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

// Chrome loads only "service_worker" from the manifest (a Worker context, so
// importScripts works); Firefox loads the "scripts" array instead, which
// already includes sync.js ahead of this file in the same global scope.
if (typeof importScripts === "function") {
  importScripts("sync.js");
}

const STORAGE_KEY = "shelfItems";
const PREFS_KEY = "shelfPrefs";
const AUTO_DELETE_ALARM = "autoDeleteSweep";

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 getPrefs() {
  const data = await chrome.storage.local.get(PREFS_KEY);
  return data[PREFS_KEY] || {};
}

// Runs on an hourly alarm so overdue items get cleaned up even when the
// shelf page is never opened. Silent — no one's necessarily watching, so
// unlike the newtab-page sweep there's no toast/undo here; the newtab page
// runs its own courtesy-toast sweep whenever it's open.
async function sweepAutoDelete() {
  const prefs = await getPrefs();
  if (!prefs.autoDeleteEnabled) return;

  const items = await getItems();
  const remaining = items.filter((item) => !isOverdueForDeletion(item, prefs));
  if (remaining.length === items.length) return;

  const merged = typeof reconcileWithSync === "function" ? await reconcileWithSync(remaining) : remaining;
  await setItems(merged);
}

async function addItem({ url, title, favIconUrl, image }) {
  if (!url) return;
  let 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 now = Date.now();
  const entry = {
    id: existingIndex >= 0 ? items[existingIndex].id : `${now}-${Math.random().toString(36).slice(2, 8)}`,
    url,
    title: title || url,
    domain: domainOf(url),
    favicon: favIconUrl || "",
    image: image || (existingIndex >= 0 ? items[existingIndex].image : ""),
    dateAdded: now,
    archived: false,
    updatedAt: now,
    surfaceCount: existingIndex >= 0 ? items[existingIndex].surfaceCount || 0 : 0,
    lastSurfacedAt: existingIndex >= 0 ? items[existingIndex].lastSurfacedAt || 0 : 0,
  };

  if (existingIndex >= 0) items.splice(existingIndex, 1);
  items.unshift(entry);
  items = typeof reconcileWithSync === "function" ? await reconcileWithSync(items) : items;
  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, "✓");
  }
});

// --- Auto-delete: hourly sweep, independent of whether the shelf is open ---
// chrome.alarms.create is idempotent (re-arming an existing alarm just
// resets it), so it's safe to call unconditionally every time this script
// runs rather than only from onInstalled.
chrome.alarms.create(AUTO_DELETE_ALARM, { periodInMinutes: 60 });
sweepAutoDelete();

chrome.alarms.onAlarm.addListener((alarm) => {
  if (alarm.name === AUTO_DELETE_ALARM) sweepAutoDelete();
});