package com.zhujizheng.IHome.util.aes;

import lombok.extern.slf4j.Slf4j;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import sun.security.krb5.internal.crypto.Aes128;

import java.nio.charset.StandardCharsets;
import java.security.*;
import java.util.Arrays;
import java.util.Base64;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.crypto.Data;
@Slf4j
public class AESUtil {

    private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/CBC/PKCS7Padding";// 默认的加密算法
    private static final String KEY = ".. .-.. --- ...- . .--. . -. --. -.-- .- -.";

    /**
     * AES 通用加密操作
     * @param content
     * @return 加密的字符串
     */
    public static String commonEncrypt(String content) {
        return AESUtil.encrypt(KEY, content);
    }


    /**
     * AES 加密操作
     *
     * @param content 待加密内容
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String key, String content) {
        if (content == null || content.length() <= 0) {
            return "";
        }
        try {
            Security.addProvider(new BouncyCastleProvider());
            // 实例化
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            byte[] byteContent = content.getBytes("utf-8");
            // 使用密钥初始化，设置为解密模式
            final byte[] iv = new byte[16];
            Arrays.fill(iv, (byte) 0x00);
            IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
            cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(key), ivParameterSpec);
            byte[] result = cipher.doFinal(byteContent);// 加密
            return Base64.getEncoder().encodeToString(result);// 通过Base64转码返回
        } catch (Exception ex) {
            Logger.getLogger(AESUtil.class.getName()).log(Level.SEVERE, null, ex);
        }

        return null;
    }

    /**
     * AES 通用解密操作
     * @param content
     * @return 解密的字符串
     */
    public static String commonDecrypt(String content) {
        return AESUtil.decrypt(KEY, content);
    }

    /**
     * AES 解密操作
     * @Param key
     * @param content
     * @return 解密的字符串
     */
    public static String decrypt(String key, String content) {
        if (content == null || content.length() <= 0) {
            return "";
        }
        try {
            Security.addProvider(new BouncyCastleProvider());
            // 实例化
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            // 使用密钥初始化，设置为解密模式
            final byte[] iv = new byte[16];
            Arrays.fill(iv, (byte) 0x00);
            IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
            cipher.init(Cipher.DECRYPT_MODE, getSecretKey(key), ivParameterSpec);
            byte[] base64Str = Base64.getDecoder().decode(content);
            // 执行操作
            byte[] result = cipher.doFinal(base64Str);
            return new String(result, StandardCharsets.UTF_8);
        } catch (Exception ex) {
            Logger.getLogger(AESUtil.class.getName()).log(Level.SEVERE, null, ex);
        }

        return null;
    }

    /**
     * 生成加密秘钥
     *
     * @return
     * @throws NoSuchAlgorithmException
     */
    private static SecretKeySpec getSecretKey(final String key) throws NoSuchAlgorithmException {
        byte[] utf8Key = key.getBytes(StandardCharsets.UTF_8);
        MessageDigest sha256Hash = MessageDigest.getInstance("SHA-256");
        byte[] sha256Key = sha256Hash.digest(utf8Key);
        return new SecretKeySpec(sha256Key, KEY_ALGORITHM);// 转换为AES专用密钥
    }

}