script.user.js

// ==UserScript==
// @name        Mouseover Popup Image Viewer
// @namespace   https://github.com/tophf
// @description Shows images and videos behind links and thumbnails.
//
// @include     *
// @run-at      document-start
//
// @grant       GM_addElement
// @grant       GM_download
// @grant       GM_getValue
// @grant       GM_getValues
// @grant       GM_openInTab
// @grant       GM_registerMenuCommand
// @grant       GM_unregisterMenuCommand
// @grant       GM_setClipboard
// @grant       GM_setValue
// @grant       GM_xmlhttpRequest
//
// @grant       GM.getValue
// @grant       GM.openInTab
// @grant       GM.registerMenuCommand
// @grant       GM.unregisterMenuCommand
// @grant       GM.setClipboard
// @grant       GM.setValue
// @grant       GM.xmlHttpRequest
//
// @version     1.4.6
// @author      tophf
//
// @original-version 2017.9.29
// @original-author  kuehlschrank
//
// @connect     *
// CSP check:
// @connect     self
// rule installer in config dialog:
// @connect     github.com
// big/trusted hostings for the built-in rules with "q":
// @connect     deviantart.com
// @connect     facebook.com
// @connect     fbcdn.com
// @connect     flickr.com
// @connect     gfycat.com
// @connect     googleusercontent.com
// @connect     gyazo.com
// @connect     imgur.com
// @connect     instagr.am
// @connect     instagram.com
// @connect     prnt.sc
// @connect     prntscr.com
// @connect     user-images.githubusercontent.com
//
// @supportURL  https://github.com/tophf/mpiv/issues
// @icon        https://raw.githubusercontent.com/tophf/mpiv/master/icon.png
// ==/UserScript==

'use strict';

//#region Globals

/** @type mpiv.Config */
let cfg;
/** @type mpiv.AppInfo */
let ai = {rule: {}};
/** @type Element */
let elSetup;
let nonce;

const doc = document;
const hostname = location.hostname;
const dotDomain = '.' + hostname;
const isFF = CSS.supports('-moz-appearance', 'none');
const AudioContext = window.AudioContext || function () {};
const {from: arrayFrom, isArray} = Array;

const PREFIX = 'mpiv-';
const NOAA_ATTR = 'data-no-aa';
const STATUS_ATTR = `${PREFIX}status`;
const MSG = Object.assign({}, ...[
  'getViewSize',
  'viewSize',
].map(k => ({[k]: `${PREFIX}${k}`})));
const WHEEL_EVENT = 'onwheel' in doc ? 'wheel' : 'mousewheel';
// time for volatile things to settle down meanwhile we postpone action
// examples: loading image from cache, quickly moving mouse over one element to another
const SETTLE_TIME = 50;
// used to detect JS code in host rules
const RX_HAS_CODE = /(^|[^-\w])return[\W\s]/;
const RX_EVAL_BLOCKED = /'Trusted(Script| Type)'|unsafe-eval/;
const RX_MEDIA_URL = /^(?!data:)[^?#]+?\.(avif|bmp|jpe?g?|gif|mp4|png|svgz?|web[mp])($|[?#])/i;
const BLANK_PIXEL = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
const ZOOM_MAX = 16;
const SYM_U = Symbol('u');
const FN_ARGS = {
  s: ['m', 'node', 'rule'],
  c: ['text', 'doc', 'node', 'rule'],
  q: ['text', 'doc', 'node', 'rule'],
  g: ['text', 'doc', 'url', 'm', 'rule', 'node', 'cb'],
};
let trustedHTML, trustedScript;
//#endregion
//#region GM4 polyfill

if (typeof GM === 'undefined' || !GM.xmlHttpRequest)
  this.GM = {__proto__: null, info: GM_info};
if (!GM.getValue)
  GM.getValue = GM_getValue; // we use it only with `await` so no need to return a Promise
if (!GM.setValue)
  GM.setValue = GM_setValue; // we use it only with `await` so no need to return a Promise
if (!GM.openInTab)
  GM.openInTab = GM_openInTab;
if (!GM.registerMenuCommand && typeof GM_registerMenuCommand === 'function')
  GM.registerMenuCommand = GM_registerMenuCommand;
if (!GM.unregisterMenuCommand && typeof GM_unregisterMenuCommand === 'function')
  GM.unregisterMenuCommand = GM_unregisterMenuCommand;
if (!GM.setClipboard)
  GM.setClipboard = GM_setClipboard;
if (!GM.xmlHttpRequest)
  GM.xmlHttpRequest = GM_xmlhttpRequest;

//#endregion

const App = {

  isEnabled: true,
  isImageTab: false,
  globalStyle: '',
  popupStyleBase: '',
  tabfix: /\.(dumpoir|greatfon|picuki)\.com$/.test(dotDomain),
  NOP: /\.(facebook|instagram|chrome|google)\.com$/.test(dotDomain) &&
    (() => {}),

  activate(info, event) {
    const {match, node, rule, url} = info;
    const auto = cfg.start === 'auto';
    const vidCtrl = cfg.videoCtrl && isVideo(node);
    if (elSetup) console.info({node, rule, url, match});
    if (auto && vidCtrl && !Events.ctrl)
      return;
    if (ai.node) App.deactivate();
    ai = info;
    ai.force = Events.ctrl;
    ai.gNum = 0;
    ai.zooming = cfg.css.includes(`${PREFIX}zooming`);
    Util.suppressTooltip();
    Calc.updateViewSize();
    Events.ctrl = false;
    Events.toggle(true);
    Events.trackMouse(event);
    if (ai.force && (auto || cfg.start === 'ctrl' || cfg.start === 'context')) {
      App.start();
    } else if ((auto || cfg.preload) && !vidCtrl && !rule.manual) {
      App.belate(auto);
    } else {
      Status.set('ready');
    }
  },

  belate(auto) {
    if (cfg.preload) {
      ai.preloadStart = auto ? now() : -1;
      App.start();
      Status.set('+preloading');
    } else {
      ai.timer = setTimeout(App.start, cfg.delay);
    }
  },

  checkProgress({start} = {}) {
    const p = ai.popup;
    if (!p)
      return;
    const w = ai.nwidth = p.naturalWidth || p.videoWidth || ai.popupLoaded && innerWidth / 2;
    const h = ai.nheight = p.naturalHeight || p.videoHeight || ai.popupLoaded && innerHeight / 2;
    if (h)
      return App.canCommit(w, h);
    if (start) {
      clearInterval(ai.timerProgress);
      ai.timerProgress = setInterval(App.checkProgress, 150);
    }
  },

  canClose: (p = ai.popup) => !p || (
    isVideo(p)
      ? !cfg.keepVids
      : document.fullscreenElement !== p
  ),

  canCommit(w, h) {
    if (!ai.force && ai.rect && !ai.gItems &&
        Math.max(w / (ai.rect.width || 1), h / (ai.rect.height || 1)) < cfg.scale) {
      App.deactivate();
      return false;
    }
    App.stopTimers();
    let wait = ai.preloadStart;
    if (wait < 0 && !ai.force || !ai.popup)
      return;
    if (wait > 0 && (wait += cfg.delay - now()) > 0) {
      ai.timer = setTimeout(App.checkProgress, wait);
    } else if ((!w || !h) && (ai.urls || []).length) {
      App.handleError({type: 'error'});
    } else {
      App.commit();
    }
    return true;
  },

  async commit() {
    const p = ai.popupShown = ai.popup;
    const isDecoded = cfg.waitLoad && isFunction(p.decode);
    if (isDecoded) {
      await p.decode();
      if (p !== ai.popup)
        return;
    }
    Status.set('-preloading');
    App.updateStyles();
    Calc.measurePopup();
    const willZoom = cfg.zoom === 'auto' || App.isImageTab && cfg.imgtab;
    const willMove = !willZoom || App.toggleZoom({keepScale: true}) === undefined;
    if (willMove)
      Popup.move();
    Bar.updateName();
    Bar.updateDetails();
    Status.set(!ai.popupLoaded && 'loading');
    ai.large = ai.nwidth > p.clientWidth + ai.extras.w ||
               ai.nheight > p.clientHeight + ai.extras.h;
    if (ai.large) {
      Status.set('+large');
      // prevent a blank bg+border in FF
      if (isFF && p.complete && !isDecoded)
        p.style.backgroundImage = `url('${p.src}')`;
    }
    if (ai.preloadStart < 0 && isFunction(p.play))
      p.play().catch(now);
  },

  deactivate({wait} = {}) {
    App.stopTimers(true);
    if (ai.req)
      tryCatch(ai.req.abort);
    if (ai.tooltip)
      ai.tooltip.node.title = ai.tooltip.text;
    Status.set(false);
    Bar.set(false);
    Events.toggle(false);
    Popup.destroy();
    if (wait) {
      App.isEnabled = false;
      setTimeout(App.enable, 200);
    }
    ai = {rule: {}};
  },

  enable() {
    App.isEnabled = true;
  },

  handleError(e, rule = ai.rule) {
    if (rule && rule.onerror === 'skip')
      return;
    if (ai.imageUrl &&
        !ai.xhr &&
        !ai.imageUrl.startsWith(location.origin + '/') &&
        location.protocol === 'https:' &&
        CspSniffer.init) {
      Popup.create(ai.imageUrl, ai.pageUrl, e);
      return;
    }
    const fe = Util.formatError(e, rule);
    if (!rule || !ai.urls || !ai.urls.length)
      console.warn(...fe);
    if (ai.urls && ai.urls.length) {
      ai.url = ai.urls.shift();
      if (ai.url) {
        App.stopTimers();
        App.startSingle();
      } else {
        App.deactivate();
      }
    } else if (ai.node) {
      Status.set('error');
      Bar.set(fe.message, 'error');
    }
  },

  /** @param {MessageEvent} e */
  onMessage(e) {
    if (typeof e.data === 'string' && e.data === MSG.getViewSize) {
      e.stopImmediatePropagation();
      for (const el of doc.getElementsByTagName('iframe')) {
        if (el.contentWindow === e.source) {
          const s = Calc.frameSize(el, window).join(':');
          e.source.postMessage(`${MSG.viewSize}:${s}`, '*');
          return;
        }
      }
    }
  },

  /** @param {MessageEvent} e */
  onMessageChild(e) {
    if (e.source === parent && typeof e.data === 'string' && e.data.startsWith(MSG.viewSize)) {
      e.stopImmediatePropagation();
      removeEventListener('message', App.onMessageChild, true);
      const [w, h, x, y] = e.data.split(':').slice(1).map(parseFloat);
      if (w && h) ai.view = {w, h, x, y};
    }
  },

  start() {
    App.updateStyles();
    if (ai.gallery)
      App.startGallery();
    else
      App.startSingle();
  },

  startSingle() {
    Status.loading();
    if (ai.force && ai.preloadStart < 0) {
      App.commit();
      return;
    }
    ai.imageUrl = null;
    if (ai.rule.follow && !ai.rule.q && !ai.rule.s) {
      Req.findRedirect();
    } else if (ai.rule.q && !isArray(ai.urls)) {
      App.startFromQ();
    } else {
      Popup.create(ai.url);
      Ruler.runC();
    }
  },

  async startFromQ() {
    try {
      const {responseText, doc, finalUrl} = await Req.getDoc(ai.url);
      const url = Ruler.runQ(responseText, doc, finalUrl);
      if (!url) {
        App.handleError(['The "q" rule did not produce any URL.', '\nRemote doc: %o', doc]);
        return;
      }
      if (RuleMatcher.isFollowableUrl(url, ai.rule)) {
        const info = RuleMatcher.find(url, ai.node, {noHtml: true});
        if (!info || !info.url)
          throw `Couldn't follow URL: ${url}`;
        Object.assign(ai, info);
        App.startSingle();
      } else {
        Popup.create(url, finalUrl);
        Ruler.runC(responseText, doc);
      }
    } catch (e) {
      App.handleError(e);
    }
  },

  async startGallery() {
    Status.loading();
    try {
      const startUrl = ai.url;
      const p = await Req.getDoc(ai.rule.s !== 'gallery' && startUrl);
      const items = await new Promise(cb => {
        const res = ai.gallery(p.responseText, p.doc, p.finalUrl, ai.match, ai.rule, ai.node, cb);
        if (res !== undefined) cb(res);
      });
      // bail out if the gallery's async callback took too long
      if (ai.url !== startUrl) return;
      ai.gNum = items.length;
      ai.gItems = items.length && items;
      if (ai.gItems) {
        const i = items.index;
        ai.gIndex = i >= 0 && items[i] ? +i :
          Gallery.findIndex(typeof i === 'string' ? i : ai.url);
        setTimeout(Gallery.next);
      } else {
        throw 'Empty gallery';
      }
    } catch (e) {
      App.handleError(e);
    }
  },

  stopTimers(bar) {
    for (const timer of ['timer', 'timerStatus', bar && 'timerBar'])
      clearTimeout(ai[timer]);
    clearInterval(ai.timerProgress);
  },

  toggleZoom({keepScale} = {}) {
    const p = ai.popup;
    if (!p || !ai.scales || ai.scales.length < 2)
      return;
    ai.zoomed = !ai.zoomed;
    ai.scale = ai.zoomed && Calc.scaleForFirstZoom(keepScale) || ai.scales[0];
    if (ai.zooming)
      p.classList.add(`${PREFIX}zooming`);
    Popup.move();
    Bar.updateDetails();
    Status.set(ai.zoomed ? 'zoom' : false);
    return ai.zoomed;
  },

  updateStyles() {
    Util.addStyle('global', (App.globalStyle || createGlobalStyle()) + cfg._getCss());
    Util.addStyle('rule', ai.rule.css || '');
  },
};

const Bar = {

  set(label, cls, prefix) {
    let b = ai.bar;
    if (typeof label !== 'string') {
      $remove(b);
      ai.bar = null;
      return;
    }
    const force = !b && 0;
    if (!b) b = ai.bar = $new('div', {id: `${PREFIX}bar`, className: `${PREFIX}${cls}`});
    ai.barText = label;
    App.updateStyles();
    Bar.updateDetails();
    Bar.setText(cfg.uiInfoCaption || cls === 'error' || cls === 'xhr' ? label : '');
    $dataset(b, 'prefix', prefix);
    setTimeout(Bar.show, 0, force);
    if (!b.parentNode) {
      doc.body.appendChild(b);
      Util.forceLayout(b);
    }
  },

  setText(text) {
    if (/<([a-z][-a-z]*)[^<>]*>[^<>]*<\/\1\s*>/i.test(text)) { // checking for <tag...>...</tag>
      ai.bar.innerHTML = trustedHTML ? trustedHTML(text) : text;
    } else {
      ai.bar.textContent = text;
    }
  },

  show(force) {
    const b = ai.bar;
    if (!force && (!cfg.uiInfo || force !== 0 && cfg.uiInfoOnce) || ai.barShown)
      return;
    clearTimeout(ai.timerBar);
    b.classList.add(PREFIX + 'show');
    $dataset(b, 'force', force === 2 ? '' : null);
    ai.timerBar = !force && setTimeout(Bar.hide, cfg.uiInfoHide * 1000);
    ai.barShown = true;
  },

  hide(force) {
    const b = ai.bar;
    if (!b || !force && (!cfg.uiInfo || b.dataset.force) || !ai.barShown)
      return;
    $dataset(b, 'force', force === 2 ? '' : null);
    b.classList.remove(PREFIX + 'show');
    ai.barShown = false;
  },

  updateName() {
    const {gItems: gi, gIndex: i, gNum: n} = ai;
    if (gi) {
      const item = gi[i];
      const noDesc = !gi.some(_ => _.desc);
      const c = [
        gi.title && (!i || noDesc) && !`${item.desc || ''}`.includes(gi.title) && gi.title || '',
        item.desc,
      ].filter(Boolean).join(' - ');
      Bar.set(c.trim() || ' ', 'gallery', n > 1 ? `${i + 1}/${n}` : null);
    } else if ('caption' in ai) {
      Bar.set(ai.caption, 'caption');
    } else if (ai.tooltip) {
      Bar.set(ai.tooltip.text, 'tooltip');
    } else {
      Bar.set(' ', 'info');
    }
  },

  updateDetails() {
    if (!ai.bar) return;
    const r = ai.rotate;
    const zoom = ai.nwidth && `${
      Math.round(ai.scale * 100)
    }%${
      ai.flipX || ai.flipY ? `, ${ai.flipX ? '⇆' : ''}${ai.flipY ? '⇅' : ''}` : ''
    }${
      r ? ', ' + (r > 180 ? r - 360 : r) + '°' : ''
    }, ${
      ai.nwidth
    } x ${
      ai.nheight
    } px, ${
      Math.round(100 * (ai.nwidth * ai.nheight / 1e6)) / 100
    } MP, ${
      Calc.aspectRatio(ai.nwidth, ai.nheight)
    }`.replace(/\x20/g, '\xA0');
    if (ai.bar.dataset.zoom !== zoom || !ai.nwidth) {
      $dataset(ai.bar, 'zoom', zoom || null);
      Bar.show();
    }
  },
};

const Calc = {

  aspectRatio(w, h) {
    for (let rat = w / h, a, b = 0; ;) {
      b++;
      a = Math.round(w * b / h);
      if (a > 10 && b > 10 || a > 100 || b > 100)
        return rat.toFixed(2);
      if (Math.abs(a / b - rat) < .01)
        return `${a}:${b}`;
    }
  },

  frameSize(elFrame, wnd) {
    if (!elFrame) return;
    const r = elFrame.getBoundingClientRect();
    const w = Math.min(r.right, wnd.innerWidth) - Math.max(r.left, 0);
    const h = Math.min(r.bottom, wnd.innerHeight) - Math.max(r.top, 0);
    const x = r.left < 0 ? -r.left : 0;
    const y = r.top < 0 ? -r.top : 0;
    return [w, h, x, y];
  },

  generateScales(fit) {
    let [scale, goal] = fit < 1 ? [fit, 1] : [1, fit];
    const zoomStep = cfg.zoomStep / 100;
    const arr = [scale];
    if (fit !== 1) {
      const diff = goal / scale;
      const steps = Math.log(diff) / Math.log(zoomStep) | 0;
      const step = steps && Math.pow(diff, 1 / steps);
      for (let i = steps; --i > 0;)
        arr.push((scale *= step));
      arr.push(scale = goal);
    }
    while ((scale *= zoomStep) <= ZOOM_MAX)
      arr.push(scale);
    return arr;
  },

