package com.newyetai.common.util;

import java.nio.charset.StandardCharsets;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.springframework.util.Base64Utils;


/**
 * @author sr on 2024-02-22 
 */
public class AESUtils {

  public static final String TRANSFORM_ECB_5 = "AES/ECB/PKCS5Padding";
  public static final String TRANSFORM_ECB_7 = "AES/ECB/PKCS7Padding";
  public static final String TRANSFORM_ECB = "AES/ECB/NoPadding";

  static {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
  }
  
  public static Cipher getCipher(String transform) throws Exception {
    if (TRANSFORM_ECB_7.equals(transform)) {
      return Cipher.getInstance(transform, "BC");
    } else {
      return Cipher.getInstance(transform);
    }
  }

  public static String encrypt(String input, String key, String transform) throws Exception {
    Cipher cipher = getCipher(transform);
    SecretKey keySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "AES");
    cipher.init(Cipher.ENCRYPT_MODE, keySpec);
    return Base64Utils.encodeToString(cipher.doFinal(input.getBytes(StandardCharsets.UTF_8)));
  }

  public static String decrypt(String input, String key, String transform)
      throws Exception {
    Cipher cipher = getCipher(transform);
    SecretKey keySpec = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), "AES");
    cipher.init(Cipher.DECRYPT_MODE, keySpec);
    return new String(cipher.doFinal(Base64Utils.decode(input.getBytes(StandardCharsets.UTF_8))),
        StandardCharsets.UTF_8);
  }

}