package public

import (
	"bytes"
	"crypto"
	"crypto/aes"
	"crypto/cipher"
	"crypto/hmac"
	"crypto/md5"
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha1"
	"crypto/sha256"
	"crypto/sha512"
	"crypto/x509"
	"encoding/base64"
	"encoding/hex"
	"encoding/json"
	"encoding/pem"
	"errors"
	"fmt"
	"io"
	"math"
	mathRand "math/rand"
	"net/http"
	"net/url"
	"regexp"
	"strconv"
	"strings"
	"time"
	"unsafe"

	"golang.org/x/crypto/sha3"

	"bet24.com/log"
	"github.com/axgle/mahonia"
)

func ConvertToString(src string, srcCode string, tagCode string) string {
	srcCoder := mahonia.NewDecoder(srcCode)
	srcResult := srcCoder.ConvertString(src)
	tagCoder := mahonia.NewEncoder(tagCode)
	return tagCoder.ConvertString(srcResult)
}

func GetUtf8(src string) string {
	return ConvertToString(src, "GB18030", "UTF-8")
}

func GetGBK(src string) string {
	return ConvertToString(src, "UTF-8", "GB18030")
}

const ENCRYPT_KEY_LENGTH = 10

func DecryptDBString(src string) string {
	lpszIn := []byte(src)
	if len(lpszIn) >= ENCRYPT_KEY_LENGTH*4 {
		szSoureLengthBuf := string([]byte{lpszIn[0], lpszIn[1]})
		nSoureLength64, _ := strconv.ParseInt(szSoureLengthBuf, 16, 0)
		nSoureLength := int(nSoureLength64)
		lpszOut := make([]byte, nSoureLength)
		for i := 0; i < nSoureLength; i++ {
			szKeyBuffer := string([]byte{lpszIn[i*4], lpszIn[i*4+1]})
			szEncryptBuffer := string([]byte{lpszIn[i*4+2], lpszIn[i*4+3]})
			uKey64, _ := strconv.ParseInt(szKeyBuffer, 16, 0)
			uEncrypt64, _ := strconv.ParseInt(szEncryptBuffer, 16, 0)
			uKey := uint8(uKey64)
			uEncrypt := uint8(uEncrypt64)
			lpszOut[i] = uKey ^ uEncrypt
		}
		return string(lpszOut)
	}
	return src
}

func StringIpToInt(ipstring string) uint32 {
	ipSegs := strings.Split(ipstring, ".")
	var ipInt int = 0
	var pos uint = 0
	for _, ipSeg := range ipSegs {
		tempInt, _ := strconv.Atoi(ipSeg)
		tempInt = tempInt << pos
		ipInt = ipInt + tempInt
		pos += 8
	}
	//fmt.Println("StringIpToInt", ipstring, ipInt)
	return uint32(ipInt)
}

func IpIntToString(ipInt uint32) string {
	ipSegs := make([]string, 4)
	var len int = len(ipSegs)
	buffer := bytes.NewBufferString("")
	for i := 0; i < len; i++ {
		tempInt := ipInt & 0xFF
		ipSegs[len-i-1] = strconv.Itoa(int(tempInt))
		ipInt = ipInt >> 8
	}
	for i := 0; i < len; i++ {
		buffer.WriteString(ipSegs[i])
		if i < len-1 {
			buffer.WriteString(".")
		}
	}
	return buffer.String()
}

// md5加密方式
func GetMd5String(s string) string {
	h := md5.New()
	h.Write([]byte(s))
	return hex.EncodeToString(h.Sum(nil))
}

func HmacSHA1(key string, data string) string {
	mac := hmac.New(sha1.New, []byte(key))
	mac.Write([]byte(data))
	return hex.EncodeToString(mac.Sum(nil))
}

func HmacSHA256(key, data string) string {
	mac := hmac.New(sha256.New, []byte(key))
	mac.Write([]byte(data))
	return hex.EncodeToString(mac.Sum(nil))
}
func SHA256(data string) string {
	hash := sha256.New()
	hash.Write([]byte(data))
	hashed := hash.Sum(nil)
	return hex.EncodeToString(hashed)
}

func HmacSHA512(key, data string) string {
	mac := hmac.New(sha512.New, []byte(key))
	mac.Write([]byte(data))
	return hex.EncodeToString(mac.Sum(nil))
}

func Hmac_SHA3_SHA512(key, data string) string {
	mac := hmac.New(sha3.New512, []byte(key))
	mac.Write([]byte(data))
	return hex.EncodeToString(mac.Sum(nil))
}