  measurePopup() {
    let {popup: p, nwidth: nw, nheight: nh} = ai;
    // overriding custom CSS to detect an unrestricted SVG that scales to the entire page
    p.setAttribute('style', 'display:inline !important;' + App.popupStyleBase);
    if (p.clientWidth > nw) {
      const w = clamp(p.clientWidth, nw, innerWidth / 2) | 0;
      nh = ai.nheight = w / nw * nh | 0;
      nw = ai.nwidth = w;
      p.style.cssText = `width: ${nw}px !important; height: ${nh}px !important;`;
    } else
      p.style.cssText = '';
    p.classList.add(`${PREFIX}show`);
    const s = getComputedStyle(p);
    const o2 = sumProps(s.outlineOffset, s.outlineWidth) * 2;
    const inw = sumProps(s.paddingLeft, s.paddingRight, s.borderLeftWidth, s.borderRightWidth);
    const inh = sumProps(s.paddingTop, s.paddingBottom, s.borderTopWidth, s.borderBottomWidth);
    const outw = o2 + sumProps(s.marginLeft, s.marginRight);
    const outh = o2 + sumProps(s.marginTop, s.marginBottom);
    ai.extras = {
      inw, inh,
      outw, outh,
      o: o2 / 2,
      w: inw + outw,
      h: inh + outh,
    };
    const fit = Math.min(
      (ai.view.w - ai.extras.w) / ai.nwidth,
      (ai.view.h - ai.extras.h) / ai.nheight) || 1;
    const isCustom = !cfg.fit && cfg.scales.length;
    let cutoff = Math.min(1, fit);
    let scaleZoom = cfg.fit === 'all' && fit || cfg.fit === 'no' && 1 || cutoff;
    if (isCustom) {
      const dst = [];
      for (const scale of cfg.scales) {
        const val = parseFloat(scale) || fit;
        dst.push(val);
        if (isCustom && typeof scale === 'string') {
          if (scale.includes('!')) cutoff = val;
          if (scale.includes('*')) scaleZoom = val;
        }
      }
      ai.scales = dst.sort(compareNumbers).filter(Calc.scaleBiggerThan, cutoff);
    } else {
      ai.scales = Calc.generateScales(fit);
    }
    ai.scale = cfg.zoom === 'auto' ? scaleZoom : Math.min(1, fit);
    ai.scaleFit = fit;
    ai.scaleZoom = scaleZoom;
  },

  rect() {
    const {node, rule} = ai;
    let n = rule.rect && node.closest(rule.rect);
    if (n) return n.getBoundingClientRect();
    const nested = (n = node).firstElementChild ? document.elementsFromPoint(ai.cx, ai.cy) : [];
    let maxArea = 0;
    let maxBounds;
    let i = 0;
    do {
      const bounds = n.getBoundingClientRect();
      const area = bounds.width * bounds.height;
      if (area > maxArea) {
        maxArea = area;
        maxBounds = bounds;
      }
    } while ((n = nested[i++]) && node.contains(n));
    return maxBounds;
  },

  scaleBiggerThan(scale, i, arr) {
    return scale >= this && (!i || Math.abs(scale - arr[i - 1]) > .01);
  },

  scaleIndex(dir) {
    const i = ai.scales.indexOf(ai.scale);
    if (i >= 0) return i + dir;
    for (
      let len = ai.scales.length,
        i = dir > 0 ? 0 : len - 1;
      i >= 0 && i < len;
      i += dir
    ) {
      if (Math.sign(ai.scales[i] - ai.scale) === dir)
        return i;
    }
    return -1;
  },

  scaleForFirstZoom(keepScale) {
    const z = ai.scaleZoom;
    return keepScale || z !== ai.scale ? z : ai.scales.find(x => x > z);
  },

  updateViewSize() {
    const view = doc.compatMode === 'BackCompat' ? doc.body : doc.documentElement;
    ai.view = {w: view.clientWidth, h: view.clientHeight, x: 0, y: 0};
    if (window === top) return;
    const [w, h] = Calc.frameSize(frameElement, parent) || [];
    if (w && h) {
      ai.view = {w, h, x: 0, y: 0};
    } else {
      addEventListener('message', App.onMessageChild, true);
      parent.postMessage(MSG.getViewSize, '*');
    }
  },
};

class Config {

  constructor({data: c, save}) {
    if (typeof c === 'string')
      c = tryJSON(c);
    if (typeof c !== 'object' || !c)
      c = {};
    const {DEFAULTS} = Config;
    c.fit = ['all', 'large', 'no', ''].includes(c.fit) ? c.fit :
      !(c.scales || 0).length || `${c.scales}` === `${DEFAULTS.scales}` ? 'large' :
        '';
    if (c.version !== DEFAULTS.version) {
      if (typeof c.hosts === 'string')
        c.hosts = c.hosts.split('\n')
          .map(s => tryJSON(s) || s)
          .filter(Boolean);
      if (c.close === true || c.close === false)
        c.zoomOut = c.close ? 'auto' : 'stay';
      for (const key in DEFAULTS)
        if (typeof c[key] !== typeof DEFAULTS[key])
          c[key] = DEFAULTS[key];
      if (c.version === 3 && c.scales[0] === 0)
        c.scales[0] = '0!';
      for (const key in c)
        if (!(key in DEFAULTS))
          delete c[key];
      c.version = DEFAULTS.version;
      if (save)
        GM.setValue('cfg', c);
    }
    if (Object.keys(cfg || {}).some(k => /^ui|^(css|globalStatus)$/.test(k) && cfg[k] !== c[k]))
      App.globalStyle = '';
    if (!isArray(c.scales))
      c.scales = [];
    c.scales = [...new Set(c.scales)].sort((a, b) => parseFloat(a) - parseFloat(b));
    Object.assign(this, DEFAULTS, c);
  }

  static async load(opts) {
    opts.data = await GM.getValue('cfg');
    return new Config(opts);
  }

  _getCss() {
    const {css} = this;
    return css.includes('{') ? css : `#${PREFIX}-popup {${css}}`;
  }
}

Config.DEFAULTS = /** @type mpiv.Config */ {
  __proto__: null,
  center: false,
  css: '',
  delay: 500,
  fit: '',
  globalStatus: false,
  // prefer ' inside rules because " will be displayed as \"
  // example: "img[src*='icon']"
  hosts: [{
    name: 'No popup for YouTube thumbnails',
    d: 'www.youtube.com',
    e: 'ytd-rich-item-renderer *, ytd-thumbnail *',
    s: '',
  }, {
    name: 'No popup for SVG/PNG icons',
    d: '',
    e: "img[src*='icon']",
    r: '//[^/]+/.*\\bicons?\\b.*\\.(?:png|svg)',
    s: '',
  }],
  imgtab: false,
  keepOnBlur: false,
  keepVids: false,
  mute: false,
  night: false,
  preload: false,
  scale: 1.05,
  scales: ['0!', 0.125, 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 5, 8, 16],
  start: 'auto',
  startAlt: 'context',
  startAltShown: false,
  uiBackgroundColor: '#ffffff',
  uiBackgroundOpacity: 100,
  uiBorderColor: '#000000',
  uiBorderOpacity: 100,
  uiBorder: 0,
  uiFadein: true,
  uiFadeinGallery: true, // some computers show white background while loading so fading hides it
  uiInfo: true,
  uiInfoCaption: true,
  uiInfoHide: 3,
  uiInfoOnce: true,
  uiShadowColor: '#000000',
  uiShadowOpacity: 80,
  uiShadow: 20,
  uiShadowOnLoad: true,
  uiPadding: 0,
  uiMargin: 0,
  version: 6,
  videoCtrl: true,
  waitLoad: false,
  xhr: true,
  zoom: 'context',
  zoomOut: 'auto',
  zoomStep: 133,
};

const CspSniffer = {

  /** @type {?Object<string,string[]>} */
  csp: null,
  selfUrl: location.origin + '/',

  // will be null when done
  init() {
    this.busy = new Promise(resolve => {
      const xhr = new XMLHttpRequest();
      xhr.open('get', location);
      xhr.timeout = Math.max(2000, (performance.timing.responseEnd - performance.timeOrigin) * 2);
      xhr.onreadystatechange = () => {
        if (xhr.readyState >= xhr.HEADERS_RECEIVED) {
          this.csp = this._parse([
            xhr.getResponseHeader('content-security-policy'),
            $prop('meta[http-equiv="Content-Security-Policy"]', 'content'),
          ].filter(Boolean).join(','));
          this.init = this.busy = xhr.onreadystatechange = null;
          xhr.abort();
          resolve();
        }
      };
      xhr.send();
    });
  },

  async check(url, allowInit) {
    if (allowInit && this.init) this.init();
    if (this.busy) await this.busy;
    const isVideo = Util.isVideoUrl(url);
    let mode;
    if (this.csp) {
      const src = this.csp[isVideo ? 'media' : 'img'];
      if (!src.some(this._srcMatches, url))
        mode = [mode, 'blob', 'data'].find(m => src.includes(`${m}:`));
    }
    return [mode || ai.xhr, isVideo];
  },

  _parse(csp) {
    if (!csp) return;
    const src = {};
    const rx = /(?:^|[;,])\s*(?:(default|img|media|script)-src|require-(trusted)-types-for) ([^;,]+)/g;
    for (let m; (m = rx.exec(csp));)
      src[m[1] || m[2]] = m[3].trim().split(/\s+/);
    if ((src.script || []).find(s => /^'nonce-(.+)'$/.test(s)))
      nonce = RegExp.$1;
    if ((src.trusted || []).includes("'script'"))
      App.NOP = () => {};
    if (!src.img) src.img = src.default || [];
    if (!src.media) src.media = src.default || [];
    for (const set of [src.img, src.media]) {
      set.forEach((item, i) => {
        if (item !== '*' && item.includes('*')) {
          set[i] = new RegExp(
            (/^\w+:/.test(item) ? '^' : '^\\w+://') +
            item
            .replace(/[.+?^$|()[\]{}]/g, '\\$&')
            .replace(/(\\\.)?(\*)(\\\.)?/g, (_, a, b, c) =>
              `${a ? '\\.?' : ''}[^:/]*${c ? '\\.?' : ''}`)
            .replace(/[^/]$/, '$&/'));
        }
      });
    }
    return src;
  },

  /** @this string */
  _srcMatches(src) {
    return src instanceof RegExp ? src.test(this) :
      src === '*' ||
      src && this.startsWith(src) && (src.endsWith('/') || this[src.length] === '/') ||
      src === "'self'" && this.startsWith(CspSniffer.selfUrl);
  },
};

const Events = {

  ctrl: false,
  hoverData: null,
  hoverTimer: 0,
  ignoreKeyHeld: false,

  onMouseOver(e) {
    let node = e.target;
    Events.ignoreKeyHeld = e.shiftKey;
    if (!App.isEnabled ||
        e.shiftKey ||
        ai.zoomed ||
        node === ai.popup ||
        node === doc.body ||
        node === doc.documentElement ||
        node === elSetup ||
        ai.gallery && ai.rectHovered ||
        !App.canClose())
      return;
    if (node.shadowRoot)
      node = Events.pierceShadow(node, e.clientX, e.clientY);
    // we don't want to process everything in the path of a quickly moving mouse cursor
    Events.hoverData = {e, node, start: now()};
    Events.hoverTimer = Events.hoverTimer || setTimeout(Events.onMouseOverThrottled, SETTLE_TIME);
    node.addEventListener('mouseout', Events.onMouseOutThrottled);
  },

  onMouseOverThrottled(force) {
    const {start, e, node, nodeOut} = Events.hoverData || {};
    if (!node || node === nodeOut && (Events.hoverData = null, 1))
      return;
    // clearTimeout + setTimeout is expensive so we'll use the cheaper perf.now() for rescheduling
    const wait = force ? 0 : start + SETTLE_TIME - now();
    const t = Events.hoverTimer = wait > 10 && setTimeout(Events.onMouseOverThrottled, wait);
    if (t)
      return;
    Events.hoverData = null;
    if (!Ruler.rules)
      Ruler.init();
    const info = RuleMatcher.adaptiveFind(node);
    if (info && info.url && info.node !== ai.node)
      App.activate(info, e);
  },

  onMouseOut(e) {
    if (!e.relatedTarget && !cfg.keepOnBlur && !e.shiftKey && App.canClose())
      App.deactivate();
  },

  onMouseOutThrottled(e) {
    const d = Events.hoverData;
    if (d) d.nodeOut = this;
    this.removeEventListener('mouseout', Events.onMouseOutThrottled);
    Events.hoverTimer = 0;
  },

  onMouseOutShadow(e) {
    const root = e.target.shadowRoot;
    if (root) {
      root.removeEventListener('mouseover', Events.onMouseOver);
      root.removeEventListener('mouseout', Events.onMouseOutShadow);
    }
  },

  onMouseMove(e) {
    Events.trackMouse(e);
    if (e.shiftKey)
      return;
    if (!ai.zoomed && !ai.rectHovered && App.canClose()) {
      App.deactivate();
    } else if (ai.zoomed) {
      Popup.move();
      const {cx, cy, view: {w, h}} = ai;
      const bx = w / 6;
      const by = h / 6;
      const onEdge = cx < bx || cx > w - bx || cy < by || cy > h - by;
      Status.set(`${onEdge ? '+' : '-'}edge`);
    }
  },

  onMouseDown({shiftKey, button, target}) {
    if (!button && target === ai.popup && ai.popup.controls && (shiftKey || !App.canClose())) {
      ai.controlled = ai.zoomed = true;
    } else if (button === 2 || shiftKey) {
      // Shift = ignore; RMB will be processed in onContext
    } else {
      App.deactivate({wait: true});
      doc.addEventListener('mouseup', App.enable, {once: true});
    }
  },

  onMouseScroll(e) {
    const dir = (e.deltaY || -e.wheelDelta) < 0 ? 1 : -1;
    if (ai.zoomed) {
      Events.zoomInOut(dir);
    } else if (ai.gNum > 1 && ai.popup) {
      Gallery.next(-dir);
    } else if (cfg.zoom === 'wheel' && dir > 0 && ai.popup) {
      App.toggleZoom();
    } else if (App.canClose()) {
      App.deactivate();
      return;
    }
    dropEvent(e);
  },

  onKeyDown(e) {
    // Synthesized events may be of the wrong type and not have a `key`
    const key = describeKey(e);
    const p = ai.popupShown;
    if (!p && key === '^Control') {
      addEventListener('keyup', Events.onKeyUp, true);
      Events.ctrl = true;
    }
    if (!p && key === '^ContextMenu')
      return Events.onContext.call(this, e);
    if (!p || e.repeat)
      return;
    switch (key) {
      case '+Shift':
        if (ai.shiftKeyTime)
          return;
        ai.shiftKeyTime = now();
        Status.set('+shift');
        if (cfg.uiInfo)
          Bar.show(1);
        if (isVideo(p))
          p.controls = true;
        return;
      case 'KeyA':
        p.toggleAttribute(NOAA_ATTR);
        break;
      case 'ArrowRight':
      case 'KeyJ':
        Gallery.next(1);
        break;
      case 'ArrowLeft':
      case 'KeyK':
        Gallery.next(-1);
        break;
      case 'KeyC':
        if (ai.bar.firstChild) {
          Bar.setText('');
          Bar.hide(0);
        } else {
          Bar.setText(ai.barText);
          Bar.show(2);
        }
        break;
      case 'KeyD':
        Req.saveFile();
        break;
      case 'KeyF':
        if (p !== document.fullscreenElement) p.requestFullscreen();
        else document.exitFullscreen();
        break;
      case 'KeyH': // flip horizontally
      case 'KeyV': // flip vertically
      case 'KeyL': // rotate left
      case 'KeyR': // rotate right
        if (!p)
          return;
        if (key === 'KeyH' || key === 'KeyV') {
          const side = !!(ai.rotate % 180) ^ (key === 'KeyH') ? 'flipX' : 'flipY';
          ai[side] = !ai[side];
        } else {
          ai.rotate = ((ai.rotate || 0) + 90 * (key === 'KeyL' ? -1 : 1) + 360) % 360;
        }
        Bar.updateDetails();
        Popup.move();
        break;
      case 'KeyI':
        (ai.barShown ? Bar.hide : Bar.show)(2);
        break;
      case 'KeyM':
        if (isVideo(p))
          p.muted = !p.muted;
        break;
      case 'KeyN':
        ai.night = p.classList.toggle(`${PREFIX}night`);
        break;
      case 'KeyT':
        GM.openInTab(Util.tabFixUrl() || p.src);
        App.deactivate();
        break;
      case 'Minus':
      case 'NumpadSubtract':
        if (ai.zoomed) {
          Events.zoomInOut(-1);
        } else {
          App.toggleZoom();
        }
        break;
      case 'Equal':
      case 'NumpadAdd':
        if (ai.zoomed) {
          Events.zoomInOut(1);
        } else {
          App.toggleZoom();
        }
        break;
      case 'Escape':
        App.deactivate({wait: true});
        break;
      case '!Alt':
        return;
      default:
        App.deactivate({wait: true});
        return;
    }
    dropEvent(e);
  },

  onKeyUp(e) {
    const p = ai.popupShown || false;
    if (e.key === 'Control') {
      if (!p) removeEventListener('keyup', Events.onKeyUp, true);
      setTimeout(() => (Events.ctrl = false));
    }
    if (p && e.key === 'Shift' && ai.shiftKeyTime) {
      Status.set('-shift');
      if (cfg.uiInfo)
        Bar.hide(1);
      if (p.controls)
        p.controls = false;
      // Chrome doesn't expose events for clicks on video controls so we'll guess
      if (ai.controlled || !isFF && now() - ai.shiftKeyTime > 500)
        ai.controlled = false;
      else if (p && (ai.zoomed || ai.rectHovered !== false))
        App.toggleZoom();
      else
        App.deactivate({wait: true});
      ai.shiftKeyTime = 0;
    } else if (
      describeKey(e) === 'Control' && !p && !Events.ignoreKeyHeld &&
      (cfg.start === 'ctrl' || cfg.start === 'context' || ai.rule.manual)
    ) {
      dropEvent(e);
      if (Events.hoverData) {
        Events.hoverData.e = e;
        Events.onMouseOverThrottled(true);
      }
      if (ai.node) {
        ai.force = true;
        App.start();
      }
    }
  },

