/**
 * extension/background.firefox.js — Firefox MV2 background page.
 *
 * Differences from Chrome MV3 background.js:
 *  - Uses `browser` namespace (WebExtensions API) via the polyfill shim
 *  - No chrome.storage.session — session data stored in memory (object)
 *    and backed by storage.local with a "__session__" prefix
 *  - No chrome.idle API in Firefox MV2 without permission; idle lock
 *    is handled via a timeout-based approach instead
 *  - chrome.action → browser.browserAction (MV2)
 *
 * All message types and storage keys are identical to background.js
 * so popup.js and content.js work without modification.
 */

// Firefox uses `browser` namespace; wrap with `chrome` alias if needed.
if (typeof chrome === 'undefined') {
  // eslint-disable-next-line no-global-assign
  chrome = browser;
}

// ── In-memory session storage shim ───────────────────────────────────────────
// Firefox MV2 does not have chrome.storage.session. We emulate it with an
// in-memory object. Data is lost when the background page is unloaded, which
// mimics the "cleared on browser close" guarantee of chrome.storage.session.

const _session = {};

const sessionStorage = {
  async get(keys) {
    if (typeof keys === 'string') keys = [keys];
    const result = {};
    for (const k of keys) result[k] = _session[k];
    return result;
  },
  async set(obj) {
    Object.assign(_session, obj);
  },
  async remove(keys) {
    if (typeof keys === 'string') keys = [keys];
    for (const k of keys) delete _session[k];
  },
  async clear() {
    for (const k of Object.keys(_session)) delete _session[k];
  },
};

// Override chrome.storage.session with our shim so the rest of the code
// works without modification.
if (!chrome.storage.session) {
  chrome.storage.session = sessionStorage;
}

// ── Idle lock (timeout-based, no chrome.idle) ─────────────────────────────────

const DEFAULT_IDLE_LOCK_SECONDS = 0;
const IDLE_TIMEOUT_KEY = 'idle_lock_seconds';
let _idleTimer = null;

async function resetIdleTimer() {
  const stored = await chrome.storage.local.get(IDLE_TIMEOUT_KEY);
  const seconds = stored[IDLE_TIMEOUT_KEY] ?? DEFAULT_IDLE_LOCK_SECONDS;
  if (_idleTimer) clearTimeout(_idleTimer);
  if (seconds === 0) return; // "Never"
  _idleTimer = setTimeout(async () => {
    console.log('[PassKeeper] Idle lock triggered after', seconds, 's');
    await chrome.storage.session.clear();
    await chrome.storage.local.remove('vault_items_cs');
    await chrome.storage.local.remove(HEALTH_STATUS_KEY);
    const tabs = await chrome.tabs.query({});
    tabs.forEach((tab) => {
      if (tab.id) chrome.browserAction.setBadgeText({ text: '', tabId: tab.id });
    });
  }, seconds * 1000);
}

resetIdleTimer();

// ── Badge helpers ─────────────────────────────────────────────────────────────

const HEALTH_STATUS_KEY = 'health_status';

async function applyHealthBadge() {
  try {
    const stored = await chrome.storage.local.get(HEALTH_STATUS_KEY);
    const health = stored[HEALTH_STATUS_KEY] || { breached: 0, weak: 0, reused: 0 };
    const hasIssues = (health.breached || 0) + (health.weak || 0) + (health.reused || 0) > 0;
    const tabs = await chrome.tabs.query({});
    for (const tab of tabs) {
      if (!tab.url?.startsWith('http')) continue;
      const current = await new Promise((res) =>
        chrome.browserAction.getBadgeText({ tabId: tab.id }, res)
      ).catch(() => '');
      if (current && current !== '' && current !== '⚠') continue;
      if (hasIssues) {
        const color = (health.breached || 0) > 0 ? '#c0392b' : '#d97706';
        chrome.browserAction.setBadgeText({ text: '⚠', tabId: tab.id });
        chrome.browserAction.setBadgeBackgroundColor({ color, tabId: tab.id });
      } else {
        chrome.browserAction.setBadgeText({ text: '', tabId: tab.id });
      }
    }
  } catch (err) {
    console.warn('[PassKeeper] applyHealthBadge error:', err);
  }
}

