import (
   "context"
   "crypto/rand"
   "crypto/rsa"
   "crypto/x509"
   "encoding/base64"
   "fmt"
   "github.com/wechatpay-apiv3/wechatpay-go/core"
   "github.com/wechatpay-apiv3/wechatpay-go/core/option"
   "github.com/wechatpay-apiv3/wechatpay-go/utils"
   "log"
   "net/http"
)

var (
   mchID                      = ""                  // merchant id
   mchCertificateSerialNumber = "" // merchant certificate serial number
   mchAPIv3Key                = ""                  // merchant api v3 key
   header                     = make(http.Header)
   ctx                        = context.Background()
   cert                       *x509.Certificate
   mchPrivateKey              *rsa.PrivateKey
   client                     *core.Client
   err                        error
)

func setup() {
   //Load platform certificate
   cert, err = utils.LoadCertificateWithPath("Path/To/Platform/Cert")
   if err != nil {
      log.Fatal(err)
   }
   // Load private key
   mchPrivateKey, err = utils.LoadPrivateKeyWithPath("Path/To/Private/Key")
   if err != nil {
      log.Fatal("load merchant private key error")
   }
   // Initialize client which is capable to update platform certificate periodically
   opts := []core.ClientOption{
      option.WithWechatPayAutoAuthCipher(mchID, mchCertificateSerialNumber, mchPrivateKey, mchAPIv3Key),
   }
   client, err = core.NewClient(ctx, opts...)
   if err != nil {
      log.Fatalf("new wechat pay client err:%s", err)
   }
}
        

func Encryption(t *testing.T) {
	var testRSACryptoUtilMchCertificateStr = `-----BEGIN CERTIFICATE-----
	-----END CERTIFICATE-----`
	testRSACryptoUtilCertificate, _ = LoadCertificate(testRSACryptoUtilMchCertificateStr)
   const message = "hello world"
   
   // 使用OAEP padding方式對證書加密
   ciphertext, _ := EncryptOAEPWithCertificate(message, testRSACryptoUtilCertificate)
   
   // 使用PKCS1 padding對證書加密
   ciphertext, _ := EncryptPKCS1v15WithCertificate(message, testRSACryptoUtilCertificate)
}
  

func TestDecryption(t *testing.T) {
	var testRSACryptoUtilPrivateKeyStr = `-----BEGIN PRIVATE KEY-----
-----END PRIVATE KEY-----`
	testRSACryptoUtilPrivateKey, _ = LoadPrivateKey(testingKey(testRSACryptoUtilPrivateKeyStr))
	const ciphertext = ""

	// 使用PKCS1 padding進行私鑰解密
	decryptMessage, _ := DecryptPKCS1v15(ciphertext, testRSACryptoUtilPrivateKey)

	// 使用OAEP padding方式私鑰解密
	decryptMessage, _ := DecryptOAEP(ciphertext, testRSACryptoUtilPrivateKey)
}

require_once('vendor/autoload.php');

use WeChatPay\Builder;
use WeChatPay\Crypto\Rsa;
use WeChatPay\Util\PemUtil;

$merchantId = '190000****';
$merchantPrivateKeyFilePath = 'file:///path/to/merchant/apiclient_key.pem';
$merchantPrivateKeyInstance = Rsa::from($merchantPrivateKeyFilePath, Rsa::KEY_TYPE_PRIVATE);
$merchantCertificateSerial = '3775B6A45ACD588826D15E583A95F5DD********';
$platformCertificateFilePath = 'file:///path/to/wechatpay/cert.pem';
$platformPublicKeyInstance = Rsa::from($platformCertificateFilePath, Rsa::KEY_TYPE_PUBLIC);
$platformCertificateSerial = PemUtil::parseCertificateSerialNo($platformCertificateFilePath);

// init a API V3 instance
$instance = Builder::factory([
    'mchid'      => $merchantId,
    'serial'     => $merchantCertificateSerial,
    'privateKey' => $merchantPrivateKeyInstance,
    'certs'      => [
        $platformCertificateSerial => $platformPublicKeyInstance,
    ],
]); 
        

    $encryptor = static function(string $msg) use ($platformPublicKeyInstance): string {
        return Rsa::encrypt($msg, $platformPublicKeyInstance, OPENSSL_PKCS1_PADDING);
    };
	$encryptedMsg =  $encryptor('HelloWorld');
  

    $decryptor = static function(string $msg) use ($merchantPrivateKeyInstance): string {
        return Rsa::decrypt($msg, $merchantPrivateKeyInstance, OPENSSL_PKCS1_PADDING);
    };
	$decryptedMsg =  $decryptor('ciphertext');