package com.yihu.jw.utils;

import com.alibaba.fastjson.JSONObject;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Map;
import java.util.TreeMap;

/**
 * @author: wangzh
 * @date: Created in 2021/10/25 9:40
 * @description:
 * @modified By:
 * @version: 0.1
 */
public class SignUtil {

    /**
     * description:
     * 1. 将jsonObject对象转换为键值以ascii值正序排列的treeMap集合,,
     * 以key1=value1,key2=value2密钥的形式拼接
     * 2. 以app_secret为key 0000000000000000为iv(向量) 进行aes-128-cbc加密 输出hex的密文(hex密文不要转成大写)
     * 3. 密文进行md5后就是sign值
     * create by: wangzh<br>
     * create time: 2022/3/18 10:50<br>
     * @param:
     * @return:
     */
    public static String buildAESMd5Sign(JSONObject jsonObject, String key, String iv){
        try {
            Map<String, Object> map = objectToMap(jsonObject);
            StringBuffer stringBuffer = new StringBuffer();
            for (Map.Entry<String, Object> entry : map.entrySet()){
                String k = entry.getKey();
                Object v = entry.getValue();
                //空值不传递，不参与签名组串
                if (null != v && !"".equals(v)) {
                    stringBuffer.append(k).append("=").append(v).append(",");
                }
            }
            // 去掉末尾的,
            String content = stringBuffer.toString();
            content = content.substring(0, content.length() - 1);
            String signAes = AesUtil.encrypt(content, key, iv);
            return toMd5(signAes);
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
    }

    /**
     * description:
     * 1. 遍历map集合,以key1=value1&key2=value2&...&key=密钥的形式拼接
     * 2. MD5加密,转换大写
     * create by: wangzh<br>
     * create time: 2021/11/4 13:45<br>
     * @param: key :
     * @return:
     */
    public static String buildSign(Map<String, Object> map, String key) {
        StringBuffer stringBuffer = new StringBuffer();
        for (Map.Entry<String, Object> entry : map.entrySet()){
            String k = entry.getKey();
            Object v = entry.getValue();
            //空值不传递，不参与签名组串
            if (null != v && !"".equals(v)) {
                stringBuffer.append(k).append("=").append(v).append("&");
            }
        }
        stringBuffer.append("key=").append(key);
        // MD5加密,结果转换为大写字符
        return toMd5(stringBuffer.toString()).toUpperCase();
    }

    /**
     * 对字符串进行MD5加密
     * @param str 需要加密的字符串
     * @return 小写MD5字符串 32位
     */
    public static String toMd5(String str) {
        String re = null;
        byte[] encrypt;
        try {
            byte[] tem = str.getBytes();
            MessageDigest md5 = MessageDigest.getInstance("md5");
            md5.reset();
            md5.update(tem);
            encrypt = md5.digest();
            StringBuilder sb = new StringBuilder();
            for (byte t : encrypt) {
                String s = Integer.toHexString(t & 0xFF);
                if (s.length() == 1) {
                    s = "0" + s;
                }
                sb.append(s);
            }
            re = sb.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return re;
    }

    /**
     * description:
     * 1.将对象转换为键值从小到大的treeMap集合<br>
     * create by: wangzh<br>
     * create time: 2021/10/25 10:13<br>
     * @param:
     * @return:
     */
    public static Map<String, Object> objectToMap(Object obj) throws Exception {
        if (obj == null){
            return null;
        }

        TreeMap<String, Object> map = new TreeMap<>();

        BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
        for (PropertyDescriptor property : propertyDescriptors) {
            String key = property.getName();
            if (key.compareToIgnoreCase("class") == 0) {
                continue;
            }
            Method getter = property.getReadMethod();
            Object value = getter != null ? getter.invoke(obj) : null;
            map.put(key, value);
        }

        return map;
    }
    
    /**
     * description: 
     * 1. 将JSONObject对象转换为键值从小到大的treeMap集合<br>
     * 2. 若JSONObject对象里还有JSONObject对象,则递归将值按key值从小到大顺序,拼接起来
     * create by: wangzh<br>
     * create time: 2021/10/25 10:18<br>
     * @param: 
     * @return: 
     */
    public static Map<String, Object> objectToMap(JSONObject obj) throws Exception {
        if (obj == null){
            return null;
        }
        TreeMap<String, Object> map = new TreeMap<>();
        for (Map.Entry<String, Object> entry : obj.getInnerMap().entrySet()) {
            map.put(entry.getKey(), getJSONObjectItemJoinValue(entry.getValue()));
        }
        return map;
    }

    /**
     * description:
     * 1. 判断jsonObject对应key值的value是否是jsonObject类型<br>
     *     1.1 是,则递归获取value对象已排列属性的值,并拼接起来
     *     1.2 不是,则直接返回value的值
     * create by: wangzh<br>
     * create time: 2021/10/28 9:59<br>
     * @param:
     * @return:
     */
    private static Object getJSONObjectItemJoinValue(Object value){
        if (value instanceof JSONObject) {
            JSONObject objectItem = (JSONObject) value;
            StringBuilder itemValue = new StringBuilder();
            // 将JSONObject对象转换为键值从小到大的treeMap集合
            TreeMap<String, Object> treeMap = new TreeMap<>();
            for (Map.Entry<String, Object> entry : objectItem.entrySet()) {
                treeMap.put(entry.getKey(), entry.getValue());
            }
            // 遍历treeMap,递归获取JSONObject对象属性的值,并拼接起来
            treeMap.values().forEach(val -> itemValue.append(getJSONObjectItemJoinValue(val)));
            return itemValue.toString();
        }else{
            return value;
        }
    }

}