intermediate tweaks and fixes for inline search

* caching of search results and downloaded style info for one day
* no prefetching of styles
* only the next search results page is prefetched in unattended fashion
* the "configure" button is shown only after installation
* join the code in one closure, regroup and simplify some functions

popup.html

@@ -118,6 +118,18 @@
     </div>
   </template>
 
+  <template data-id="searchNav">
+    <div>
+      <button data-role="prev" i18n-title="paginationPrevious" disabled>◄</button>
+      <label>
+        <span data-role="page" i18n-title="paginationCurrent">-</span>
+        /
+        <span data-role="total" i18n-title="paginationTotal">-</span>
+      </label>
+      <button data-role="next" i18n-title="paginationNext" disabled>►</button>
+    </div>
+  </template>
+
   <template data-id="emptySearchResult">
     <div class="search-result-empty"></div>
   </template>
@@ -182,7 +194,6 @@
           </label>
         </span>
       </div>
-      <div id="search-results-error" class="hidden"></div>
       <div id="write-style">
         <span id="write-style-for" i18n-text="writeStyleFor"></span>
       </div>
@@ -200,16 +211,10 @@
   </div>
 
   <div id="search-results" class="hidden">
+    <div id="search-results-nav-top"></div>
+    <div id="search-results-error" class="hidden"></div>
     <div id="search-results-list"></div>
-    <div id="search-results-nav">
+    <div id="search-results-nav-bottom"></div>
-      <button id="search-results-nav-prev" i18n-title="paginationPrevious" disabled>&#8592;</button>
-      <label>
-        <span id="search-results-nav-current-page" i18n-title="paginationCurrent">-</span>
-        /
-        <span id="search-results-nav-total-pages" i18n-title="paginationTotal">-</span>
-      </label>
-      <button id="search-results-nav-next" i18n-title="paginationNext" disabled>&#8594;</button>
-    </div>
   </div>
 
   <svg xmlns="http://www.w3.org/2000/svg" style="display: none !important;">

popup/search-results.css

@@ -12,7 +12,7 @@ body.search-results-shown {
   font-weight: bold;
   padding: 5px;
   text-align: center;
-  margin-right: 20px;
+  margin: -.5rem 0 1rem;
 }
 
 #search-results-list {
@@ -20,7 +20,8 @@ body.search-results-shown {
   min-height: 200px;
 }
 
-.search-result, .search-result-empty {
+.search-result,
+.search-result-empty {
   position: relative;
   padding: .75rem;
   min-height: 160px;
@@ -41,6 +42,11 @@ body.search-results-shown {
   transform: scale(.75);
 }
 
+.search-result-fadein {
+  animation: fadein 1s;
+  animation-fill-mode: both;
+}
+
 .search-result-screenshot {
   height: 140px;
   width: 100%;
@@ -182,22 +188,26 @@ body.search-results-shown {
   margin: 3px;
 }
 
-#search-results-nav {
+#search-results-nav-top,
+#search-results-nav-bottom {
   flex-direction: row;
   text-align: center;
   word-break: keep-all;
-  opacity: 1.0;
+  margin-bottom: 1rem;
-  margin-bottom: 10px;
 }
 
-#search-results-nav label {
+#search-results-nav-top button,
-  width: 40px;
+#search-results-nav-bottom button {
-  display: inline-block;
+  -webkit-appearance: none;
-  word-break: keep-all;
+  background: none;
+  border: none;
+  padding: .25rem 1rem;
+  margin: 0 .5rem;
 }
 
-#search-results-nav button {
+#search-results-nav-top button:hover,
-  text-align: center;
+#search-results-nav-bottom button:hover {
+  text-shadow: 0 0 2px currentColor;
 }
 
 #find-styles-inline-group label {
@@ -212,7 +222,6 @@ body.search-results-shown {
   -ms-user-select: none;
   user-select: none;
   pointer-events: none;
-  opacity: 0;
   position: absolute;
   top: 0;
   left: 0;
@@ -220,12 +229,13 @@ body.search-results-shown {
   width: 200px; /* don't change! use "transform: scale(.75)" */
   height: 200px; /* don't change! use "transform: scale(.75)" */
   margin: auto;
-  animation: fadein 1s;
+  animation: lds-spinner 1s reverse;
+  animation-fill-mode: both;
 }
 
 @keyframes lds-spinner {
   0% {
-    opacity: .5;
+    opacity: .25;
   }
 
   100% {

popup/search-results.js

@@ -8,60 +8,126 @@ window.addEventListener('showStyles:done', function _() {
     return;
   }
 