  onContext(e) {
    if (Events.ignoreKeyHeld)
      return;
    const p = ai.popupShown;
    if (cfg.zoom === 'context' && p && App.toggleZoom()) {
      dropEvent(e);
    } else if (!p && (!cfg.videoCtrl || !isVideo(ai.node) || Events.ctrl) && (
      cfg.start === 'context' ||
      cfg.start === 'contextMK' ||
      cfg.start === 'contextM' && (e.button === 2) ||
      cfg.start === 'contextK' && (e.button !== 2) ||
      (cfg.start === 'auto' && ai.rule.manual)
    )) {
      // right-clicked on an image while the context menu is shown for something else
      if (!ai.node && !Events.hoverData)
        Events.onMouseOver(e);
      Events.onMouseOverThrottled(true);
      if (ai.node) {
        ai.force = true;
        App.start();
        dropEvent(e);
      }
    } else if (p) {
      setTimeout(App.deactivate, SETTLE_TIME, {wait: true});
    }
  },

  onVisibility(e) {
    Events.ctrl = false;
  },

  pierceShadow(node, x, y) {
    for (let root; (root = node.shadowRoot);) {
      root.addEventListener('mouseover', Events.onMouseOver, {passive: true});
      root.addEventListener('mouseout', Events.onMouseOutShadow);
      const inner = root.elementFromPoint(x, y);
      if (!inner || inner === node)
        break;
      node = inner;
    }
    return node;
  },

  toggle(enable) {
    const onOff = enable ? 'addEventListener' : 'removeEventListener';
    const passive = {passive: true, capture: true};
    window[onOff]('mousemove', Events.onMouseMove, passive);
    window[onOff]('mouseout', Events.onMouseOut, passive);
    window[onOff]('mousedown', Events.onMouseDown, passive);
    window[onOff]('keyup', Events.onKeyUp, true);
    window[onOff](WHEEL_EVENT, Events.onMouseScroll, {passive: false, capture: true});
    ai.node.removeEventListener('mouseout', Events.onMouseOutThrottled);
  },

  trackMouse(e) {
    const cx = ai.cx = e.clientX;
    const cy = ai.cy = e.clientY;
    const r = ai.rect || (ai.rect = Calc.rect());
    ai.rectHovered =
      cx > r.left - 2 && cx < r.right + 2 &&
      cy > r.top - 2 && cy < r.bottom + 2;
  },

  zoomInOut(dir) {
    const i = Calc.scaleIndex(dir);
    const n = ai.scales.length;
    if (i >= 0 && i < n)
      ai.scale = ai.scales[i];
    const zo = cfg.zoomOut;
    if (i <= 0 && zo !== 'stay') {
      if (ai.scaleFit < ai.scale * .99) {
        ai.scales.unshift(ai.scale = ai.scaleFit);
      } else if ((i <= 0 && zo === 'close' || i < 0 && !ai.rectHovered) && ai.gNum < 2) {
        App.deactivate({wait: true});
        return;
      }
      ai.zoomed = zo !== 'unzoom';
    } else {
      ai.popup.classList.toggle(`${PREFIX}zoom-max`, ai.scale >= 4 && i >= n - 1);
    }
    if (ai.zooming)
      ai.popup.classList.add(`${PREFIX}zooming`);
    Popup.move();
    Bar.updateDetails();
  },
};

const Gallery = {

  makeParser(g) {
    return isFunction(g) ? g : Gallery.defaultParser;
  },

  findIndex(gUrl) {
    return Math.max(0, ai.gItems.findIndex(({url}) => isArray(url) ? url.includes(gUrl) : url === gUrl));
  },

  next(dir) {
    if (dir) ai.gIndex = Gallery.nextIndex(dir);
    const item = ai.gItem = ai.gItems[ai.gIndex];
    if (isArray(item.url)) {
      ai.urls = item.url.slice(1);
      ai.url = item.url[0];
    } else {
      ai.urls = null;
      ai.url = item.url;
    }
    ai.gItemNext = ai.gItems[Gallery.nextIndex(dir || 1)];
    App.startSingle();
    Bar.updateName();
    if (dir) Bar.show(0);
  },

  nextIndex(dir) {
    return (ai.gIndex + dir + ai.gNum) % ai.gNum;
  },

  defaultParser(text, doc, docUrl, m, rule) {
    const {g} = rule;
    const gi = g.index;
    const qEntry = g.entry;
    const qCaption = ensureArray(g.caption);
    const qImage = g.image || 'img';
    const qTitle = g.title;
    const fix =
      (typeof g.fix === 'string' ? Util.newFunction('s', 'isURL', g.fix) : g.fix) ||
      (s => s.trim());
    const elems = [...$$(qEntry || qImage, doc)];
    const items = elems.map(processEntry).filter(Boolean);
    items.title = processTitle();
    items.index =
      RX_HAS_CODE.test(gi) ? Util.newFunction('items', 'node', gi)(items, ai.node) :
        typeof gi === 'string' ? Req.findImageUrl(tryCatch($, gi, doc), docUrl) :
          gi == null ? Math.max(0, elems.indexOf(ai.node)) :
            gi;
    return items;

    function processEntry(entry) {
      const item = {};
      try {
        const img = qEntry ? $(qImage, entry) : entry;
        item.url = fix(Req.findImageUrl(img, docUrl), true);
        item.desc = qCaption.map(processCaption, entry).filter(Boolean).join(' - ');
      } catch (e) {}
      return item.url && item;
    }
    function processCaption(sel) {
      const el = !sel ? this
        : $(sel, this) ||
          $orSelf(sel, this.previousElementSibling) ||
          $orSelf(sel, this.nextElementSibling);
      return el && fix(Ruler.runCHandler.default(el) || el.textContent);
    }
    function processTitle() {
      const el = $(qTitle, doc);
      return el && fix(el.getAttribute('content') || el.textContent) || '';
    }
    function $orSelf(selector, el) {
      if (el && !el.matches(qEntry))
        return el.matches(selector) ? el : $(selector, el);
    }
  },
};

const Menu = window === top && GM.registerMenuCommand && {
  curAltName: '',
  unreg: GM.unregisterMenuCommand,
  makeAltName: () => Menu.unreg
    ? `MPIV: auto-start is ${cfg.start === 'auto' ? 'ON' : 'OFF'}`
    : 'MPIV: toggle auto-start',
  register() {
    GM.registerMenuCommand('MPIV: configure', setup);
    Menu.registerAlt();
  },
  registerAlt() {
    if (cfg.startAltShown) {
      Menu.curAltName = Menu.makeAltName();
      GM.registerMenuCommand(Menu.curAltName, Menu.onAltToggled);
    }
  },
  reRegisterAlt() {
    const old = Menu.curAltName;
    if (old && Menu.unreg) Menu.unreg(old);
    if (!old || Menu.unreg) Menu.registerAlt();
  },
  onAltToggled() {
    const wasAuto = cfg.start === 'auto';
    if (wasAuto) {
      cfg.start = cfg.startAlt || (cfg.startAlt = 'context');
    } else {
      cfg.startAlt = cfg.start;
      cfg.start = 'auto';
    }
    Menu.reRegisterAlt();
  },
};

const Popup = {

  async create(src, pageUrl, error) {
    let p = ai.popup, blank;
    const inGallery = p && !cfg.uiFadeinGallery && ai.gItems && !ai.zooming;
    if (inGallery && p === document.fullscreenElement) {
      Popup.destroyBlob();
    } else if (p) {
      Popup.destroy();
      p = null;
    }
    ai.imageUrl = src;
    if (!src)
      return;
    const myAi = ai;
    let [xhr, isVideo] = await CspSniffer.check(src, error);
    if (ai !== myAi)
      return;
    if (!xhr && error) {
      App.handleError(error);
      return;
    }
    Object.assign(ai, {pageUrl, xhr});
    if (xhr)
      [src, isVideo] = await Req.getImage(src, pageUrl, xhr).catch(App.handleError) || [];
    let vol;
    if (ai !== myAi || !src || isVideo && (vol = await GM.getValue('volume'), ai !== myAi))
      return;
    if (p) {
      p.src = blank = BLANK_PIXEL;
      p.classList.remove(PREFIX + 'show');
      p.removeAttribute('style');
      ai.popupShown = null;
      ai.popupLoaded = false;
    } else p = ai.popup = isVideo ? PopupVideo.create(vol) : $new('img');
    p.id = `${PREFIX}popup`;
    p.src = src;
    p.addEventListener('error', App.handleError);
    if ((ai.night = (ai.night != null ? ai.night : cfg.night)))
      p.classList.add(`${PREFIX}night`);
    if (ai.zooming)
      p.addEventListener('transitionend', Popup.onZoom);
    $dataset(p, 'galleryFlip', inGallery ? '' : null);
    p.toggleAttribute('loaded', !!inGallery);
    const poo = ai.popover || typeof p.showPopover === 'function' && $('[popover]:popover-open');
    ai.popover = poo && poo.getBoundingClientRect().width && ($css(poo, {opacity: 0}), poo) || null;
    if (p.parentElement !== doc.body)
      doc.body.insertBefore(p, ai.bar && ai.bar.parentElement === doc.body && ai.bar || null);
    await 0;
    if (ai.popup !== p || App.checkProgress({start: true}) === false)
      return;
    if (!blank && p.complete)
      Popup.onLoad.call(p);
    else if (!isVideo)
      p.addEventListener('load', Popup.onLoad, {once: true});
  },

  destroy() {
    const p = ai.popup;
    if (!p) return;
    p.removeEventListener('load', Popup.onLoad);
    p.removeEventListener('error', App.handleError);
    if (ai.popover) {
      ai.popover.style.removeProperty('opacity');
      ai.popover = null;
    }
    if (isFunction(p.pause))
      p.pause();
    p.remove();
    Popup.destroyBlob();
    ai.zoomed = ai.popup = ai.popupLoaded = null;
  },

  destroyBlob() {
    if (!ai.blobUrl) return;
    setTimeout(URL.revokeObjectURL, SETTLE_TIME, ai.blobUrl);
    ai.blobUrl = null;
  },

  move() {
    let x, y;
    const {cx, cy, extras, view} = ai;
    const vw = view.w - extras.outw;
    const vh = view.h - extras.outh;
    const w0 = ai.scale * ai.nwidth + extras.inw;
    const h0 = ai.scale * ai.nheight + extras.inh;
    const isSwapped = ai.rotate % 180;
    const w = isSwapped ? h0 : w0;
    const h = isSwapped ? w0 : h0;
    if (!ai.zoomed && ai.gNum < 2 && !cfg.center) {
      const r = ai.rect;
      const rx = (r.left + r.right) / 2;
      const ry = (r.top + r.bottom) / 2;
      if (vw - r.right - 40 > w || w < r.left - 40) {
        if (h < vh - 60)
          y = clamp(ry - h / 2, 30, vh - h - 30);
        x = rx > vw / 2 ? r.left - 40 - w : r.right + 40;
      } else if (vh - r.bottom - 40 > h || h < r.top - 40) {
        if (w < vw - 60)
          x = clamp(rx - w / 2, 30, vw - w - 30);
        y = ry > vh / 2 ? r.top - 40 - h : r.bottom + 40;
      }
    }
    if (x == null) {
      x = vw > w
        ? (vw - w) / 2 + view.x
        : (vw - w) * clamp(5 / 3 * ((cx - view.x) / vw - .2), 0, 1);
    }
    if (y == null) {
      y = vh > h
        ? (vh - h) / 2 + view.y
        : (vh - h) * clamp(5 / 3 * ((cy - view.y) / vh - .2), 0, 1);
    }
    const diff = isSwapped ? (w0 - h0) / 2 : 0;
    x += extras.o - diff;
    y += extras.o + diff;
    $css(ai.popup, {
      transform: `translate(${Math.round(x)}px, ${Math.round(y)}px) ` +
                 `rotate(${ai.rotate || 0}deg) ` +
                 `scale(${ai.flipX ? -1 : 1},${ai.flipY ? -1 : 1})`,
      width: `${Math.round(w0)}px`,
      height: `${Math.round(h0)}px`,
    });
  },

  onLoad() {
    if (this === ai.popup) {
      this.setAttribute('loaded', '');
      ai.popupLoaded = true;
      Status.set('-loading');
      let i = ai.gItem;
      if (i) i.url = this.src;
      if ((i = ai.gItemNext))
        Popup.preload(this, i);
    }
  },

  onZoom() {
    this.classList.remove(`${PREFIX}zooming`);
  },

  async preload(p, item, u = item.url, el = $new('img')) {
    ai.gItemNext = null;
    if (!isArray(u)) {
      el.src = u;
      return;
    }
    for (const arr = u; p === ai.popup && item.url === arr && (u = arr[0]);) {
      const {type} = await new Promise(cb => {
        el.src = u;
        el.onload = el.onerror = cb;
      });
      if (arr[0] === u)
        arr.shift();
      if (type === 'load') {
        item.url = u;
        break;
      }
    }
  },
};

const PopupVideo = {
  create(volume) {
    ai.bufBar = false;
    ai.bufStart = now();
    return $new('video', {
      autoplay: ai.preloadStart !== -1,
      controls: true,
      muted: cfg.mute || new AudioContext().state === 'suspended',
      loop: true,
      volume: clamp(+volume || .5, 0, 1),
      onprogress: PopupVideo.progress,
      oncanplaythrough: PopupVideo.progressDone,
      onvolumechange: PopupVideo.rememberVolume,
    });
  },

  progress() {
    const {duration} = this;
    if (duration && this.buffered.length && now() - ai.bufStart > 2000) {
      const pct = Math.round(this.buffered.end(0) / duration * 100);
      if (ai.bar && (ai.bufBar |= pct > 0 && pct < 50))
        Bar.set(`${pct}% of ${Math.round(duration)}s`, 'xhr');
    }
  },

  progressDone() {
    this.onprogress = this.oncanplaythrough = null;
    if (ai.bar && ai.bar.classList.contains(`${PREFIX}xhr`))
      Bar.set(false);
    Popup.onLoad.call(this);
  },

  rememberVolume() {
    GM.setValue('volume', this.volume);
  },
};

const Ruler = {
/*
 'u' works only with URLs so it's ignored if 'html' is true
   ||some.domain = matches some.domain, anything.some.domain, etc.
   |foo = url or text must start with foo
   ^ = separator like / or ? or : but not a letter/number, not %._-
       when used at the end like "foo^" it additionally matches when the source ends with "foo"
 'r' is checked only if 'u' matches first
*/
  init() {
    const errors = new Map();
    const src = cfg.hosts || [];
    const uniq = src.filter((r, i, arr) => !i || !Util.deepEqual(r, arr[i - 1]));
    if (uniq.length < src.length)
      GM.setValue('cfg', cfg);
    /** @type mpiv.HostRule[] */
    const rules = Ruler.rules = uniq.map(Ruler.parse, errors).filter(Boolean);
    const hasGMAE = typeof GM_addElement === 'function';
    const canEval = nonce || (nonce = ($('script[nonce]') || {}).nonce || '') || hasGMAE;
    const evalId = canEval && `${GM_info.script.name}${Math.random()}`;
    const evalRules = [];
    const evalCode = [`window[${JSON.stringify(evalId)}]=[`];
    for (const [rule, err] of errors.entries()) {
      if (!RX_EVAL_BLOCKED.test(err)) {
        App.handleError('Invalid custom host rule:', rule);
        continue;
      }
      if (canEval) {
        evalCode.push(evalRules.length ? ',' : '',
          '[', rules.indexOf(rule), ',{',
          ...Object.keys(FN_ARGS)
            .map(k => RX_HAS_CODE.test(rule[k]) && `${k}(${FN_ARGS[k]}){${rule[k]}},`)
            .filter(Boolean),
          '}]');
      }
      evalRules.push(rule);
    }
    if (evalRules.length) {
      let result, wnd;
      if (canEval) {
        const GMAE = hasGMAE
          ? GM_addElement // eslint-disable-line no-undef
          : (tag, {textContent: txt}) => document.head.appendChild(
            Object.assign(document.createElement(tag), {
              textContent: trustedScript ? trustedScript(txt) : txt,
              nonce,
            }));
        evalCode.push(']; document.currentScript.remove();');
        GMAE('script', {textContent: evalCode.join('')});
        result = (wnd = unsafeWindow)[evalId] ||
          isFF && (wnd = wnd.wrappedJSObject)[evalId];
      }
      if (result) {
        for (const [index, fns] of result)
          Object.assign(rules[index], fns);
        delete wnd[evalId];
      } else {
        console.warn('Site forbids compiling JS code in these custom rules', evalRules);
      }
    }

