package main

import (
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"math/rand"
	"os"
	"time"
)

func exists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return true, err
}

func GetRandomString(l int) string {
	str := "0123456789abcdefghijklmnopqrstuvwxyz"
	bytes := []byte(str)
	result := []byte{}
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for i := 0; i < l; i++ {
		result = append(result, bytes[r.Intn(len(bytes))])
	}
	return string(result)
}

func GetSHA256HashCode(message []byte) string {
	hash := sha256.New()
	//输入数据
	hash.Write(message)
	//计算哈希值
	bytes := hash.Sum(nil)
	//将字符串编码为16进制格式,返回字符串
	hashCode := hex.EncodeToString(bytes)
	//返回哈希值
	return hashCode
}

func formatJson(v interface{}) []byte {
	marshal, _ := json.Marshal(v)
	return marshal
	//var b bytes.Buffer
	//json.Indent(&b, marshal, "", "  ")
	//
	//return b.Bytes()
}

func StringListContain(list []string, target string) bool {
	if list == nil {
		return false
	}
	for _, item := range list {
		if item == target {
			return true
		}
	}
	return false
}