Reddit expand media and comments

Shows pictures and some videos right after the link, loads and expands comment threads.

このスクリプトの質問や評価の投稿はこちら通報はこちらへお寄せください。
// ==UserScript==
// @name           Reddit expand media and comments
// @description    Shows pictures and some videos right after the link, loads and expands comment threads.
// @icon           https://www.redditstatic.com/desktop2x/img/favicon/apple-icon-72x72.png
//
// @version        1.0.13
//
// @author         wOxxOm
// @namespace      wOxxOm.scripts
// @license        MIT License
//
// @match          *://*.reddit.com/*
//
// @grant          GM_addStyle
// @grant          GM_getValue
// @grant          GM_setValue
// @grant          GM_registerMenuCommand
// @grant          GM_xmlhttpRequest
//
// @grant          GM.addStyle
// @grant          GM.getValue
// @grant          GM.setValue
// @grant          GM.registerMenuCommand
// @grant          GM.xmlHttpRequest
//
// @connect        freeimage.host
// @connect        gfycat.com
// @connect        gph.is
// @connect        gstatic.com
// @connect        gyazo.com
// @connect        ibb.co
// @connect        iili.io
// @connect        images.app.goo.gl
// @connect        imgchest.com
// @connect        imgshare.io
// @connect        imgur.com
// @connect        instagram.com
// @connect        pasteall.org
// @connect        pasteboard.co
// @connect        postimg.cc
// @connect        prnt.sc
// @connect        prntscr.com
// @connect        sakugabooru.com
// @connect        streamable.com
// @connect        tenor.com
// @connect        www.google.com
// ==/UserScript==

'use strict';

const isOldReddit = !!(unsafeWindow.wrappedJSObject || unsafeWindow).reddit;
if (isOldReddit && !/^\/(user|([^/]+\/){2}comments)\//.test(location.pathname))
  return;

//#region Init

const $ = (sel, base = document) => base.querySelector(sel);
const $$ = (sel, base = document) => base.querySelectorAll(sel);
const stringifyConfig = c => (c.expandComments ? '+' : '-') + c.imgurQuality;
const parseConfig = str => {
  const m = `${str || ''}`.match(/^\s*([-+])?\s*([a-z])?/i) || [];
  return {
    expandComments: m[1] !== '-',
    imgurQuality: (m[2] || 'h').toLowerCase(),
  };
};
const cfg = {};
const gm = typeof GM !== 'undefined' ? GM : {
  getValue: k => Promise.resolve(GM_getValue(k)),
  setValue: (k, v) => Promise.resolve(GM_setValue(k, v)),
  addStyle: GM_addStyle,
  xmlHttpRequest: GM_xmlhttpRequest,
};
(gm.registerMenuCommand || GM_registerMenuCommand)('REM&C: Configure', configure);

const CLASS = 'reddit-inline-media';
const CLASS_ALBUM = CLASS + '-album';
const CLASS_SMALL = CLASS + '-small'; // for user profiles where pics are often repeated
const OVERFLOW_ATTR = 'data-overflow';
const MORE_SELECTOR = '[id^="moreComments-"] p, .morecomments a, .deepthread a';
const REQUEST_THROTTLE_MS = isOldReddit ? 500 : 100;

