youtube.js

(() => {
  'use strict';

  const INCO = chrome.extension.inIncognitoContext;

  const O = {
    enum(arr){
      var obj = O.obj();
      obj.name = index => arr[index];

      arr.forEach((name, index) => {
        obj[name] = index;
      });

      return obj;
    },

    cap(str, lowerOthers=0){
      if(lowerOthers) str = str.toLowerCase();
      return `${str[0].toUpperCase()}${str.substring(1)}`;
    },

    obj(proto=null){ return Object.create(proto); },

    raf(f){
      requestAnimationFrame(f);
    },

    raf2(f){
      O.raf(() => O.raf(f));
    },
  };

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const isWatchPage = /[\?\&]v\=/.test(location.href);

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const PREVENT_TITLE_TRANSLATION = 0;

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const PORT = 27000;
  const TIME = 1e3;

  const OLD = location.href.includes('&uold');
  const OVERLAY = !location.href.includes('&uove');

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const stats = O.enum([
    'NOT_QUEUED',
    'DOWNLOADING',
    'DOWNLOADED',
  ]);

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const blackList = [
  ];

  const requiredWhiteList = [
  ];

  const chs = [
  ];

  const timeOffsets = OVERLAY ? {
  } : {};

  Object.setPrototypeOf(timeOffsets, null);

  for(let chName in timeOffsets){
    let ch = timeOffsets[chName];

    if(location.href.includes('&u'))
      ch[1] += 6;

    if(ch.length < 3)
      ch.push([null, null, null, null]);

    if(ch.length < 4)
      ch.push([]);
  }

  const symbsArr = [
    'status',
  ];

  const symbs = Object.create(null);

  for(const name of symbsArr)
    symbs[name] = Symbol(name);

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  let targetTitle = null;

  const setTitle = title => {
    targetTitle = title;
  };

  const updateTitle = () => {
    if(targetTitle !== null && !/^\u034F?$/.test(document.title))
      document.title = targetTitle;

    setTimeout(updateTitle, 1e3);
  };

  updateTitle();

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  const sanitizeTitle = (channel, title) => {
    channel = channel.split('');
    title = title.split('');

    let channelN = normalizeChars(channel);
    let titleN = normalizeChars(title);
    let index = -1;

    findIndex: for(let i = 0; i <= titleN.length - channelN.length; i++){
      for(let j = 0; j !== channelN.length; j++)
        if(titleN[i + j] !== channelN[j])
          continue findIndex;

      index = i;
      break findIndex;
    }

    if(index !== -1){
      const reg = /[ -\/:-@\[-`\{-~\u24D2\u2714]/;
      const opnReg = /[\(\[\{]/;
      const clsReg = /[\)\]\}]/;

      const title1 = title.slice(0, index);
      const title2 = title.slice(index + channel.length);
      let parens = 0;

      title = title1.length > title2.length ? title1 : title2;

      while(title.length !== 0 && (reg.test(title[0]) || parens !== 0)){
        const chr = title[0];

        if(opnReg.test(chr)){
          if(parens === 0) break;
          parens++;
        }else if(clsReg.test(chr)){
          if(parens !== 0) parens--;
        }

        title = title.slice(1);
      }

      parens = 0;

      while(title.length !== 0 && (reg.test(title[title.length - 1]) || parens !== 0)){
        const chr = title[title.length - 1];

        if(clsReg.test(chr)){
          if(parens === 0) break;
          parens++;
        }else if(opnReg.test(chr)){
          if(parens !== 0) parens--;
        }

        title = title.slice(0, title.length - 1);
      }
    }

    title = title.join('');

    extraCheck: {
      const reg = /^\s*i\s+/i;
      const m1 = title.match(reg);
      const m2 = [...title].reverse().join('').match(reg);

      if(m1 !== null) title = title.slice(m1[0].length);
      if(m2 !== null) title = title.slice(0, title.length - m2[0].length);
    }
    
    specificChannels: {
      const cn = channelN.join('');
      
      if(cn === 'tweag'){
        const prefix = '@rae: ';
        
        if(title.startsWith(prefix))
          title = title.slice(prefix.length);
        
        break specificChannels;
      }
    }

    if(title.endsWith(' by'))
      title = title.slice(0, title.length - 3).trimRight();

    return title;
  };

  const normalizeChars = chars => {
    return chars.map(a => {
      a = a.toLowerCase();
      return a;
    });
  };

