re-nav/source/background-scripts/initialize.ts

import browser from 'webextension-polyfill';

import storage from '../redirect/storage.js';

async function browserActionClicked() {
  await browser.runtime.openOptionsPage();
}

if (import.meta.env.VITE_BROWSER === 'chromium') {
  browser.action.onClicked.addListener(browserActionClicked);
} else {
  browser.browserAction.onClicked.addListener(browserActionClicked);
}

browser.runtime.onInstalled.addListener(async () => {
  if (import.meta.env.DEV) {
    await browser.runtime.openOptionsPage();
  }
});

browser.webNavigation.onBeforeNavigate.addListener(async (details) => {
  if (!details.url.startsWith('http') || details.frameId > 0) {
    return;
  }

  const {latestTime} = await browser.storage.local.get('latestTime');
  const redirectDelta = Date.now() - (latestTime ?? 0);
  if (redirectDelta < 100) {
    return;
  }

  const tab = await browser.tabs.query({active: true, lastFocusedWindow: true});
  const currentTabUrl =
    tab[0]?.url === undefined ? undefined : new URL(tab[0].url);

  const url = new URL(details.url);
  const {latestUrl} = await browser.storage.local.get('latestUrl');
  if (redirectDelta < 30_000 && url.href === latestUrl) {
    return;
  }

  for (const redirect of await storage.getRedirects()) {
    if (!redirect.parameters.enabled) {
      continue;
    }

    if (redirect.isMatch(url)) {
      // Don't redirect if the URL before going to a new page is also a match.
      // This will happen when the user is already on a website that has a
      // redirect, but for whatever reason hasn't redirected. So it's safe to
      // assume that they want to stay on this website, rather than get
      // redirected.
      if (currentTabUrl !== undefined && redirect.isMatch(currentTabUrl)) {
        break;
      }

      const redirectedUrl = redirect.redirect(url);
      await browser.tabs.update(details.tabId, {url: redirectedUrl.href});
      await browser.storage.local.set({
        latestTime: Date.now(),
        latestUrl: url.href,
      });
      break;
    }
  }
});