+  //region Init
+
+  const BODY_CLASS = 'search-results-shown';
+  const RESULT_ID_PREFIX = 'search-result-';
+
+  const BASE_URL = 'https://userstyles.org';
+  const UPDATE_URL = 'https://update.userstyles.org/%.md5';
+
+  // normal category is just one word like 'github' or 'google'
+  // but for some sites we need a fallback
+  //   key: category.tld
+  //   value <string>: use as category
+  //   value true: fallback to search_terms
+  const CATEGORY_FALLBACK = {
+    'userstyles.org': 'userstyles.org',
+    'last.fm': true,
+    'Stylus': true,
+  };
+  const RX_CATEGORY = /^(?:.*?)([^.]+)(?:\.com?)?\.(\w+)$/;
+
+  const DISPLAY_PER_PAGE = 10;
+  // Millisecs to wait before fetching next batch of search results.
+  const DELAY_AFTER_FETCHING_STYLES = 0;
+  // Millisecs to wait before fetching .JSON for next search result.
+  const DELAY_BEFORE_SEARCHING_STYLES = 0;
+
+  const BLANK_PIXEL_DATA = 'data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAA' +
+                           'C1HAwCAAAAC0lEQVR42mOcXQ8AAbsBHLLDr5MAAAAASUVORK5CYII=';
+
+  // TODO: add -
+  const CACHE_SIZE = 1e6;
+  const CACHE_PREFIX = 'usoSearchCache/';
+  const CACHE_DURATION = 24 * 3600e3;
+  const CACHE_CLEANUP_THROTTLE = 60e3;
+  const CACHE_EXCEPT_PROPS = ['css', 'discussions', 'additional_info'];
+
+  let searchTotalPages;
+  let searchCurrentPage = 1;
+  let searchExhausted = false;
+
+  const processedResults = [];
+  const unprocessedResults = [];
+
+  let loading = false;
+  // Category for the active tab's URL.
+  let category;
+  let scrollToFirstResult = true;
+
+  let displayedPage = 1;
+  let totalPages = 1;
+  let totalResults = 0;
+
+  // fade-in when the entry took that long to replace its placeholder
+  const FADEIN_THRESHOLD = 50;
+
+  const dom = {};
+
   Object.assign($('#find-styles-link'), {
-    href: searchUserstyles().getSearchPageURL(tabURL),
+    href: getSearchPageURL(tabURL),
     onclick(event) {
-      if (!prefs.get('popup.findStylesInline')) {
+      if (!prefs.get('popup.findStylesInline') || dom.container) {
         handleEvent.openURLandHide.call(this, event);
         return;
       }
 
       $('#find-styles-inline-group').classList.add('hidden');
+      this.textContent = this.title;
+      this.title = '';
 
-      const searchResults = searchResultsController();
+      init();
-      searchResults.init();
+      load();
-      searchResults.load();
 
       event.preventDefault();
     },
   });
 
-  /**
+  return;
-   * Represents the search results within the Stylus popup.
-   * @returns {Object} Includes load(), next(), and prev() methods to alter the search results.
-   */
-  function searchResultsController() {
-    const DISPLAYED_RESULTS_PER_PAGE = 10; // Number of results to display in popup.html
-    const DELAY_AFTER_FETCHING_STYLES = 0; // Millisecs to wait before fetching next batch of search results.
-    const DELAY_BEFORE_SEARCHING_STYLES = 0; // Millisecs to wait before fetching .JSON for next search result.
-    const searchAPI = searchUserstyles();
-    const unprocessedResults = []; // Search results not yet processed.
-    const processedResults = []; // Search results that are not installed and apply ot the page (includes 'json' field with full style).
-    const BLANK_PIXEL_DATA = 'data:image/gif;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAA' +
-                             'C1HAwCAAAAC0lEQVR42mOcXQ8AAbsBHLLDr5MAAAAASUVORK5CYII=';
-    const UPDATE_URL = 'https://update.userstyles.org/%.md5';
-    const ENTRY_ID_PREFIX = 'search-result-';
-
-    let scrollToFirstResult = true;
-    let loading = false;
-    let category; // Category for the active tab's URL.
-    let currentDisplayedPage = 1; // Current page number in popup.html
-
-    return {init, load, next, prev};
 