const META_OG_IMG = 'meta[property="og:image"]';
const META_TW_IMG = 'meta[name="twitter:image"]';
const RULES = [{
  /* imgur **********************************/
  u: [
    'imgur.com/a/',
    'imgur.com/gallery/',
  ],
  r: /(a|gallery)\/(\w+)\/?([#.]\w+)?$/,
  s: 'https://imgur.com/ajaxalbums/getimages/$2/hit.json?all=true',
  q: json =>
    json.data.images.map(img =>
      img && `https://i.imgur.com/${img.hash}${img.ext}`),
}, {
  u: 'imgur.com/',
  r: /\.com\/\w+\/?(\?.*)?$/,
  q: `link[rel="image_src"], meta[name="twitter:player:stream"], ${META_TW_IMG}, ${META_OG_IMG}`,
}, {
  /* generic **********************************/
  u: [
    '//freeimage.host/i/',
    '//imgshare.io/image/',
    '//prnt.sc/',
  ],
  q: META_OG_IMG,
  xhr: true,
}, {
  u: [
    '//gyazo.com/',
    '//pasteboard.co/',
  ],
  q: META_TW_IMG,
  xhr: true,
}, {
  u: [
    'instagram.com/p/',
    '//gph.is/',
    '//ibb.co/',
    '//images.app.goo.gl/',
    '//postimg.cc/',
    '//tenor.com/view/',
  ],
  q: META_OG_IMG,
}, {
  u: ['//imgchest.com/'],
  q: doc => [].map.call($$(META_OG_IMG, doc), el => el.content),
}, {
  /* individual sites **********************************/
  u: '.gstatic.com/images?',
}, {
  u: '//streamable.com/',
  q: 'video',
}, {
  u: '//gfycat.com/',
  q: 'source[src*=".webm"], .actual-gif-image',
}, {
  u: '//giphy.com/gifs/',
  r: /gifs\/([^/]+-)?(\w+)/,
  s: 'https://media.giphy.com/media/$2/giphy.gif',
}, {
  u: '//pasteall.org/',
  q: '.center-fit',
}, {
  u: '//prntscr.com/',
  r: /\.com\/(\w+)$/i,
  s: 'https://prnt.sc/$1',
  q: META_OG_IMG,
  xhr: true,
}, {
  r: /^(https:\/\/www\.reddit\.com\/)gallery(\/\w+)$/i,
  s: '$1comments$2.json',
  q: json => Object.values(json[0].data.children[0].data.media_metadata)
    .map(v => v.s.u.replace(/&/g, '&')),
}, {
  u: 'https://www.sakugabooru.com/post/show/',
  q: '#highres',
}, {
  u: 'youtu',
  r: /\/\/(?:youtu\.be\/|(?:(?:www|m)\.)?youtube\.com\/.*?[&?/]v[=/])([^&?/#]+)/,
  s: 'https://i.ytimg.com/vi/$1/default.jpg',
}, {
  u: '//pbs.twimg.com/media/',
  r: /.+?(\?format=|\.\w+:)\w+/,
}, {
  u: '.gifv',
  r: /(.+?)\.gifv(\?.*)?$/i,
  s: '$1.mp4$2',
}];
// last rule: direct images
RULES.push({
  r: /\.(jpe?g|png|gif|webm|mp4)(\?.*)?$/i,
});
for (const rule of RULES)
  if (rule.u && !Array.isArray(rule.u))
    rule.u = [rule.u];

// language=CSS
(gm.addStyle || (
  css => (document.head || document.documentElement)
    .appendChild(Object.assign(document.createElement('style'), {textContent: css}))
))(`
  .${CLASS} {
    max-width: 100%;
    display: block;
  }
  .${CLASS}[data-src] {
    padding-top: 400px;
  }
  .${CLASS}:hover {
    outline: 2px solid #3bbb62;
  }
  .${CLASS}.${CLASS_SMALL} {
    max-height: 25vh;
  }
  .${CLASS_ALBUM} {
    overflow-y: auto;
    max-height: calc(100vh - 100px);
    margin: .5em 0;
  }
  .${CLASS_ALBUM}[${OVERFLOW_ATTR}] {
    -webkit-mask-image: linear-gradient(white 75%, transparent);
    mask-image: linear-gradient(white 75%, transparent);
  }
  .${CLASS_ALBUM}[${OVERFLOW_ATTR}]:hover {
    -webkit-mask-image: none;
    mask-image: none;
  }
  .${CLASS_ALBUM} > :nth-child(n + 2) {
    margin-top: 1em;
  }
`);

let pageUrl = location.pathname;
let moreTimer;
const observers = new Map();
const more = [];
const toStop = new Set();
const menu = {
  get el() {
    return $(isOldReddit ? '.drop-choices.inuse' : '[role="menu"]');
  },
  resolve: null,
  observer: new MutationObserver(() => {
    const {el} = menu;
    if (!el || isOldReddit && !el.classList.contains('inuse')) {
      menu.observer.disconnect();
      menu.resolve();
    }
  }),
  observerConfig: isOldReddit ?
    {attributes: true, attributeFilter: ['class']} :
    {childList: true},
};
const scrollObserver = new IntersectionObserver(onScroll, {rootMargin: '150% 0px'});

gm.getValue('imgurQuality').then(v => {
  Object.assign(cfg, parseConfig(v));
  onMutation([{
    addedNodes: [document.body],
  }]);
  new MutationObserver(onMutation)
    .observe(document.body, {subtree: true, childList: true});
});