// base64编码
func Base64EncodeStr(src string) string {
	return string(base64.StdEncoding.EncodeToString([]byte(src)))
}

// base64解码
func Base64DecodeStr(src string) string {
	a, err := base64.StdEncoding.DecodeString(src)
	if err != nil {
		return ""
	}
	return string(a)
}

// 加密数据
func AesEncrypt(origData, key []byte) ([]byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}
	blockSize := block.BlockSize()
	origData = PKCS5Padding(origData, blockSize)
	blockMode := cipher.NewCBCEncrypter(block, key[:blockSize])
	crypted := make([]byte, len(origData))
	blockMode.CryptBlocks(crypted, origData)
	return crypted, nil
}

// 解密数据
func AesDecrypt(crypted, key []byte) ([]byte, error) {
	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}
	blockSize := block.BlockSize()
	blockMode := cipher.NewCBCDecrypter(block, key[:blockSize])
	origData := make([]byte, len(crypted))

	blockMode.CryptBlocks(origData, crypted)
	origData = PKCS5UnPadding(origData)
	return origData, nil
}

// 加密解密需要数据一定的格式， 如果愿数据不符合要求，需要加一些padding
func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(ciphertext, padtext...)
}

// 加密解密需要数据一定的格式， 如果愿数据不符合要求，需要加一些padding
func PKCS5UnPadding(origData []byte) []byte {
	length := len(origData)
	unpadding := int(origData[length-1])
	return origData[:(length - unpadding)]
}

// 根据经纬度计算两点之间距离(米)
func GetDistance(lat1, lng1, lat2, lng2 float64) float64 {
	radius := 6378137.0 //赤道半径
	rad := math.Pi / 180.0
	lat1 = lat1 * rad
	lng1 = lng1 * rad
	lat2 = lat2 * rad
	lng2 = lng2 * rad
	theta := lng2 - lng1
	dist := math.Acos(math.Sin(lat1)*math.Sin(lat2) + math.Cos(lat1)*math.Cos(lat2)*math.Cos(theta))
	return dist * radius
}

// HttpSMSCode请求并获取返回信息
func HttpSMSCode(number, smsSendMsg, authSecret, smsPostUrl, code string) (string, error) {

	//发送的验证码短息内容
	sendMsg := fmt.Sprintf(smsSendMsg, code)

	//设置提交数据
	data := struct {
		AuthSecret string `json:"authSecret"`
		Number     string `json:"number"`
		Sms        string `json:"sms"`
	}{
		AuthSecret: authSecret,
		Number:     number,
		Sms:        sendMsg,
	}

	buf, _ := json.Marshal(data)

	msg := string(buf)
	log.Debug("httpSMSCode data=%s", msg)

	//请求
	body := HttpPostByJson(smsPostUrl, msg)

	//打印返回文本
	return string(body), nil
}

// HttpSMSSend请求并获取返回信息
func HttpSMSSend(phone, smsSendMsg, smsAppID, smsApiKey, smsPostUrl string) (string, error) {
	if phone == "" || smsSendMsg == "" || smsAppID == "" || smsApiKey == "" || smsPostUrl == "" {
		return "空信息", nil
	}

	client := http.Client{}

	// 设置提交数据
	data := fmt.Sprintf("account=%v&password=%v&mobile=%v&content=%v",
		smsAppID, smsApiKey, phone, smsSendMsg)

	log.Debug("httpPostSMSCode data=%v", data)

	// 请求
	request, err := http.NewRequest("POST", smsPostUrl, strings.NewReader(data))
	if err != nil {
		log.Release("httpPostSMSCode send Request failer err=%v", err)
		return "", err // handle error
	}

	// 设置Content-Type
	request.Header.Set("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8")

	response, err := client.Do(request) // 返回
	if err != nil {
		log.Release("httpPostSMSCode client.Do return failer err=%v", err)
		return "", err
	}

	defer response.Body.Close()

	body, err := io.ReadAll(response.Body)
	if err != nil {
		return "", err
	}

	// 打印返回文本
	log.Debug(string(body))
	return string(body), nil
}

// HttpWithdraw请求提现并获取返回信息
func HttpWithdraw(postUrl, data string) (string, error) {

