// Biz Connect — technician desktop client (Electron main process).
//
// This is a thin shell: it loads the live Connect web UI from the server origin, so every
// relative /api and /ws URL in the web app keeps working unchanged. What it adds over a
// browser tab:
//   - native full-screen capture for "Share Screen" (setDisplayMediaRequestHandler)
//   - a real desktop window (no browser chrome), persisted login session
//   - external links open in the user's browser, not inside the app
//
// Server origin is configurable so the same build works against prod or a dev server.
const { app, BrowserWindow, session, desktopCapturer, shell, Menu, MenuItem, Tray, ipcMain, nativeImage, Notification } = require('electron');
const path = require('path');
const fs = require('fs');
const os = require('os');
const crypto = require('crypto');

// A stable per-install id (persisted in userData), so the server can count installs and
// associate them with the user who signs in. Created once, then reused across launches.
function getInstallId() {
  try {
    const p = path.join(app.getPath('userData'), 'install-id');
    if (fs.existsSync(p)) { const v = fs.readFileSync(p, 'utf8').trim(); if (v) return v; }
    const id = crypto.randomUUID();
    fs.writeFileSync(p, id);
    return id;
  } catch (_) { return 'unknown'; }
}
// The renderer (web app) reads this synchronously to report telemetry after login.
ipcMain.on('get-install-info', (e) => {
  e.returnValue = { installId: getInstallId(), appVersion: app.getVersion(), os: process.platform + ' ' + os.release() };
});
// Auto-update: only NATIVE shell changes (this .exe) need this — all web/UI changes arrive
// live from the server. Checks the self-hosted feed (publish config in package.json →
// https://remote.bizgaze.com/downloads/latest.yml), downloads in the background, and installs
// on the next restart. No-op in dev (unpackaged).
let autoUpdater = null;
try { ({ autoUpdater } = require('electron-updater')); } catch (_) { /* not installed in dev */ }
let _lastUpdateCheck = 0;
// Background update check — called on launch, on a timer, AND whenever the window is revealed from the tray
// (so re-opening the app actually looks for a new version instead of waiting up to 6h). Throttled so rapid
// tray open/close doesn't spam the feed. Combined with autoInstallOnAppQuit=true (set in whenReady), a
// downloaded update installs the next time the app truly quits — e.g. a normal PC restart — so close-to-tray
// users get updated even if they never pick "Quit" from the tray icon.
function bgUpdateCheck() {
  if (!app.isPackaged || !autoUpdater) return;
  const now = Date.now();
  if (now - _lastUpdateCheck < 10 * 60 * 1000) return; // at most once / 10 min
  _lastUpdateCheck = now;
  autoUpdater.checkForUpdates().catch(() => {});
}
// #12: manual "Check for updates" from Settings. Returns the current status; the background updater
// (configured in app.whenReady) downloads and prompts to restart when a build is ready.
ipcMain.handle('check-updates', async () => {
  const current = app.getVersion();
  if (!app.isPackaged || !autoUpdater) return { status: 'dev', current };
  try {
    const r = await autoUpdater.checkForUpdates();
    const v = r && r.updateInfo && r.updateInfo.version;
    return (v && v !== current) ? { status: 'available', version: v, current } : { status: 'current', current };
  } catch (e) { return { status: 'error', message: String((e && e.message) || e), current }; }
});
// #3: restart-and-install, triggered from the web update banner's "Restart" button.
ipcMain.handle('restart-to-update', () => { try { if (autoUpdater) autoUpdater.quitAndInstall(); } catch (_) {} });
// Chat toast: sender/group avatar + message; clicking it raises the app and opens that chat.
// Uses Electron's OWN Notification (native, no SnoreToast) whose 'click' event fires reliably.
const APP_ID = 'com.bizgaze.connect.desktop';