    // optimization: a rule is created only when on domain
    switch (dotDomain.match(/[^.]+(?=\.com?(?:\.[^.]+)?$)|[^.]+\.[^.]+$|$/)[0]) {

      case '4chan.org': rules.push({
        e: '.is_catalog .thread a[href*="/thread/"], .catalog-thread a[href*="/thread/"]',
        q: '.op .fileText a',
        css: '#post-preview{display:none}',
      }); break;

      case 'amazon': rules.push({
        r: /.+?images\/I\/.+?\./,
        s: m => {
          const uh = doc.getElementById('universal-hover');
          return uh ? '' : m[0] + 'jpg';
        },
        css: '#zoomWindow{display:none!important;}',
      }); break;

      case 'bing': rules.push({
        e: 'a[m*="murl"]',
        r: /murl&quot;:&quot;(.+?)&quot;/,
        s: '$1',
        html: true,
      }); break;

      case 'deviantart': rules.push({
        e: 'a[href*="/art/"] img[src*="/v1/"]',
        r: /^(.+)\/v1\/\w+\/[^/]+\/(.+)-\d+.(\.\w+)(\?.+)/,
        s: ([, base, name, ext, tok], node) => {
          let v = Util.getReactChildren(node.closest('a'), 'props.deviation.media.types');
          return v && (v = v.find(t => t.t === 'fullview')) && `${base}${
            v.c ? v.c.replace('<prettyName>', name)
              : `/v1/fill/w_${v.w},h_${v.h}/${name}-fullview${ext}`}${tok}`;
        },
      }, {
        e: '.dev-view-deviation img',
        s: () => [
          $('.dev-page-download').href,
          $('.dev-content-full').src,
        ].filter(Boolean),
      }, {
        e: 'a[data-hook=deviation_link]',
        q: 'link[as=image]',
      }); break;

      case 'discord': rules.push({
        u: '||discordapp.net/external/',
        r: /\/https?\/(.+)/,
        s: '//$1',
        follow: true,
      }); break;

      case 'dropbox': rules.push({
        r: /(.+?&size_mode)=\d+(.*)/,
        s: '$1=5$2',
      }); break;

      case 'facebook': rules.push({
        e: 'a[href^="/photo/?"], a[href^="https://www.facebook.com/photo"]',
        s: (m, el) => (m = Util.getReactChildren(el.parentNode)) &&
          pick(m, (m[0] ? '0.props.linkProps' : 'props') + '.passthroughProps.origSrc'),
      }); break;

      case 'flickr': if (pick(unsafeWindow, 'YUI_config.flickr.api.site_key')) rules.push({
        r: /flickr\.com\/photos\/[^/]+\/(\d+)/,
        s: m => `https://www.flickr.com/services/rest/?${
          new URLSearchParams({
            photo_id: m[1],
            api_key: unsafeWindow.YUI_config.flickr.api.site_key,
            method: 'flickr.photos.getSizes',
            format: 'json',
            nojsoncallback: 1,
          }).toString()}`,
        q: text => JSON.parse(text).sizes.size.pop().source,
        anonymous: true,
      }); break;

      case 'github': rules.push({
        r: new RegExp([
          /(avatars.+?&s=)\d+/,
          /(raw\.github)(\.com\/.+?\/img\/.+)$/,
          /\/(github)(\.com\/.+?\/)blob\/([^/]+\/.+?\.(?:avif|webp|png|jpe?g|bmp|gif|cur|ico|svg))$/,
        ].map(rx => rx.source).join('|')),
        s: m => `https://${
          m[1] ? `${m[1]}460` :
            m[2] ? `${m[2]}usercontent${m[3]}` :
              $('.AppHeader-context-item > .octicon-lock')
                ? `${m[4]}${m[5]}raw/${m[6]}`
                : `raw.${m[4]}usercontent${m[5]}${m[6]}`
        }`,
      }); break;

      case 'google': if (/[&?]tbm=isch(&|$)/.test(location.search)) rules.push({
        e: 'a[href*="imgres?imgurl="] img',
        s: (m, node) => new URLSearchParams(node.closest('a').search).get('imgurl'),
        follow: true,
      }, {
        e: '[data-tbnid] a:not([href])',
        s: (m, a) => {
          const a2 = $('a[jsaction*="mousedown"]', a.closest('[data-tbnid]')) || a;
          new MutationObserver((_, mo) => {
            mo.disconnect();
            App.isEnabled = true;
            a.alt = a2.innerText;
            const {left, top} = a.getBoundingClientRect();
            Events.onMouseOver({target: $('img', a), clientX: left, clientY: top});
          }).observe(a, {attributes: true, attributeFilter: ['href']});
          a2.dispatchEvent(new MouseEvent('mousedown', {bubbles: true}));
          a2.dispatchEvent(new MouseEvent('mouseup', {bubbles: true}));
        },
      }); break;

      case 'instagram': rules.push({
        e: 'a[href*="/p/"],' +
          'article [role="button"][tabindex="0"],' +
          'article [role="button"][tabindex="0"] div',
        s: (m, node, rule) => {
          let data, a, n, img, src;
          if (location.pathname.startsWith('/p/') || location.pathname.startsWith('/tv/')) {
            img = $('img[srcset], video', node.parentNode);
            if (img && (isVideo(img) || parseFloat(img.sizes) > 900))
              src = (img.srcset || img.currentSrc).split(',').pop().split(' ')[0];
          }
          if (!src && (n = node.closest('a[href*="/p/"], article'))) {
            a = n.tagName === 'A' ? n : $('a[href*="/p/"]', n);
          }
          const numPics = a && pick(data, 'edge_sidecar_to_children.edges.length') ||
            a && pick(data, 'carousel_media_count');
          Ruler.toggle(rule, 'q', data && data.is_video && !data.video_url);
          Ruler.toggle(rule, 'g', a && (numPics > 1 || /<\w+[^>]+carousel/i.test(a.innerHTML)));
          rule.follow = !data && !rule.g;
          rule._data = data;
          rule._img = img;
          return (
            !a && !src ? false :
              !data || rule.q || rule.g ? `${src || a.href}${rule.g ? '?__a=1&__d=dis' : ''}` :
                data.video_url || data.display_url);
        },
        c: (html, doc, node, rule) =>
          rule._getCaption(rule._data) || (rule._img || 0).alt || '',
        follow: true,
        _q: 'meta[property="og:video"]',
        _g(text, doc, url, m, rule) {
          const json = tryJSON(text);
          const media =
            pick(json, 'graphql.shortcode_media') ||
            pick(json, 'items.0');
          const items =
            pick(media, 'edge_sidecar_to_children.edges', res => res.map(e => ({
              url: e.node.video_url || e.node.display_url,
            }))) ||
            pick(media, 'carousel_media', res => res.map(e => ({
              url: pick(e, 'video_versions.0.url') || pick(e, 'image_versions2.candidates.0.url'),
            })));
          items.title = rule._getCaption(media) || '';
          return items;
        },
        _getCaption: data => pick(data, 'caption.text') ||
          pick(data, 'edge_media_to_caption.edges.0.node.text'),
      }); break;

      case 'reddit': rules.push({
        u: '||i.reddituploads.com/',
      }, {
        e: '[data-url*="i.redd.it"] img[src*="thumb"]',
        s: (m, node) => $propUp(node, 'data-url'),
      }, {
        r: /preview(\.redd\.it\/\w+\.(jpe?g|png|gif))/,
        s: 'https://i$1',
      }); break;

      case 'stackoverflow': rules.push({
        e: '.post-tag, .post-tag img',
        s: '',
      }); break;

      case 'startpage': rules.push({
        r: /[&?]piurl=([^&]+)/,
        s: '$1',
        follow: true,
      }); break;

      case 'tumblr': rules.push({
        e: 'div.photo_stage_img, div.photo_stage > canvas',
        s: (m, node) => /http[^"]+/.exec(node.style.cssText + node.getAttribute('data-img-src'))[0],
        follow: true,
      }); break;

      case 'twitter': rules.push({
        e: '.grid-tweet > .media-overlay',
        s: (m, node) => node.previousElementSibling.src,
        follow: true,
      }); break;
    }

    rules.push(
      {
        r: /[/?=](https?%3A%2F%2F[^&]+)/i,
        s: '$1',
        follow: true,
        onerror: 'skip',
      },
      {
        u: [
          '||500px.com/photo/',
          '||cl.ly/',
          '||cweb-pix.com/',
          '//ibb.co/',
          '||imgcredit.xyz/image/',
        ],
        r: /\.\w+\/.+/,
        q: 'meta[property="og:image"]',
      },
      {
        u: 'attachment.php',
        r: /attachment\.php.+attachmentid/,
      },
      {
        u: '||abload.de/image',
        q: '#image',
      },
      {
        u: '||deviantart.com/art/',
        s: (m, node) =>
          /\b(film|lit)/.test(node.className) || /in Flash/.test(node.title) ?
            '' :
            m.input,
        q: [
          '#download-button[href*=".jpg"]',
          '#download-button[href*=".jpeg"]',
          '#download-button[href*=".gif"]',
          '#download-button[href*=".png"]',
          '#gmi-ResViewSizer_fullimg',
          'img.dev-content-full',
        ],
      },
      {
        u: '||dropbox.com/s',
        r: /com\/sh?\/.+\.(jpe?g|gif|png)/i,
        q: (text, doc) =>
          $prop('img.absolute-center', 'src', doc).replace(/(size_mode)=\d+/, '$1=5') || false,
      },
      {
        r: /[./]ebay\.[^/]+\/itm\//,
        q: text =>
          text.match(/https?:\/\/i\.ebayimg\.com\/[^.]+\.JPG/i)[0]
            .replace(/~~60_\d+/, '~~60_57'),
      },
      {
        u: '||i.ebayimg.com/',
        s: (m, node) =>
          $('.zoom_trigger_mask', node.parentNode) ? '' :
            m.input.replace(/~~60_\d+/, '~~60_57'),
      },
      {
        u: '||fastpic.',
        s: (m, node, rule) => {
          const a = node.closest('a');
          const url = decodeURIComponent(Req.findImageUrl(a || node))
            .replace(/\/i(\d+)\.(\w+\.\w+\/)\w+/, '/$2$1')
            .replace(/^\w+:\/\/fastpic[^/]+((?:\/\d+){3})\/\w+(\/\w+\.\w+).*/,
              'https://fastpic.org/view$1$2.html');
          Ruler.toggle(rule, 'q', url.includes('.html'));
          return a || url.includes('.png') ? url : [url, url.replace(/\.jpe?g/, '.png')];
        },
        _q: 'img[src*="/big/"]',
      },
      {
        u: '||flickr.com/photos/',
        r: /photos\/([0-9]+@N[0-9]+|[a-z0-9_-]+)\/([0-9]+)/,
        s: m =>
          m.input.indexOf('/sizes/') < 0 ?
            `https://www.flickr.com/photos/${m[1]}/${m[2]}/sizes/sq/` :
            false,
        q: (text, doc) => {
          const links = $$('.sizes-list a', doc);
          return 'https://www.flickr.com' + links[links.length - 1].getAttribute('href');
        },
        follow: true,
      },
      {
        u: '||flickr.com/photos/',
        r: /\/sizes\//,
        q: '#allsizes-photo > img',
      },
      {
        u: '||gfycat.com/',
        r: /(gfycat\.com\/)(gifs\/detail\/|iframe\/)?([a-z]+)/i,
        s: 'https://$1$3',
        q: 'meta[content$=".webm"], #webmsource, source[src$=".webm"], .actual-gif-image',
      },
      {
        u: [
          '||googleusercontent.com/proxy',
          '||googleusercontent.com/gadgets/proxy',
        ],
        r: /\.com\/(proxy|gadgets\/proxy.+?(http.+?)&)/,
        s: m => m[2] ? decodeURIComponent(m[2]) : m.input.replace(/w\d+-h\d+($|-p)/, 'w0-h0'),
      },
      {
        u: [
          '||googleusercontent.com/',
          '||ggpht.com/',
        ],
        s: m => m.input.includes('webcache.') ? '' :
          m.input.replace(/\/s\d{2,}-[^/]+|\/w\d+-h\d+/, '/s0')
            .replace(/([&?]sz)?=[-\w]+([&#].*)?/, ''),
      },
      {
        u: '||gravatar.com/',
        r: /([a-z0-9]{32})/,
        s: 'https://gravatar.com/avatar/$1?s=200',
      },
      {
        u: '//gyazo.com/',
        r: /\bgyazo\.com\/\w{32,}(\.\w+)?/,
        s: (m, _, rule) => Ruler.toggle(rule, 'q', !m[1]) ? m.input : `https://i.${m[0]}`,
        _q: 'link[rel="image_src"]',
      },
      {
        u: '||hostingkartinok.com/show-image.php',
        q: '.image img',
      },
      {
        u: [
          '||imagecurl.com/images/',
          '||imagecurl.com/viewer.php',
        ],
        r: /(?:images\/(\d+)_thumb|file=(\d+))(\.\w+)/,
        s: 'https://imagecurl.com/images/$1$2$3',
      },
      {
        u: '||imagebam.com/',
        r: /^(https:\/\/)thumbs\d+(\.imagebam\.com\/).*?([^/]+)_t\./,
        s: '$1www$2view/$3',
        q: 'img.main-image',
      },
      {
        u: '||www.imagebam.com/view/',
        q: 'img.main-image',
      },
      {
        u: '||imageban.ru/thumbs',
        r: /(.+?\/)thumbs(\/\d+)\.(\d+)\.(\d+\/.*)/,
        s: '$1out$2/$3/$4',
      },
      {
        u: [
          '||imageban.ru/show',
          '||imageban.net/show',
          '||ibn.im/',
        ],
        q: '#img_main',
      },
      {
        u: '||imageshack.us/img',
        r: /img(\d+)\.(imageshack\.us)\/img\\1\/\d+\/(.+?)\.th(.+)$/,
        s: 'https://$2/download/$1/$3$4',
      },
      {
        u: '||imageshack.us/i/',
        q: '#share-dl',
      },
      {
        u: '||imageteam.org/img',
        q: 'img[alt="image"]',
      },
      {
        u: [
          '||imagetwist.com/',
          '||imageshimage.com/',
        ],
        r: /(\/\/|^)[^/]+\/[a-z0-9]{8,}/,
        q: 'img.pic',
        xhr: true,
      },
      {
        u: '||imageupper.com/i/',
        q: '#img',
        xhr: true,
      },
      {
        u: '||imagevenue.com/',
        q: 'a[data-toggle="full"] img',
      },
      {
        u: '||imagezilla.net/show/',
        q: '#photo',
        xhr: true,
      },
      {
        u: [
          '||images-na.ssl-images-amazon.com/images/',
          '||media-imdb.com/images/',
        ],
        r: /images\/.+?\.jpg/,
        s: '/V1\\.?_.+?\\.//g',
      },
      {
        u: '||imgbox.com/',
        r: /\.com\/([a-z0-9]+)$/i,
        q: '#img',
        xhr: hostname !== 'imgbox.com',
      },
      {
        u: '||imgclick.net/',
        r: /\.net\/(\w+)/,
        q: 'img.pic',
        xhr: true,
        post: m => `op=view&id=${m[1]}&pre=1&submit=Continue%20to%20image...`,
      },
      {
        u: '.imgcredit.xyz/',
        r: /^https?(:.*\.xyz\/\d[\w/]+)\.md(.+)/,
        s: ['https$1$2', 'https$1.png'],
      },
      {
        u: [
          '||imgflip.com/i/',
          '||imgflip.com/gif/',
        ],
        r: /\/(i|gif)\/([^/?#]+)/,
        s: m => `https://i.imgflip.com/${m[2]}${m[1] === 'i' ? '.jpg' : '.mp4'}`,
      },
      {
        u: [
          '||imgur.com/a/',
          '||imgur.com/gallery/',
        ],
        s: 'gallery', // suppressing an unused network request for remote `document`
        async g() {
          let u = `https://imgur.com/ajaxalbums/getimages/${ai.url.split(/[/?#]/)[4]}/hit.json?all=true`;
          let info = tryJSON((await Req.gmXhr(u)).responseText) || 0;
          let images = (info.data || 0).images || [];
          if (!images[0]) {
            info = (await Req.gmXhr(ai.url)).responseText.match(/postDataJSON=(".*?")<|$/)[1];
            info = tryJSON(tryJSON(info)) || 0;
            images = info.media;
          }
          const items = [];
          for (const img of images) {
            const meta = img.metadata || img;
            items.push({
              url: img.url ||
                (u = `https://i.imgur.com/${img.hash}`) && (
                  img.ext === '.gif' && img.animated !== false ?
                    [`${u}.webm`, `${u}.mp4`, u] :
                    u + img.ext
                ),
              desc: [meta.title, meta.description].filter(Boolean).join(' - '),
            });
          }
          if (items[0] && info.title && !`${items[0].desc || ''}`.includes(info.title))
            items.title = info.title;
          return items;
        },
      },
      {
        u: '||imgur.com/',
        r: /((?:[a-z]{2,}\.)?imgur\.com\/)((?:\w+,)+\w*)/,
        s: 'gallery',
        g: (text, doc, url, m) =>
          m[2].split(',').map(id => ({
            url: `https://i.${m[1]}${id}.jpg`,
          })),
      },
      {
        u: '||imgur.com/',
        r: /([a-z]{2,}\.)?imgur\.com\/(r\/[a-z]+\/|[a-z0-9]+#)?([a-z0-9]{5,})($|\?|\.(mp4|[a-z]+))/i,
        s: (m, node) => {
          if (/memegen|random|register|search|signin/.test(m.input))
            return '';
          const a = node.closest('a');
          if (a && a !== node && /(i\.([a-z]+\.)?)?imgur\.com\/(a\/|gallery\/)?/.test(a.href))
            return false;
          // postfixes: huge, large, medium, thumbnail, big square, small square
          const id = m[3].replace(/(.{7})[hlmtbs]$/, '$1');
          const ext = m[5] ? m[5].replace(/gifv?/, 'webm') : 'jpg';
          const u = `https://i.${(m[1] || '').replace('www.', '')}imgur.com/${id}.`;
          return ext === 'webm' ?
            [`${u}webm`, `${u}mp4`, `${u}gif`] :
            u + ext;
        },
      },
      {
        u: [
          '||instagr.am/p/',
          '||instagram.com/p/',
          '||instagram.com/tv/',
        ],
        s: m => m.input.substr(0, m.input.lastIndexOf('/')).replace('/liked_by', '') +
        '/?__a=1&__d=dis',
        q: m => (m = tryJSON(m)) && (
          m = pick(m, 'graphql.shortcode_media') || pick(m, 'items.0') || 0
        ) && (
          m.video_url ||
          m.display_url ||
          pick(m, 'video_versions.0.url') ||
          pick(m, 'carousel_media.0.image_versions2.candidates.0.url') ||
          pick(m, 'image_versions2.candidates.0.url')
        ),
        rect: 'div.PhotoGridMediaItem',
        c: m => (m = tryJSON(m)) && (
          pick(m, 'items.0.caption.text') ||
          pick(m, 'graphql.shortcode_media.edge_media_to_caption.edges.0.node.text') ||
          ''
        ),
      },
      {
        u: [
          '||livememe.com/',
          '||lvme.me/',
        ],
        r: /\.\w+\/([^.]+)$/,
        s: 'http://i.lvme.me/$1.jpg',
      },
      {
        u: '||lostpic.net/image',
        q: '.image-viewer-image img',
      },
      {
        u: '||makeameme.org/meme/',
        r: /\/meme\/([^/?#]+)/,
        s: 'https://media.makeameme.org/created/$1.jpg',
      },
      {
        u: '||photobucket.com/',
        r: /(\d+\.photobucket\.com\/.+\/)(\?[a-z=&]+=)?(.+\.(jpe?g|png|gif))/,
        s: 'https://i$1$3',
        xhr: !dotDomain.endsWith('.photobucket.com'),
      },
      {
        u: '||piccy.info/view3/',
        r: /(.+?\/view3)\/(.*)\//,
        s: '$1/$2/orig/',
        q: '#mainim',
      },
      {
        u: '||pimpandhost.com/image/',
        r: /(.+?\/image\/[0-9]+)/,
        s: '$1?size=original',
        q: 'img.original',
      },
      {
        u: [
          '||pixroute.com/',
          '||imgspice.com/',
        ],
        r: /\.html$/,
        q: 'img[id]',
        xhr: true,
      },
      {
        u: '||postima',
        r: /postima?ge?\.org\/image\/\w+/,
        q: [
          'a[href*="dl="]',
          '#main-image',
        ],
      },
      {
        u: [
          '||prntscr.com/',
          '||prnt.sc/',
        ],
        r: /\.\w+\/.+/,
        q: 'meta[property="og:image"]',
        xhr: true,
      },
      {
        u: '||radikal.ru/',
        r: /\.ru\/(fp|.+?\.html)|^(.+?)t\.jpg/,
        s: (m, node, rule) =>
          m[2] && /radikal\.ru[\w%/]+?(\.\w+)/.test($propUp(node, 'href')) ? m[2] + RegExp.$1 :
            Ruler.toggle(rule, 'q', m[1]) ? m.input : [m[2] + '.jpg', m[2] + '.png'],
        _q: text => text.match(/https?:\/\/\w+\.radikal\.ru[\w/]+\.(jpg|gif|png)/i)[0],
      },
      {
        u: '||tumblr.com',
        r: /_500\.jpg/,
        s: ['/_500/_1280/', ''],
      },
      {
        u: '||twimg.com/media/',
        r: /.+?format=(jpe?g|png|gif)/i,
        s: '$0&name=orig',
      },
      {
        u: '||twimg.com/media/',
        r: /.+?\.(jpe?g|png|gif)/i,
        s: '$0:orig',
      },
      {
        u: '||twimg.com/1/proxy',
        r: /t=([^&_]+)/i,
        s: m => atob(m[1]).match(/http.+/),
      },
      {
        u: '||twimg.com/',
        r: /\/profile_images/i,
        s: '/_(reasonably_small|normal|bigger|\\d+x\\d+)\\././g',
      },
      {
        u: '||pic.twitter.com/',
        r: /\.com\/[a-z0-9]+/i,
        q: text => text.match(/https?:\/\/twitter\.com\/[^/]+\/status\/\d+\/photo\/\d+/i)[0],
        follow: true,
      },
      {
        u: '||twitpic.com/',
        r: /\.com(\/show\/[a-z]+)?\/([a-z0-9]+)($|#)/i,
        s: 'https://twitpic.com/show/large/$2',
      },
      {
        u: '||wiki',
        r: /\/(?:thumb|images)\/.+\.(?:jpe?g|gif|png|svg)/i,
        s: m => m.input.replace(/\/(thumb(?=\/)|\d+px[^/]+(?=$|\?))/g, '')
          .replace(/\/(scale-to-width(-[a-z]+)?\/\d+|(zoom-crop|smart)(\/(width|height)\/\d+)+)/g, '/'),
        xhr: !hostname.includes('wiki'),
      },
      {
        u: '||ytimg.com/vi/',
        r: /(.+?\/vi\/[^/]+)/,
        s: '$1/0.jpg',
        rect: '.video-list-item',
      },
      {
        u: '/viewer.php?file=',
        r: /(.+?)\/viewer\.php\?file=(.+)/,
        s: '$1/images/$2',
        xhr: true,
      },
      {
        u: '/thumb_',
        r: /\/albums.+\/thumb_[^/]/,
        s: '/thumb_//',
      },
      {
        u: [
          '.th.jp',
          '.th.gif',
          '.th.png',
        ],
        r: /(.+?\.)th\.(jpe?g?|gif|png|svg|webm)$/i,
        s: '$1$2',
        follow: true,
      },
      {
        r: RX_MEDIA_URL,
      }
    );
  },

