Search Twitch VOD chat replay Node.js script

search_twitch_chat.js

/* jshint esversion: 6 */

/*
 * Usage: node search_twitch_chat.js <numeric_video_id> "<keyword_regex>"
 * the video id is in the URL e.g. https://www.twitch.tv/username/v/VIDEO_ID
 * if you have minimist installed, you can pass --start <unix_time_seconds> --tick <wait_per_request_ms>
 */

() => {
  'use strict';

  let http = require('https');

  let argv = {_: process.argv.slice(2)};
  try {
    argv = require('minimist')(process.argv.slice(2));
  } catch (e) {
    console.error('\x1b[33mWarning: minimist is not installed.\x1b[39m');
  }

  const CHAT_CHUNK_DUR = 30;
  const REQUEST_TICK = argv.tick || 40;

  let videoId = argv._[0];
  let keyword = argv._[1];
  let keywordRx = new RegExp(`(?:^|\\W)(?:${keyword})(?=$|\\W)`, 'gi');

  let reqInfo = videoId => ({
    host: 'api.twitch.tv',
    path: `/kraken/videos/v${videoId}`
  });

  let reqChat = (start, videoId) => ({
    host: 'rechat.twitch.tv',
    path: `/rechat-messages?start=${start}&video_id=v${videoId}`
  });

  makeRequest(reqInfo(videoId), json => {
    let createdAt = new Date(json.created_at).getTime()/1000;
    let start = argv.start || createdAt;
    let end = createdAt + json.length;

    console.log(new Date(start * 1000).toLocaleString() +
      ' to ' +
      new Date(end * 1000).toLocaleTimeString());
    console.log(`${json.channel.display_name} playing ${json.game} (${json.title.trim()})`);
    console.log(`Searching for keyword: \x1b[94m"${keyword}"\x1b[39m\n`);

    let loop = setInterval(() => {
      if (start > end) {
        clearInterval(loop);
        return;
      }
      start += CHAT_CHUNK_DUR;
      scrape(start);
    }, REQUEST_TICK);
  });

  function makeRequest(settings, callback) {
    let chunked = '';
    let req = http.request(settings)
      .on('error', console.error)
      .on('response', resp => resp
        .on('data', data => chunked += data.toString())
        .on('end', () => chunked && callback(JSON.parse(chunked))));

    req.end();
  }

  function scrape(offset) {
    makeRequest(reqChat(offset, videoId), json => {
      if (json.data) {
        for (let msg of json.data) {
          let attrs = msg.attributes;
          var record = attrs.from + ': ' + attrs.message;
          if (keywordRx.test(record)) {
            var coloredMsg = record.replace(keywordRx, '\x1b[94m$&\x1b[39m');
            console.log(`\x1b[90m${new Date(attrs.timestamp).toLocaleTimeString()}\x1b[39m ${coloredMsg}`);
          }
        }
      }
    });
  }

}();