package com.dsh.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Map;
import java.util.TreeMap;

/**
 * @author 张鹏
 * @date 2020/9/1 11:20
 * <p>
 * 加密方法
 */
public class SignUtils {

    /**
     * 请求url的所有参数拼接成字符串
     *
     * @param map
     * @return
     */
    public static String createQueryString(Map<String, String> map) {
        if (map.isEmpty()) {
            return null;
        }
        StringBuilder res = new StringBuilder();
        for (String key : map.keySet()) {
            String value = map.get(key);
            if (null == key || "".equals(key)) {
                continue;
            }
            try {
                if (null != value && !"".equals(value)) {
                    res.append(key).append("=").append(URLEncoder.encode(value, "UTF-8")).append("&");
                } else {
                    res.append(key).append("=").append(value).append("&");
                }
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        }
        if (res.length() > 1) {
            return res.substring(0, res.length() - 1);
        }
        return null;
    }

    /**
     * 通过md5进行加密
     *
     * @param source 要加密的数据
     * @return
     * @throws NoSuchAlgorithmException
     */
    private static String getMd5(String source) throws NoSuchAlgorithmException {
        MessageDigest digest = MessageDigest.getInstance("md5");
        byte[] bytes = source.getBytes();
        byte[] targetBytes = digest.digest(bytes);
        char[] characters = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
        StringBuilder builder = new StringBuilder();
        for (byte b : targetBytes) {
            int high = (b >> 4) & 15;
            int low = b & 15;
            char highChar = characters[high];
            char lowChar = characters[low];
            builder.append(highChar).append(lowChar);
        }

        return builder.toString();
    }


    /**
     * 进行MD5加密
     *
     * @param qs
     * @param time
     * @param salt
     * @return
     */
    public static String getSign(String qs, long time, String salt) {
        try {
            return getMd5(String.format("%s&time=%d&salt=%s", qs, time, salt));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 功能：将一个Map按照Key字母升序构成一个QueryString. 并且加入时间混淆的hash串
     *
     * @param queryMap query内容
     * @param time     加密时候，为当前时间；解密时，为从querystring得到的时间；
     * @param salt     加密salt
     * @return
     */
    public static String createHashedQueryString(Map<String, String> queryMap, long time, String salt) {
        Map<String, String> map = new TreeMap<String, String>(queryMap);
        //生成queryString方法可自己编写
        String qs = createQueryString(map);
        if (qs == null) {
            return null;
        }
        time = time / 1000;
        String hash = getSign(qs, time, salt).toUpperCase();
        String thqs = String.format("%s&time=%d&hash=%s", qs, time, hash);
        return thqs;
    }

//    public static void main(String[] args) {
//        // 需要传递的参数
//        Map<String, String> params = new HashMap<String, String>();
//        params.put("userid", "A00000000001");
//        params.put("name", "测试直播");
//        params.put("desc", "每晚八点");
//        params.put("authtype", "1");
//        params.put("publisherpass", "admin123");
//        params.put("assistantpass", "admin123");
//        params.put("templatetype", "5");
//        params.put("playpass", "admin123");
//        params.put("livestarttime", "2020-03-05 20:00:00");
//
//        //秘钥
//        String salt = "LASD8SD8SDN23K";
//        //当前时间戳
//        long time = System.currentTimeMillis();
//        //生成http请求参数
//        String str = createHashedQueryString(params, time, salt);
//        System.out.println("加密后的字符串:" + str);
//    }
}