package com.moon.server.helper;

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

@SuppressWarnings("ALL")
public class AesHelper {
    private static final String DEFAULT_KEY = "A#s_lF_sErve_k.y";

    private static final String KEY_ALGORITHM = "AES";

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

    public static String decrypt(String encrypt) throws Exception {
        return decrypt(encrypt, DEFAULT_KEY);
    }

    public static String encrypt(String content) throws Exception {
        return encrypt(content, DEFAULT_KEY);
    }

    private static String base64Encode(byte[] bytes) {
        return Base64.getEncoder().encodeToString(bytes);
    }

    private static byte[] base64Decode(String base64Code) {
        return StringHelper.isEmpty(base64Code) ? null : Base64.getDecoder().decode(base64Code);
    }

    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"));
    }

    public static String encrypt(String content, String encryptKey) throws Exception {
        return base64Encode(aesEncryptToBytes(content, encryptKey));
    }

    public static String decrypt(String encryptStr, String decryptKey) throws Exception {
        return StringHelper.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
    }

    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);
    }
}