//#endregion

function onMutation(mutations) {
  if (pageUrl !== location.pathname) {
    pageUrl = location.pathname;
    observers.forEach(o => o.disconnect());
    observers.clear();
    stopOffscreenImages();
  }
  const items = [];
  let someElementsAdded;
  for (const {addedNodes} of mutations) {
    for (const node of addedNodes) {
      if (!node.localName)
        continue;
      someElementsAdded = true;
      for (const a of node.localName === 'a' ? [node] : node.getElementsByTagName('a')) {
        if (a.href.startsWith('https://www.reddit.com/r/') ||
            isOldReddit && a.closest('.side, .title, #header'))
          continue;
        const data = findMatchingRule(a);
        if (data)
          items.push(data);
      }
    }
  }
  if (someElementsAdded && !moreTimer && cfg.expandComments)
    moreTimer = setTimeout(observeShowMore, 500);
  if (items.length)
    setTimeout(maybeExpand, 0, items);
}

function onScroll(entries, observer) {
  const stoppingScheduled = toStop.size > 0;
  const expanders = [];
  for (const e of entries) {
    let el = e.target;
    if (el.localName === 'ins') {
      toggleAttribute(el.parentNode, OVERFLOW_ATTR, !e.isIntersecting);
      continue;
    }
    const rect = e.boundingClientRect;
    if (!e.isIntersecting) {
      if ((rect.bottom < -innerHeight * 2 || rect.top > innerHeight * 2) &&
          el.src && !el.dataset.src && observers.has(el))
        toStop.add(el);
      continue;
    } else if (el.classList.contains(CLASS_ALBUM)) {
      observer.unobserve(el);
      el.appendChild(document.createElement('ins'));
      const io = new IntersectionObserver(onScroll, {root: el});
      for (const c of el.children)
        io.observe(c);
      observers.set(el, io);
      continue;
    }
    if (stoppingScheduled)
      toStop.delete(el);
    const isImage = el.localName === 'img';
    if (el.dataset.src && (isImage || el.localName === 'video')) {
      el.src = el.dataset.src;
      el.addEventListener(isImage ? 'load' : 'loadedmetadata', unobserveOnLoad);
      delete el.dataset.src;
      continue;
    }
    if (el.localName === 'a' && el.id) {
      // switch to an unfocusable element to prevent the link
      // from stealing focus and scrolling the view
      const el2 = document.createElement('span');
      el2.setAttribute('onclick', el.getAttribute('onclick'));
      el2.setAttribute('id', el.id);
      el.parentNode.replaceChild(el2, el);
      el = el2;
    }
    expanders[rect.top >= 0 && rect.bottom <= innerHeight ? 'unshift' : 'push'](el);
  }
  expanders.forEach(expandNextComment);
  if (!stoppingScheduled && toStop.size)
    setTimeout(stopOffscreenImages, 100);
}

function stopOffscreenImages() {
  for (const el of toStop) {
    if (el.naturalWidth || el.videoWidth)
      continue;
    el.dataset.src = el.src;
    el.removeAttribute('src');
  }
  toStop.clear();
}

function findMatchingRule(a) {
  let url = a.href;
  for (const rule of RULES) {
    if (rule.u && !rule.u.find(includedInThis, url))
      continue;
    const {r} = rule;
    const m = !r || url.match(r);
    if (!m)
      continue;
    if (r && rule.s)
      url = url.slice(0, m.index + m[0].length).replace(r, rule.s).slice(m.index);
    return {a, rule, url};
  }
}

