package io.dataease.utils;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.StringUtils;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import static java.nio.charset.StandardCharsets.UTF_8;

public class AesUtils {

    public static String aesDecrypt(String src, String secretKey, String iv) {
        if (StringUtils.isBlank(secretKey)) {
            throw new RuntimeException("secretKey is empty");
        }
        try {
            byte[] raw = secretKey.getBytes(UTF_8);
            SecretKeySpec secretKeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec iv1 = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, iv1);
            byte[] encrypted1 = Base64.decodeBase64(src);
            byte[] original = cipher.doFinal(encrypted1);
            return new String(original, UTF_8);
        } catch (BadPaddingException | IllegalBlockSizeException e) {
            // 解密的原字符串为非加密字符串，则直接返回原字符串
            return src;
        } catch (Exception e) {
            throw new RuntimeException("decrypt error，please check parameters", e);
        }
    }
}