// Resolve the sender/group avatar to a local temp PNG for the toast icon. Accepts either a data:
// URL (legacy) or an http(s) DP URL, which we download (external photos can't be drawn to a canvas
// in the renderer without tainting it, so the renderer now passes the URL straight through).
function tmpPngPath() { return path.join(app.getPath('temp'), 'bizc-toast-' + crypto.randomBytes(4).toString('hex') + '.png'); }
// Cache downloaded DPs for the session (keyed by URL) so the SAME sender's photo is instant on the
// next notification — the first one may still show without a photo if the download is slow, but after
// that it's cached. Cached files are NOT deleted after use.
const avatarCache = new Map();
function avatarToTempPng(src) {
  return new Promise((resolve) => {
    try {
      if (!src) return resolve(null);
      const cached = avatarCache.get(src);
      if (cached) { try { if (fs.existsSync(cached)) return resolve(cached); } catch (_) {} avatarCache.delete(src); }
      if (/^data:image\/png;base64,/.test(src)) { const p = tmpPngPath(); fs.writeFileSync(p, Buffer.from(src.split(',')[1], 'base64')); avatarCache.set(src, p); return resolve(p); }
      if (/^https?:\/\//i.test(src)) {
        const mod = src.startsWith('https') ? require('https') : require('http');
        const p = tmpPngPath(); const file = fs.createWriteStream(p);
        const req = mod.get(src, (res) => {
          if (res.statusCode !== 200) { res.resume(); file.close(() => { try { fs.unlinkSync(p); } catch (_) {} }); return resolve(null); }
          res.pipe(file); file.on('finish', () => file.close(() => { avatarCache.set(src, p); resolve(p); }));
        });
        req.on('error', () => resolve(null));
        req.setTimeout(4000, () => { try { req.destroy(); } catch (_) {} resolve(null); });
        return;
      }
      resolve(null);
    } catch (_) { resolve(null); }
  });
}

// ---- Hard refresh -------------------------------------------------------------------------------
// The app closes to TRAY, so it can run for weeks on the page it first loaded and never see a new web
// deploy. This clears the shell's HTTP cache and reloads ignoring cache, so a stale UI is always
// recoverable. Reachable from: the in-app "Refresh" banner / Settings, Ctrl+R (reload),
// Ctrl+Shift+R or F5 (hard reload), and the tray menu.
async function hardReloadWin() {
  try { await session.fromPartition('persist:bizconnect').clearCache(); } catch (_) {}
  try { if (win && !win.isDestroyed()) win.webContents.reloadIgnoringCache(); } catch (_) {}
}
ipcMain.handle('hard-reload', async () => { await hardReloadWin(); return true; });

// ---- Remote control: OS input injection for a screen the local user is SHARING ----
// The renderer (share flow) forwards a viewer's mouse/keyboard events here for injection. Injection is
// HARD-GATED behind an explicit consent flag (rcArmed): nothing is injected until the local user clicks
// "Allow control", and it stops the instant they revoke or the session ends. nut-js is optional — if the
// native module isn't present it degrades to a no-op (no crash), so control simply won't take effect.
let injector = null;
try { injector = require('./input/inject'); } catch (_) { injector = null; }
let rcArmed = false;
// The renderer arms/disarms control (mirrors the on-screen consent banner). Disarming releases any
// stuck keys immediately.
ipcMain.on('rc-arm', (_e, on) => { rcArmed = !!on; if (!rcArmed && injector && injector.releaseAll) { try { injector.releaseAll(); } catch (_) {} } });
ipcMain.on('rc-input', (_e, evt) => { if (rcArmed && injector && injector.inject && evt) { try { injector.inject(evt); } catch (_) {} } });
// Whether OS injection is even possible on this machine (native module loaded). The renderer uses this
// to show "control needs the desktop app" vs an actual Allow prompt.
ipcMain.on('rc-available', (e) => { e.returnValue = !!(injector && injector.available); });