   function init() {
-      $('#search-results-nav-prev').onclick = prev;
+    document.body.classList.add(BODY_CLASS);
-      $('#search-results-nav-next').onclick = next;
+
-      document.body.classList.add('search-results-shown');
+    dom.container = $('#search-results');
+    dom.error = $('#search-results-error');
+
+    dom.nav = {};
+    const navOnClick = {prev, next};
+    for (const place of ['top', 'bottom']) {
+      const nav = $('#search-results-nav-' + place);
+      nav.appendChild(template.searchNav.cloneNode(true));
+      dom.nav[place] = nav;
+      for (const child of $$('[data-role]', nav)) {
+        const role = child.dataset.role;
+        child.onclick = navOnClick[role];
+        nav['_' + role] = child;
+      }
+    }
+
+    dom.list = $('#search-results-list');
+
     addEventListener('styleDeleted', ({detail}) => {
-        const entries = [...$('#search-results-list').children];
+      const entries = [...dom.list.children];
       const entry = entries.find(el => el._result.installedStyleId === detail.id);
       if (entry) {
         entry._result.installed = false;
         renderActionButtons(entry);
       }
     });
+
+    addEventListener('styleAdded', ({detail: {style: {md5Url}}}) => {
+      const usoId = md5Url && md5Url.match(/\d+|$/)[0];
+      const entry = usoId && $('#' + RESULT_ID_PREFIX + usoId);
+      if (entry) {
+        entry._result.installed = true;
+        renderActionButtons(entry);
       }
+    });
+  }
+
+  //endregion
+  //region Loader
 
   /**
    * Sets loading status of search results.
@@ -70,14 +136,8 @@ window.addEventListener('showStyles:done', function _() {
   function setLoading(isLoading) {
     if (loading !== isLoading) {
       loading = isLoading;
-
+      // Refresh elements that depend on `loading` state.
-        render(); // Refresh elements that depend on `loading` state.
+      render();
-
-        if (isLoading) {
-          showSpinner('#search-results');
-        } else {
-          $.remove('#search-results > .lds-spinner');
-        }
     }
   }
 
@@ -87,75 +147,13 @@ window.addEventListener('showStyles:done', function _() {
       new Array(12).fill($create('div')).map(e => e.cloneNode())));
   }
 
-    function render() {
+  /** Increments displayedPage and loads results. */
-      let startIndex = (currentDisplayedPage - 1) * DISPLAYED_RESULTS_PER_PAGE;
-      const endIndex = currentDisplayedPage * DISPLAYED_RESULTS_PER_PAGE;
-
-      const list = $('#search-results-list');
-
-      // keep rendered elements with ids in the range of interest
-      for (let i = 0; i < DISPLAYED_RESULTS_PER_PAGE;) {
-        const el = list.children[i];
-        if (!el) {
-          break;
-        }
-        if (el.id === 'search-result-' + (processedResults[startIndex] || {}).id) {
-          startIndex++;
-          i++;
-        } else {
-          el.remove();
-        }
-      }
-
-      const displayedResults = processedResults.slice(startIndex, endIndex);
-      displayedResults.forEach(createSearchResultNode);
-
-      $('#search-results-nav-prev').disabled = (currentDisplayedPage <= 1 || loading);
-      $('#search-results-nav-current-page').textContent = currentDisplayedPage;
-
-      let totalResultsCount = processedResults.length;
-      if (unprocessedResults.length > 0) {
-        // Add 1 page if there's results left to process.
-        totalResultsCount += DISPLAYED_RESULTS_PER_PAGE;
-      }
-      const totalPageCount = Math.ceil(Math.max(1, totalResultsCount / DISPLAYED_RESULTS_PER_PAGE));
-      $('#search-results-nav-next').disabled = (currentDisplayedPage >= totalPageCount || loading);
-      $('#search-results-nav-total-pages').textContent = totalPageCount;
-
-      // Fill in remaining search results with blank results + spinners
-      const maxResults = currentDisplayedPage < totalPageCount
-        ? DISPLAYED_RESULTS_PER_PAGE
-        : displayedResults.length + unprocessedResults.length;
-      for (let i = list.children.length; i < maxResults; i++) {
-        const entry = template.emptySearchResult.cloneNode(true);
-        list.appendChild(entry);
-        showSpinner(entry);
-      }
-
-      if (scrollToFirstResult && list.children[0]) {
-        scrollToFirstResult = false;
-        if (!FIREFOX || FIREFOX >= 55) {
-          list.children[0].scrollIntoView({behavior: 'smooth', block: 'start'});
-        }
-      }
-    }
-
-    /**
-     * @returns {Boolean} If we should process more results.
-     */
-    function shouldLoadMore() {
-      return (processedResults.length < currentDisplayedPage * DISPLAYED_RESULTS_PER_PAGE);
-    }
-
-    function loadMoreIfNeeded() {
-      if (shouldLoadMore()) {
-        setTimeout(load, DELAY_BEFORE_SEARCHING_STYLES);
-      }
-    }
-
-    /** Increments currentDisplayedPage and loads results. */
   function next() {
-      currentDisplayedPage += 1;
+    if (loading) {
+      debounce(next, 100);
+      return;
+    }
+    displayedPage += 1;
     scrollToFirstResult = true;
     render();
     loadMoreIfNeeded();
@@ -163,7 +161,11 @@ window.addEventListener('showStyles:done', function _() {
 
