package com.se.common.core.utils;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

/**
 * AES加密工具
 *
 * @author WWW
 * @date 2024-08-25
 */
@SuppressWarnings("ALL")
public class AesUtils {
    /**
     * 密钥长度必须是16
     */
    private static final String DEFAULT_KEY = "A#s_zZ_sErve_k.y";

    private static final String KEY_ALGORITHM = "AES";

    /**
     * 算法
     */
    private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";

    /**
     * aes解密
     *
     * @param encrypt 内容
     * @return
     * @throws Exception
     */
    public static String decrypt(String encrypt) throws Exception {
        return decrypt(encrypt, DEFAULT_KEY);
    }

    /**
     * aes加密
     *
     * @param content 内容
     * @return
     * @throws Exception
     */
    public static String encrypt(String content) throws Exception {
        return encrypt(content, DEFAULT_KEY);
    }

    /**
     * base 64 encode
     *
     * @param bytes 待编码的byte[]
     * @return 编码后的base64 code
     */
    private static String base64Encode(byte[] bytes) {
        return Base64.getEncoder().encodeToString(bytes);
    }

    /**
     * base 64 decode
     *
     * @param base64Code 待解码的base64 code
     * @return 解码后的byte[]
     * @throws Exception
     */
    private static byte[] base64Decode(String base64Code) {
        return StringUtils.isEmpty(base64Code) ? null : Base64.getDecoder().decode(base64Code);
    }

    /**
     * AES加密
     *
     * @param content    待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的byte[]
     * @throws Exception
     */
    private static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
        // KeyGenerator kGen = KeyGenerator.getInstance(KEY_ALGORITHM)
        // kGen.init(128)

        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), KEY_ALGORITHM));

        return cipher.doFinal(content.getBytes("utf-8"));
    }

    /**
     * AES加密为base 64 code
     *
     * @param content    待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的base 64 code
     * @throws Exception
     */
    public static String encrypt(String content, String encryptKey) throws Exception {
        return base64Encode(aesEncryptToBytes(content, encryptKey));
    }

    /**
     * 将base 64 code AES解密
     *
     * @param encryptStr 待解密的base 64 code
     * @param decryptKey 解密密钥
     * @return 解密后的string
     * @throws Exception
     */
    public static String decrypt(String encryptStr, String decryptKey) throws Exception {
        return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
    }

    /**
     * AES解密
     *
     * @param encryptBytes 待解密的byte[]
     * @param decryptKey   解密密钥
     * @return 解密后的String
     * @throws Exception
     */
    private static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
        // KeyGenerator kGen = KeyGenerator.getInstance(KEY_ALGORITHM)
        // kGen.init(128)

        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), KEY_ALGORITHM));
        byte[] decryptBytes = cipher.doFinal(encryptBytes);

        return new String(decryptBytes);
    }
}