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  {
    const raf = requestAnimationFrame;
    let a = 0;

    const f = () => {
      let e;

      if(e = qs('#movie_player')){
        const e1 = qs('#masthead-container');

        if(e1){
          if(e.classList.contains('ytp-fullscreen')){
            // e1.classList.add('ublock-hidden-yt');
            e1.style.display = 'none';
          }else{
            // e1.classList.remove('ublock-hidden-yt');
            e1.style.display = 'block';
          }
        }
      }

      raf(f);
    };

    f();
  }

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  let loaded = 0;
  let fixedTitle = 0;
  let scheduled = 0;
  let stopped = 0;

  window.addEventListener('load', () => {
    loaded = 1;
  });

  if(0) document.addEventListener('DOMContentLoaded', () => {
    var video = qs('video');
    if(!video) return;

    var prev = 0;
    var curr = 0;
    var buf = 0;
    var t = Date.now();

    requestAnimationFrame(check);

    function check(){
      var f = null;

      curr = video.currentTime;

      if(curr >= prev){
        if(
            !buf  &&
            curr === prev &&
            Date.now() - t > 2e3 &&
            !video.paused
          ){
          f = onBuffering;
          buf = 1;
        }

        if(
            buf &&
            curr > prev &&
            !video.paused
          ){
          f = onReady;
          buf = 0;
        }
      }

      prev = curr;

      if(f) f();
      requestAnimationFrame(check);
    }

    function onBuffering(){}

    function onReady(){
      video.currentTime -= 5;
      t = Date.now();
    }
  });

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  var musicMode = 0;
  var enableDow = 1;

  var emptyTimeOffsets = [null, null, [null, null, null, null]];

  var safeElem = document.createElement('input');
  safeElem.style.display = 'none';
  safeElem.id = 'ublock_safe';
  safeElem.type = 'hidden';
  safeElem.value = 0;

  ////////////////////////////////////////////////////////////////////////////////////////////////////

  main();

  function main(){
    var url = location.href;
    var focused = musicMode;
    var disabledSearch = 0;
    var debugMode = 0;
    var ended = 0;
    var currentSrc = null;

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    if(isWatchPage){
      let video = null;

      const f = () => {
        if(video === null)
          video = qs('video');

        if(video){
          if(!video.ublock_videoListeners){
            video.ublock_ytVideoListeners = 1;

            video.onended = () => {
              ended = 1;
            };
          }

          checkVideoTime();

          if(currentSrc !== video.currentSrc){
            ended = 0;
          }

          if(musicMode && !ended && video.paused && currentSrc !== video.currentSrc){
            currentSrc = video.currentSrc;
            playVideo();
          }
        }

        setTimeout(f, TIME);
      };

      setTimeout(f, TIME);
    }

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    document.addEventListener('DOMContentLoaded', () => {
      var e = qs('body');

      var m = location.href.match(/[\?\&]ub\=(\d+)(?:[^\d]|$)/);
      if(m !== null){
        var n = Number(m[1]);
        e.classList.add(`ub${n}`);
      }

      e.classList.add('ublock-safe');

      block();
    });

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    setVideoQuality: if(isWatchPage){
      const LOG = 0;

      const tryFunc = async func => {
        let done = 0;

        try{
          done = await func();
        }catch{}

        if(!done)
          return setTimeout(() => tryFunc(func));

        if(LOG) log('Done');
      };

      const raf = () => new Promise(res => {
        requestAnimationFrame(() => res());
      });

      tryFunc(async () => {
        qs('[data-tooltip-target-id="ytp-settings-button"]').click();
        await raf();

        [...qsa('div.ytp-menuitem-label')].find(e => {
          return e.innerText.trim() === 'Quality';
        }).click();
        await raf();

        const opts = [...qsa('.ytp-popup.ytp-settings-menu .ytp-menuitem-label')].map(e => {
          return [e, e.innerText.trim()];
        });

        const preferred = !INCO ? [
          '1080',
          '720',
          '480',
          '360',
          '240',
          '144',
        ] : ['144'];

        for(const pref of preferred){
          const prefStr = `${pref}p`;
          const info = opts.find(([a, b]) => b.includes(prefStr));
          if(!info) continue;

          const opt = info[0];
          opt.click();

          if(LOG) log(pref);
          return 1;
        }

        return 0;
      });