function maybeExpand(items) {
  for (const item of items) {
    const {a, rule} = item;
    const {href} = a;
    const text = a.textContent.trim();
    if (
      text &&
      !a.getElementsByTagName('img')[0] &&
      !/^https?:\/\/\S+?\.{3}$/.test(text) &&
      !a.closest(
        '.scrollerItem,' +
        '[contenteditable="true"],' +
        `a[href="${href}"] + * a[href="${href}"],` +
        `img[src="${href}"] + * a[href="${href}"]`) &&
      (
        isOldReddit ||
        // don't process insides of a post except for its text
        !a.closest('[data-test-id="post-content"]') ||
        a.closest('[data-click-id="text"]')
      )
    ) {
      try {
        (rule.q ? expandRemote : expand)(item);
      } catch (e) {
        // console.debug(e, item);
      }
    }
  }
}

function expand({a, url = a.href, isAlbum}) {
  const isVideo = /(webm|gifv|mp4)(\?.*)?$/i.test(url);
  if (!isVideo && url.includes('://i.imgur.com/'))
    url = setImgurQuality(url);
  let el = isAlbum ? a.lastElementChild : a.nextElementSibling;
  if (!el || el.src !== url && el.dataset.src !== url) {
    el = document.createElement(isVideo ? 'video' : 'img');
    el.dataset.src = url;
    el.className = CLASS + (location.pathname.startsWith('/user/') ? ' ' + CLASS_SMALL : '');
    a.insertAdjacentElement(isAlbum ? 'beforeEnd' : 'afterEnd', el);
    if (isVideo) {
      el.controls = true;
      el.preload = 'metadata';
    }
    scrollObserver.observe(el);
  }
  return !isAlbum && el;
}

async function expandRemote(item) {
  const {url, rule} = item;
  const r = await download(url);
  const text = r.response;
  const isJSON = /^content-type:.*?\/json/mi.test(r.responseHeaders);
  const doc = isJSON ? tryJSONparse(text) : parseDoc(text, url);
  switch (typeof rule.q) {
    case 'string': {
      if (!isJSON)
        expandRemoteFromSelector(doc, item);
      return;
    }
    case 'function': {
      let urls;
      try {
        urls = await rule.q(doc, text, item);
      } catch (e) {}
      if (urls && urls.length) {
        urls = Array.isArray(urls) ? urls : [urls];
        expandFromUrls(urls, item);
      }
      return;
    }
  }
}

async function expandRemoteFromSelector(doc, {rule, url, a}) {
  if (!doc)
    return;
  const el = doc.querySelector(rule.q);
  if (!el)
    return;
  let imageUrl = el.href || el.src || el.content;
  if (!imageUrl)
    return;
  if (rule.xhr)
    imageUrl = await downloadAsBase64({imageUrl, url});
  if (imageUrl)
    expand({a, url: imageUrl});
}

function expandFromUrls(urls, {a}) {
  const isAlbum = urls.length > 1;
  if (isAlbum) {
    if (a.nextElementSibling && a.nextElementSibling.classList.contains(CLASS_ALBUM))
      return;
    a = a.insertAdjacentElement('afterEnd', document.createElement('div'));
    a.className = CLASS_ALBUM;
    scrollObserver.observe(a);
  }
  for (const url of urls) {
    if (url)
      a = expand({a, url, isAlbum}) || a;
  }
}

async function expandNextComment(el) {
  if (el)
    more.push(el);
  else
    more.shift();
  if (more.length === 1 || !el && more.length) {
    if (menu.el) {
      await new Promise(resolve => {
        menu.resolve = resolve;
        menu.observer.observe(isOldReddit ? menu.el : document.body, menu.observerConfig);
      });
    }
    const a = more[0];
    if (a.href) {
      expandDeepThread(a);
    } else {
      a.dispatchEvent(new MouseEvent('click', {bubbles: true}));
    }
    a.removeAttribute('onclick');
    more.forEach((el, i) => {
      scrollObserver.unobserve(el);
      if (i) scrollObserver.observe(el);
    });
    more.length = 1;
    setTimeout(expandNextComment, REQUEST_THROTTLE_MS);
  }
}

