package util

import (
	"crypto/hmac"
	"crypto/md5"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"math/rand"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"
	"unsafe"
)

func Sha256(message string) string {
	h := sha256.New()
	h.Write([]byte(message))
	res := h.Sum(nil)
	return hex.EncodeToString(res)
}

func ComputeHmacSha256Base64(message string, secret string) string {
	key := []byte(secret)
	h := hmac.New(sha256.New, key)
	h.Write([]byte(message))
	abs := h.Sum(nil)
	return base64.StdEncoding.EncodeToString(abs)
}


func Hik_ComputeSignatureBase64(appKey string, appSecret string, httpMethod string, accept string, contentType string, date string, url string) string {
	httpHeaders := httpMethod +"\n" + accept + "\n" + contentType + "\n"+ date +"\n"
	customHeaders := "x-ca-key:"+ appKey +"\n"
	msg := httpHeaders + customHeaders + url
	return ComputeHmacSha256Base64(msg, appSecret)
}

type SliceMock struct {
	addr uintptr
	len int
	cap int
}

func GetIBytes(v interface{}) []byte {
	len := unsafe.Sizeof(v)
	dataBytes := &SliceMock{
		addr: uintptr(unsafe.Pointer(&v)),
		cap: int(len),
		len: int(len),
	}
	b := *(*[]byte)(unsafe.Pointer(dataBytes))
	return b
}

func MD5Base64(s []byte) string {
	sum := md5.Sum(s)
	return base64.StdEncoding.EncodeToString(sum[:])
}

func GenValidateCode(width int) string {
	numeric := [10]byte{0,1,2,3,4,5,6,7,8,9}
	r := len(numeric)
	rand.Seed(time.Now().UnixNano())

	var sb strings.Builder
	for i := 0; i < width; i++ {
		fmt.Fprintf(&sb, "%d", numeric[ rand.Intn(r) ])
	}
	str := sb.String()
	if strings.HasPrefix(str, "0") {
		pI := RandInt(1,9)
		str = strconv.Itoa(pI) + str[1:]
	}
	return str
}

//生成区间随机数
func RandInt(min, max int) int {
	if min >= max || min ==0 ||max == 0 {
		return max
	}
	return rand.Intn(max-min) + min
}


func GetAppRootPath() string {
	file,err:= exec.LookPath(os.Args[0])
	if err != nil {
		return ""
	}
	p, err := filepath.Abs(file)
	if err != nil {
		return ""
	}
	return filepath.Dir(p)
}