// Pre-warm the DP cache for the renderer's contacts (called after chats load), so the FIRST
// notification from anyone already has their photo — no per-toast download wait.
ipcMain.handle('precache-avatars', async (_e, urls = []) => {
  try { for (const u of (Array.isArray(urls) ? urls : []).slice(0, 100)) { try { await avatarToTempPng(u); } catch (_) {} } } catch (_) {}
  return true;
});

// Keep STRONG references to live notifications. Electron/Windows garbage-collects a Notification
// with no reference, which closed the toast within ~1s and made clicks do nothing.
const activeNotifs = new Set();

// Resolves {open} when the toast is clicked (renderer then opens that chat), else null.
ipcMain.handle('reply-notification', async (_e, payload = {}) => {
  if (!Notification.isSupported()) return null;
  // Fire the toast IMMEDIATELY — NEVER block on a download (waiting made notifications lag; a late
  // call/chat alert is worse than one without a photo). Use the DP only if it's ALREADY cached
  // (instant). If not, kick off a background fetch so the SAME sender's NEXT notification has it.
  // Contacts are also pre-warmed on load (precache-avatars), so the photo is usually already cached.
  let img = null;
  try {
    const src = payload.avatar;
    if (src && /^data:image\//i.test(src)) {
      img = await avatarToTempPng(src); // generated icon (initials/group) — synchronous, always use immediately
    } else if (src) {
      const c = avatarCache.get(src);
      if (c && fs.existsSync(c)) img = c; // http DP already warmed (contacts pre-cached on load) → instant
      else avatarToTempPng(src).catch(() => {}); // not cached yet → fire now, warm for next time
    }
  } catch (_) {}
  return await new Promise((resolve) => {
    let done = false;
    let n;
    const finish = (v) => {
      if (done) return; done = true;
      if (n) { activeNotifs.delete(n); }
      resolve(v); // note: img is cached, not deleted
    };
    try {
      // No timeoutType:'never' — on Windows that added an unwanted "Close" action button. Windows'
      // default toast behavior + our strong reference keep it visible long enough; the in-app call
      // popup provides the persistent Join/Decline for calls.
      n = new Notification({
        title: payload.title || 'Biz Connect',
        body: payload.body || '',
        icon: img ? nativeImage.createFromPath(img) : undefined,
        silent: false,
      });
      activeNotifs.add(n); // strong ref → toast isn't collected; click stays live
      n.on('click', () => {
        if (win) { if (win.isMinimized()) win.restore(); win.show(); win.focus(); } // raise the app
        finish({ kind: payload.kind, id: payload.id, open: true });
      });
      n.on('close', () => finish(null)); // user/system dismissed it → no action
      n.show();
      setTimeout(() => finish(null), payload.persistent ? 45000 : 25000); // don't leak the promise
    } catch (_) { finish(null); }
  });
});

// Windows attributes notifications to the AppUserModelID. Without setting it, toasts read
// "electron.app.<name>"; setting it to the installer's appId makes Windows resolve the
// installed "Biz Connect" shortcut, so notifications show "Biz Connect".
app.setAppUserModelId('com.bizgaze.connect.desktop');

// Renderer asks (via preload) to raise the window — e.g. when an OS notification is clicked.
ipcMain.on('focus-window', () => {
  if (!win) return;
  if (win.isMinimized()) win.restore();
  win.show();
  win.focus();
});

// Unread badge on the taskbar icon. The renderer computes the count (chats with unread) and
// draws the badge image (it has a canvas); Windows shows it via an overlay icon, macOS/Linux
// via the dock badge count.
ipcMain.on('set-unread', (_e, { count, dataUrl } = {}) => {
  try {
    if (typeof app.setBadgeCount === 'function') app.setBadgeCount(count || 0); // macOS/Linux dock
    if (!win) return;
    const overlay = (count > 0 && dataUrl) ? nativeImage.createFromDataURL(dataUrl) : null;
    win.setOverlayIcon(overlay, count > 0 ? (count + ' unread chats') : ''); // Windows taskbar
  } catch (_) {}
});

