stylus/background/background.js

/* global dbExec, getStyles, saveStyle */
/* global handleCssTransitionBug */
'use strict';

// eslint-disable-next-line no-var
var browserCommands, contextMenus;

// *************************************************************************
// preload the DB
tryCatch(getStyles);

// *************************************************************************
// register all listeners
chrome.runtime.onMessage.addListener(onRuntimeMessage);

{
  const listener =
    URLS.chromeProtectsNTP
      ? webNavigationListenerChrome
      : webNavigationListener;

  chrome.webNavigation.onBeforeNavigate.addListener(data =>
    listener(null, data));

  chrome.webNavigation.onCommitted.addListener(data =>
    listener('styleApply', data));

  chrome.webNavigation.onHistoryStateUpdated.addListener(data =>
    listener('styleReplaceAll', data));

  chrome.webNavigation.onReferenceFragmentUpdated.addListener(data =>
    listener('styleReplaceAll', data));
}

chrome.contextMenus.onClicked.addListener((info, tab) =>
  contextMenus[info.menuItemId].click(info, tab));

if ('commands' in chrome) {
  // Not available in Firefox - https://bugzilla.mozilla.org/show_bug.cgi?id=1240350
  chrome.commands.onCommand.addListener(command => browserCommands[command]());
}

// *************************************************************************
// set the default icon displayed after a tab is created until webNavigation kicks in
prefs.subscribe(['iconset'], () => updateIcon({id: undefined}, {}));
updateIcon({id: undefined}, {});

// *************************************************************************
{
  const onInstall = ({reason}) => {
    chrome.runtime.onInstalled.removeListener(onInstall);
    const manifest = chrome.runtime.getManifest();
    // Open FAQs page once after installation to guide new users.
    // Do not display it in development mode.
    if (reason === 'install' && manifest.update_url) {
      setTimeout(openURL, 100, {
        url: 'http://add0n.com/stylus.html'
      });
    }
    // reset L10N cache on update
    if (reason === 'update') {
      localStorage.L10N = JSON.stringify({
        browserUIlanguage: chrome.i18n.getUILanguage(),
      });
    }
    // TODO: remove in the future
    // embed style digests
    chrome.storage.local.get(null, data => {
      const digestKeys = Object.keys(data).filter(key => key.startsWith('originalDigest'));
      if (!digestKeys.length) {
        return;
      }
      chrome.storage.local.remove(digestKeys);
      getStyles().then(styles => {
        for (const style of styles) {
          const digest = data['originalDigest' + style.id];
          if (!style.originalDigest && digest) {
            style.originalDigest = digest;
            dbExec('put', style);
          }
        }
      });
    });
  };
  // bind for 60 seconds max and auto-unbind if it's a normal run
  chrome.runtime.onInstalled.addListener(onInstall);
  setTimeout(onInstall, 60e3, {reason: 'unbindme'});
}

// *************************************************************************
// browser commands
browserCommands = {
  openManage() {
    openURL({url: 'manage.html'});
  },
  styleDisableAll(info) {
    prefs.set('disableAll', info ? info.checked : !prefs.get('disableAll'));
  },
};

// *************************************************************************
// context menus
contextMenus = Object.assign({
  'show-badge': {
    title: 'menuShowBadge',
    click: info => prefs.set(info.menuItemId, info.checked),
  },
  'disableAll': {
    title: 'disableAllStyles',
    click: browserCommands.styleDisableAll,
  },
  'open-manager': {
    title: 'openStylesManager',
    click: browserCommands.openManage,
  },
}, !FIREFOX && prefs.get('editor.contextDelete') && {
  'editor.contextDelete': {
    title: 'editDeleteText',
    type: 'normal',
    contexts: ['editable'],
    documentUrlPatterns: [URLS.ownOrigin + 'edit*'],
    click: (info, tab) => {
      chrome.tabs.sendMessage(tab.id, {method: 'editDeleteText'});
    },
  }
});

{
  const createContextMenus = (ids = Object.keys(contextMenus)) => {
    for (const id of ids) {
      const item = Object.assign({id}, contextMenus[id]);
      const prefValue = prefs.readOnlyValues[id];
      item.title = chrome.i18n.getMessage(item.title);
      if (!item.type && typeof prefValue === 'boolean') {
        item.type = 'checkbox';
        item.checked = prefValue;
      }
      if (!item.contexts) {
        item.contexts = ['browser_action'];
      }
      delete item.click;
      chrome.contextMenus.create(item, ignoreChromeError);
    }
  };
  createContextMenus();
  const toggleableIds = Object.keys(contextMenus).filter(key =>
    typeof prefs.readOnlyValues[key] === 'boolean');
  prefs.subscribe(toggleableIds, (id, checked) => {
    if (id === 'editor.contextDelete') {
      if (checked) {
        createContextMenus([id]);
      } else {
        chrome.contextMenus.remove(id, ignoreChromeError);
      }
    } else {
      chrome.contextMenus.update(id, {checked}, ignoreChromeError);
    }
  });
}