   /** Decrements currentPage and loads results. */
   function prev() {
-      currentDisplayedPage = Math.max(1, currentDisplayedPage - 1);
+    if (loading) {
+      debounce(next, 100);
+      return;
+    }
+    displayedPage = Math.max(1, displayedPage - 1);
     scrollToFirstResult = true;
     render();
   }
@@ -180,43 +182,58 @@ window.addEventListener('showStyles:done', function _() {
     } else {
       message = 'Error loading search results: ' + reason;
     }
-      $('#search-results').classList.add('hidden');
+    dom.error.textContent = message;
-      $('#search-results-error').textContent = message;
+    dom.error.classList.remove('hidden');
-      $('#search-results-error').classList.remove('hidden');
   }
 
   /**
    * Initializes search results container, starts fetching results.
    */
   function load() {
-      if (unprocessedResults.length > 0) {
+    if (searchExhausted) {
-        // Keep processing search results if there are any.
+      if (!processedResults.length) {
-        processNextResult();
-      } else if (searchAPI.isExhausted()) {
-        // Stop if no more search results.
-        if (processedResults.length === 0) {
-          // No results
         error(404);
       }
-      } else {
+      return;
-        setLoading(true);
-        // Search for more results.
-        $('#search-results').classList.remove('hidden');
-        $('#search-results-error').classList.add('hidden');
-
-        // Discover "category" for the URL, then search.
-        category = searchAPI.getCategory(tabURL);
-        searchAPI.search(category)
-          .then(searchResults => {
-            setLoading(false);
-            if (searchResults.data.length === 0) {
-              throw 404;
     }
-            unprocessedResults.push(unprocessedResults, ...searchResults.data);
+
+    setLoading(true);
+    dom.container.classList.remove('hidden');
+    dom.error.classList.add('hidden');
+
+    let pass = category ? 1 : 0;
+    category = category || getCategory();
+
+    search({category})
+      .then(function process(results) {
+        const data = results.data.filter(sameCategory);
+        pass++;
+        if (pass === 1 && !data.length) {
+          category = getCategory({keepTLD: true});
+          return search({category, restart: true}).then(process);
+        }
+        const numIrrelevant = results.data.length - data.length;
+        totalResults = results.current_page === 1 ? results.total_entries : totalResults;
+        totalResults = Math.max(0, totalResults - numIrrelevant);
+        totalPages = Math.ceil(totalResults / DISPLAY_PER_PAGE);
+
+        if (data.length) {
+          setLoading(false);
+          unprocessedResults.push(...data);
           processNextResult();
+        } else if (numIrrelevant) {
+          load();
+        } else {
+          return Promise.reject(404);
+        }
       })
       .catch(error);
   }
+
+  function loadMoreIfNeeded() {
+    if (processedResults.length < (displayedPage + 1) * DISPLAY_PER_PAGE) {
+      setTimeout(load, DELAY_BEFORE_SEARCHING_STYLES);
+    }
   }
 
