extension/service-worker.js

const DEFAULT_SETTINGS = {
  apiUrl: "http://127.0.0.1:8000",
  minimumScore: 55,
  maxItems: 250,
};

chrome.runtime.onInstalled.addListener(async () => {
  const stored = await chrome.storage.local.get(Object.keys(DEFAULT_SETTINGS));
  await chrome.storage.local.set({ ...DEFAULT_SETTINGS, ...stored });
  await chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true });
});

chrome.runtime.onStartup.addListener(async () => {
  await chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true });
});

async function getSettings() {
  const stored = await chrome.storage.local.get(Object.keys(DEFAULT_SETTINGS));
  return { ...DEFAULT_SETTINGS, ...stored };
}

async function getActiveWebTab() {
  const [tab] = await chrome.tabs.query({ active: true, currentWindow: true });
  if (!tab?.id || !tab.url || !/^https?:\/\//i.test(tab.url)) {
    throw new Error("Open a normal HTTP or HTTPS page before running the audit.");
  }
  return tab;
}

async function ensureContentScript(tabId) {
  await chrome.scripting.executeScript({
    target: { tabId },
    files: ["content-script.js"],
  });
}

async function sendToTab(tabId, message) {
  return chrome.tabs.sendMessage(tabId, message);
}

async function callApi(path, options = {}) {
  const settings = await getSettings();
  const apiUrl = String(settings.apiUrl).replace(/\/+$/, "");
  const response = await fetch(`${apiUrl}${path}`, options);
  const payload = await response.json().catch(() => ({}));
  if (!response.ok) {
    throw new Error(payload.error || `API request failed with status ${response.status}`);
  }
  return payload;
}

async function runScan() {
  const tab = await getActiveWebTab();
  const settings = await getSettings();
  await ensureContentScript(tab.id);

  const pageData = await sendToTab(tab.id, {
    type: "COLLECT_VISIBLE_TEXT",
    maxItems: settings.maxItems,
  });
  if (!pageData?.items?.length) {
    return {
      status: "success",
      page: { title: tab.title || "", url: tab.url },
      scanned: 0,
      flagged: 0,
      results: [],
    };
  }

  const analysis = await callApi("/api/analyze-texts", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ items: pageData.items }),
  });
  const flaggedResults = analysis.results.filter(
    (result) => result.isDarkPattern && result.confidence >= settings.minimumScore,
  );

  await sendToTab(tab.id, {
    type: "APPLY_AUDIT_RESULTS",
    results: flaggedResults,
  });

  return {
    status: "success",
    page: { title: tab.title || "", url: tab.url },
    scanned: analysis.analyzed,
    flagged: flaggedResults.length,
    minimumScore: settings.minimumScore,
    results: flaggedResults,
  };
}

async function clearHighlights() {
  const tab = await getActiveWebTab();
  await ensureContentScript(tab.id);
  await sendToTab(tab.id, { type: "CLEAR_AUDIT_RESULTS" });
  return { status: "success" };
}

async function focusResult(elementId) {
  const tab = await getActiveWebTab();
  await ensureContentScript(tab.id);
  await sendToTab(tab.id, {
    type: "FOCUS_AUDIT_RESULT",
    elementId,
  });
  return { status: "success" };
}

async function testConnection() {
  const health = await callApi("/api/health");
  return { status: "success", health };
}

async function saveSettings(settings) {
  const apiUrl = String(settings.apiUrl || DEFAULT_SETTINGS.apiUrl).trim();
  let parsedUrl;
  try {
    parsedUrl = new URL(apiUrl);
  } catch {
    throw new Error("Enter a valid local API URL.");
  }
  if (
    parsedUrl.protocol !== "http:" ||
    !["127.0.0.1", "localhost"].includes(parsedUrl.hostname)
  ) {
    throw new Error("For privacy, the extension only connects to a localhost API.");
  }

  const minimumScore = Math.min(
    95,
    Math.max(20, Number(settings.minimumScore) || DEFAULT_SETTINGS.minimumScore),
  );
  const maxItems = Math.min(
    300,
    Math.max(25, Number(settings.maxItems) || DEFAULT_SETTINGS.maxItems),
  );
  const normalized = {
    apiUrl: parsedUrl.origin,
    minimumScore,
    maxItems,
  };
  await chrome.storage.local.set(normalized);
  return { status: "success", settings: normalized };
}

chrome.runtime.onMessage.addListener((message, _sender, sendResponse) => {
  const actions = {
    RUN_SCAN: runScan,
    CLEAR_HIGHLIGHTS: clearHighlights,
    FOCUS_RESULT: () => focusResult(message.elementId),
    TEST_CONNECTION: testConnection,
    GET_SETTINGS: getSettings,
    SAVE_SETTINGS: () => saveSettings(message.settings || {}),
  };
  const action = actions[message?.type];
  if (!action) {
    return false;
  }

  Promise.resolve(action())
    .then((result) => sendResponse({ ok: true, ...result }))
    .catch((error) => sendResponse({ ok: false, error: error.message }));
  return true;
});