      // const key = 'setPlaybackQuality';
      // let setQualityFunc = null;
      //
      // const sem = new Semaphore(0);
      //
      // const makeDesc = func => ({
      //   get(){
      //     return func;
      //   },
      //
      //   set(func){
      //     Object.defineProperty(this, key, makeDesc(func));
      //
      //     if(String(func).includes('setPlaybackQualityRange')){
      //       log('here');
      //       setQualityFunc = func.bind(this);
      //       // setTimeout(() => {
      //       //   sem.signal();
      //       // }, 10e3);
      //     }
      //   },
      // });
      //
      // Object.defineProperty(Object.prototype, key, makeDesc());
      //
      // window.addEventListener('load', evt => {
      //   (async () => {
      //     await sem.wait();
      //     setQualityFunc('hd1080');
      //     log('ok');
      //   })()//.catch(log);
      // });
    }

    ////////////////////////////////////////////////////////////////////////////////////////////////////

    var lastAction = Date.now();

    aels();

    function aels(){
      window.addEventListener('keydown', evt => {
        var activeElem = document.activeElement;

        if(activeElem){
          var tag = activeElem.tagName;
          if(tag === 'INPUT' || tag === 'TEXTAREA') return 0;
        }

        if(evt.altKey || evt.ctrlKey || evt.shiftKey)
          return;

        /*var v = qs('video');
        if(v) var ct = v.currentTime;*/

        switch(evt.code){
          /*case 'ArrowLeft': pd(); v && v.currentTime = ct - 5; break;
          case 'ArrowRight': pd(); v && v.currentTime = ct + 5; break;*/

          case 'KeyQ': toggleControls(evt); scheduleBlocking(); break;
          case 'KeyW': toggleRelated(evt); scheduleBlocking(); break;
          case 'KeyE': toggleDescription(evt); scheduleBlocking(); break;
          case 'KeyR': toggleComments(evt); scheduleBlocking(); break;
          // case 'KeyY': exitPlaylist(evt); break;
          case 'KeyA': evt.preventDefault(); musicMode ^= 1; break;

          case 'KeyD':
            evt.preventDefault();

            var urls = [
              sessionStorage.ublockYTAudio,
              sessionStorage.ublockYTVideo,
            ];

            server({
              type: 'download',
              id: location.href.match(/[\?\&]v\=([^\&\#]+)/)[1],
              channel: getChName(),
              title: document.title.substring(0, document.title.length - 10),
              urls,
            });
            break;

          case 'F8':
            debugMode = 1;
            evt.preventDefault();
            break;
        }

        function pd(){
          evt.preventDefault();
          evt.stopPropagation();
        }
      });

      window.addEventListener('mousedown', evt => {
        if(evt.button !== 0) return;
        if(!evt.target.closest('a:not(.ytd-toggle-button-renderer)')) return;

        lastAction = Date.now();

        var ee, e, i;

        ee = document.querySelector('#items');
        if(ee){
          ee = ee.querySelectorAll('.style-scope.ytd-watch-next-secondary-results-renderer');
          for(i = 0; i < ee.length; i++){
            e = ee[i];
            hideElem(e);
          }
        }

        toggleVideo(0);
        toggleRelated(null, 1);

        ended = 0;
      });

      window.addEventListener('mousemove', evt => {
        if(musicMode) return;

        focused = 1;
      });

      window.addEventListener('focus', evt => {
        if(musicMode) return;

        if(focused){
          toggleRelated(null, 1);
        }

        focused = 1;
      });

      window.addEventListener('blur', evt => {
        if(musicMode) return;

        if(focused){
          toggleRelated(null, 1);
        }

        focused = 0;
      });
    }

    const scheduleBlocking = () => {
      if(!stopped) return;
      if(scheduled) return;
      stopped = 0;
      scheduled = 1;
      setTimeout(block, TIME);
    };

    function block(){
      scheduled = 0;

      if(debugMode){
        debugMode = 0;
        // debugger;
      }

      var eee, ee, e, i, j;

      if(!disabledSearch)
        disabledSearch = tryToDisableSearch();

      e = document.querySelector('input[id="search"][disabled]');
      if(e){
        e.value = '';
        e.blur();
        e.removeAttribute('autofocus');
      }