  format(rule, {expand} = {}) {
    const s = Util.stringify(rule, null, ' ');
    return expand ?
      /* {"a": ...,
          "b": ...,
          "c": ...
         } */
      s.replace(/^{\s+/g, '{') :
      /* {"a": ..., "b": ..., "c": ...} */
      s.replace(/\n\s*/g, ' ').replace(/^({)\s|\s+(})$/g, '$1$2');
  },

  fromElement(el) {
    const text = el.textContent.trim();
    if (text.startsWith('{') &&
        text.endsWith('}') &&
        /[{,]\s*"[degqrsu]"\s*:\s*"/.test(text)) {
      const rule = tryJSON(text);
      return rule && Object.keys(rule).some(k => /^[degqrsu]$/.test(k)) && rule;
    }
  },

  isValidE2: ([k, v]) => k.trim() && typeof v === 'string' && v.trim(),

  /** @returns mpiv.HostRule | Error | false | undefined */
  parse(rule) {
    const isBatchOp = this instanceof Map;
    try {
      if (typeof rule === 'string')
        rule = JSON.parse(rule);
      if ('d' in rule && typeof rule.d !== 'string')
        rule.d = undefined;
      else if (isBatchOp && rule.d && !hostname.includes(rule.d))
        return false;
      let {e} = rule;
      if (e != null) {
        e = typeof e === 'string' ? e.trim()
          : isArray(e) ? e.join(',').trim()
            : Object.entries(e).every(Ruler.isValidE2) && e;
        if (!e)
          throw new Error('Invalid syntax for "e". Examples: ' +
            '"e": ".image" or ' +
            '"e": [".image1", ".image2"] or ' +
            '"e": {".parent": ".image"} or ' +
            '"e": {".parent1": ".image1", ".parent2": ".image2"}');
        if (isBatchOp) rule.e = e || undefined;
      }
      let compileTo = isBatchOp ? rule : {};
      if (rule.r)
        compileTo.r = new RegExp(rule.r, 'i');
      if (App.NOP)
        compileTo = {};
      for (const key of Object.keys(FN_ARGS)) {
        if (RX_HAS_CODE.test(rule[key])) {
          const fn = Util.newFunction(...FN_ARGS[key], rule[key]);
          if (fn !== App.NOP || !isBatchOp) {
            compileTo[key] = fn;
          } else if (isBatchOp) {
            this.set(rule, 'unsafe-eval');
          }
        }
      }
      return rule;
    } catch (err) {
      if (isBatchOp) {
        this.set(rule, err);
        return rule;
      } else {
        return err;
      }
    }
  },

  runC(text, doc = document) {
    const fn = Ruler.runCHandler[typeof ai.rule.c] || Ruler.runCHandler.default;
    ai.caption = fn(text, doc);
  },

  runCHandler: {
    function: (text, doc) =>
      ai.rule.c(text || doc.documentElement.outerHTML, doc, ai.node, ai.rule),
    string: (text, doc) => {
      const el = $many(ai.rule.c, doc);
      return !el ? '' :
        el.getAttribute('content') ||
        el.getAttribute('title') ||
        el.textContent;
    },
    default: (text, doc, el = ai.node) =>
      (ai.tooltip || 0).text ||
      el.alt ||
      $propUp(el, 'title') ||
      Req.getFileName(
        el.tagName === (ai.popup || 0).tagName
          ? ai.url
          : el.src || $propUp(el, 'href')),
  },

  runQ(text, doc, docUrl) {
    let url;
    if (isFunction(ai.rule.q)) {
      url = ai.rule.q(text, doc, ai.node, ai.rule);
      if (isArray(url)) {
        ai.urls = url.slice(1);
        url = url[0];
      }
    } else {
      const el = $many(ai.rule.q, doc);
      url = Req.findImageUrl(el, docUrl);
    }
    return url;
  },

  /** @returns {?boolean|mpiv.RuleMatchInfo} */
  runE(rule, e, node) {
    let p, img, res, info;
    for (const selParent in e) {
      if ((p = node.closest(selParent)) && (img = $(e[selParent], p))) {
        if (img === node)
          res = true;
        else if ((info = RuleMatcher.adaptiveFind(img, {rules: [rule]})))
          return info;
      }
    }
    return res;
  },

  /** @returns {?Array} if falsy then the rule should be skipped */
  runS(node, rule, m) {
    let urls = [], u;
    for (const s of ensureArray(rule.s))
      urls.push(
        typeof s === 'string' ? Util.decodeUrl(Ruler.substituteSingle(s, m)) :
          isFunction(s) ? s(m, node, rule) :
            s);
    if (rule.q && urls.length > 1) {
      console.warn('Rule discarded: "s" array is not allowed with "q"\n%o', rule);
      return;
    }
    if (isArray(u = urls[0]))
      u = [urls = u][0];
    return u === '' /* "stop all rules" */ ? urls
      : u && arrayFrom(new Set(urls), Util.decodeUrl);
  },

  /** @returns {boolean} */
  runU(rule, url) {
    const u = rule[SYM_U] || (rule[SYM_U] = UrlMatcher(rule.u));
    return u.fn.call(u.data, url);
  },

  substituteSingle(s, m) {
    if (!m || m.input == null) return s;
    if (s.startsWith('/') && !s.startsWith('//')) {
      const mid = s.search(/[^\\]\//) + 1;
      const end = s.lastIndexOf('/');
      const re = new RegExp(s.slice(1, mid), s.slice(end + 1));
      return m.input.replace(re, s.slice(mid + 1, end));
    }
    if (m.length && s.includes('$')) {
      const maxLength = Math.floor(Math.log10(m.length)) + 1;
      s = s.replace(/\$(\d{1,3})/g, (text, num) => {
        for (let i = maxLength; i >= 0; i--) {
          const part = num.slice(0, i) | 0;
          if (part < m.length)
            return (m[part] || '') + num.slice(i);
        }
        return text;
      });
    }
    return s;
  },

  toggle(rule, prop, condition) {
    rule[prop] = condition ? rule[`_${prop}`] : null;
    return condition;
  },
};

const RuleMatcher = {

  /** @returns {Object} */
  adaptiveFind(node, opts) {
    const tn = node.tagName;
    const src = node.currentSrc || node.src || '';
    const isPic = tn === 'IMG' || tn === 'VIDEO' && Util.isVideoUrlExt(src);
    let a, info, url;
    // note that data URLs aren't passed to rules as those may have fatally ineffective regexps
    if (tn !== 'A') {
      url = isPic && !src.startsWith('data:') && Util.rel2abs(src);
      info = RuleMatcher.find(url, node, opts);
    }
    if (!info && (a = node.closest('A'))) {
      const ds = a.dataset;
      url = ds.expandedUrl || ds.fullUrl || ds.url || a.href || '';
      url = url.includes('//t.co/') ? 'https://' + a.textContent : url;
      url = !url.startsWith('data:') && url;
      info = RuleMatcher.find(url, a, opts);
    }
    if (!info && isPic)
      info = {node, rule: {}, url: src};
    return info;
  },

  /** @returns ?mpiv.RuleMatchInfo */
  find(url, node, {noHtml, rules, skipRules} = {}) {
    let tn, isPic, html, h;
    for (const rule of rules || Ruler.rules) {
      let e, m;
      if (skipRules && skipRules.includes(rule) ||
          rule.u && (!url || !Ruler.runU(rule, url)) ||
          !rules && (e = rule.e) &&
            !(m = typeof e === 'string' ? node.matches(e) : Ruler.runE(rule, e, node)))
        continue;
      if (m && m.url)
        return m;
      const {r, s} = rule;
      let hasS = s != null;
      h = !(noHtml && rule === ai.rule) && (r || hasS) && rule.html && (html || (html = node.outerHTML));
      if (r) {
        m = h ? r.exec(h) : url && r.exec(url);
      } else {
        m = ['']; m[0] = m.input = h || url || ''; m.index = 0;
      }
      if (!m)
        continue;
      if (s === '')
        return {};
      // a rule with follow:true for the currently hovered IMG produced a URL,
      // but we'll only allow it to match rules without 's' in the nested find call
      if (!hasS && !skipRules && (tn ? isPic : isPic = (tn = node.tagName) === 'IMG' || tn === 'VIDEO'))
        continue;
      hasS &= s !== 'gallery';
      const urls = hasS ? Ruler.runS(node, rule, m) : [m.input];
      if (urls)
        return RuleMatcher.makeInfo(hasS, rule, m, node, skipRules, urls);
    }
  },

  /** @returns ?mpiv.RuleMatchInfo */
  makeInfo(hasS, rule, match, node, skipRules, urls) {
    let info;
    let url = `${urls[0]}`;
    const follow = url && hasS && !rule.q && RuleMatcher.isFollowableUrl(url, rule);
    if (url)
      url = Util.rel2abs(url);
    else
      info = {};
    if (follow)
      info = RuleMatcher.find(url, node, {skipRules: [...skipRules || [], rule]});
    if (!info && (!follow || RX_MEDIA_URL.test(url))) {
      const xhr = cfg.xhr && rule.xhr;
      info = {
        match,
        node,
        rule,
        url,
        urls: urls.length > 1 ? urls.slice(1) : null,
        gallery: rule.g && Gallery.makeParser(rule.g),
        post: isFunction(rule.post) ? rule.post(match) : rule.post,
        xhr: xhr != null ? xhr : isSecureContext && !url.startsWith(location.protocol),
      };
    }
    return info;
  },

  isFollowableUrl(url, rule) {
    const f = rule.follow;
    return isFunction(f) ? f(url) : f;
  },
};

const Req = {

  gmXhr(url, opts = {}) {
    if (ai.req)
      tryCatch(ai.req.abort);
    return new Promise((resolve, reject) => {
      const {anonymous} = ai.rule || {};
      ai.req = GM.xmlHttpRequest(Object.assign({
        url,
        anonymous,
        withCredentials: !anonymous,
        method: 'GET',
        timeout: 30e3,
      }, opts, {
        onload: done,
        onerror: done,
        ontimeout() {
          ai.req = null;
          reject(`Timeout fetching ${url}`);
        },
      }));
      function done(r) {
        ai.req = null;
        if (r.status < 400 && !r.error)
          resolve(r);
        else
          reject(`Server error ${r.status} ${r.error}\nURL: ${url}`);
      }
    });
  },

  async getDoc(url) {
    if (!url) {
      // current document
      return {
        doc,
        finalUrl: location.href,
        responseText: doc.documentElement.outerHTML,
      };
    }
    const r = await (!ai.post ?
      Req.gmXhr(url) :
      Req.gmXhr(url, {
        method: 'POST',
        data: ai.post,
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Referer': url,
        },
      }));
    r.doc = $parseHtml(r.responseText);
    return r;
  },

  async getImage(url, pageUrl, xhr = ai.xhr) {
    ai.bufBar = false;
    ai.bufStart = now();
    const response = await Req.gmXhr(url, {
      responseType: 'blob',
      headers: {
        Accept: 'image/png,image/*;q=0.8,*/*;q=0.5',
        Referer: pageUrl || (isFunction(xhr) ? xhr() : url),
      },
      onprogress: Req.getImageProgress,
    });
    Bar.set(false);
    const type = Req.guessMimeType(response);
    let b = response.response;
    if (!b) throw 'Empty response';
    if (b.type !== type)
      b = b.slice(0, b.size, type);
    const res = xhr === 'blob'
      ? (ai.blobUrl = URL.createObjectURL(b))
      : await Req.blobToDataUrl(b);
    return [res, type.startsWith('video')];
  },

  getImageProgress(e) {
    if (!ai.bufBar && now() - ai.bufStart > 3000 && e.loaded / e.total < 0.5)
      ai.bufBar = true;
    if (ai.bufBar) {
      const pct = e.loaded / e.total * 100 | 0;
      const size = e.total / 1024 | 0;
      Bar.set(`${pct}% of ${size} kiB`, 'xhr');
    }
  },

  async findRedirect() {
    try {
      const {finalUrl} = await Req.gmXhr(ai.url, {
        method: 'HEAD',
        headers: {
          'Referer': location.href.split('#', 1)[0],
        },
      });
      const info = RuleMatcher.find(finalUrl, ai.node, {noHtml: true});
      if (!info || !info.url)
        throw `Couldn't follow redirection target: ${finalUrl}`;
      Object.assign(ai, info);
      App.startSingle();
    } catch (e) {
      App.handleError(e);
    }
  },

  async saveFile() {
    const url = ai.popup.src || ai.popup.currentSrc;
    let name = Req.getFileName(ai.imageUrl || url);
    if (!name.includes('.'))
      name += '.jpg';
    if (url.startsWith('blob:') || url.startsWith('data:')) {
      $new('a', {href: url, download: name})
        .dispatchEvent(new MouseEvent('click'));
    } else {
      Status.set('+loading');
      const onload = () => Status.set('-loading');
      const gmDL = typeof GM_download === 'function';
      (gmDL ? GM_download : GM.xmlHttpRequest)({
        url,
        name,
        headers: {Referer: url},
        method: 'get', // polyfilling GM_download
        responseType: 'blob', // polyfilling GM_download
        overrideMimeType: 'application/octet-stream', // polyfilling GM_download
        onerror: e => {
          Bar.set(`Could not download ${name}: ${e.error || e.message || e}.`, 'error');
          onload();
        },
        onprogress: Req.getImageProgress,
        onload({response}) {
          onload();
          if (!gmDL) { // polyfilling GM_download
            const a = Object.assign(document.createElement('a'), {
              href: URL.createObjectURL(response),
              download: name,
            });
            a.dispatchEvent(new MouseEvent('click'));
            setTimeout(URL.revokeObjectURL, 10e3, a.href);
          }
        },
      });
    }
  },