   /**
@@ -226,44 +243,94 @@ window.addEventListener('showStyles:done', function _() {
    * Recurses until shouldLoadMore() is false.
    */
   function processNextResult() {
-      if (!shouldLoadMore()) {
+    const result = unprocessedResults.shift();
-        return;
+    if (!result) {
-      }
-
-      if (unprocessedResults.length === 0) {
-        // No more results to process
       loadMoreIfNeeded();
       return;
     }
-
+    const md5Url = UPDATE_URL.replace('%', result.id);
-      // Process the next result in the queue.
+    getStylesSafe({md5Url}).then(([installedStyle]) => {
-      const nextResult = unprocessedResults.shift();
-      getStylesSafe({md5Url: UPDATE_URL.replace('%', nextResult.id)})
-        .then(([installedStyle]) => {
       if (installedStyle) {
-            setTimeout(processNextResult);
+        totalResults = Math.max(0, totalResults - 1);
-            return;
+      } else {
-          }
+        processedResults.push(result);
-          if (nextResult.category !== 'site') {
-            setTimeout(processNextResult);
-            return;
-          }
-          // Style not installed.
-          // Get "style_settings" (customizations)
-          searchAPI.fetchStyle(nextResult.id)
-            .then(userstyleObject => {
-              // Store style settings for detecting customization later.
-              nextResult.style_settings = userstyleObject.style_settings;
-              processedResults.push(nextResult);
         render();
-              setTimeout(processNextResult, DELAY_AFTER_FETCHING_STYLES);
+      }
-            })
+      setTimeout(processNextResult, !installedStyle && DELAY_AFTER_FETCHING_STYLES);
-            .catch(reason => {
-              console.log('processNextResult(', nextResult.id, ') => [ERROR]: ', reason);
-              setTimeout(processNextResult, DELAY_AFTER_FETCHING_STYLES);
     });
+  }
+
+  //endregion
+  //region UI
+
+  function render() {
+    let start = (displayedPage - 1) * DISPLAY_PER_PAGE;
+    const end = displayedPage * DISPLAY_PER_PAGE;
+
+    let plantAt = 0;
+    let slot = dom.list.children[0];
+
+    // keep rendered elements with ids in the range of interest
+    while (
+      plantAt < DISPLAY_PER_PAGE &&
+      slot && slot.id === 'search-result-' + (processedResults[start] || {}).id
+    ) {
+      slot = slot.nextElementSibling;
+      plantAt++;
+      start++;
+    }
+
+    const plantEntry = entry => {
+      if (slot) {
+        dom.list.replaceChild(entry, slot);
+        slot = entry.nextElementSibling;
+      } else {
+        dom.list.appendChild(entry);
+      }
+      entry.classList.toggle('search-result-fadein',
+        !slot || performance.now() - slot._plantedTime > FADEIN_THRESHOLD);
+      return entry;
+    };
+
+    while (start < Math.min(end, processedResults.length)) {
+      plantEntry(createSearchResultNode(processedResults[start++]));
+      plantAt++;
+    }
+
+    for (const place in dom.nav) {
+      const nav = dom.nav[place];
+      nav._prev.disabled = displayedPage <= 1;
+      nav._next.disabled = displayedPage >= totalPages;
+      nav._page.textContent = displayedPage;
+      nav._total.textContent = totalPages;
+    }
+
+    // Fill in remaining search results with blank results + spinners
+    const maxResults = end > totalResults &&
+      totalResults % DISPLAY_PER_PAGE ||
+      DISPLAY_PER_PAGE;
+    while (plantAt < maxResults) {
+      if (!slot || slot.id.startsWith(RESULT_ID_PREFIX)) {
+        const entry = plantEntry(template.emptySearchResult.cloneNode(true));
+        entry._plantedTime = performance.now();
+        showSpinner(entry);
+      }
+      plantAt++;
+    }
+
+    while (dom.list.children.length > maxResults) {
+      dom.list.lastElementChild.remove();
+    }
+
+    if (scrollToFirstResult && dom.list.children[0]) {
+      scrollToFirstResult = false;
+      if (!FIREFOX || FIREFOX >= 55) {
+        setTimeout(() => {
+          dom.container.scrollIntoView({behavior: 'smooth', block: 'start'});
         });
       }
+    }
+  }
 
   /**
    * Constructs and adds the given search result to the popup's Search Results container.
@@ -287,26 +354,32 @@ window.addEventListener('showStyles:done', function _() {
     const entry = template.searchResult.cloneNode(true);
     Object.assign(entry, {
       _result: result,
-        id: ENTRY_ID_PREFIX + result.id,
+      id: RESULT_ID_PREFIX + result.id,
     });
 
     Object.assign($('.search-result-title', entry), {
       onclick: handleEvent.openURLandHide,
-        href: searchAPI.BASE_URL + result.url
+      href: BASE_URL + result.url
     });
 
     const displayedName = result.name.length < 300 ? result.name : result.name.slice(0, 300) + '...';
     $('.search-result-title span', entry).textContent = tWordBreak(displayedName);
 
