// Shelf — background service worker
// Works under both the `chrome` namespace (Chrome/Edge) and Firefox's
// chrome.* alias for WebExtensions.

const STORAGE_KEY = "shelfItems";

function domainOf(url) {
  try {
    return new URL(url).hostname.replace(/^www\./, "");
  } catch {
    return "";
  }
}

async function getItems() {
  const data = await chrome.storage.local.get(STORAGE_KEY);
  return data[STORAGE_KEY] || [];
}

async function setItems(items) {
  await chrome.storage.local.set({ [STORAGE_KEY]: items });
}

async function addItem({ url, title, favIconUrl, image }) {
  if (!url) return;
  const items = await getItems();

  // De-dupe: if already saved, just bump it to the top and refresh metadata.
  const existingIndex = items.findIndex((i) => i.url === url);
  const entry = {
    id: existingIndex >= 0 ? items[existingIndex].id : `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
    url,
    title: title || url,
    domain: domainOf(url),
    favicon: favIconUrl || "",
    image: image || (existingIndex >= 0 ? items[existingIndex].image : ""),
    dateAdded: Date.now(),
    archived: false,
  };

  if (existingIndex >= 0) items.splice(existingIndex, 1);
  items.unshift(entry);
  await setItems(items);
  return entry;
}

async function flashBadge(tabId, text) {
  try {
    await chrome.action.setBadgeText({ text, tabId });
    await chrome.action.setBadgeBackgroundColor({ color: "#C47A4A", tabId });
    setTimeout(() => {
      chrome.action.setBadgeText({ text: "", tabId }).catch(() => {});
    }, 1400);
  } catch {
    // tabId may be gone; ignore.
  }
}

// Try to grab a screenshot of the *currently active* tab. This only works
// for the page the user is actually looking at (browser security), so it's
// used when saving the current page, not for arbitrary right-clicked links.
async function captureScreenshot(windowId) {
  try {
    const dataUrl = await chrome.tabs.captureVisibleTab(windowId, {
      format: "jpeg",
      quality: 55,
    });
    return dataUrl;
  } catch {
    return "";
  }
}

// --- Toolbar icon click: save the current page ---
chrome.action.onClicked.addListener(async (tab) => {
  if (!tab || !tab.url || tab.url.startsWith("chrome://") || tab.url.startsWith("about:")) {
    return;
  }
  const image = await captureScreenshot(tab.windowId);
  await addItem({ url: tab.url, title: tab.title, favIconUrl: tab.favIconUrl, image });
  flashBadge(tab.id, "✓");
});

// --- Context menus: right-click a page or a link ---
chrome.runtime.onInstalled.addListener(() => {
  chrome.contextMenus.create({
    id: "save-page-later",
    title: "Save page for later",
    contexts: ["page"],
  });
  chrome.contextMenus.create({
    id: "save-link-later",
    title: "Save link for later",
    contexts: ["link"],
  });
});

chrome.contextMenus.onClicked.addListener(async (info, tab) => {
  if (info.menuItemId === "save-page-later") {
    if (!tab || !tab.url) return;
    const image = await captureScreenshot(tab.windowId);
    await addItem({ url: tab.url, title: tab.title, favIconUrl: tab.favIconUrl, image });
    flashBadge(tab.id, "✓");
  }

  if (info.menuItemId === "save-link-later") {
    if (!info.linkUrl) return;
    const linkTitle = info.linkText && info.linkText.trim() ? info.linkText.trim() : info.linkUrl;
    // No screenshot for links we haven't navigated to — favicon/title only.
    await addItem({ url: info.linkUrl, title: linkTitle, favIconUrl: "", image: "" });
    if (tab && tab.id) flashBadge(tab.id, "✓");
  }
});