      eee = document.querySelectorAll('#items');
      for(i = 0; i < eee.length; i++){
        ee = eee[i].querySelectorAll('.style-scope.ytd-watch-next-secondary-results-renderer');

        for(j = 0; j < ee.length; j++){
          e = ee[j];
          if(!e.querySelector('.ublock_safe')) continue;

          var html = e.innerHTML;

          if(blackList.some(a => a.test(html)) || !requiredWhiteList.every(a => a.test(html))){
            if(1){
              remove(e);
            }else{
              showElem(e);
              e.style.backgroundColor = 'red';
            }
          }else{
            showElem(e);
          }
        }
      }

      ee = document.querySelectorAll('#video-title:not(.ublock_safe)');
      for(i = 0; i < ee.length; i++){
        e = ee[i];
        if(e[symbs.status]) continue;

        var url;
        if(e.className === 'A') url = e.href;
        else url = e.closest('a').href;

        if(/https\:\/\/www\.youtube\.com\/(?:channel|user)\//.test(location.href)){
          const channelElem = [...qsa('title')].find(a => {
            const title = a.textContent.trim();
            return title && title !== '\u034f';
          });

          if(!channelElem) continue;

          let str;

          {
            str = channelElem.textContent.trim().replace(/[\r\n].*/s, '').trim();
            if(!str) continue;

            const strBlacklist = ' - YouTube';

            if(str.endsWith(strBlacklist))
              str = str.slice(0, str.length - strBlacklist.length);
          }

          const channel = str;
          const title = sanitizeTitle(channel, e.textContent.trim());

          e.textContent = title;
          e.title = title;

          setTitle(channel);
        }

        e[symbs.status] = 1;

        if(!PREVENT_TITLE_TRANSLATION){
          e.classList.add('ublock_safe');
          continue;
        }

        rf(url, e, updateTitle);
      }

      for(const e of qsa('ytd-grid-video-renderer:not(.ublock-safe)')){
        const e1 = qs(e, '#byline-container');
        if(!e1) continue;

        if(!e1.hasAttribute('hidden')){
          // remove(e);
          // continue;
          remove(e1);
        }

        showElem(e);
      }

      if(isWatchPage){
        const ee = document.querySelectorAll('h1.title:not(.ublock_safe)');
        for(let i = 0; i < ee.length; i++){
          const e = ee[i];
          if(e[symbs.status]) continue;

          const next = () => {
            const channelElem = qs('#channel-name.ytd-video-owner-renderer');
            if(!channelElem) return;
            const channel = channelElem.textContent.trim().replace(/[\r\n].*/s, '').trim();
            if(!channel) return;
            let title = e.textContent.trim();
            if(!title) return;

            e[symbs.status] = 1;

            title = sanitizeTitle(channel, title);

            e.textContent = title;
            e.classList.add('ublock_safe');

            fixedTitle = 1;
          };

          if(!PREVENT_TITLE_TRANSLATION){
            next();
            continue;
          }

          rf(location.href, e, (...args) => {
            updateTitle(...args);
            next();
          });
        }
      }

      if(url !== window.location.href){
        url = window.location.href;
        if(/^www\.youtube\.com\/(?:channel|user)\/[^\/]+$/.test(url.match(/^[^\/]+?\:\/\/(.+)/)[1])){
          hideElem(document.documentElement);
          window.location.href = url.replace(/$/, '/videos');
        }
      }

      {
        let e;

        for(e of qsa('ytd-comment-thread-renderer:not(.ublock-safe)')){
          if(
            qs(e, '#pinned-comment-badge:not(*[hidden])') ||
            qs(e, 'ytd-author-comment-badge-renderer')
          ){
            remove(e);
          }else{
            e.classList.add('ublock-safe');
          }
        }

        for(e of qsa('#description:not(.ublock-safe)')){
          //e.closest('ytd-expander').removeAttribute('collapsed');

          if(getChName() === chs[0]){
          }

          e.classList.add('ublock-safe');
        }
      }

      for(const e of qsa('a[href*="&list="]:not(.ublock-safe)')){
        const {href} = e;

        if(!/\?v=/.test(href)){
          show(e);
          continue;
        }

        e.href = href.slice(0, href.indexOf('&'));
        show(e);
      }

      url = window.location.href;

