package crypter

import (
	"encoding/hex"
	"errors"
	"log"
	"strings"

	"crypto/rand"

	"fmt"

	"github.com/tjfoc/gmsm/sm2"
	"github.com/tjfoc/gmsm/x509"
)

func Sm2EncryptWithHexKey(message string, public_key string) (string, error) {

	sm2PubKey, err := x509.ReadPublicKeyFromHex(public_key)
	if err != nil {
		fmt.Println("Error parsing SM2 public key:", err)
		return "", err
	}

	// 待加密的数据
	data := []byte(message)

	// 使用SM2公钥加密数据
	ciphertext, err := sm2.Encrypt(sm2PubKey, data, rand.Reader, sm2.C1C3C2)
	if err != nil {
		log.Println("Error encrypting data with SM2:", err)
		return "", errors.New("Error encrypting data with SM2," + err.Error())
	}

	if err != nil {
		log.Println("Error encrypting data with SM2:", err)
		return "", errors.New("Error encrypting data with SM2")
	}

	return hex.EncodeToString(ciphertext), nil
	// return base64.StdEncoding.EncodeToString(ciphertext), nil

}

func Sm2DecryptWithHexKey(message string, private_key string) (string, error) {

	sm2PriKey, err := x509.ReadPrivateKeyFromHex(private_key)
	if err != nil {
		fmt.Println("Error parsing SM2 private key:", err)
		return "", err
	}
	// 待加密的数据
	data, err := hex.DecodeString(message) //base64.StdEncoding.DecodeString(message) //
	if err != nil {
		fmt.Println("Error base64 message:", err)
		return "", err
	}

	// 使用SM2私钥加密数据
	ciphertext, err := sm2.Decrypt(sm2PriKey, data, sm2.C1C3C2)
	if err != nil {
		log.Println("Error decrypting data with SM2:", err)
		return "", errors.New("Error encrypting data with SM2:" + err.Error())
	}

	return string(ciphertext), nil

}

func CreateHexKey() (string, string, error) {
	// 生成SM2密钥对
	priv, err := sm2.GenerateKey(rand.Reader)
	if err != nil {
		return "", "", err
	}
	// 将私钥转换为PEM格式的字符串
	privPem := x509.WritePrivateKeyToHex(priv)

	pubPem := x509.WritePublicKeyToHex(priv.Public().(*sm2.PublicKey))

	return strings.ToUpper(privPem), strings.ToUpper(pubPem), err
}