package com.zjrs.ggfw.portal.utils;


import com.zjrs.ggfw.portal.controller.EMSController;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

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

/**
 * AES加解密工具类
 */
public class AESUtil {
    private static final Logger LOG = LoggerFactory.getLogger(EMSController.class);
    /**
     * 加密
     *
     * @param content  需要加密的内容
     * @param password 加密密码
     * @return
     */
    public static String encrypt(String content, String password) {
        try {
            SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes());
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, secureRandom);
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            byte[] byteContent = content.getBytes("UTF-8");
            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
            String result = parseByte2HexStr(cipher.doFinal(byteContent));//加密
            return result;
        } catch (Exception e) {
            LOG.error(("[AESUtil.encrypt]加密异常"));
            return null;
        }

    }

    /**
     * 解密
     *
     * @param content  待解密内容
     * @param password 解密密钥
     * @return
     */
    public static String decrypt(String content, String password){
        try{
            SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes());
            byte[] contentTemp = parseHexStr2Byte(content);
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, secureRandom);
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
            String result = new String(cipher.doFinal(contentTemp), "UTF-8");//解密
            return result;
        }catch (Exception e){
            LOG.error(("[AESUtil.encrypt]解密异常"));
            return null;
        }
    }

    /**
     * 解密
     *
     * @param content  待解密内容
     * @param password 解密密钥
     * @return
     */
    public static String decrypt(String content, String password, String encryptedSign) {
        try {
            Integer num = null;
            if (!StringUtils.isEmpty(encryptedSign)) {
                num = Integer.valueOf(encryptedSign);
            }
            SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
            secureRandom.setSeed(password.getBytes());
            byte[] contentTemp = parseHexStr2Byte(content);
            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(num, secureRandom);
            SecretKey secretKey = kgen.generateKey();
            byte[] enCodeFormat = secretKey.getEncoded();
            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
            Cipher cipher = Cipher.getInstance("AES");// 创建密码器
            cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
            String result = new String(cipher.doFinal(contentTemp), "UTF-8");//解密
            return result;
        } catch (Exception e) {
            LOG.error(("[AESUtil.encrypt]解密异常"));
            return null;
        }

    }

    /**
     * 将二进制转换成16进制
     *
     * @param buf
     * @return
     */
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    /**
     * 将16进制转换为二进制
     *
     * @param hexStr
     * @return
     */
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }
}
