package common

import (
	"crypto/aes"
	"crypto/cipher"
	"encoding/base64"
	"github.com/gogf/gf/v2/crypto/gmd5"
	"strings"
)

// 假设p()就是md5
func p(data string) []byte {
	return []byte(gmd5.MustEncryptString(data))
}

//func p(hexStr string) []byte {
//	bytes, _ := hex.DecodeString(hexStr)
//	return bytes
//}

func Encrypt(plaintext string, keyPrefix string) (string, error) {

	// 生成key和iv
	key := p(keyPrefix + "piaofan@123")
	iv := p(keyPrefix + "piaofan@456")[:16]

	// plaintext to bytes
	plaintextBytes := []byte(plaintext)

	// 创建AES加密器
	block, err := aes.NewCipher(key)
	if err != nil {
		return "", err
	}

	// 初始化CBC模式
	stream := cipher.NewCBCEncrypter(block, iv)

	// 加密
	ciphertext := make([]byte, len(plaintextBytes))
	stream.CryptBlocks(ciphertext, plaintextBytes)

	// 返回base64编码的ciphertext
	return base64.StdEncoding.EncodeToString(ciphertext), nil

}

func Decrypt(base64Ciphertext string, keyPrefix string) (string, error) {
	// base64解码ciphertext
	ciphertext, err := base64.StdEncoding.DecodeString(base64Ciphertext)
	if err != nil {
		return "", err
	}

	// 生成key和iv
	key := p(keyPrefix + "piaofan@123")
	iv := p(keyPrefix + "piaofan@456")[:16]

	//g.Log().Infof(context.Background(), "key: %s", gconv.String(key))

	// 创建AES解密器
	block, err := aes.NewCipher(key)
	if err != nil {
		return "", err
	}

	// 初始化CBC模式
	stream := cipher.NewCBCDecrypter(block, iv)

	// 解密
	plaintext := make([]byte, len(ciphertext))
	stream.CryptBlocks(plaintext, ciphertext)

	return strings.TrimSpace(string(plaintext)), nil

}