error) {
	if err != nil {
		panic(err)
	}
}

//解密
func decodeText(text string) string {
	var pointer int
	var result string
	for pointer < len(text) {
		lengthB := SubString(text, pointer, 3)
		pointer += 3
		length, _ := strconv.ParseInt(lengthB, 2, 64)
		var tempStr string
		for i := 0; i < int(length); i++ {
			charB := SubString(text, pointer, 4)
			pointer += 4
			char, _ := strconv.ParseInt(charB, 2, 0)
			tempStr = tempStr + numToChar(char)
		}
		tenStr, _ := hex.DecodeString(tempStr)
		result += string(tenStr)
	}

	return result
}

//获取子字符串
func SubString(str string, begin, length int) (substr string) {
	// 将字符串的转换成[]rune
	rs := []rune(str)
	lth := len(rs)

	// 简单的越界判断
	if begin < 0 {
		begin = 0
	}
	if begin >= lth {
		begin = lth
	}
	end := begin + length
	if end > lth {
		end = lth
	}

	// 返回子串
	return string(rs[begin:end])
}