  getFileName(url) {
    return decodeURIComponent(url).split(/[#?&]/, 1)[0].split('/').pop();
  },

  blobToDataUrl(blob) {
    return new Promise((resolve, reject) => {
      const fr = new FileReader();
      fr.onload = () => resolve(fr.result);
      fr.onerror = reject;
      fr.readAsDataURL(blob);
    });
  },

  guessMimeType({responseHeaders, finalUrl}) {
    if (/Content-Type:\s*(\S+)/i.test(responseHeaders) &&
        !RegExp.$1.includes('text/plain'))
      return RegExp.$1;
    const ext = Util.extractFileExt(finalUrl) || 'jpg';
    switch (ext.toLowerCase()) {
      case 'bmp': return 'image/bmp';
      case 'gif': return 'image/gif';
      case 'jpe': return 'image/jpeg';
      case 'jpeg': return 'image/jpeg';
      case 'jpg': return 'image/jpeg';
      case 'mp4': return 'video/mp4';
      case 'png': return 'image/png';
      case 'svg': return 'image/svg+xml';
      case 'tif': return 'image/tiff';
      case 'tiff': return 'image/tiff';
      case 'webm': return 'video/webm';
      default: return 'application/octet-stream';
    }
  },

  findImageUrl(n, url) {
    if (!n) return;
    let html;
    const path =
      n.getAttribute('data-src') || // lazy loaded src, whereas current `src` is an empty 1x1 pixel
      n.getAttribute('src') ||
      n.getAttribute('data-m4v') ||
      n.getAttribute('href') ||
      n.getAttribute('content') ||
      (html = n.outerHTML).includes('http') &&
      html.match(/https?:\/\/[^\s"<>]+?\.(jpe?g|gif|png|svg|web[mp]|mp4)[^\s"<>]*|$/i)[0];
    return !!path && Util.rel2abs(Util.decodeHtmlEntities(path),
      $prop('base[href]', 'href', n.ownerDocument) || url);
  },
};

const Status = {

  set(status) {
    if (!status && !cfg.globalStatus) {
      if (ai.node) ai.node.removeAttribute(STATUS_ATTR);
      return;
    }
    const prefix = cfg.globalStatus ? PREFIX : '';
    const action = status && /^[+-]/.test(status) && status[0];
    const name = status && `${prefix}${action ? status.slice(1) : status}`;
    const el = cfg.globalStatus ? doc.documentElement :
      name === 'edge' ? ai.popup :
        ai.node;
    if (!el) return;
    const attr = cfg.globalStatus ? 'class' : STATUS_ATTR;
    const oldValue = (el.getAttribute(attr) || '').trim();
    const cls = new Set(oldValue ? oldValue.split(/\s+/) : []);
    switch (action) {
      case '-':
        cls.delete(name);
        break;
      case false:
        for (const c of cls)
          if (c.startsWith(prefix) && c !== name)
            cls.delete(c);
      // fallthrough to +
      case '+':
        if (name)
          cls.add(name);
        break;
    }
    const newValue = [...cls].join(' ');
    if (newValue !== oldValue)
      el.setAttribute(attr, newValue);
  },

  loading(force) {
    if (!force) {
      clearTimeout(ai.timerStatus);
      ai.timerStatus = setTimeout(Status.loading, SETTLE_TIME, true);
    } else if (!ai.popupLoaded) {
      Status.set('+loading');
    }
  },
};

const UrlMatcher = (() => {
  // string-to-regexp escaped chars
  const RX_ESCAPE = /[.+*?(){}[\]^$|]/g;
  // rx for '^' symbol in simple url match
  const RX_SEP = /[^\w%._-]/y;
  const RXS_SEP = RX_SEP.source;
  return match => {
    const results = [];
    for (const s of ensureArray(match)) {
      const pinDomain = s.startsWith('||');
      const pinStart = !pinDomain && s.startsWith('|');
      const endSep = s.endsWith('^');
      let fn;
      let needle = s.slice(pinDomain * 2 + pinStart, -endSep || undefined);
      if (needle.includes('^')) {
        let plain = '';
        for (const part of needle.split('^'))
          if (part.length > plain.length)
            plain = part;
        const rx = new RegExp(
          (pinStart ? '^' : '') +
          (pinDomain ? '^(([^/:]+:)?//)?([^./]*\\.)*?' : '') +
          needle.replace(RX_ESCAPE, '\\$&').replace(/\\\^/g, RXS_SEP) +
          (endSep ? `(?:${RXS_SEP}|$)` : ''), 'i');
        needle = [plain, rx];
        fn = regexp;
      } else if (pinStart) {
        fn = endSep ? equals : starts;
      } else if (pinDomain) {
        const slashPos = needle.indexOf('/');
        const domain = slashPos > 0 ? needle.slice(0, slashPos) : needle;
        needle = [needle, domain, slashPos > 0, endSep];
        fn = startsDomainPrescreen;
      } else if (endSep) {
        fn = ends;
      } else {
        fn = has;
      }
      results.push({fn, data: needle});
    }
    return results.length > 1 ?
      {fn: checkArray, data: results} :
      results[0];
  };
  function checkArray(s) {
    return this.some(checkArrayItem, s);
  }
  function checkArrayItem(item) {
    return item.fn.call(item.data, this);
  }
  function ends(s) {
    return s.endsWith(this) || (
      s.length > this.length &&
      s.indexOf(this, s.length - this.length - 1) >= 0 &&
      endsWithSep(s));
  }
  function endsWithSep(s, pos = s.length - 1) {
    RX_SEP.lastIndex = pos;
    return RX_SEP.test(s);
  }
  function equals(s) {
    return s.startsWith(this) && (
      s.length === this.length ||
      s.length === this.length + 1 && endsWithSep(s));
  }
  function has(s) {
    return s.includes(this);
  }
  function regexp(s) {
    return s.includes(this[0]) && this[1].test(s);
  }
  function starts(s) {
    return s.startsWith(this);
  }
  function startsDomainPrescreen(url) {
    return url.includes(this[0]) && startsDomain.call(this, url);
  }
  function startsDomain(url) {
    let hostStart = url.indexOf('//');
    if (hostStart && url[hostStart - 1] !== ':')
      return;
    hostStart = hostStart < 0 ? 0 : hostStart + 2;
    const host = url.slice(hostStart, (url.indexOf('/', hostStart) + 1 || url.length + 1) - 1);
    const [needle, domain, pinDomainEnd, endSep] = this;
    let start = pinDomainEnd ? host.length - domain.length : 0;
    for (; ; start++) {
      start = host.indexOf(domain, start);
      if (start < 0)
        return;
      if (!start || host[start - 1] === '.')
        break;
    }
    start += hostStart;
    if (url.lastIndexOf(needle, start) !== start)
      return;
    const end = start + needle.length;
    return !endSep || end === host.length || end === url.length || endsWithSep(url, end);
  }
})();

const Util = {

  addStyle(name, css) {
    const id = `${PREFIX}style:${name}`;
    const el = doc.getElementById(id) ||
               css && $new('style', {id});
    if (!el) return;
    if (el.textContent !== css)
      el.textContent = css;
    if (el.parentElement !== doc.head)
      doc.head.appendChild(el);
    return el;
  },

  color(color, opacity = cfg[`ui${color}Opacity`]) {
    return (color.startsWith('#') ? color : cfg[`ui${color}Color`]) +
           (0x100 + Math.round(opacity / 100 * 255)).toString(16).slice(1);
  },

  decodeHtmlEntities(s) {
    return s
      .replace(/&quot;/g, '"')
      .replace(/&apos;/g, '\'')
      .replace(/&lt;/g, '<')
      .replace(/&gt;/g, '>')
      .replace(/&amp;/g, '&');
  },

  // decode only if the main part of the URL is encoded to preserve the encoded parameters
  decodeUrl(url) {
    if (!url || typeof url !== 'string') return url;
    const iPct = url.indexOf('%');
    const iColon = url.indexOf(':');
    return iPct >= 0 && (iPct < iColon || iColon < 0) ?
      decodeURIComponent(url) :
      url;
  },

  deepEqual(a, b) {
    if (!a || !b || typeof a !== 'object' || typeof a !== typeof b)
      return a === b;
    if (isArray(a)) {
      return isArray(b) &&
        a.length === b.length &&
        a.every((v, i) => Util.deepEqual(v, b[i]));
    }
    const keys = Object.keys(a);
    return keys.length === Object.keys(b).length &&
      keys.every(k => Util.deepEqual(a[k], b[k]));
  },

  extractFileExt: url => (url = RX_MEDIA_URL.exec(url)) && url[1],

  forceLayout(node) {
    // eslint-disable-next-line no-unused-expressions
    node.clientHeight;
  },

  formatError(e, rule) {
    const arr = isArray(e);
    const msg = arr ? e[0] : e.message;
    const {url: u, imageUrl: iu} = ai;
    e = msg ? e :
      e.readyState && 'Request failed.' ||
      e.type === 'error' && `File can't be displayed.${
        $('div[bgactive*="flashblock"]', doc) ? ' Check Flashblock settings.' : ''
      }` ||
      e;
    let fmt;
    const res = [
      fmt = '%c%s%c', 'font-weight:bold', arr ? msg : e, 'font-weight:normal',
      (fmt += '\nNode: %o', ai.node),
      (fmt += '\nRule: %o', rule),
      u && (fmt += '\nURL: %s', u),
      iu && iu !== u && (fmt += '\nFile: %s', iu),
      ...arr ? (fmt += e[1], e.slice(2)) : [],
      e.stack,
    ].filter(Boolean);
    res[0] = fmt;
    res.message = msg || e;
    return res;
  },

  getReactChildren(el, path) {
    if (isFF) el = el.wrappedJSObject || el;
    for (const k of Object.keys(el))
      if (typeof k === 'string' && k.startsWith('__reactProps'))
        return (el = el[k].children) && (path ? pick(el, path) : el);
  },

  isVideoUrl: url => url.startsWith('data:video') || Util.isVideoUrlExt(url),

  isVideoUrlExt: url => (url = Util.extractFileExt(url)) && /^(webm|mp4)$/i.test(url),

  newFunction(...args) {
    try {
      return App.NOP || (trustedScript
        // eslint-disable-next-line no-eval
        ? window.eval(trustedScript(`(function anonymous(${args.slice(0, -1).join(',')}){${args.slice(-1)[0]}})`))
        : new Function(...args)
      );
    } catch (e) {
      if (!RX_EVAL_BLOCKED.test(e.message))
        throw e;
      App.NOP = () => {};
      return App.NOP;
    }
  },

  rel2abs(rel, abs = location.href) {
    try {
      return /^(data:|blob:|[-\w]+:\/\/)/.test(rel) ? rel :
        new URL(rel, abs).href;
    } catch (e) {
      return rel;
    }
  },

  stringify(...args) {
    const p = Array.prototype;
    const {toJSON} = p;
    if (toJSON) p.toJSON = null;
    const res = JSON.stringify(...args);
    if (toJSON) p.toJSON = toJSON;
    return res;
  },

  suppressTooltip() {
    for (const node of [
      ai.node.parentNode,
      ai.node,
      ai.node.firstElementChild,
    ]) {
      const t = (node || 0).title;
      if (t && t !== node.textContent && !doc.title.includes(t) && !/^https?:\S+$/.test(t)) {
        ai.tooltip = {node, text: t};
        node.title = '';
        break;
      }
    }
  },

  tabFixUrl() {
    const {tabfix = App.tabfix} = ai.rule;
    return tabfix && ai.popup.tagName === 'IMG' && !ai.xhr &&
           flattenHtml(`data:text/html;charset=utf8,
      <style>
        body {
          margin: 0;
          padding: 0;
          background: #222;
        }
        .fit {
          overflow: hidden
        }
        .fit > img {
          max-width: 100vw;
          max-height: 100vh;
        }
        body > img {
          margin: auto;
          position: absolute;
          left: 0;
          right: 0;
          top: 0;
          bottom: 0;
        }
      </style>
      <body class=fit>
        <img onclick="document.body.classList.toggle('fit')" src="${ai.popup.src}">
      </body>
    `).replace(/\x20?([:>])\x20/g, '$1').replace(/#/g, '%23');
  },
};

async function setup({rule} = {}) {
  if (!isFunction(doc.body.attachShadow)) {
    alert('Cannot show MPIV config dialog: the browser is probably too old.\n' +
          'You can edit the script\'s storage directly in your userscript manager.');
    return;
  }
  const RULE = setup.RULE || (setup.RULE = Symbol('rule'));
  let uiCfg;
  let root = (elSetup || 0).shadowRoot;
  let {blankRuleElement} = setup;
  let mover, moveX = 0, moveY = 0, moveBaseX = 0, moveBaseY = 0;
  /** @type {{[id:string]: HTMLElement}} */
  const UI = setup.UI = new Proxy({}, {
    get(_, id) {
      return root.getElementById(id);
    },
  });
  if (!elSetup)
    build();
  if (elSetup.parentElement !== doc.body) {
    init(await Config.load({save: true}));
    doc.body.append(elSetup);
  }
  if (rule)
    installRule(rule);

  function build() {
    elSetup = $new('div', {contentEditable: true});
    root = elSetup.attachShadow({mode: 'open'});
    root.append(...createSetupElement());
    initEvents();
  }

  function init(data) {
    uiCfg = data;
    renderAll();
    renderVolatiles();
    renderRules();
    requestAnimationFrame(() => {
      UI.css.style.minHeight = clamp(UI.css.scrollHeight, 40, elSetup.clientHeight / 4) + 'px';
    });
  }

  function initEvents() {
    UI._mover.onmousedown = e => {
      if (e.button || eventModifiers(e))
        return;
      if (!mover) {
        mover = UI._cssSetup.sheet;
        mover.insertRule(':host {}');
        mover = mover.cssRules[1];
      }
      addEventListener('mousemove', onMove, true);
      addEventListener('mouseup', onMoveDone, true);
      addEventListener('keydown', onMoveKey, true);
      moveX = e.x - moveBaseX;
      moveY = e.y - moveBaseY;
      $css(mover, {opacity: .75});
    };
    UI._apply.onclick = UI._cancel.onclick = UI._ok.onclick = UI._x.onclick = closeSetup;
    UI._export.onclick = e => {
      dropEvent(e);
      GM.setClipboard(Util.stringify(collectConfig(), null, '  '));
      UI._exportNotification.hidden = false;
      setTimeout(() => (UI._exportNotification.hidden = true), 1000);
    };
    UI._import.onclick = e => {
      dropEvent(e);
      const s = prompt('Paste settings:');
      if (s)
        init(new Config({data: s}));
    };
    UI._install.onclick = setupRuleInstaller;
    const /** @type {HTMLTextAreaElement} */ cssApp = UI._cssApp;
    UI._reveal.onclick = e => {
      e.preventDefault();
      cssApp.hidden = !cssApp.hidden;
      if (!cssApp.hidden) {
        if (!cssApp.value) {
          App.updateStyles();
          cssApp.value = App.globalStyle.trim();
          cssApp.setSelectionRange(0, 0);
        }
        cssApp.focus();
      }
    };
    UI.start.onchange = function () {
      UI[PREFIX + 'setup'].dataset.start = this.value;
    };
    UI.xhr.onclick = ({target: el}) => el.checked || confirm($propUp(el, 'title'));
    // color
    for (const el of $$('[type="color"]', root)) {
      el.oninput = colorOnInput;
      el.elSwatch = el.nextElementSibling;
      el.elOpacity = UI[el.id.replace('Color', 'Opacity')];
      el.elOpacity.elColor = el;
    }
    function onMove({x, y}) {
      x = moveBaseX = clamp(x - moveX, -innerWidth + CSS_SETUP_X * 4, elSetup.clientWidth - CSS_SETUP_X);
      y = moveBaseY = clamp(y - moveY, 0, innerHeight - CSS_SETUP_X * 3);
      $css(mover, {transform: `translate(${x}px, ${y}px)`});
      UI._ul.style.maxHeight = `calc(100vh - ${CSS_SETUP_MAX_Y + y - CSS_SETUP_X}px)`;
    }
    function onMoveDone() {
      removeEventListener('mousemove', onMove, true);
      removeEventListener('mouseup', onMoveDone, true);
      removeEventListener('keydown', onMoveKey, true);
      $css(mover, {opacity: ''});
    }
    function onMoveKey(e) {
      if (e.key === 'Escape' && !eventModifiers(e)) {
        e.stopPropagation();
        onMove({x: moveX, y: moveY});
        onMoveDone();
      }
    }
    function colorOnInput() {
      this.elSwatch.style.setProperty('--color',
        Util.color(this.value, this.elOpacity.valueAsNumber));
    }
    // range
    for (const el of $$('[type="range"]', root)) {
      el.oninput = rangeOnInput;
      el.onblur = rangeOnBlur;
      el.addEventListener('focusin', rangeOnFocus);
    }
    function rangeOnBlur(e) {
      if (this.elEdit && e.relatedTarget !== this.elEdit)
        this.elEdit.onblur(e);
    }
    function rangeOnFocus() {
      if (this.elEdit) return;
      const {min, max, step, value} = this;
      this.elEdit = $new('input', {
        value, min, max, step,
        className: 'range-edit',
        style: `left: ${this.offsetLeft}px; margin-top: ${this.offsetHeight + 1}px`,
        type: 'number',
        elRange: this,
        onblur: rangeEditOnBlur,
        oninput: rangeEditOnInput,
      });
      this.insertAdjacentElement('afterend', this.elEdit);
    }
    function rangeOnInput() {
      this.title = (this.dataset.title || '').replace('$', this.value);
      if (this.elColor) this.elColor.oninput();
      if (this.elEdit) this.elEdit.valueAsNumber = this.valueAsNumber;
    }
    // range-edit
    function rangeEditOnBlur(e) {
      if (e.relatedTarget !== this.elRange) {
        this.remove();
        this.elRange.elEdit = null;
      }
    }
    function rangeEditOnInput() {
      this.elRange.valueAsNumber = this.valueAsNumber;
      this.elRange.oninput();
    }
    // prevent the main page from interpreting key presses in inputs as hotkeys
    // which may happen since it sees only the outer <div> in the event |target|
    root.addEventListener('keydown', e => !e.altKey && !e.metaKey && e.stopPropagation(), true);
  }