async function updateBadgeForTab(tabId, url) {
  try {
    const { vault_items } = await chrome.storage.session.get('vault_items');
    if (!vault_items?.length) {
      chrome.browserAction.setBadgeText({ text: '', tabId });
      return;
    }
    let hostname;
    try { hostname = new URL(url).hostname.replace(/^www\./, ''); } catch {
      chrome.browserAction.setBadgeText({ text: '', tabId }); return;
    }
    const matches = vault_items.filter((item) => {
      if (item.item_type !== 'password' || !item.plain?.url) return false;
      try {
        const h = new URL(item.plain.url).hostname.replace(/^www\./, '');
        return h === hostname || h.endsWith(`.${hostname}`) || hostname.endsWith(`.${h}`);
      } catch { return false; }
    });
    if (matches.length > 0) {
      chrome.browserAction.setBadgeText({ text: String(matches.length), tabId });
      chrome.browserAction.setBadgeBackgroundColor({ color: '#1a73e8', tabId });
    } else {
      const stored = await chrome.storage.local.get(HEALTH_STATUS_KEY);
      const health = stored[HEALTH_STATUS_KEY] || {};
      const hasIssues = (health.breached || 0) + (health.weak || 0) + (health.reused || 0) > 0;
      if (hasIssues) {
        const color = (health.breached || 0) > 0 ? '#c0392b' : '#d97706';
        chrome.browserAction.setBadgeText({ text: '⚠', tabId });
        chrome.browserAction.setBadgeBackgroundColor({ color, tabId });
      } else {
        chrome.browserAction.setBadgeText({ text: '', tabId });
      }
    }
  } catch { /* tab may have closed */ }
}

async function refreshAllBadges() {
  const tabs = await chrome.tabs.query({});
  for (const tab of tabs) {
    if (tab.url?.startsWith('http')) updateBadgeForTab(tab.id, tab.url);
  }
}

// ── Tab events ────────────────────────────────────────────────────────────────

chrome.tabs.onActivated.addListener(async ({ tabId }) => {
  resetIdleTimer();
  try {
    const tab = await chrome.tabs.get(tabId);
    if (tab.url?.startsWith('http')) updateBadgeForTab(tabId, tab.url);
  } catch {}
});

chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  if (changeInfo.status === 'complete' && tab.url?.startsWith('http')) {
    updateBadgeForTab(tabId, tab.url);
  }
});

// ── Message handler ───────────────────────────────────────────────────────────

chrome.runtime.onMessage.addListener((msg, sender, sendResponse) => {
  resetIdleTimer();

  if (msg.type === 'FORMS_DETECTED') {
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'SET_IDLE_TIMEOUT') {
    resetIdleTimer(); sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'OPEN_VAULT') {
    chrome.tabs.create({ url: 'https://pwkeeper.ngodanguyen.tech/vault' });
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'OPEN_GENERATOR') {
    chrome.storage.session.set({ popup_nav: 'generator' });
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'KEEPALIVE') {
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'VAULT_UPDATED') {
    refreshAllBadges();
    const payload = { type: 'VAULT_UPDATED', vault_items: msg.vault_items || [] };
    chrome.tabs.query({}, (tabs) => {
      tabs.forEach((tab) => {
        if (tab.url?.startsWith('http://') || tab.url?.startsWith('https://')) {
          chrome.tabs.sendMessage(tab.id, payload).catch(() => {});
        }
      });
    });
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'SAVE_CREDENTIALS') {
    chrome.storage.local.set({ pending_save: msg.data });
    chrome.browserAction.setBadgeText({ text: '!' });
    chrome.browserAction.setBadgeBackgroundColor({ color: '#c0392b' });
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'HEALTH_UPDATE') {
    const { breached = 0, weak = 0, reused = 0 } = msg;
    chrome.storage.local.set({ [HEALTH_STATUS_KEY]: { breached, weak, reused } });
    applyHealthBadge();
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'CLEAR_SAVE_BADGE') {
    chrome.browserAction.setBadgeText({ text: '' });
    applyHealthBadge();
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'WEB_SESSION_SYNC') {
    chrome.storage.session.set({ access_token: msg.access_token, enc_key_salt: msg.enc_key_salt || '' });
    chrome.storage.local.set({ refresh_token: msg.refresh_token, ...(msg.enc_key_salt ? { enc_key_salt: msg.enc_key_salt } : {}) });
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'WEB_SESSION_CLEAR') {
    chrome.storage.session.remove(['access_token', 'vault_key_jwk', 'vault_items', 'enc_key_salt']);
    chrome.storage.local.remove('refresh_token');
    sendResponse({ ok: true }); return false;
  }
  if (msg.type === 'EXT_SESSION_SYNC') {
    chrome.tabs.query({ url: 'https://pwkeeper.ngodanguyen.tech/*' }, (tabs) => {
      tabs.forEach((tab) => {
        chrome.tabs.sendMessage(tab.id, { type: 'INJECT_SESSION', access_token: msg.access_token, refresh_token: msg.refresh_token, enc_key_salt: msg.enc_key_salt }).catch(() => {});
      });
    });
    sendResponse({ ok: true }); return false;
  }
  return false;
});