     const screenshot = $('.search-result-screenshot', entry);
-      let screenshotUrl = result.screenshot_url;
+    let url = result.screenshot_url;
-      if (screenshotUrl === null) {
+    if (!url) {
-        screenshotUrl = BLANK_PIXEL_DATA;
+      url = BLANK_PIXEL_DATA;
       screenshot.classList.add('no-screenshot');
-      } else if (RegExp(/^[0-9]*_after.(jpe?g|png|gif)$/i).test(screenshotUrl)) {
+    } else if (/^[0-9]*_after.(jpe?g|png|gif)$/i.test(url)) {
-        screenshotUrl = searchAPI.BASE_URL + '/style_screenshot_thumbnails/' + screenshotUrl;
+      url = BASE_URL + '/style_screenshot_thumbnails/' + url;
+    }
+    screenshot.src = url;
+    if (url !== BLANK_PIXEL_DATA) {
+      screenshot.classList.add('search-result-fadein');
+      screenshot.onload = () => {
+        screenshot.classList.remove('search-result-fadein');
+      };
     }
-      screenshot.src = screenshotUrl;
 
     const description = result.description
       .replace(/<[^>]*>/g, '')
@@ -319,7 +392,7 @@ window.addEventListener('showStyles:done', function _() {
     Object.assign($('.search-result-author-link', entry), {
       textContent: result.user.name,
       title: result.user.name,
-        href: searchAPI.BASE_URL + '/users/' + result.user.id,
+      href: BASE_URL + '/users/' + result.user.id,
       onclick(event) {
         event.stopPropagation();
         handleEvent.openURLandHide.call(this, event);
@@ -349,9 +422,8 @@ window.addEventListener('showStyles:done', function _() {
     Object.assign($('.search-result-install-count', entry), {
       textContent: result.total_install_count.toLocaleString()
     });
-      renderActionButtons(entry);
 
-      $('#search-results-list').appendChild(entry);
+    renderActionButtons(entry);
     return entry;
   }
 
@@ -363,13 +435,13 @@ window.addEventListener('showStyles:done', function _() {
     installButton.onclick = onInstallClicked;
 
     const result = entry._result;
-      if (result.style_settings.length > 0) {
+    if ((result.style_settings || []).length > 0) {
       // Style has customizations
       installButton.classList.add('customize');
       uninstallButton.classList.add('customize');
 
       const customizeButton = $('.search-result-customize', entry);
-        customizeButton.dataset.href = searchAPI.BASE_URL + result.url;
+      customizeButton.dataset.href = BASE_URL + result.url;
       customizeButton.dataset.sendMessage = JSON.stringify({method: 'openSettings'});
       customizeButton.classList.remove('hidden');
       customizeButton.onclick = function (event) {
@@ -404,91 +476,80 @@ window.addEventListener('showStyles:done', function _() {
     showSpinner(entry);
     installButton.disabled = true;
 
-      // Fetch .JSON style
+    // Fetch settings to see if we should display "configure" button
-      searchAPI.fetchStyleJson(result)
+    Promise.all([
-        .then(userstyleJson => {
+      fetchStyleJson(result),
-          userstyleJson.reason = 'install';
+      fetchStyleSettings(result),
-          if (result.style_settings.length) {
+    ])
-            // this will make the popup show a config-on-homepage icon
+    .then(([style, settings]) => {
-            userstyleJson.updateUrl += '?';
+      // show a 'config-on-homepage' icon in the popup
-          }
+      style.updateUrl += settings.length ? '?' : '';
-          // Install style
+      // show a 'style installed' tooltip in the manager
-          saveStyleSafe(userstyleJson)
+      style.reason = 'install';
+      return saveStyleSafe(style);
+    })
     .then(savedStyle => {
-              // Success: Store installed styleId, mark as installed.
       result.installed = true;
       result.installedStyleId = savedStyle.id;
       renderActionButtons(entry);
-
-              $.remove('.lds-spinner', entry);
-              installButton.disabled = false;
-            });
     })
     .catch(reason => {
       const usoId = result.id;
-          console.log('install:saveStyleSafe(usoID:', usoId, ') => [ERROR]: ', reason);
+      console.debug('install:saveStyleSafe(usoID:', usoId, ') => [ERROR]: ', reason);
       alert('Error while downloading usoID:' + usoId + '\nReason: ' + reason);
-
+    })
+    .then(() => {
       $.remove('.lds-spinner', entry);
       installButton.disabled = false;
     });
-      return true;
+
+    function fetchStyleSettings(result) {
+      return result.style_settings ||
+        fetchStyle(result.id).then(style => {
+          result.style_settings = style.style_settings || [];
+          return result.style_settings;
+        });
+    }
   }
 
-  } // End of searchResultsController
+  //endregion
-});
+  //region USO API wrapper
 
