package com.eitc.common.utils;

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

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;










public class CryptoUtil {

    private final static String IV = "1234567890123456";//需要前端与后端配置一致
    private final static String KEY = "1234567890123456";

    /***
     * 加密
     * @param  data 要加密的数据
     * @return encrypt
     */
    public static String encrypt(String data){
        return encrypt(data, KEY, IV);
    }

    public static Object decryptObject(Object obj) throws Exception{
        return ObjectUtils.decryptObjectValues(obj);
    }

    /***
     * param data 需要解密的数据
     * 调用desEncrypt（）方法
     */
    public static String decrypt(String data){
        return decrypt(data, KEY, IV);
    }

    /**
     * 加密方法
     * @param data  要加密的数据
     * @param key 加密key
     * @param iv 加密iv
     * @return 加密的结果
     */
    private static String encrypt(String data, String key, String iv){
        try {
            //"算法/模式/补码方式"NoPadding PkcsPadding
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            int blockSize = cipher.getBlockSize();

            byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }

            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);

            return Base64.encodeBase64String(encrypted);

        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 解密方法
     * @param data 要解密的数据
     * @param key  解密key
     * @param iv 解密iv
     * @return 解密的结果
     */
    private static String decrypt(String data, String key, String iv){
        try {
            if(StringUtils.isEmpty(data)) {
                return "";
            }
            byte[] encrypted1 = new Base64().decode(data);
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivSpec = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
            byte[] original = cipher.doFinal(encrypted1);
            return new String(original, StandardCharsets.UTF_8).trim();

        } catch (Exception e) {
            e.printStackTrace();
            return "解析错误";
        }
    }

    public static void main(String[] args) {
        String a = encrypt("123456");
        System.out.println(a);
        String b = decrypt(a);
        System.out.println(b);
    }
}
