package ink.wgink.util;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.StringUtils;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;
import java.security.Security;

public class AesUtil {

    private static final String IV_STRING = "16-Bytes--String";
    /**
     * PKCS#7
     */
    public static final String PKCS_7 = "PKCS7Padding";
    /**
     * PKCS#5
     */
    public static final String PKCS_5 = "PKCS5Padding";

    /**
     * AES加密
     *
     * @param encodeRule
     * @param content
     * @return
     * @throws Exception
     */
    public static String aesEncoder(String encodeRule, String content) {
        try {
            // 1.构造秘钥生成器
            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
            // 2.根据编码规则构建秘钥生成器
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(encodeRule.getBytes());
            keyGenerator.init(128, random);
            // 3.产生堆成秘钥
            SecretKey secretKey = keyGenerator.generateKey();
            // 4.对称秘钥原始数组
            byte[] secretKeyByte = secretKey.getEncoded();
            // 5.生成AES秘钥
            SecretKey key = new SecretKeySpec(secretKeyByte, "AES");
            // 6.初始化密码器
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            // 8.获取加密内容字节数组
            byte[] contentByte = content.getBytes("UTF-8");
            // 9.加密
            return new String(Base64.encodeBase64(cipher.doFinal(contentByte)));
        } catch (Exception e) {
            throw new AesEncodeException(e.getMessage(), e);
        }
    }

    /**
     * AES解密
     *
     * @param encodeRule
     * @param content
     * @return
     */
    public static String aesDecoder(String encodeRule, String content) {
        try {
            // 1.构建秘钥生成器
            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
            // 2.根据编码规则构建秘钥生成器
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(encodeRule.getBytes());
            keyGenerator.init(128, random);
            // 3.生成对称解密秘钥
            SecretKey secretKey = keyGenerator.generateKey();
            // 4.对称秘钥原始数组
            byte[] secretKeyByte = secretKey.getEncoded();
            // 5.生成AES秘钥
            SecretKey key = new SecretKeySpec(secretKeyByte, "AES");
            // 6.初始化密码器
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, key);
            // 7.要解密内容的字节数组
            byte[] contentByte = Base64.decodeBase64(content);
            // 8.解密
            return new String(cipher.doFinal(contentByte), "UTF-8");
        } catch (Exception e) {
            throw new AesDecodeException(e.getMessage(), e);
        }
    }

    /**
     * 通用aes加密，兼容IOS
     *
     * @param key
     * @param content
     * @return
     */
    public static String aesCommonEncoder(String key, String content) {
        try {
            byte[] encryptedBytes = aesCommonEncodeDetail(key, content, IV_STRING.getBytes(), PKCS_5);
            return new String(Base64.encodeBase64(encryptedBytes), "UTF-8");
        } catch (Exception e) {
            throw new AesEncodeException(e.getMessage(), e);
        }
    }

    /**
     * 通用aes加密，兼容IOS
     *
     * @param key
     * @param content
     * @param paddingType
     * @return
     */
    public static byte[] aesCommonEncodeDetail(String key, String content, byte[] ivBytes, String paddingType) {
        try {
            byte[] byteContent = content.getBytes("UTF-8");
            byte[] enCodeFormat = key.getBytes();
            SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
            IvParameterSpec ivParameterSpec = new IvParameterSpec(ivBytes);
            if (StringUtils.equals(paddingType, PKCS_7)) {
                Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            }
            Cipher cipher = Cipher.getInstance("AES/CBC/" + paddingType);
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
            return cipher.doFinal(byteContent);
        } catch (Exception e) {
            throw new AesEncodeException(e.getMessage(), e);
        }
    }

    /**
     * aes通用解密，兼容IOS
     *
     * @param key
     * @param content
     * @return
     * @throws Exception
     */
    public static String aesCommonDecoder(String key, String content) {
        try {
            byte[] encryptedBytes = Base64.decodeBase64(content);
            byte[] keyBytes = key.getBytes();
            byte[] result = aesCommonDecoderDetail(keyBytes, encryptedBytes, IV_STRING.getBytes(), PKCS_5);
            return new String(result, "UTF-8");
        } catch (Exception e) {
            throw new AesDecodeException(e.getMessage(), e);
        }

    }

    /**
     * aes cbc 通用解密
     *
     * @param keyBytes       秘钥字节数组
     * @param encryptedBytes 密文字节数组
     * @param ivBytes        向量字节数组
     * @param paddingType    填充类型
     * @return
     */
    public static byte[] aesCommonDecoderDetail(byte[] keyBytes, byte[] encryptedBytes, byte[] ivBytes, String paddingType) {
        try {
            SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");
            IvParameterSpec ivParameterSpec = new IvParameterSpec(ivBytes);
            Cipher cipher;
            if (StringUtils.equals(paddingType, PKCS_7)) {
                Security.addProvider(new BouncyCastleProvider());
            }
            cipher = Cipher.getInstance("AES/CBC/" + paddingType);
            cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);
            return cipher.doFinal(encryptedBytes);
        } catch (Exception e) {
            throw new AesDecodeException(e.getMessage(), e);
        }
    }

    /**
     * AES解密异常
     */
    public static class AesDecodeException extends RuntimeException {

        public AesDecodeException() {
        }

        public AesDecodeException(String message) {
            super(message);
        }

        public AesDecodeException(String message, Throwable cause) {
            super(message, cause);
        }

        public AesDecodeException(Throwable cause) {
            super(cause);
        }

        public AesDecodeException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
            super(message, cause, enableSuppression, writableStackTrace);
        }
    }

    /**
     * AES加密异常
     */
    public static class AesEncodeException extends RuntimeException {

        public AesEncodeException() {
        }

        public AesEncodeException(String message) {
            super(message);
        }

        public AesEncodeException(String message, Throwable cause) {
            super(message, cause);
        }

        public AesEncodeException(Throwable cause) {
            super(cause);
        }

        public AesEncodeException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
            super(message, cause, enableSuppression, writableStackTrace);
        }
    }

}