-/**
+  function getSearchPageURL() {
- * Library for interacting with userstyles.org
+    const category = getCategory();
- * @returns {Object} Exposed methods representing the search results on userstyles.org
+    return BASE_URL +
- */
+      '/styles/browse/' +
-function searchUserstyles() {
+      (category in CATEGORY_FALLBACK ? '?search_terms=' : '') +
-  const BASE_URL = 'https://userstyles.org';
+      category;
-  const CACHE_PREFIX = 'usoSearchCache';
-  const CACHE_DURATION = 1 * 3600e3;
-  let totalPages;
-  let currentPage = 1;
-  let exhausted = false;
-
-  return {BASE_URL, getCategory, getSearchPageURL, isExhausted, search, fetchStyleJson, fetchStyle};
-
-  /**
-   * @returns {Boolean} If there are no more results to fetch from userstyles.org
-   */
-  function isExhausted() {
-    return exhausted;
-  }
-
-  function getSearchPageURL(url) {
-    const category = getCategory(url);
-    if (category === 'STYLUS') {
-      return BASE_URL + '/styles/browse/?search_terms=Stylus';
-    } else {
-      return BASE_URL + '/styles/browse/' + category;
-    }
   }
 
   /**
    * Resolves the Userstyles.org "category" for a given URL.
-   * @param {String} url The URL to a webpage.
-   * @returns {Promise<String>} The category for a URL, or the hostname if category is not found.
    */
-  function getCategory(url) {
+  function getCategory({keepTLD} = {}) {
-    const u = tryCatch(() => new URL(url));
+    const u = tryCatch(() => new URL(tabURL));
     if (!u) {
-      return ''; // Invalid URL
+      // Invalid URL
+      return '';
     } else if (u.protocol === 'file:') {
-      return 'file:'; // File page
+      return 'file:';
     } else if (u.protocol === location.protocol) {
-      return 'STYLUS'; // Stylus page
+      return 'Stylus';
     } else {
       // Website address, strip TLD & subdomain
-      let domain = u.hostname.replace(/^www\.|(\.com?)?\.\w+$/g, '').split('.').pop();
+      const [, category = u.hostname, tld = ''] = u.hostname.match(RX_CATEGORY) || [];
-      if (domain === 'userstyles') {
+      const categoryWithTLD = category + '.' + tld;
-        domain = 'userstyles.org';
+      const fallback = CATEGORY_FALLBACK[categoryWithTLD];
+      return fallback === true && categoryWithTLD || fallback || category + (keepTLD ? tld : '');
     }
-      return domain;
   }
+
+  function sameCategory(result) {
+    return result.subcategory && (
+      category === result.subcategory ||
+      category === 'Stylus' && /^(chrome|moz)-extension$/.test(result.subcategory) ||
+      category.replace('.', '').toLowerCase() === result.subcategory.replace('.', '').toLowerCase()
+    );
   }
 
   /**
@@ -522,8 +583,7 @@ function searchUserstyles() {
    * @returns {Promise<Object>} An object containing info about the style, e.g. name, author, etc.
    */
   function fetchStyle(userstylesId) {
-    return readCache(userstylesId)
+    return readCache(userstylesId).then(json => json ||
-      .then(json => json ||
       download(BASE_URL + '/api/v1/styles/' + userstylesId, {
         method: 'GET',
         headers: {
@@ -532,27 +592,37 @@ function searchUserstyles() {
         },
         responseType: 'json',
         body: null
-        }).then(writeCache));
+      }).then(json => {
+        for (const prop of CACHE_EXCEPT_PROPS) {
+          delete json[prop];
+        }
+        writeCache(json);
+        return json;
+      }));
   }
 
   /**
    * Fetches (and JSON-parses) search results from a userstyles.org search API.
-   * Automatically sets currentPage and totalPages.
+   * Automatically sets searchCurrentPage and searchTotalPages.
    * @param {string} category The usrestyles.org "category" (subcategory) OR a any search string.
    * @return {Object} Response object from userstyles.org
    */
-  function search(category) {
+  function search({category, restart}) {
-    if (totalPages !== undefined && currentPage > totalPages) {
+    if (restart) {
+      searchCurrentPage = 1;
+      searchTotalPages = undefined;
+    }
+    if (searchTotalPages !== undefined && searchCurrentPage > searchTotalPages) {
       return Promise.resolve({'data':[]});
     }
 
     const searchURL = BASE_URL +
       '/api/v1/styles/subcategory' +
       '?search=' + encodeURIComponent(category) +
-      '&page=' + currentPage +
+      '&page=' + searchCurrentPage +
       '&country=NA';
 