  function closeSetup(event) {
    const isApply = this.id === '_apply';
    if (event && (this.id === '_ok' || isApply)) {
      cfg = uiCfg = collectConfig({save: true, clone: isApply});
      Ruler.init();
      Menu.reRegisterAlt();
      if (isApply)
        return renderVolatiles();
    }
    $remove(elSetup);
    elSetup = null;
  }

  function collectConfig({save, clone} = {}) {
    let data = {};
    for (const el of $$('input[id], select[id]', root))
      data[el.id] = el.type === 'checkbox' ? el.checked :
        (el.type === 'number' || el.type === 'range') ? el.valueAsNumber :
          el.value || '';
    Object.assign(data, {
      css: UI.css.value.trim(),
      delay: UI.delay.valueAsNumber * 1000,
      hosts: collectRules(),
      scale: clamp(UI.scale.valueAsNumber / 100, 0, 1) + 1,
      scales: UI.scales.value
        .trim()
        .split(/[,;]*\s+/)
        .map(x => x.replace(',', '.'))
        .filter(x => !isNaN(parseFloat(x))),
    });
    if (clone)
      data = JSON.parse(Util.stringify(data));
    return new Config({data, save});
  }

  function collectRules() {
    return [...UI._rules.children]
      .map(el => [el.value.trim(), el[RULE]])
      .sort((a, b) => a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : 0)
      .map(([s, json]) => json || s)
      .filter(Boolean);
  }

  function checkRule({target: el}) {
    let json, error, title;
    const prev = el.previousElementSibling;
    if (el.value) {
      json = Ruler.parse(el.value);
      error = json instanceof Error && (json.message || String(json));
      const invalidDomain = !error && json && typeof json.d === 'string' &&
        !/^[-.a-z0-9]*$/i.test(json.d);
      title = [invalidDomain && 'Disabled due to invalid characters in "d"', error]
        .filter(Boolean).join('\n');
      el.classList.toggle('invalid-domain', invalidDomain);
      el.classList.toggle('matching-domain', !!json.d && hostname.includes(json.d));
      if (!prev)
        el.insertAdjacentElement('beforebegin', blankRuleElement.cloneNode());
    } else if (prev) {
      prev.focus();
      el.remove();
    }
    el[RULE] = !error && json;
    el.title = title;
    el.setCustomValidity(error || '');
  }

  async function focusRule({target: el, relatedTarget: from}) {
    if (el === this)
      return;
    await new Promise(setTimeout);
    if (el[RULE] && el.rows < 2) {
      let i = el.selectionStart;
      const txt = el.value = Ruler.format(el[RULE], {expand: true});
      i += txt.slice(0, i).match(/^\s*/gm).reduce((len, s) => len + s.length, 0);
      el.setSelectionRange(i, i);
      el.rows = txt.match(/^/gm).length;
    }
    if (!this.contains(from))
      from = [...$$('[style*="height"]', this)].find(_ => _ !== el);
  }

  function installRule(rule) {
    const inputs = UI._rules.children;
    let el = [...inputs].find(el => Util.deepEqual(el[RULE], rule));
    if (!el) {
      el = inputs[0];
      el[RULE] = rule;
      el.value = Ruler.format(rule);
      el.hidden = false;
      const i = Math.max(0, collectRules().indexOf(rule));
      inputs[i].insertAdjacentElement('afterend', el);
      inputs[0].insertAdjacentElement('beforebegin', blankRuleElement.cloneNode());
    }
    const rect = el.getBoundingClientRect();
    if (rect.bottom < 0 ||
        rect.bottom > el.parentNode.offsetHeight)
      el.scrollIntoView();
    el.classList.add('highlight');
    el.addEventListener('animationend', () => el.classList.remove('highlight'), {once: true});
    el.focus();
  }

  function renderRules() {
    const rules = UI._rules;
    rules.addEventListener('input', checkRule);
    rules.addEventListener('focusin', focusRule);
    rules.addEventListener('paste', focusRule);
    blankRuleElement =
      setup.blankRuleElement =
        setup.blankRuleElement || rules.firstElementChild.cloneNode();
    if (blankRuleElement.nextElementSibling) {
      rules.textContent = '';
      rules.appendChild(blankRuleElement.cloneNode());
    }
    for (const rule of uiCfg.hosts || []) {
      const el = blankRuleElement.cloneNode();
      el.value = typeof rule === 'string' ? rule : Ruler.format(rule);
      rules.appendChild(el);
      checkRule({target: el});
    }
    const search = UI._search;
    search.oninput = () => {
      setup.search = search.value;
      const s = search.value.toLowerCase();
      for (const el of rules.children)
        el.hidden = s && !el.value.toLowerCase().includes(s);
    };
    search.value = setup.search || '';
    if (search.value)
      search.oninput();
  }

  function renderVolatiles() {
    UI.scales.value = uiCfg.scales.join(' ').trim() || Config.DEFAULTS.scales.join(' ');
    UI._css.textContent = cfg._getCss();
  }

  function renderAll() {
    for (const el of $$('input[id], select[id], textarea[id]', root))
      if (el.id in uiCfg)
        el[el.type === 'checkbox' ? 'checked' : 'value'] = uiCfg[el.id];
    for (const el of $$('input[type="range"]', root))
      el.oninput();
    for (const el of $$('a[href^="http"]', root))
      Object.assign(el, {target: '_blank', rel: 'noreferrer noopener external'});
    UI.delay.valueAsNumber = uiCfg.delay / 1000;
    UI.scale.valueAsNumber = Math.round(clamp(uiCfg.scale - 1, 0, 1) * 100);
    UI.start.onchange();
  }
}

function setupClickedRule(event) {
  let rule;
  const el = event.target.closest('blockquote, code, pre');
  if (el && !event.button && !eventModifiers(event) && (rule = Ruler.fromElement(el))) {
    dropEvent(event);
    setup({rule});
  }
}

/** @this {HTMLButtonElement} */
async function setupRuleInstaller(e) {
  dropEvent(e);
  const parent = setup.UI._rules2;
  this.disabled = true;
  this.textContent = 'Loading...';
  let rules;

  try {
    rules = extractRules(await Req.getDoc(this.parentElement.href));
    this.textContent = 'Rules loaded.';
    const el = $new('select', {
      size: 8,
      style: 'width: 100%',
      ondblclick: e => e.target !== el && maybeSetup(e),
      onkeyup: e => e.key === 'Enter' && maybeSetup(e),
    }, rules.map(renderRule));
    const i = el.selectedIndex = findMatchingRuleIndex();
    parent.append(
      $new('div#_installHint', [
        'Double-click the rule (or select and press Enter) to add it. ',
        'Click ', $new('code', 'Apply'), ' or ', $new('code', 'OK'), ' to confirm.',
      ]),
      el
    );
    if (i) requestAnimationFrame(() => {
      const optY = el.selectedOptions[0].offsetTop - el.offsetTop;
      el.scrollTo(0, optY - el.offsetHeight / 2);
    });
    el.focus();
  } catch (e) {
    parent.textContent = 'Error loading rules: ' + (e.message || e);
  }

  function extractRules({doc}) {
    // sort by name
    return [...$$('#wiki-body tr', doc)]
      .map(tr => [
        tr.cells[0].textContent.trim(),
        Ruler.fromElement(tr.cells[1]),
      ])
      .filter(([name, r]) =>
        name && r && (!r.d || hostname.includes(r.d)))
      .sort(([a], [b]) =>
        (a = a.toLowerCase()) < (b = b.toLowerCase()) ? -1 :
          a > b ? 1 :
            0);
  }

  function findMatchingRuleIndex() {
    const dottedHost = `.${hostname}.`;
    let maxCount = 0, maxIndex = 0, index = 0;
    for (const [name, {d}] of rules) {
      let count = !!(d && hostname.includes(d)) * 10;
      for (const part of name.toLowerCase().split(/[^a-z\d.-]+/i))
        count += dottedHost.includes(`.${part}.`) && part.length;
      if (count > maxCount) {
        maxCount = count;
        maxIndex = index;
      }
      index++;
    }
    return maxIndex;
  }

  function renderRule([name, rule]) {
    return $new('option', {
      textContent: name,
      title: Ruler.format(rule, {expand: true})
        .replace(/^{|\s*}$/g, '')
        .split('\n')
        .slice(0, 12)
        .map(renderTitleLine)
        .filter(Boolean)
        .join('\n'),
    });
  }

  function renderTitleLine(line, i, arr) {
    return (
      // show ... on 10th line if there are more lines
      i === 9 && arr.length > 10 ? '...' :
        i > 10 ? '' :
          // truncate to 100 chars
          (line.length > 100 ? line.slice(0, 100) + '...' : line)
            // strip the leading space
            .replace(/^\s/, ''));
  }

  function maybeSetup(e) {
    if (!eventModifiers(e))
      setup({rule: rules[e.currentTarget.selectedIndex][1]});
  }
}

const CSS_SETUP_X = 20;
const CSS_SETUP_MAX_Y = 200;
const CSS_SETUP = /*language=css*/ `
  :host {
    all: initial !important;
    position: fixed !important;
    z-index: 2147483647 !important;
    top: ${CSS_SETUP_X}px !important;
    right: 20px !important;
    padding: 1.5em !important;
    color: #000 !important;
    --bg: #eee;
    background: var(--bg) !important;
    box-shadow: 5px 5px 25px 2px #000 !important;
    width: 33em !important;
    border: 1px solid black !important;
    display: flex !important;
    flex-direction: column !important;
  }
  main {
    font: 12px/15px sans-serif;
  }
  main:not([data-start=auto]) [data-start-auto] {
    opacity: .5;
  }
  table {
    text-align:left;
  }
  ul {
    min-height: 430px;
    max-height: calc(100vh - ${CSS_SETUP_MAX_Y}px);
    margin: 0 0 15px 0;
    padding: 0;
    list-style: none;
  }
  li {
    margin: 0;
    padding: .25em 0;
  }
  li.options {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  li.row {
    align-items: start;
    flex-wrap: wrap;
  }
  li.row label {
    display: flex;
    flex-direction: row;
    align-items: center;
  }
  li.row input {
    margin-right: .25em;
  }
  li.stretch label {
    flex: 1;
    white-space: nowrap;
  }
  li.stretch label > span {
    display: flex;
    flex-direction: row;
    flex: 1;
  }
  label {
    display: inline-flex;
    flex-direction: column;
  }
  label:not(:last-child) {
    margin-right: 1em;
  }
  input, select {
    min-height: 1.3em;
    box-sizing: border-box;
  }
  input[type=checkbox] {
    margin-left: 0;
  }
  input[type=number] {
    width: 4em;
  }
  input:not([type=checkbox])  {
    padding: 0 .25em;
  }
  input[type=range] {
    flex: 1;
    width: 100%;
    margin: 0 .25em;
    padding: 0;
    filter: saturate(0);
    opacity: .5;
  }
  u + input[type=range] {
    max-width: 3em;
  }
  input[type=range]:hover {
    filter: none;
    opacity: 1;
  }
  input[type=color] {
    position: absolute;
    width: calc(1.5em + 2px);
    opacity: 0;
    cursor: pointer;
  }
  u {
    position: relative;
    flex: 0 0 1.5em;
    height: 1.5em;
    border: 1px solid #888;
    pointer-events: none;
    color: #888;
    background-image:
      linear-gradient(45deg, currentColor 25%, transparent 25%, transparent 75%, currentColor 75%),
      linear-gradient(45deg, currentColor 25%, transparent 25%, transparent 75%, currentColor 75%);
    background-size: .5em .5em;
    background-position: 0 0, .25em .25em;
  }
  u::after {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    content: "";
    background-color: var(--color);
  }
  .range-edit {
    position: absolute;
    box-shadow: 0 0.25em 1em #000;
    z-index: 99;
  }
  textarea {
    resize: vertical;
    margin: 1px 0;
    font: 11px/1.25 Consolas, monospace;
  }
  :invalid {
    background-color: #f002;
    border-color: #800;
  }
  code {
    font-weight: bold;
  }
  a {
    text-decoration: none;
    color: LinkText;
    cursor: pointer;
  }
  a:hover {
    text-decoration: underline;
  }
  button {
    padding: .2em .5em;
    margin-right: 1em;
  }
  kbd {
    padding: 1px 6px;
    font-weight: bold;
    font-family: Consolas, monospace;
    border: 1px solid #888;
    border-radius: 3px;
    box-shadow: inset 1px 1px 5px #8888, .25px .5px 2px #0008;
  }
  .column {
    display: flex;
    flex-direction: column;
  }
  .flex {
    display: flex;
  }
  .highlight {
    animation: 2s fade-in cubic-bezier(0, .75, .25, 1);
    animation-fill-mode: both;
  }
  #_rules > * {
    word-break: break-all;
  }
  #_rules > :not(:focus) {
    overflow: hidden; /* prevents wrapping in FF */
  }
  .invalid-domain {
    opacity: .5;
  }
  .matching-domain {
    border-color: #56b8ff;
    background: #d7eaff;
  }
  #_mover {
    cursor: move;
    user-select: none;
    position: absolute;
    top: 0;
    left: 8px;
    right: 24px;
    height: 24px;
    text-align: center;
    background: linear-gradient(transparent 10px, currentColor 10px, currentColor 11px, transparent 11px,
      transparent 13px, currentColor 13px, currentColor 14px, transparent 14px);
  }
  #_mover::after {
    content: 'MPIV ${GM.info.script.version}';
    font: bold 20px/1.3 sans;
    background: var(--bg);
    padding: 0 1ex;
  }
  #_x {
    position: absolute;
    top: 0;
    right: 0;
    padding: 4px 8px;
    cursor: pointer;
    user-select: none;
  }
  #_x:hover {
    background-color: #8884;
  }
  #_cssApp {
    color: seagreen;
  }
  #_exportNotification {
    color: green;
    font-weight: bold;
    position: absolute;
    bottom: 4px;
    right: 26px;
  }
  #_installHint {
    color: green;
  }
  #_usage {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: 1em;
  }
  #_usage th {
    font-weight: normal;
    padding-right: .5em;
  }
  #_usage tr:nth-last-child(n + 2) > :not(br) {
    white-space: pre-line;
    border-bottom: 1px dotted #8888;
  }
  #_usage kbd {
    font-family: monospace;
    font-weight: bold;
  }
  @keyframes fade-in {
    from { background-color: deepskyblue }
    to {}
  }
  @media (prefers-color-scheme: dark) {
    :host {
      color: #aaa !important;
      --bg: #333 !important;
    }
    a {
      color: deepskyblue;
    }
    button {
      background: linear-gradient(-5deg, #333, #555);
      border: 1px solid #000;
      box-shadow: 0 2px 6px #181818;
      border-radius: 3px;
      cursor: pointer;
    }
    button:hover {
      background: linear-gradient(-5deg, #333, #666);
    }
    textarea, input, select {
      background: #111;
      color: #BBB;
      border: 1px solid #555;
    }
    input[type=checkbox] {
      filter: invert(1);
    }
    input[type=range] {
      filter: invert(1) saturate(0);
    }
    input[type=range]:hover {
      filter: invert(1);
    }
    kbd {
      border-color: #666;
    }
    @supports (-moz-appearance: none) {
      input[type=checkbox],
      input[type=range],
      input[type=range]:hover {
        filter: none;
      }
    }
    .range-edit {
      box-shadow: 0 .5em 1em .5em #000;
    }
    .matching-domain {
      border-color: #0065af;
      background: #032b58;
      color: #ddd;
    }
    #_cssApp {
      color: darkseagreen;
    }
    #_installHint {
      color: greenyellow;
    }
    ::-webkit-scrollbar {
      width: 14px;
      height: 14px;
      background: #333;
    }
    ::-webkit-scrollbar-button:single-button {
      background: radial-gradient(circle at center, #555 40%, #333 40%)
    }
    ::-webkit-scrollbar-track-piece {
      background: #444;
      border: 4px solid #333;
      border-radius: 8px;
    }
    ::-webkit-scrollbar-thumb {
      border: 3px solid #333;
      border-radius: 8px;
      background: #666;
    }
    ::-webkit-resizer {
      background: #111 linear-gradient(-45deg, transparent 3px, #888 3px, #888 4px, transparent 4px, transparent 6px, #888 6px, #888 7px, transparent 7px) no-repeat;
      border: 2px solid transparent;
    }
  }
`;