// *************************************************************************
// [re]inject content scripts
{
  const NTP = 'chrome://newtab/';
  const PING = {method: 'ping'};
  const ALL_URLS = '<all_urls>';
  const contentScripts = chrome.runtime.getManifest().content_scripts;
  // expand * as .*?
  const wildcardAsRegExp = (s, flags) => new RegExp(
      s.replace(/[{}()[\]/\\.+?^$:=!|]/g, '\\$&')
        .replace(/\*/g, '.*?'), flags);
  for (const cs of contentScripts) {
    cs.matches = cs.matches.map(m => (
      m === ALL_URLS ? m : wildcardAsRegExp(m)
    ));
  }

  const injectCS = (cs, tabId) => {
    chrome.tabs.executeScript(tabId, {
      file: cs.js[0],
      runAt: cs.run_at,
      allFrames: cs.all_frames,
      matchAboutBlank: cs.match_about_blank,
    }, ignoreChromeError);
  };

  const pingCS = (cs, {id, url}) => {
    cs.matches.some(match => {
      if ((match === ALL_URLS || url.match(match))
        && (!url.startsWith('chrome') || url === NTP)) {
        chrome.tabs.sendMessage(id, PING, pong => {
          if (!pong) {
            injectCS(cs, id);
          }
          ignoreChromeError();
        });
        return true;
      }
    });
  };

  queryTabs().then(tabs =>
    tabs.forEach(tab => {
      // skip lazy-loaded aka unloaded tabs that seem to start loading on message in FF
      if (!FIREFOX || tab.width) {
        contentScripts.forEach(cs =>
          setTimeout(pingCS, 0, cs, tab));
      }
    }));
}


// *************************************************************************

function webNavigationListener(method, {url, tabId, frameId}) {
  getStyles({matchUrl: url, enabled: true, asHash: true}).then(styles => {
    if (method && URLS.supported(url) && tabId >= 0) {
      if (method === 'styleApply') {
        handleCssTransitionBug(tabId, frameId, styles);
      }
      chrome.tabs.sendMessage(tabId, {
        method,
        // ping own page so it retrieves the styles directly
        styles: url.startsWith(URLS.ownOrigin) ? 'DIY' : styles,
      }, {
        frameId
      }, ignoreChromeError);
    }
    // main page frame id is 0
    if (frameId === 0) {
      updateIcon({id: tabId, url}, styles);
    }
  });
}


function webNavigationListenerChrome(method, data) {
  // Chrome 61.0.3161+ doesn't run content scripts on NTP
  if (
    !data.url.startsWith('https://www.google.') ||
    !data.url.includes('/_/chrome/newtab?')
  ) {
    webNavigationListener(method, data);
    return;
  }
  getTab(data.tabId).then(tab => {
    if (tab.url === 'chrome://newtab/') {
      data.url = tab.url;
    }
    webNavigationListener(method, data);
  });
}


function updateIcon(tab, styles) {
  if (tab.id < 0) {
    return;
  }
  if (URLS.chromeProtectsNTP && tab.url === 'chrome://newtab/') {
    styles = {};
  }
  if (styles) {
    stylesReceived(styles);
    return;
  }
  getTabRealURL(tab)
    .then(url => getStyles({matchUrl: url, enabled: true, asHash: true}))
    .then(stylesReceived);

  function stylesReceived(styles) {
    let numStyles = styles.length;
    if (numStyles === undefined) {
      // for 'styles' asHash:true fake the length by counting numeric ids manually
      numStyles = 0;
      for (const id of Object.keys(styles)) {
        numStyles += id.match(/^\d+$/) ? 1 : 0;
      }
    }
    const disableAll = 'disableAll' in styles ? styles.disableAll : prefs.get('disableAll');
    const postfix = disableAll ? 'x' : numStyles === 0 ? 'w' : '';
    const color = prefs.get(disableAll ? 'badgeDisabled' : 'badgeNormal');
    const text = prefs.get('show-badge') && numStyles ? String(numStyles) : '';
    const iconset = ['', 'light/'][prefs.get('iconset')] || '';
    const path = 'images/icon/' + iconset;
    chrome.browserAction.setIcon({
      tabId: tab.id,
      path: {
        // Material Design 2016 new size is 16px
        16: `${path}16${postfix}.png`,
        32: `${path}32${postfix}.png`,
        // Chromium forks or non-chromium browsers may still use the traditional 19px
        19: `${path}19${postfix}.png`,
        38: `${path}38${postfix}.png`,
        // TODO: add Edge preferred sizes: 20, 25, 30, 40
      },
    }, () => {
      if (chrome.runtime.lastError || tab.id === undefined) {
        return;
      }
      // Vivaldi bug workaround: setBadgeText must follow setBadgeBackgroundColor
      chrome.browserAction.setBadgeBackgroundColor({color});
      getTab(tab.id).then(realTab => {
        // skip pre-rendered tabs
        if (realTab.index >= 0) {
          chrome.browserAction.setBadgeText({text, tabId: tab.id});
        }
      });
    });
  }
}


function onRuntimeMessage(request, sender, sendResponse) {
  // prevent browser exception bug on sending a response to a closed tab
  sendResponse = (send => data => tryCatch(send, data))(sendResponse);
  switch (request.method) {
    case 'getStyles':
      getStyles(request).then(sendResponse);
      return KEEP_CHANNEL_OPEN;

    case 'saveStyle':
      saveStyle(request).then(sendResponse);
      return KEEP_CHANNEL_OPEN;

    case 'healthCheck':
      dbExec()
        .then(() => sendResponse(true))
        .catch(() => sendResponse(false));
      return KEEP_CHANNEL_OPEN;

    case 'download':
      download(request.url)
        .then(sendResponse)
        .catch(() => sendResponse(null));
      return KEEP_CHANNEL_OPEN;
  }
}