// Server origin: a PACKAGED build (the installer) points at production; running from source in dev
// (`npm start`, unpackaged) defaults to the local server so you can test the shell against localhost
// with no flags or separate "local" build. SERVER_URL always overrides (e.g. point dev at prod).
const SERVER_URL = (process.env.SERVER_URL || (app.isPackaged ? 'https://remote.bizgaze.com' : 'http://localhost:8090')).replace(/\/+$/, '');

let win;
let splash;
let tray = null;
let isQuitting = false; // true only during a real Quit (tray menu / before-quit) — otherwise close = hide to tray

// Close-to-tray: closing the window HIDES it instead of quitting, so the app keeps running in the
// background with its chat WebSocket alive. That's what lets call/message notifications still fire when
// the window is "closed" (General #1/#2) — a fully-quit Electron app gets no push. The tray icon + menu
// bring it back or quit for real.
function createTray() {
  if (tray) return;
  try {
    let img = nativeImage.createFromPath(path.join(__dirname, 'tray.ico'));
    if (img.isEmpty()) img = nativeImage.createFromPath(path.join(process.resourcesPath || __dirname, 'tray.ico'));
    tray = new Tray(img.isEmpty() ? nativeImage.createEmpty() : img);
    tray.setToolTip('Biz Connect');
    const showApp = () => { if (!win) return createWindow(); if (win.isMinimized()) win.restore(); win.show(); win.focus(); };
    tray.setContextMenu(Menu.buildFromTemplate([
      { label: 'Open Biz Connect', click: showApp },
      { label: 'Refresh app (get latest)', click: () => { showApp(); hardReloadWin(); } },
      { type: 'separator' },
      { label: 'Quit', click: () => { isQuitting = true; app.quit(); } },
    ]));
    tray.on('click', showApp);       // single-click (Windows)
    tray.on('double-click', showApp);
  } catch (_) { tray = null; }
}

// A tiny brand-blue splash (splash.html) shown while the web UI loads, so launch feels instant
// and on-brand instead of a blank window. Closed as soon as the main window is ready to show.
function createSplash() {
  splash = new BrowserWindow({
    width: 440, height: 440, frame: false, resizable: false, center: true,
    backgroundColor: '#1F3B73', skipTaskbar: true, alwaysOnTop: true, show: true,
    webPreferences: { contextIsolation: true, nodeIntegration: false },
  });
  splash.loadFile(path.join(__dirname, 'splash.html'));
  splash.on('closed', () => { splash = null; });
}
function closeSplash() { if (splash) { try { splash.close(); } catch (_) {} splash = null; } }

function createWindow() {
  win = new BrowserWindow({
    width: 1200,
    height: 800,
    minWidth: 880,
    minHeight: 600,
    title: 'Biz Connect',
    backgroundColor: '#1F3B73',
    show: false, // reveal only once the page is ready — the splash covers the gap
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false,
      // Persist cookies/localStorage so the technician stays logged in between launches.
      partition: 'persist:bizconnect',
      // Keep the renderer at full speed when the window is in the BACKGROUND/minimized. Electron
      // throttles hidden windows by default, which stalled the chat WebSocket's onmessage + timers —
      // so incoming messages and their notifications only landed when you refocused the app (the
      // "notifications slow / messages don't update live" report). Off = real-time even in the tray.
      backgroundThrottling: false,
    },
  });

  // Reveal the main window when its first paint is ready, and retire the splash. A fallback
  // timer guarantees we never get stuck on the splash if the load stalls.
  const reveal = () => { closeSplash(); if (win && !win.isVisible()) { win.show(); win.focus(); } };
  win.once('ready-to-show', reveal);
  setTimeout(reveal, 12000);
  // Every time the window is shown — X-to-tray then reopened, taskbar click, relaunch (second-instance),
  // tray icon — check for a new version. This is the catch-all that covers ALL reveal paths (closing the
  // window with the X and opening it again included), not just minimize/restore. Throttled to 1/10 min.
  win.on('show', () => bgUpdateCheck());