async function expandDeepThread(a) {
  try {
    a.style.opacity = .25;
    const url = a.href;
    const doc = parseDoc(await (await fetch(url)).text(), url);
    const table = $('.sitetable.nestedlisting', doc);
    const thing = $('.thing', table);
    const oldThing = document.getElementById(thing.id);
    if (oldThing) {
      oldThing.replaceWith(thing);
    } else {
      table.classList.remove('nestedlisting');
      a.closest('.thing').replaceWith(table);
    }
  } catch (e) {}
}

function observeShowMore() {
  moreTimer = 0;
  if ($(MORE_SELECTOR)) {
    for (const el of $$(MORE_SELECTOR)) {
      scrollObserver.observe(el);
    }
  }
}

function tryJSONparse(str) {
  try {
    return JSON.parse(str);
  } catch (e) {}
}

function download(options) {
  return new Promise((resolve, reject) => {
    gm.xmlHttpRequest(Object.assign({
      method: 'GET',
      onload: resolve,
      onerror: reject,
    }, typeof options === 'string' ? {url: options} : options));
  });
}

async function downloadAsBase64({imageUrl, url}) {
  let {response: blob} = await download({
    url: imageUrl,
    headers: {
      Referer: url,
    },
    responseType: 'blob',
  });

  if (blob.type !== getMimeType(imageUrl))
    blob = blob.slice(0, blob.size, getMimeType(imageUrl));

  return new Promise(resolve => {
    Object.assign(new FileReader(), {
      onload: e => resolve(e.target.result),
    }).readAsDataURL(blob);
  });
}

function parseDoc(text, url) {
  const doc = new DOMParser().parseFromString(text, 'text/html');
  if (!doc.querySelector('base'))
    doc.head.appendChild(doc.createElement('base')).href = url;
  return doc;
}

function getMimeType(url) {
  const ext = (url.match(/\.(\w+)(\?.*)?$|$/)[1] || '').toLowerCase();
  return 'image/' + (ext === 'jpg' ? 'jpeg' : ext);
}

function toggleAttribute(el, name, state) {
  const oldState = el.hasAttribute(name);
  if (state && !oldState)
    el.setAttribute(name, '');
  else if (!state && oldState)
    el.removeAttribute(name);
}

function unobserveOnLoad() {
  this.removeEventListener(this.localName === 'img' ? 'load' : 'loadedmetadata', unobserveOnLoad);
  const io = observers.get(this);
  if (io) io.unobserve(this);
}

function includedInThis(needle) {
  const i = this.indexOf(needle);
  // URL should have something after `u` part if that ends with '/'
  return i >= 0 && (!this.endsWith('/') || this.length > i + needle.length);
}

function setImgurQuality(url) {
  const i = url.lastIndexOf('/') + 1;
  const j = url.lastIndexOf('.');
  const ext = url.slice(j);
  return url.slice(0, Math.min(i + 7, j)) + (i && j > i && !/webm|mp4/.test(ext) ? cfg.imgurQuality : '') + '.jpg';
}

function configure() {
  const str = stringifyConfig(cfg);
  const q = prompt(
    'Toggle comment expansion and set imgur quality like +h or -b where ' +
    '+ or - toggles comment expansion and h, l, m, t, b, s sets imgur quality: ' +
    'Huge, Large, Medium, Thumbnail, Big square, Small square, or no letter to use default.',
    str);
  if (q == null) return;
  const cfg2 = parseConfig(q);
  const str2 = stringifyConfig(cfg2);
  if (str2 === str) return;
  gm.setValue('imgurQuality', str2);
  if (cfg.imgurQuality !== cfg2.imgurQuality) {
    const selector = `.${CLASS}!, .${CLASS_SMALL}!, .${CLASS}@, .${CLASS_SMALL}@`
      .replace(/!/g, '[src*="imgur.com"]').replace(/@/g, '[data-src*="imgur.com"]');
    for (const el of $$(selector)) {
      const src = el.src || el.dataset.src;
      const newSrc = setImgurQuality(src);
      if (src !== newSrc)
        el.setAttribute(el.src ? 'src' : 'data-src', newSrc);
    }
  }
  if (cfg.expandComments !== cfg2.expandComments) {
    if (cfg2.expandComments) {
      observeShowMore();
    } else {
      clearTimeout(moreTimer);
      more.length = moreTimer = 0;
    }
  }
  Object.assign(cfg, cfg2);
}