package com.qiniu.hugo.miku;

import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.security.MessageDigest;

public class TimestampAntiLeechUrl {

    private static final char[] DIGITS_LOWER = {
        '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'
    };

    public static void main(String[] args) {
        // 推流（Publish）
        String publishUrl = "rtmp://test.miku.com/sdk-live/test";
        long t1 = System.currentTimeMillis()/1000 + 20*60;
        String publishKey = "test";
        System.out.println(signUrl(publishUrl, publishKey, t1));

        // HLS 播放（Play）
        String hlsUrl = "http://test.miku.com/sdk-live/test.m3u8";
        long t2 = System.currentTimeMillis()/1000 + 20*60;
        String playKey = "test";
        System.out.println(signUrl(hlsUrl, playKey, t2));
    }

    public static String signUrl(String url, String key, long expireTs) {
        try {
            String path = url.substring(url.indexOf("/", url.indexOf("//") + 2));
            // 保留斜杠，仅编码其他字符
            String encodedPath = URLEncoder.encode(path, "UTF-8").replace("%2F", "/");
            String t = String.valueOf(expireTs);
            String toSign = key + encodedPath + t;
            String sign = md5Lower(toSign);
            return String.format("%s?sign=%s&t=%s", url, sign, t);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    private static String md5Lower(String src) throws Exception {
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(src.getBytes(Charset.forName("UTF-8")));
        byte[] bytes = md.digest();
        return encodeHex(bytes);
    }

    private static String encodeHex(byte[] data) {
        char[] out = new char[data.length << 1];
        for (int i = 0, j = 0; i < data.length; i++) {
            out[j++] = DIGITS_LOWER[(0xF0 & data[i]) >>> 4];
            out[j++] = DIGITS_LOWER[0x0F & data[i]];
        }
        return new String(out);
    }
}