  // The menu bar is hidden, so the usual reload accelerators don't exist — wire them by hand. Without
  // these there was literally no way to force the app off a stale page.
  win.webContents.on('before-input-event', (e, input) => {
    if (input.type !== 'keyDown') return;
    const k = String(input.key || '').toLowerCase();
    const mod = input.control || input.meta;
    if ((mod && k === 'r') || k === 'f5') {
      e.preventDefault();
      if (input.shift || k === 'f5') hardReloadWin();           // hard: clear cache + reload
      else { try { win.webContents.reload(); } catch (_) {} }   // plain reload
    }
  });

  // Close = hide to tray (keep running for notifications). First time, tell the user where it went.
  let toldTray = false;
  win.on('close', (e) => {
    if (isQuitting) return; // real quit → let it close
    e.preventDefault();
    win.hide();
    if (!toldTray && Notification.isSupported()) {
      toldTray = true;
      try { const n = new Notification({ title: 'Biz Connect is still running', body: 'It stays in the system tray so you keep getting calls & messages. Quit from the tray icon.' }); n.show(); } catch (_) {}
    }
  });

  // Open the landing page (same entry as the website): the "before login" screen with the
  // no-login "Share my screen" option + sign-in. It redirects logged-in users straight to /home.
  win.loadURL(SERVER_URL + '/');

  // Links: EXTERNAL ones go to the system browser. OUR OWN urls (e.g. a meeting invite link clicked in
  // chat) must NOT spawn a second app window (#5) — navigate the main window instead.
  win.webContents.setWindowOpenHandler(({ url }) => {
    if (!url.startsWith(SERVER_URL)) { shell.openExternal(url); return { action: 'deny' }; }
    try { if (win && !win.isDestroyed()) { if (win.isMinimized()) win.restore(); win.show(); win.focus(); win.loadURL(url); } } catch (_) {}
    return { action: 'deny' };
  });

  // Spell-check menu. Two ways in:
  //  - RIGHT-click: full editing menu (suggestions + cut/copy/paste), the standard desktop behavior.
  //  - LEFT-click on a misspelled word: the renderer asks us (spell-suggest) to synthesize a
  //    right-click at that point, so Chromium hands us the real dictionary suggestions — then we show
  //    a SUGGESTIONS-ONLY menu. This gives the user corrections on a plain left click.
  win.webContents.on('context-menu', (_e, params) => {
    const fromLeftClick = spellClickPending; spellClickPending = false;
    if (fromLeftClick) {
      if (!params.misspelledWord) return; // clicked a correctly-spelled word → no menu, don't disturb typing
      const menu = new Menu();
      for (const s of (params.dictionarySuggestions || [])) menu.append(new MenuItem({ label: s, click: () => win.webContents.replaceMisspelling(s) }));
      if (!menu.items.length) menu.append(new MenuItem({ label: 'No suggestions', enabled: false }));
      menu.append(new MenuItem({ type: 'separator' }));
      menu.append(new MenuItem({ label: 'Add to dictionary', click: () => win.webContents.session.addWordToSpellCheckerDictionary(params.misspelledWord) }));
      menu.popup();
      return;
    }
    const menu = new Menu();
    for (const s of (params.dictionarySuggestions || [])) {
      menu.append(new MenuItem({ label: s, click: () => win.webContents.replaceMisspelling(s) }));
    }
    if (params.misspelledWord) {
      if (params.dictionarySuggestions && params.dictionarySuggestions.length) menu.append(new MenuItem({ type: 'separator' }));
      menu.append(new MenuItem({ label: 'Add to dictionary', click: () => win.webContents.session.addWordToSpellCheckerDictionary(params.misspelledWord) }));
    }
    if (params.isEditable || params.editFlags.canCopy) {
      if (menu.items.length) menu.append(new MenuItem({ type: 'separator' }));
      if (params.editFlags.canCut) menu.append(new MenuItem({ role: 'cut' }));
      if (params.editFlags.canCopy) menu.append(new MenuItem({ role: 'copy' }));
      if (params.isEditable) menu.append(new MenuItem({ role: 'paste' }));
      if (params.isEditable && params.editFlags.canSelectAll) menu.append(new MenuItem({ role: 'selectAll' }));
    }
    if (menu.items.length) menu.popup();
  });
}
// Set just before we synthesize a right-click from a renderer LEFT-click, so the context-menu handler
// knows to show a suggestions-only menu (and to stay silent on correctly-spelled words).
let spellClickPending = false;
ipcMain.on('spell-suggest', (_e, pos) => {
  try {
    if (!win || win.isDestroyed() || !pos) return;
    const x = Math.round(pos.x), y = Math.round(pos.y);
    if (!(x >= 0 && y >= 0)) return;
    spellClickPending = true;
    win.webContents.sendInputEvent({ type: 'mouseDown', x, y, button: 'right', clickCount: 1 });
    win.webContents.sendInputEvent({ type: 'mouseUp', x, y, button: 'right', clickCount: 1 });
    setTimeout(() => { spellClickPending = false; }, 500); // guard: clear if no context-menu fired
  } catch (_) { spellClickPending = false; }
});