	//log.Debug("HttpWithdraw postUrl=%s  data=%s", postUrl, data)

	client := http.Client{}

	//请求
	request, err := http.NewRequest("POST", postUrl, strings.NewReader(data))
	//request, err := http.NewRequest("GET", url, nil)
	if err != nil {
		log.Release("HttpWithdraw send Request failer err=%v", err)
		return "", err // handle error
	}

	//设置Content-Type
	request.Header.Set("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8")

	response, err := client.Do(request) //返回
	if err != nil {
		log.Release("HttpWithdraw client.Do return failer err=%v", err)
		return "", err
	}

	defer response.Body.Close()

	body, err := io.ReadAll(response.Body)
	if err != nil {
		return "", err
	}

	//打印返回文本
	//log.Debug(string(body))
	return string(body), nil
}

// 检查手机号并返回手机号
func CheckTelValid(tel string) (string, error) {
	reg := regexp.MustCompile(`^(\()?(\+62|62|0)(\d{2,3})?\)?[ .-]?\d{2,4}[ .-]?\d{2,4}[ .-]?\d{2,4}$`)
	matchs := reg.FindStringSubmatch(tel)
	if len(matchs) <= 0 {
		errString := fmt.Sprintf("tel format fail %s", tel)
		return "", errors.New(errString)
	}

	return tel, nil
}

func Sha256WithRsa(source, secret string) string {
	decodeString, err := base64.StdEncoding.DecodeString(secret)
	if err != nil {
		panic(err)
	}
	private, err := x509.ParsePKCS8PrivateKey(decodeString)
	if err != nil {
		panic(err)
	}

	//h := crypto.Hash.New(crypto.SHA256)
	h := sha256.New()
	h.Write([]byte(source))
	hashed := h.Sum(nil)
	signature, err := rsa.SignPKCS1v15(rand.Reader, private.(*rsa.PrivateKey),
		crypto.SHA256, hashed)
	if err != nil {
		panic(err)
	}

	return base64.StdEncoding.EncodeToString(signature)
}

// 根据SHA256WithRSA算法获取签名对象实例
func VerifyRsaSignBySHA256(content string, sign string, publicKey string) error {
	publicKeyByte, err := base64.StdEncoding.DecodeString(publicKey)
	if err != nil {
		return err
	}
	pub, err := x509.ParsePKIXPublicKey(publicKeyByte)
	if err != nil {
		return err
	}
	hashed := sha256.Sum256([]byte(content))
	signature, err := base64.StdEncoding.DecodeString(sign)
	if err != nil {
		return err
	}
	return rsa.VerifyPKCS1v15(pub.(*rsa.PublicKey), crypto.SHA256, hashed[:], signature)
}

// 根据SHA1WithRSA算法获取签名对象实例
func VerifyRsaSignBySHA1(content string, sign string, publicKey string) error {
	publicKeyByte, err := base64.StdEncoding.DecodeString(publicKey)
	if err != nil {
		return err
	}
	pub, err := x509.ParsePKIXPublicKey(publicKeyByte)
	if err != nil {
		return err
	}
	hashed := sha1.Sum([]byte(content))
	signature, err := base64.StdEncoding.DecodeString(sign)
	if err != nil {
		return err
	}
	return rsa.VerifyPKCS1v15(pub.(*rsa.PublicKey), crypto.SHA1, hashed[:], signature)
}

func CheckMobile(phone string) bool {
	// 匹配规则
	// ^1第一位为一
	// [345789]{1} 后接一位345789 的数字
	// \\d \d的转义 表示数字 {9} 接9位
	// $ 结束符
	regRuler := "^1[345789]{1}\\d{9}$"

	// 正则调用规则
	reg := regexp.MustCompile(regRuler)

	// 返回 MatchString 是否匹配
	return reg.MatchString(phone)
}

const (
	letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

	// 6 bits to represent a letter index
	letterIdBits = 6
	// All 1-bits as many as letterIdBits
	letterIdMask = 1<<letterIdBits - 1
	letterIdMax  = 63 / letterIdBits
)

