background.js

/**
 * ShopSpy background service worker.
 * Responsibilities:
 *   • Auto-detect Shopify on page load and set the toolbar badge
 *     (green = Shopify, grey = not).
 *   • Cache the last detection result per tab so the popup opens instantly.
 */

const GREEN = "#1f9d55";
const GREY = "#9ca3af";

// tabId → { isShopify, origin, checkedAt }
const detectionCache = {};

/** Lightweight in-page probe — cheap enough to run on every load. */
function detectShopify() {
  try {
    const S = window.Shopify;
    const html = document.documentElement ? document.documentElement.outerHTML : "";
    const lc = html.toLowerCase();
    const isShopify =
      !!S ||
      lc.includes("cdn.shopify.com") ||
      lc.includes("myshopify.com") ||
      !!document.querySelector(
        'link[href*="cdn.shopify.com"], script[src*="cdn.shopify.com"], meta[name="shopify-digital-wallet"]'
      );
    return { isShopify, shop: S && S.shop ? S.shop : null };
  } catch (e) {
    return { isShopify: false, shop: null };
  }
}

function setBadge(tabId, isShopify) {
  try {
    chrome.action.setBadgeText({ tabId, text: isShopify ? "✓" : "" });
    chrome.action.setBadgeBackgroundColor({ tabId, color: isShopify ? GREEN : GREY });
    if (chrome.action.setBadgeTextColor) {
      chrome.action.setBadgeTextColor({ tabId, color: "#ffffff" });
    }
    chrome.action.setTitle({
      tabId,
      title: isShopify ? "ShopSpy — Shopify store detected" : "ShopSpy — not a Shopify store"
    });
  } catch (e) {
    /* tab may have closed */
  }
}

async function runDetection(tabId, url) {
  if (!url || !/^https?:/i.test(url)) {
    setBadge(tabId, false);
    return;
  }
  let origin = null;
  try {
    origin = new URL(url).origin;
  } catch (e) {
    /* ignore */
  }
  try {
    const [res] = await chrome.scripting.executeScript({
      target: { tabId },
      world: "MAIN",
      func: detectShopify
    });
    const isShopify = !!(res && res.result && res.result.isShopify);
    detectionCache[tabId] = { isShopify, origin, checkedAt: Date.now() };
    setBadge(tabId, isShopify);
  } catch (e) {
    // Injection blocked (chrome://, web store, etc.)
    detectionCache[tabId] = { isShopify: false, origin, checkedAt: Date.now() };
    setBadge(tabId, false);
  }
}

// Auto-scan when a page finishes loading.
chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  if (changeInfo.status === "complete" && tab && tab.url) {
    runDetection(tabId, tab.url);
  }
});

// Re-badge when the user switches tabs.
chrome.tabs.onActivated.addListener(async ({ tabId }) => {
  const cached = detectionCache[tabId];
  if (cached) {
    setBadge(tabId, cached.isShopify);
  } else {
    try {
      const tab = await chrome.tabs.get(tabId);
      if (tab && tab.url) runDetection(tabId, tab.url);
    } catch (e) {
      /* ignore */
    }
  }
});

chrome.tabs.onRemoved.addListener((tabId) => {
  delete detectionCache[tabId];
});

// Popup asks for (or forces a refresh of) the cached detection result.
chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
  if (msg && msg.type === "getDetection" && typeof msg.tabId === "number") {
    (async () => {
      if (msg.forceRefresh) {
        try {
          const tab = await chrome.tabs.get(msg.tabId);
          await runDetection(msg.tabId, tab.url);
        } catch (e) {
          /* ignore */
        }
      }
      sendResponse(detectionCache[msg.tabId] || { isShopify: false, origin: null });
    })();
    return true; // async response
  }
});