// The full Connect experience needs several web capabilities that Electron denies by
// default. We grant them for our own trusted origin:
//   - media            → camera + mic for meetings/calls (getUserMedia)
//   - display-capture  → "Share my screen" (getDisplayMedia)
//   - notifications    → in-app alerts
//   - clipboard, fullscreen, pointerLock → chat paste + meeting UX
// Without this, meetings silently have no camera/mic and notifications never fire.
const GRANTED = new Set([
  'media', 'display-capture', 'notifications',
  'clipboard-read', 'clipboard-sanitized-write', 'fullscreen', 'pointerLock',
]);

// Custom "Share your screen" picker. Enumerates screens + windows, shows a branded modal grid with
// live thumbnails, and resolves to the chosen desktopCapturer source (or null if cancelled). Replaces
// the unreliable OS system picker. Only one picker at a time.
let pickerWin = null;
function pickShareSource() {
  return new Promise((resolve) => {
    let settled = false;
    const finish = (v) => { if (settled) return; settled = true; ipcMain.removeListener('picker-choose', onChoose); if (pickerWin && !pickerWin.isDestroyed()) { try { pickerWin.close(); } catch (_) {} } pickerWin = null; resolve(v); };
    let allSources = [];
    const onChoose = (_e, id) => {
      if (!id) return finish(null);
      finish(allSources.find((s) => s.id === id) || null);
    };
    desktopCapturer.getSources({ types: ['screen', 'window'], thumbnailSize: { width: 320, height: 200 }, fetchWindowIcons: true })
      .then((sources) => {
        allSources = sources;
        const payload = { screen: [], window: [] };
        for (const s of sources) {
          const bucket = s.id.startsWith('screen:') ? 'screen' : 'window';
          payload[bucket].push({
            id: s.id,
            name: s.name || (bucket === 'screen' ? 'Screen' : 'Window'),
            thumb: s.thumbnail ? s.thumbnail.toDataURL() : '',
            appIcon: s.appIcon && !s.appIcon.isEmpty() ? s.appIcon.toDataURL() : null,
          });
        }
        if (pickerWin && !pickerWin.isDestroyed()) { try { pickerWin.close(); } catch (_) {} }
        pickerWin = new BrowserWindow({
          width: 760, height: 560, parent: win || undefined, modal: !!win, resizable: true,
          minimizable: false, maximizable: false, title: 'Share your screen', backgroundColor: '#f4f6fb',
          show: false, autoHideMenuBar: true,
          webPreferences: { preload: undefined, nodeIntegration: true, contextIsolation: false },
        });
        pickerWin.setMenu(null);
        pickerWin.loadFile(path.join(__dirname, 'picker.html'));
        pickerWin.once('ready-to-show', () => { pickerWin.show(); pickerWin.webContents.send('picker-sources', payload); });
        pickerWin.on('closed', () => { if (!settled) finish(null); }); // closed via the X → cancel
        ipcMain.on('picker-choose', onChoose);
      })
      .catch(() => finish(null));
  });
}