// 指定随机的字符串
func RandStr(n int) string {
	var src = mathRand.NewSource(time.Now().UnixNano())
	b := make([]byte, n)
	// A rand.Int63() generates 63 random bits, enough for letterIdMax letters!
	for i, cache, remain := n-1, src.Int63(), letterIdMax; i >= 0; {
		if remain == 0 {
			cache, remain = src.Int63(), letterIdMax
		}
		if idx := int(cache & letterIdMask); idx < len(letters) {
			b[i] = letters[idx]
			i--
		}
		cache >>= letterIdBits
		remain--
	}
	return *(*string)(unsafe.Pointer(&b))
}

// 解密【模拟了Java SHA1PRNG处理】
func Sha1Decrypt(data, key string) (string, error) {
	dataByte, _ := Hex2bin(data)
	keys, err := AesSha1prng([]byte(key), 128)
	if err != nil {
		return "", err
	}
	block, err := aes.NewCipher(generateKey(keys))
	if err != nil {
		return "", err
	}
	decrypted := make([]byte, len(dataByte))
	size := block.BlockSize()
	for bs, be := 0, size; bs < len(dataByte); bs, be = bs+size, be+size {
		block.Decrypt(decrypted[bs:be], dataByte[bs:be])
	}
	decrypted = PKCS5UnPadding(decrypted)
	return string(decrypted), nil
}

// 加密【模拟了Java SHA1PRNG处理】
func Sha1Encrypt(data, key []byte) (string, error) {
	keys, err := AesSha1prng(key, 128)
	if err != nil {
		return "", err
	}
	block, err := aes.NewCipher(generateKey(keys))
	if err != nil {
		return "", err
	}
	data = PKCS5Padding(data, block.BlockSize())
	decrypted := make([]byte, len(data))
	size := block.BlockSize()
	for bs, be := 0, size; bs < len(data); bs, be = bs+size, be+size {
		block.Encrypt(decrypted[bs:be], data[bs:be])
	}
	return Bin2hex(decrypted), nil
}

// 模拟java SHA1PRNG 处理
func AesSha1prng(keyBytes []byte, encryptLength int) ([]byte, error) {
	hashs := Sha1(Sha1(keyBytes))
	maxLen := len(hashs)
	realLen := encryptLength / 8
	if realLen > maxLen {
		return nil, errors.New("invalid length")
	}

	return hashs[0:realLen], nil
}

func Sha1(data []byte) []byte {
	h := sha1.New()
	h.Write(data)
	bs := h.Sum(nil)
	h.Reset()
	return bs
}

// 生成密钥
func generateKey(key []byte) (genKey []byte) {
	genKey = make([]byte, 16)
	copy(genKey, key)
	for i := 16; i < len(key); {
		for j := 0; j < 16 && i < len(key); j, i = j+1, i+1 {
			genKey[j] ^= key[i]
		}
	}
	return genKey
}

func Bin2hex(b []byte) string {
	return base64.StdEncoding.EncodeToString(b)
}

func Hex2bin(x string) ([]byte, error) {
	return base64.StdEncoding.DecodeString(x)
}

// MD5withRSA 签名
func MD5withRSASign(params url.Values, keys string) error {
	quUrl, err := url.QueryUnescape(params.Encode())
	if err != nil {
		return err
	}
	out, err := rsaSignWithMd5(quUrl, keys)
	if err != nil {
		return err
	}
	params.Add("sign", out)
	return nil
}

// 签名开始
func rsaSignWithMd5(data string, prvKey string) (sign string, err error) {
	//如果密钥是urlSafeBase64的话需要处理下
	prvKey = Base64URLDecode(prvKey)
	keyBytes, err := base64.StdEncoding.DecodeString(prvKey)
	if err != nil {
		return "", err
	}
	privateKey, err := x509.ParsePKCS8PrivateKey(keyBytes)
	if err != nil {
		return "", err
	}
	h := md5.New()
	h.Write([]byte(data))
	hash := h.Sum(nil)
	signature, err := rsa.SignPKCS1v15(rand.Reader, privateKey.(*rsa.PrivateKey), crypto.MD5, hash[:])
	if err != nil {
		return "", err
	}
	out := base64.RawURLEncoding.EncodeToString(signature)
	return out, nil
}

// 验签（MD5withRSA）
func VerifyMD5withRSA(params url.Values, key string) error {
	sign := params.Get("sign")
	params.Del("sign")
	quUrl, _ := url.QueryUnescape(params.Encode())
	return rsaVerifySignWithMd5(quUrl, sign, key)
}

