package com.xc.xcspringboot.demo;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Formatter;

/**
 * https://work.weixin.qq.com/api/doc/90000/90136/90506
 *
 * @author tl19638
 * @date 2020/8/18
 */
public class 簽名演算法 {

    
 
public static void main(String[] args) throws Exception {
        String genNonce = genNonce();
        System.out.println("noncestr:" + genNonce);

        long timestamp = System.currentTimeMillis() / 1000;
        System.out.println("timestamp:" + timestamp);

        String sign = sign("https://www.sogou.com", genNonce, timestamp, "eaed581b260d754b1adf54d7875adc27");
        System.out.println(
 
"sign:" + sign);
    }


    /**
     * 模擬生成隨機 nonce 字串
     *
     * @return 隨機字串
     */
    private static String genNonce() {
        return bytesToHex(Long.toString(System.nanoTime()).getBytes(StandardCharsets.UTF_8));
    }

    private static String bytesToHex(final byte[] hash) {
        Formatter formatter 
 
= new Formatter();
        for (byte b : hash) {
            formatter.format("%02x", b);
        }
        String result = formatter.toString();
        formatter.close();
        return result;
    }

    private static String sign(String url, String nonce, Long timestamp, String ticket) throws Exception {
        String plain = String.format("jsapi_ticket=%s&noncestr=%s&timestamp=%d&url=%s", ticket, nonce, timestamp, url);
        System.out.println("plain:" + plain);
        try {
            MessageDigest sha1 = MessageDigest.getInstance("SHA-1");
            sha1.reset();
            sha1.update(plain.getBytes(StandardCharsets.UTF_8));
            return bytesToHex(sha1.digest());
        } catch (NoSuchAlgorithmException e) {
            // throw new LeysenException("jsapi_ticket計算簽名錯誤");
            throw new Exception("jsapi_ticket計算簽名錯誤");
        }
    }


}