function configureSession() {
  const ses = session.fromPartition('persist:bizconnect');
  // getDisplayMedia: show OUR OWN branded screen/window picker. The Electron `useSystemPicker`
  // option silently no-ops on many Windows 11 builds (it needs a specific WebRTC feature) and then
  // auto-shares the primary display with no choice — which is exactly the "no picker appears" bug.
  // So we enumerate sources ourselves and pop a picker window (pickShareSource) to let the user
  // pick a specific screen or window.
  ses.setDisplayMediaRequestHandler((request, callback) => {
    pickShareSource().then((source) => {
      callback(source ? { video: source, audio: 'loopback' } : {}); // {} = user cancelled → no share
    }).catch(() => callback({}));
  }, { useSystemPicker: false });
  // Async grant (getUserMedia, notifications, …)
  ses.setPermissionRequestHandler((_wc, permission, callback) => callback(GRANTED.has(permission)));
  // Sync check (some getUserMedia paths query this before requesting)
  ses.setPermissionCheckHandler((_wc, permission) => GRANTED.has(permission));
  // Spell check for the message box (red squiggles) with right-click corrections. Uses the OS
  // dictionaries; en-US by default plus whatever the OS UI language is, so mixed typing still checks.
  try {
    ses.setSpellCheckerEnabled(true);
    const langs = ['en-US'];
    const sys = (app.getLocale && app.getLocale()) || '';
    const avail = (ses.availableSpellCheckerLanguages || []);
    if (sys && sys !== 'en-US' && (!avail.length || avail.includes(sys))) langs.push(sys);
    ses.setSpellCheckerLanguages(langs);
  } catch (_) {}
  // Downloads go STRAIGHT to the OS Downloads folder — no "where do you want to save?" dialog. If a file of
  // the same name already exists, suffix " (n)" so nothing is overwritten. (item.setSavePath suppresses the
  // save dialog entirely.)
  ses.on('will-download', (_e, item) => {
    try {
      const dir = app.getPath('downloads');
      const name = item.getFilename() || 'download';
      const ext = path.extname(name), base = path.basename(name, ext);
      let target = path.join(dir, name), n = 1;
      while (fs.existsSync(target)) target = path.join(dir, `${base} (${n++})${ext}`);
      item.setSavePath(target);
      // Since we suppressed the save dialog, the download would otherwise be completely silent. Give feedback
      // when it finishes: a notification (click → reveal the file in Explorer) so the user knows it saved and
      // where. Also tell the web UI so it can show its own toast. On failure, say so.
      item.once('done', (_ev, state) => {
        try {
          const ok = state === 'completed';
          const savedName = ok ? path.basename(target) : (item.getFilename() || 'file');
          // Always tell the web UI (it shows a branded toast when the window is up).
          try { if (win && !win.isDestroyed()) win.webContents.send('download-done', { name: savedName, path: ok ? target : '', ok }); } catch (_) {}
          // If the window is focused, that toast is enough — skip the native notification to avoid a double
          // notice. If the app is minimized/in the tray, show a native notification instead (click → reveal).
          const focused = win && !win.isDestroyed() && win.isVisible() && win.isFocused();
          if (!focused && Notification.isSupported()) {
            if (ok) { const note = new Notification({ title: 'Download complete', body: savedName + ' — saved to your Downloads folder. Click to show it.' }); note.on('click', () => { try { shell.showItemInFolder(target); } catch (_) {} }); note.show(); }
            else new Notification({ title: 'Download failed', body: savedName + ' could not be saved.' }).show();
          }
        } catch (_) {}
      });
    } catch (_) {}
  });
}