function createSetupElement() {
  const MPIV_BASE_URL = 'https://github.com/tophf/mpiv/wiki/';
  const scalesHint = 'Leave it empty and click Apply or OK to restore the default values.';
  const $newLink = (text, href, props) =>
    $new('a', Object.assign({target: '_blank'}, href && {href}, props), text);
  const $newCheck = (label, id, title = '', props) =>
    $new('label', Object.assign({title}, props), [
      $new('input', {id, type: 'checkbox'}),
      label,
    ]);
  const $newKbd = s => s[0] === '{' ? $new('kbd', s.slice(1, -1)) : s;
  const $newRange = (id, title = '', min = 0, max = 100, step = 1, type = 'range') =>
    $new('input', {id, min, max, step, type, 'data-title': title});
  const $newSelect = (label, id, values) =>
    $new('label', [
      label,
      $new('select', {id}, Object.entries(values).map(([k, v]) =>
        $new('option', Object.assign({value: k}, typeof v === 'object' ? v : {textContent: v})))),
    ]);
  const $newTR = ([name, val]) =>
    $new('tr', !name ? $new('br') : [
      $new('th', ((name = name.split(/(\n)/))[0] = $new('b', name[0])) && name),
      $new('td', val.split(/({.+?})/).map($newKbd)),
    ]);
  const kAutoTooltip = '...when the "popup shows" option is "automatically"';
  const kAutoProps = {'data-start-auto': ''};
  return [
    $new('style#_cssSetup', CSS_SETUP),
    $new('style#_css'),
    $new(`main#${PREFIX}setup`, [
      $new('#_mover'),
      $new('#_x', 'x'),
      $new('ul#_ul.column', [
        $new('details', {style: 'order:1; padding-top: .5em;'}, [
          $new('summary', {style: 'cursor: pointer'},
            $new('b', 'Help & hotkeys...')),
          $new('#_usage', [
            $new('table', [
              ['Activate', 'hover the target'],
              ['Deactivate', 'move cursor off target, or click, or zoom out fully'],
              ['Ignore target', 'hold {Shift} ⏵ hover the target ⏵ release the key'],
              ['Freeze popup', 'hold {Shift} ⏵ leave the target ⏵ release the key'],
              ['Force-activate\n(videos or small pics)', 'hold {Ctrl} ⏵ hover the target ⏵ release the key'],
            ].map($newTR)),
            $new('table', [
              ['Start zooming', 'configurable (automatic or via right-click)\nor tap {Shift} while popup is visible'],
              ['Zoom', 'mouse wheel'],
              [],
              ['Rotate', '{L} {r} for "left" or "right"'],
              ['Flip/mirror', '{h} {v} for "horizontal" or "vertical"'],
              ['Previous/next\n(in album)', 'mouse wheel, {j} {k} or {←} {→} keys'],
            ].map($newTR)),
            $new('table', [
              ['Antialiasing', '{a}'],
              ['Caption in info', '{c}'],
              ['Download', '{d}'],
              ['Fullscreen', '{f}'],
              ['Info', '{i}'],
              ['Mute', '{m}'],
              ['Night mode', '{n}'],
              ['Open in tab', '{t}'],
            ].map($newTR)),
          ]),
        ]),
        $new('li.options.stretch', [
          $newSelect('Popup shows on', 'start', {
            context: 'Right-click / \u2261 / Ctrl',
            contextMK: 'Right-click / \u2261',
            contextM: 'Right-click',
            contextK: {
              textContent: '\u2261 key',
              title: '\u2261 is the Menu key (near the right Ctrl)',
            },
            ctrl: 'Ctrl',
            auto: 'automatically',
          }),
          $new('label', {title: kAutoTooltip, ...kAutoProps},
            ['after, sec', $newRange('delay', 'seconds', .05, 10, .05, 'number')]),
          $new('label', {title: '(if the full version of the hovered image is ...% larger)'},
            ['if larger, %', $newRange('scale', null, 0, 100, 1, 'number')]),
          $newSelect('Zoom activates on', 'zoom', {
            context: 'Right click / Shift',
            wheel: 'Wheel up / Shift',
            shift: 'Shift',
            auto: 'automatically',
          }),
          $newSelect('...and zooms to', 'fit', {
            'all': 'fit to window',
            'large': 'fit if larger',
            'no': '100%',
            '': {textContent: 'custom', title: 'Use custom scale factors'},
          }),
        ]),
        $new('li.options', [
          $new('label', ['Zoom step, %', $newRange('zoomStep', null, 100, 400, 1, 'number')]),
          $newSelect('When fully zoomed out:', 'zoomOut', {
            stay: 'stay in zoom mode',
            auto: 'stay if still hovered',
            unzoom: 'undo zoom mode',
            close: 'close popup',
          }),
          $new('label', {
            style: 'flex: 1',
            title: `
              Scale factors to use when “zooms to” selector is set to “custom”.
              0 = fit to window,
              0! = same as 0 but also removes smaller values,
              * after a value marks the default zoom factor, for example: 1*
              The popup won't shrink below the image's natural size or window size for bigger mages.
              ${scalesHint}
            `.trim().replace(/\n\s+/g, '\r'),
          }, ['Custom scale factors:', $new('input#scales', {placeholder: scalesHint})]),
        ]),
        $new('li.options.row', [
          $new([
            $newCheck('Centered*', 'center',
              '...or try to keep the original link/thumbnail unobscured by the popup'),
            $newCheck('Preload on hover*', 'preload',
              'Provides smoother experience but increases network traffic'),
            $newCheck('Require Ctrl key for video*', 'videoCtrl', kAutoTooltip, kAutoProps),
            $newCheck('Mute videos*', 'mute', 'Hotkey: "m" in the popup'),
            $newCheck('Keep playing video*', 'keepVids',
              '...until you press Esc key or click elsewhere'),
            $newCheck('Keep preview on blur*', 'keepOnBlur',
              'i.e. when mouse pointer moves outside the page'),
          ]),
          $new([
            $newCheck('Show complete image*', 'waitLoad',
              '...or immediately show a partial image while still loading'),
            $newCheck('Shadow only when complete*', 'uiShadowOnLoad',
              '...to avoid showing the semi-transparent background while still loading from a slow site'),
            $new('div.flex', {style: 'align-items:center'}, [
              $newCheck('Info: show for', 'uiInfo', 'Hotkey: "i" (or hold "Shift") in the popup'),
              $new('input#uiInfoHide', {min: 1, step: 'any', type: 'number'}),
              'sec',
            ]),
            $newCheck('Info: only once*', 'uiInfoOnce', '...or every time the info changes'),
            $newCheck('Info: caption*', 'uiInfoCaption', 'Hotkey: "c" in the popup'),
            $newCheck('Fade-in transition', 'uiFadein'),
            $newCheck('Fade-in transition in gallery', 'uiFadeinGallery'),
          ]),
          $new([
            $newCheck('Night mode*', 'night', 'Hotkey: "n" in the popup'),
            $newCheck('Run in image tabs', 'imgtab'),
            $newCheck('Spoof hotlinking*', 'xhr',
              'Disable only if you spoof the HTTP headers yourself'),
            $newCheck('Set status on <html>*', 'globalStatus',
              "Causes slowdowns so don't enable unless you explicitly use it in your custom CSS"),
            $newCheck('Auto-start switch in menu*', 'startAltShown',
              "Show a switch for 'auto-start' mode in userscript manager menu"),
          ]),
        ]),
        $new('li.options.stretch', [
          $new('label', [
            'Background',
            $new('span', [
              $new('input#uiBackgroundColor', {type: 'color'}), $new('u'),
              $newRange('uiBackgroundOpacity', 'Opacity: $%'),
            ]),
          ]),
          $new('label', [
            'Border color, opacity, size',
            $new('span', [
              $new('input#uiBorderColor', {type: 'color'}), $new('u'),
              $newRange('uiBorderOpacity', 'Opacity: $%'),
              $newRange('uiBorder', 'Border size: $px', 0, 20),
            ]),
          ]),
          $new('label', [
            'Shadow color, opacity, size',
            $new('span', [
              $new('input#uiShadowColor', {type: 'color'}), $new('u'),
              $newRange('uiShadowOpacity', 'Opacity: $%'),
              $newRange('uiShadow', 'Shadow blur radius: $px\n"0" disables the shadow.', 0, 20),
            ]),
          ]),
          $new('label', ['Padding', $new('span', $newRange('uiPadding', 'Padding: $px'))]),
          $new('label', ['Margin', $new('span', $newRange('uiMargin', 'Margin: $px'))]),
        ]),
        $new('li', [
          $newLink('Custom CSS:', `${MPIV_BASE_URL}Custom-CSS`),
          ' e.g. ', $new('b', '#mpiv-popup { animation: none !important }'),
          $newLink('View the built-in CSS', '', {
            id: '_reveal',
            tabIndex: 0,
            style: 'float: right',
            title: 'You can copy parts of it to override them in your custom CSS',
          }),
          $new('.column', [
            $new('textarea#css', {spellcheck: false}),
            $new('textarea#_cssApp', {spellcheck: false, hidden: true, readOnly: true, rows: 30}),
          ]),
        ]),
        $new('li.flex', {style: 'justify-content: space-between;'}, [
          $new('div',
            $newLink('Custom host rules:', `${MPIV_BASE_URL}Custom-host-rules`)),
          $new('div', {style: 'white-space: pre-line'}, [
            'To disable, put any symbol except ', $new('code', 'a..z 0..9 - .'),
            '\nin "d" value, for example ', $new('code', '"d": "!foo.com"'),
          ]),
          $new('div',
            $new('input#_search',
              {type: 'search', placeholder: 'Search', style: 'width: 10em; margin-left: 1em'})),
        ]),
        $new('li', {
          style: 'margin-left: -3px; margin-right: -3px; overflow-y: auto; ' +
                 'padding-left: 3px; padding-right: 3px;',
        }, [
          $new('div#_rules.column',
            $new('textarea', {spellcheck: false, rows: 1})),
        ]),
        $new('li#_rules2'),
      ]),
      $new('div.flex', [
        $new('button#_ok', {accessKey: 'o'}, 'OK'),
        $new('button#_apply', {accessKey: 'a'}, 'Apply'),
        $new('button#_cancel', 'Cancel'),
        $new('a', {href: `${MPIV_BASE_URL}Rules`, style: 'margin: 0 auto'},
          $new('button#_install', {style: 'color: inherit'}, 'Find rule...')),
        $new('button#_import', 'Import'),
        $new('button#_export', {style: 'margin: 0'}, 'Export'),
        $new('div#_exportNotification', {hidden: true}, 'Copied to clipboard'),
      ]),
    ]),
  ];
}

function createGlobalStyle() {
  App.globalStyle = /*language=CSS*/ (String.raw`
#\mpiv-bar {
  position: fixed;
  z-index: 2147483647;
  top: 0;
  left: 0;
  right: 0;
  text-align: center;
  font-family: sans-serif;
  font-size: 15px;
  font-weight: bold;
  background: #0005;
  color: white;
  padding: 4px 10px;
  text-shadow: .5px .5px 2px #000;
  transition: opacity 1s ease .25s;
  opacity: 0;
}
#\mpiv-bar[data-force] {
  transition: none;
}
#\mpiv-bar.\mpiv-show {
  opacity: 1;
}
#\mpiv-bar[data-zoom][data-prefix]::before {
  content: "[" attr(data-prefix) "] ";
  color: gold;
}
#\mpiv-bar[data-zoom]:not(:empty)::after {
  content: " (" attr(data-zoom) ")";
  opacity: .8;
}
#\mpiv-bar[data-zoom]:empty::after {
  content: attr(data-zoom);
}
#\mpiv-popup.\mpiv-show {
  display: inline;
}
#\mpiv-popup {
  display: none;
  cursor: none;
  box-shadow: none;
${cfg.uiFadein ? String.raw`
  animation: .2s \mpiv-fadein both;
  transition: box-shadow .25s, background-color .25s;
  ` : ''}
${App.popupStyleBase = `
  border: none;
  box-sizing: border-box;
  background-size: cover;
  position: fixed;
  z-index: 2147483647;
  padding: 0;
  margin: 0;
  top: 0;
  left: 0;
  width: auto;
  height: auto;
  transform-origin: center;
  max-width: none;
  max-height: none;
`}
}
#\mpiv-popup.\mpiv-show {
  ${cfg.uiBorder ? `border: ${cfg.uiBorder}px solid ${Util.color('Border')};` : ''}
  ${cfg.uiPadding ? `padding: ${cfg.uiPadding}px;` : ''}
  ${cfg.uiMargin ? `margin: ${cfg.uiMargin}px;` : ''}
}
#\mpiv-popup.\mpiv-show${cfg.uiShadowOnLoad ? '[loaded]' : ''} {
  background-color: ${Util.color('Background')};
  ${cfg.uiShadow ? `box-shadow: 2px 4px ${cfg.uiShadow}px 4px ${Util.color('Shadow')};` : ''}
}
#\mpiv-popup[data-gallery-flip] {
  animation: none;
  transition: none;
}
#\mpiv-popup[${NOAA_ATTR}],
#\mpiv-popup.\mpiv-zoom-max {
  image-rendering: pixelated;
}
#\mpiv-popup.\mpiv-night:not(#\\0) {
  box-shadow: 0 0 0 ${Math.max(screen.width, screen.height)}px #000;
}
body:has(#\mpiv-popup.\mpiv-night)::-webkit-scrollbar {
  background: #000;
}
#\mpiv-setup {
}
@keyframes \mpiv-fadein {
  from {
    opacity: 0;
    border-color: transparent;
  }
  to {
    opacity: 1;
  }
}
` + (cfg.globalStatus ? String.raw`
:root.\mpiv-loading:not(.\mpiv-preloading) *:hover {
  cursor: progress !important;
}
:root.\mpiv-edge #\mpiv-popup {
  cursor: default;
}
:root.\mpiv-error *:hover {
  cursor: not-allowed !important;
}
:root.\mpiv-ready *:hover,
:root.\mpiv-large *:hover {
  cursor: zoom-in !important;
}
:root.\mpiv-shift *:hover {
  cursor: default !important;
}
` : String.raw`
[\mpiv-status~="loading"]:not([\mpiv-status~="preloading"]):hover {
  cursor: progress;
}
[\mpiv-status~="edge"]:hover {
  cursor: default;
}
[\mpiv-status~="error"]:hover {
  cursor: not-allowed;
}
[\mpiv-status~="ready"]:hover,
[\mpiv-status~="large"]:hover {
  cursor: zoom-in;
}
[\mpiv-status~="shift"]:hover {
  cursor: default;
}
`)).replace(/\\mpiv-status/g, STATUS_ATTR).replace(/\\mpiv-/g, PREFIX);
  App.popupStyleBase = App.popupStyleBase.replace(/;/g, '!important;');
  return App.globalStyle;
}

//#region Global utilities

const clamp = (v, min, max) =>
  v < min ? min : v > max ? max : v;

const compareNumbers = (a, b) =>
  a - b;

const flattenHtml = str =>
  str.trim().replace(/\n\s*/g, '');

const dropEvent = e =>
  (e.preventDefault(), e.stopPropagation());

const ensureArray = v =>
  isArray(v) ? v : [v];

/** @param {KeyboardEvent} e */
const eventModifiers = e =>
  (e.altKey ? '!' : '') +
  (e.ctrlKey ? '^' : '') +
  (e.metaKey ? '#' : '') +
  (e.shiftKey ? '+' : '');

/** @param {KeyboardEvent} e */
const describeKey = e => eventModifiers(e) + (e.key && e.key.length > 1 ? e.key : e.code);

const isFunction = val => typeof val === 'function';

const isVideo = el => el && el.tagName === 'VIDEO';

const now = performance.now.bind(performance);

const sumProps = (...props) => {
  let sum = 0;
  for (const p of props)
    sum += parseFloat(p) || 0;
  return sum;
};

const tryCatch = (fn, ...args) => {
  try {
    return fn(...args);
  } catch (e) {}
};

const tryJSON = str =>
  tryCatch(JSON.parse, str);

const pick = (obj, path, fn) => {
  if (obj && path)
    for (const p of path.split('.'))
      if (obj) obj = obj[p]; else break;
  return fn && obj !== undefined ? fn(obj) : obj;
};

const $ = (sel, node = doc) =>
  node.querySelector(sel) || false;

const $$ = (sel, node = doc) =>
  node.querySelectorAll(sel);

const $new = (sel, props, children) => {
  if (typeof sel !== 'string') {
    children = props;
    props = sel;
    sel = '';
  }
  if (!children && props != null && ({}).toString.call(props) !== '[object Object]') {
    children = props;
    props = null;
  }
  const isFrag = sel === 'fragment';
  const [, tag, id, cls] = sel.match(/^(\w*)(?:#([^.]+))?(?:\.(.+))?$/);
  const el = isFrag ? doc.createDocumentFragment() : doc.createElement(tag || 'div');
  if (id) el.id = id;
  if (cls) el.className = cls.replace(/\./g, ' ');
  if (props) {
    for (const [k, v] of Object.entries(props)) {
      if (!k.startsWith('data-')) {
        el[k] = v;
      } else if (v != null) {
        el.setAttribute(k, v);
      }
    }
  }
  if (children != null) {
    if (isArray(children))
      el.append(...children.filter(Boolean));
    else if (children instanceof Node)
      el.appendChild(children);
    else
      el.textContent = children;
  }
  return el;
};

const $css = (el, props) =>
  Object.entries(props).forEach(([k, v]) =>
    el.style.setProperty(k, v, 'important'));

const $parseHtml = str =>
  new DOMParser().parseFromString(str, 'text/html');

const $many = (q, doc) => {
  for (const selector of ensureArray(q)) {
    const el = selector && $(selector, doc);
    if (el)
      return el;
  }
};

const $prop = (sel, prop, node = doc) =>
  (node = $(sel, node)) && node[prop] || '';

const $propUp = (node, prop) =>
  (node = node.closest(`[${prop}]`)) &&
  (prop.startsWith('data-') ? node.getAttribute(prop) : node[prop]) ||
  '';

const $remove = node =>
  node && node.remove();

const $dataset = ({dataset: d}, key, val) =>
  val == null ? delete d[key] : (d[key] = val);

//#endregion
//#region Init

(async () => {
  cfg = await Config.load({save: true});
  if (!doc.body) {
    await new Promise(resolve =>
      new MutationObserver((_, mo) => doc.body && (mo.disconnect(), resolve()))
        .observe(document, {subtree: true, childList: true}));
  }
  const el = doc.body.firstElementChild;
  if (el) {
    App.isImageTab = el === doc.body.lastElementChild && el.matches('img, video');
    App.isEnabled = cfg.imgtab || !App.isImageTab;
  }
  if (Menu) Menu.register();
  addEventListener('mouseover', Events.onMouseOver, true);
  addEventListener('contextmenu', Events.onContext, true);
  addEventListener('keydown', Events.onKeyDown, true);
  addEventListener('visibilitychange', Events.onVisibility, true);
  addEventListener('blur', Events.onVisibility, true);
  if (['greasyfork.org', 'github.com'].includes(hostname))
    addEventListener('click', setupClickedRule, true);
  addEventListener('message', App.onMessage, true);
})();

if (window.trustedTypes) {
  const TT = window.trustedTypes;
  const CP = 'createPolicy';
  const createPolicy = TT[CP];
  TT[CP] = function ovr(name, opts) {
    let fn;
    const p = createPolicy.call(TT, name, opts);
    if ((trustedHTML || opts[fn = 'createHTML'] && (trustedHTML = p[fn].bind(p))) &&
        (trustedScript || opts[fn = 'createScript'] && (trustedScript = p[fn].bind(p))) &&
        TT[CP] === ovr)
      delete TT[CP];
    return p;
  };
}

//#endregion