// 验签开始
func rsaVerifySignWithMd5(originalData, signData, pubKey string) error {
	sign, err := base64.RawURLEncoding.DecodeString(signData)
	if err != nil {
		return err
	}
	pubKey = Base64URLDecode(pubKey)
	public, err := base64.StdEncoding.DecodeString(pubKey)
	if err != nil {
		return err
	}
	pub, err := x509.ParsePKIXPublicKey(public)
	if err != nil {
		return err
	}
	hash := md5.New()
	hash.Write([]byte(originalData))
	return rsa.VerifyPKCS1v15(pub.(*rsa.PublicKey), crypto.MD5, hash.Sum(nil), sign)
}

// MD5withRSA 解密
func MD5withRSADecrypt(sign, privateKey string) string {
	key := chunkSplit(privateKey, 64, "\n")
	key = fmt.Sprintf("-----BEGIN RSA PRIVATE KEY-----\n%s\n-----END RSA PRIVATE KEY-----", key)
	decodedBytes, err := base64.StdEncoding.DecodeString(sign)
	if err != nil {
		return ""
	}
	block, _ := pem.Decode([]byte(key))
	if block == nil {
		return ""
	}
	keys, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return ""
	}
	resCrypto := ""
	for _, v := range strSplit(string(decodedBytes), 128) {
		// 使用 RSA 私钥解密密文
		plaintext, errs := rsa.DecryptPKCS1v15(rand.Reader, keys.(*rsa.PrivateKey), []byte(v))
		if errs != nil {
			return ""
		}
		resCrypto += string(plaintext)
	}
	return resCrypto
}

// 字符串分割密文
func strSplit(s string, chunkSize int) []string {
	var chunks []string
	for i := 0; i < len(s); i += chunkSize {
		end := i + chunkSize
		if end > len(s) {
			end = len(s)
		}
		chunks = append(chunks, s[i:end])
	}
	return chunks
}

// 块分割
func chunkSplit(s string, chunkLen int, separator string) string {
	var result strings.Builder
	for i := 0; i < len(s); i += chunkLen {
		end := i + chunkLen
		if end > len(s) {
			end = len(s)
		}
		result.WriteString(s[i:end])
		if end < len(s) {
			result.WriteString(separator)
		}
	}
	return result.String()
}

//因为Base64转码后可能包含有+,/,=这些不安全的URL字符串，所以要进行换字符
// '+' -> '-'
// '/' -> '_'
// '=' -> ''
// 字符串长度不足4倍的位补"="

func Base64URLDecode(data string) string {
	var missing = (4 - len(data)%4) % 4
	data += strings.Repeat("=", missing) //字符串长度不足4倍的位补"="
	data = strings.Replace(data, "_", "/", -1)
	data = strings.Replace(data, "-", "+", -1)
	return data
}

func Base64UrlSafeEncode(data string) string {
	safeUrl := strings.Replace(data, "/", "_", -1)
	safeUrl = strings.Replace(safeUrl, "+", "-", -1)
	safeUrl = strings.Replace(safeUrl, "=", "", -1)
	return safeUrl
}

// 生成码
func GenCode(length int) string {
	var chars = []byte("ABCDEFGHJKLMNPQRTUVWXYZ123456789")
	code := make([]byte, length)
	clen := len(chars)
	for i := 0; i < length; i++ {
		index := mathRand.Intn(clen)
		code[i] = byte(chars[index])
	}

	return string(code)
}

// SlicePage 分页算法(pageIndex 页索引、pageSize 页大小、nums 总记录数)
// exploreList := manager.Mgr.GetExploreList()
//
//	totalCount := len(exploreList)
//	start, end := public.SlicePage(req.PageIndex, req.PageSize, totalCount)
//	rsp.RecordCount = totalCount
//	rsp.List = this.getOwnerList(exploreList[start:end])
func SlicePage(pageIndex, pageSize, nums int) (start, end int) {
	if pageIndex <= 0 {
		pageIndex = 1
	}

	if pageSize < 0 {
		pageSize = 10
	}

	if pageSize > nums {
		return 0, nums
	}

	// 计算起始行
	start = (pageIndex - 1) * pageSize

	// 计算终止行
	end = start + pageSize

	if end > nums {
		end = nums
	}

	if start > end {
		return 0, 0
	}

	// 起始、终止位置
	return start, end
}