// Single-instance: a tray app must not spawn a second copy. If another launch happens, focus the
// existing window (restoring it from the tray) instead.
if (!app.requestSingleInstanceLock()) {
  app.quit();
} else {
  app.on('second-instance', () => { if (win) { if (win.isMinimized()) win.restore(); win.show(); win.focus(); } });
}
app.on('before-quit', () => { isQuitting = true; });

app.whenReady().then(() => {
  configureSession();
  createSplash();
  createWindow();
  createTray(); // keep the app reachable while its window is hidden to tray
  Menu.setApplicationMenu(null); // hide the default menu bar; the web UI is the chrome
  app.on('activate', () => { if (BrowserWindow.getAllWindows().length === 0) createWindow(); else if (win) { win.show(); win.focus(); } });
  // Check for shell updates on launch, then every 6 hours. Only in packaged builds.
  if (app.isPackaged && autoUpdater) {
    // #3: surface update progress to the web UI so the user can SEE an update is downloading /
    // installing, instead of it happening silently in the background.
    const sendUpdate = (data) => { try { if (win && !win.isDestroyed()) win.webContents.send('update-event', data); } catch (_) {} };
    autoUpdater.on('checking-for-update', () => sendUpdate({ phase: 'checking' }));
    autoUpdater.on('update-available', (info) => sendUpdate({ phase: 'available', version: info && info.version }));
    autoUpdater.on('update-not-available', () => sendUpdate({ phase: 'current' }));
    autoUpdater.on('download-progress', (p) => sendUpdate({ phase: 'downloading', percent: Math.round((p && p.percent) || 0) }));
    autoUpdater.on('error', () => sendUpdate({ phase: 'error' }));
    // When an update finishes downloading, tell the web UI so it can show a BRANDED "Update ready —
    // Restart now" banner (restartToUpdate IPC does the install). No native dialog — that was
    // unbranded. It still installs on next launch if the user never clicks Restart.
    autoUpdater.on('update-downloaded', (info) => {
      sendUpdate({ phase: 'ready', version: info && info.version });
      // If the window is hidden in the tray, the branded in-app banner isn't visible — nudge with a native
      // notification so tray users know an update is waiting (it also installs automatically on next quit).
      try { if ((!win || !win.isVisible()) && Notification.isSupported()) new Notification({ title: 'Biz Connect update ready', body: 'Version ' + ((info && info.version) || '') + ' installs when you restart. Open Biz Connect to restart now.' }).show(); } catch (_) {}
    });
    // Install a downloaded update on the next real quit (PC restart / tray-Quit) even if the user never
    // clicks "Restart now" — so close-to-tray users don't get stuck on an old version. (This is the
    // electron-updater default; set explicitly to be safe.)
    autoUpdater.autoInstallOnAppQuit = true;
    // checkForUpdates (NOT ...AndNotify): ...AndNotify pops electron-updater's OWN native "Update ready
    // — Restart/Later" toast on download, which duplicated our branded in-app banner (the user saw TWO
    // restart prompts). Plain checkForUpdates still auto-downloads and fires 'update-downloaded'.
    bgUpdateCheck();
    setInterval(bgUpdateCheck, 6 * 60 * 60 * 1000);
  }
});

// With close-to-tray the window is HIDDEN, not destroyed, so this normally won't fire while the app is
// meant to keep running. Only quit here if we're actually quitting (belt-and-braces).
app.on('window-all-closed', () => { if (isQuitting && process.platform !== 'darwin') app.quit(); });
