package com.ssm.manage.utils;


import com.alibaba.fastjson.JSONObject;
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.AlgorithmParameters;
import java.security.Security;
import java.util.Arrays;

public class authorizedLoginUtil {

    /**
     * 小程序授权登录发送请求获取openid等参数
     * @param code 登录时获取的 code
     * @return
     */
//    public static Map authorizedLoginGet(String code){
//        JsonNode jsonNode = HttpUtils.doGet("https://api.weixin.qq.com/sns/jscode2session"
//                +"?appid="+WxLoginControlller.APPID //小程序appid
//                +"&secret="+WxLoginControlller.APP_SECRET //小程序appSecret
//                +"&js_code="+code //登录时获取的 code
//                +"&grant_type=authorization_code"); //授权类型,固定值authorization_code
//        Map map = new ObjectMapper().convertValue(jsonNode, Map.class);
//        return map;
//    }

    /**
     * 使用前端传过来的encryptedData解密
     * @param encryptedData
     * @param sessionKey 发送请求获取的sessionKey
     * @param iv
     * @return
     */
    public static JSONObject useEncryptedDataDecode(String encryptedData, String sessionKey, String iv){
        // 被加密的数据
        byte[] dataByte = Base64.decode(encryptedData);
        // 加密秘钥
        byte[] keyByte = Base64.decode(sessionKey);
        // 偏移量
        byte[] ivByte = Base64.decode(iv);

        try {
            // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                JSONObject jsonObject = JSONObject.parseObject(result);
                return jsonObject ;

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

}