      const stop = (
        isWatchPage &&
        loaded &&
        fixedTitle
      );

      if(stop){
        stopped = 1;
        return;
      }

      setTimeout(block, TIME);
    }

    function checkVideoTime(){
      document.body.appendChild(safeElem);

      var elem = document.querySelector('.ytd-video-owner-renderer a');
      var video = document.querySelector('video');
      if(!(elem && video)) return;

      toggleVideo(1);

      var channel = elem.textContent.trim();

      if(!(channel in timeOffsets)){
        updateOverlayElem(emptyTimeOffsets);
        return video.ublock_start = 0;
      }

      var offsets = timeOffsets[channel];
      updateOverlayElem(offsets);

      var duration = video.duration;

      // if(duration < offsets[0] + offsets[1] + 60)
      //   offsets[0] = offsets[1] = 0;

      if(location.href.includes('&uof'))
        offsets[0] = offsets[1] = 0;

      var start = offsets[0];
      var end = duration - offsets[1];
      var time = video.currentTime;

      video.ublock_start = start;

      if(time < start){
        pauseVideo();

        O.raf2(() => {
          video.currentTime = start;
        });

        return;
      }

      if(time > end && time != duration){
        pauseVideo();

        O.raf2(() => {
          video.currentTime = duration;
          ended = 1;
        });

        return;
      }
    }

    function updateOverlayElem(timeOffsets){
      var elem = document.querySelector('#ublock_yt-overlay');

      if(!elem){
        var elem = document.createElement('input');
        document.body.appendChild(elem);
        elem.type = 'hidden';
        elem.style.display = 'none';
        elem.id = 'ublock_yt-overlay';
      }

      elem.value = JSON.stringify(timeOffsets.slice(2));
    }

    function tryToDisableSearch(){
      var e = document.querySelector('input[id="search"]');
      if(!e) return 0;

      if(e !== document.activeElement){
        e.value = '';
        e.disabled = 1;
      }

      var ee = e.parentNode;

      ee.addEventListener('click', () => {
        e.disabled = 0;
        e.focus();
      });

      e.addEventListener('blur', () => {
        e.value = '';
        e.disabled = 1;
      });

      return 1;
    }

    function toggleVideo(s){
      var video = document.querySelector('video');
      if(!video) return;

      if(s) showElem(video);
      else hideElem(video);
    }

    function toggleControls(evt){
      var selectors = [
        '.ytp-chrome-bottom',
        '.ytp-popup.ytp-settings-menu',
        '.ytp-tooltip.ytp-bottom',
      ];

      if(!toggleControls.elem){
        var elem = document.createElement('div');
        document.head.appendChild(elem);

        elem.style.width = '0px';
        elem.style.height = '0px';

        toggleControls.elem = elem;
      }

      var mainElem = toggleControls.elem;
      toggleElem(mainElem);

      return selectors.reduce((a, selector) => {
        if(toggleElem(selector, evt, mainElem)){
          var parent = document.querySelector(selector);
          var ee, e, i;

          ee = parent.querySelectorAll('*');
          for(i = 0; i < ee.length; i++){
            e = ee[i];
            toggleElem(e, null, mainElem);
          }

          return 1;
        }

        return a;
      }, 0);
    }

    function toggleRelated(evt, forceHide=0){
      var selector = '#secondary,#items.style-scope.ytd-watch-next-secondary-results-renderer,yt-next-continuation,*[id*="continuation"],*[class*="continuation"]';

      if(forceHide){
        const elems = document.querySelectorAll(selector);
        let found = 0;

        for(var i = 0; i < elems.length; i++){
          var elem = elems[i];

          if(getComputedStyle(elem).opacity !== '0'){
            toggleElem(elem);
            found = 1;
            continue;
          }

