package utils

import (
	"crypto/md5"
	"encoding/base64"
	"encoding/hex"
	"io/ioutil"
	"math/rand"
	"os"
	"strings"
	"time"

	"github.com/google/uuid"
)

func Hmac(data string) string {
	h := md5.New()
	h.Write([]byte(data))
	return hex.EncodeToString(h.Sum(nil))
}

func IsStringEmpty(str string) bool {
	return strings.Trim(str, " ") == ""
}

func GetUUID() string {
	u := uuid.New()
	return strings.ReplaceAll(u.String(), "-", "")
}

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

	if os.IsNotExist(err) {
		return false
	}

	return false
}

func Base64ToImage(imageBase64 string) ([]byte, error) {
	image, err := base64.StdEncoding.DecodeString(imageBase64)
	if err != nil {
		return nil, err
	}

	return image, nil
}

func GetDirFiles(dir string) ([]string, error) {
	dirList, err := ioutil.ReadDir(dir)
	if err != nil {
		return nil, err
	}

	filesRet := make([]string, 0)

	for _, file := range dirList {
		if file.IsDir() {
			files, err := GetDirFiles(dir + string(os.PathSeparator) + file.Name())
			if err != nil {
				return nil, err
			}

			filesRet = append(filesRet, files...)
		} else {
			filesRet = append(filesRet, dir+string(os.PathSeparator)+file.Name())
		}
	}

	return filesRet, nil
}

func GetCurrentTimeStamp() int64 {
	return time.Now().UnixNano() / 1e6
}

// slice去重
func RemoveRepByMap(slc []string) []string {
	result := []string{}
	tempMap := map[string]byte{}
	for _, e := range slc {
		l := len(tempMap)
		tempMap[e] = 0
		if len(tempMap) != l {
			result = append(result, e)
		}
	}
	return result
}

// #取得随机字符串：通过打乱slice来操作
func GetRandString(length int, char string, rand_x int64) string {
	if length < 1 {
		return ""
	}

	if len(char) <= 6 || len(char) <= length {
		char = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
	}

	charArr := strings.Split(char, "")
	ran := rand.New(rand.NewSource(time.Now().UnixMilli() + rand_x))

	l := len(charArr)
	for i := l - 1; i > 0; i-- {
		r := ran.Intn(i)
		charArr[r], charArr[i] = charArr[i], charArr[r]
	}
	rchar := charArr[:length]
	return strings.Join(rchar, "")
}