-    const cacheKey = category + '/' + currentPage;
+    const cacheKey = category + '/' + searchCurrentPage;
 
     return readCache(cacheKey)
       .then(json => json ||
@@ -570,55 +640,84 @@ function searchUserstyles() {
           return json;
         }))
       .then(json => {
-        currentPage = json.current_page + 1;
+        searchCurrentPage = json.current_page + 1;
-        totalPages = json.total_pages;
+        searchTotalPages = json.total_pages;
-        exhausted = (currentPage > totalPages);
+        searchExhausted = (searchCurrentPage > searchTotalPages);
         return json;
       }).catch(reason => {
-        exhausted = true;
+        searchExhausted = true;
         return Promise.reject(reason);
       });
   }
 
+  //endregion
+  //region Cache
+
   function readCache(id) {
-    return BG.chromeLocal.getLZValue(CACHE_PREFIX + id).then(data => {
+    const key = CACHE_PREFIX + id;
-      if (!data || Date.now() - data.cacheWriteDate < CACHE_DURATION) {
+    return BG.chromeLocal.getValue(key).then(item => {
-        return data;
+      if (!cacheItemExpired(item)) {
+        return tryJSONparse(BG.LZString.decompressFromUTF16(item.payload));
+      } else if (item) {
+        chrome.storage.local.remove(key);
       }
-      BG.chromeLocal.remove(CACHE_PREFIX + id);
     });
   }
 
-  function writeCache(data) {
+  function writeCache(data, debounced) {
-    debounce(cleanupCache, 10e3);
+    if (!debounced) {
-    data.cacheWriteDate = Date.now();
+      debounce(writeCache, 100, data, true);
-    return BG.chromeLocal.setLZValue(CACHE_PREFIX + data.id, data)
+      return data;
-      .then(() => data);
+    } else {
+      debounce(cleanupCache, CACHE_CLEANUP_THROTTLE);
+      return BG.chromeLocal.setValue(CACHE_PREFIX + data.id, {
+        payload: BG.LZString.compressToUTF16(JSON.stringify(data)),
+        date: Date.now(),
+      }).then(() => data);
+    }
+  }
+
+  function cacheItemExpired(item) {
+    return !item || !item.date || Date.now() - item.date > CACHE_DURATION;
   }
 
   function cleanupCache() {
-    new Promise(resolve =>
+    if (!chrome.storage.local.getBytesInUse) {
-      chrome.storage.local.getBytesInUse &&
+      chrome.storage.local.get(null, cleanupCacheInternal);
-      chrome.storage.local.getBytesInUse(null, resolve) ||
+    } else {
-      1e9
+      chrome.storage.local.getBytesInUse(null, size => {
-    )
+        if (size > CACHE_SIZE) {
-    .then(size => size > 1e6 || Promise.reject())
+          chrome.storage.local.get(null, cleanupCacheInternal);
-    .then(() => BG.chromeLocal.getValue(CACHE_PREFIX + 'Cleanup'))
+        }
-    .then((lastCleanup = 0) =>
+        ignoreChromeError();
-      Date.now() - lastCleanup > CACHE_DURATION &&
+      });
-      chrome.storage.local.get(null, storage => {
-        const expired = [];
-        for (const key in storage) {
-          if (key.startsWith(CACHE_PREFIX) &&
-              Date.now() - storage[key].cacheWriteDate > CACHE_DURATION) {
-            expired.push(key);
     }
   }
-        if (expired.length) {
+
-          chrome.storage.local.remove(expired);
+  function cleanupCacheInternal(storage) {
+    const sortedByTime = Object.keys(storage)
+      .filter(key => key.startsWith(CACHE_PREFIX))
+      .map(key => Object.assign(storage[key], {key}))
+      .sort((a, b) => a.date - b.date);
+    const someExpired = cacheItemExpired(sortedByTime[0]);
+    const expired = someExpired ? sortedByTime.filter(cacheItemExpired) :
+      sortedByTime.slice(0, sortedByTime.length / 2);
+    const toRemove = expired.length ? expired : sortedByTime;
+    if (toRemove.length) {
+      chrome.storage.local.remove(toRemove.map(item => item.key), ignoreChromeError);
     }
-        BG.chromeLocal.setValue(CACHE_PREFIX + 'Cleanup', Date.now());
+    ignoreChromeError();
-      }))
-    .catch(ignoreChromeError);
   }
-}
+
+  //endregion
+
+  function objectPick(obj, keys) {
+    const result = {};
+    for (const k in obj) {
+      if (keys.includes(k)) {
+        result[k] = obj[k];
+      }
+    }
+    return result;
+  }
+});