          // elem.style.setProperty('pointer-events', 'auto', 'important');
        }

        return found;
      }

      const toggled = toggleElem(selector, evt, qs('#secondary'));
      if(!toggled) return 0;

      return 1;
    }

    function toggleDescription(evt){
      return toggleElem('ytd-expander.ytd-video-secondary-info-renderer', evt);
    }

    function toggleComments(evt){
      // if(INCO) return 1;
      return toggleElem('ytd-comments', evt);
    }

    function exitPlaylist(evt){
      evt.preventDefault('ublock');
      evt.stopPropagation('ublock');
      location.href = `/watch?v=${location.href.match(/[\?\&]v=((?:[^\&]|$)*)/)[1]}`;
    }

    function playVideo(){
      var evt = new CustomEvent('ublock_ytVideo', {detail: 1});
      window.dispatchEvent(evt);
    }

    function pauseVideo(){
      hideElem(document.querySelector('video'));
      var evt = new CustomEvent('ublock_ytVideo', {detail: 0});
      window.dispatchEvent(evt);
    }

    function show(e){
      e.classList.add('ublock-safe');
    }

    function toggleElem(selector, evt=null, mainElem=null){
      var activeElem = document.activeElement;

      if(activeElem){
        var tag = activeElem.tagName;
        if(tag == 'INPUT' || tag == 'TEXTAREA') return 0;
      }

      if(evt) evt.preventDefault();

      var elems = typeof selector == 'string' ? document.querySelectorAll(selector) : [selector];
      if(!elems.length) return 0;

      var visible;

      for(var i = 0; i < elems.length; i++){
        var elem = elems[i];

        if(i === 0){
          var computedStyle = getComputedStyle(mainElem || elem);
          visible = computedStyle.opacity === '1';
        }

        if(visible) hideElem(elem);
        else showElem(elem);

        // elem.style.setProperty('pointer-events', visible ? 'none' : 'auto', 'important');
      }

      return 1;
    }

    function showElem(elem){
      if(elem.tagName === 'VIDEO'){
        safeElem.value = 1;
        return;
      }

      // if(elem.tagName.toLowerCase() === 'ytd-compact-video-renderer') debugger;

      elem.classList.remove('ublock-hidden-yt');
      elem.classList.add('ublock-visible-yt');

      // elem.style.setProperty('pointer-events', 'auto', 'important');
    }

    function hideElem(elem){
      if(elem.tagName === 'VIDEO'){
        safeElem.value = 0;
      }

      elem.classList.remove('ublock-visible-yt');
      elem.classList.add('ublock-hidden-yt');

      // elem.style.setProperty('pointer-events', 'none', 'important');
    }

    function remove(e){
      // if(e.tagName.toLowerCase() === 'ytd-grid-video-renderer') debugger;
      e.remove();
    }

    function updateTitle(url, str, e){
      const match = url.match(/[?&]v=(.{11})/);
      if(match === null) return;

      const id = match[1];
      const m = str.match(new RegExp(`"videoId":"${id}","title":("(?:[^\\\\"]|\\\\.)+")`));
      let title;

      if(m === null){
        title = '_ublock_error_';
      }else{
        title = JSON.parse(m[1]);
      }

      e.innerHTML = '';
      let text = document.createTextNode(title);
      e.appendChild(text);

      e.classList.add('ublock_safe');
    }

    function getChName(){
      const e = qs('#channel-name.ytd-video-owner-renderer');
      if(!e) return null;
      return e.textContent.trim().replace(/[\r\n][\s\S]*/, '').trim();
    }

    function rf(url, data, cb){
      var xhr = new XMLHttpRequest();

      xhr.onreadystatechange = () => {
        if(xhr.readyState !== 4) return;
        cb(url, xhr.responseText, data);
      };

      xhr.open('GET', url);
      xhr.send(null);
    }

    function server(data, cb=nop){
      if(!enableDow) return cb(null);
      var xhr = new XMLHttpRequest();

      xhr.onreadystatechange = () => {
        if(xhr.readyState !== 4) return;
        if(xhr.status !== 200){
          enableDow = 0;
          return cb(null);
        }
        cb(JSON.parse(xhr.responseText));
      };

      xhr.open('POST', `http://localhost:${PORT}`);
      xhr.send(JSON.stringify(data));
    }
  }

  function qs(a, b=null){
    if(b === null){
      b = a;
      a = document;
    }

    return a.querySelector(b);
  }

  function qsa(a, b=null){
    if(b === null){
      b = a;
      a = document;
    }

    return a.querySelectorAll(b);
  }

  function decode(str){
    return str.split('').
      map(a => a.charCodeAt(0) - 32).
      map(a => 94 - a).
      map(a => String.fromCharCode(32 + a)).
      join('');
  }

  function log(...a){
    console.log(...a);
    return a[a.length - 1];
  }

  function nop(){}
})();