// 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, 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 */ }
// 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';

// Write the avatar the renderer drew (a data: URL) to a temp PNG for the toast icon.
function writeTempPng(dataUrl) {
  try {
    if (!dataUrl || !/^data:image\/png;base64,/.test(dataUrl)) return null;
    const p = path.join(app.getPath('temp'), 'bizc-toast-' + crypto.randomBytes(4).toString('hex') + '.png');
    fs.writeFileSync(p, Buffer.from(dataUrl.split(',')[1], 'base64'));
    return p;
  } catch (_) { return null; }
}

// Resolves {open} when the toast is clicked (renderer then opens that chat), else null.
ipcMain.handle('reply-notification', (_e, payload = {}) => new Promise((resolve) => {
  if (!Notification.isSupported()) return resolve(null);
  const img = writeTempPng(payload.avatar);
  let done = false;
  const finish = (v) => { if (!done) { done = true; if (img) { try { fs.unlinkSync(img); } catch (_) {} } resolve(v); } };
  try {
    const n = new Notification({
      title: payload.title || 'Biz Connect',
      body: payload.body || '',
      icon: img ? nativeImage.createFromPath(img) : undefined,
      silent: false,
    });
    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));
    n.show();
    setTimeout(() => finish(null), 30000); // don't leave the promise pending forever
  } 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;

// 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',
    },
  });

  // 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);

  // 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 + '/');

  // Open target=_blank / external links in the system browser instead of a new Electron window.
  win.webContents.setWindowOpenHandler(({ url }) => {
    if (!url.startsWith(SERVER_URL)) { shell.openExternal(url); return { action: 'deny' }; }
    return { action: 'allow' };
  });
}

// 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',
]);

function configureSession() {
  const ses = session.fromPartition('persist:bizconnect');
  // getDisplayMedia needs an explicit source. Default to the primary display + loopback audio.
  // A production build can swap this for a source-picker window.
  ses.setDisplayMediaRequestHandler((request, callback) => {
    desktopCapturer.getSources({ types: ['screen', 'window'] }).then((sources) => {
      callback(sources.length ? { video: sources[0], audio: 'loopback' } : {});
    }).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));
}

app.whenReady().then(() => {
  configureSession();
  createSplash();
  createWindow();
  Menu.setApplicationMenu(null); // hide the default menu bar; the web UI is the chrome
  app.on('activate', () => { if (BrowserWindow.getAllWindows().length === 0) createWindow(); });
  // Check for shell updates on launch, then every 6 hours. Only in packaged builds.
  if (app.isPackaged && autoUpdater) {
    const check = () => autoUpdater.checkForUpdatesAndNotify().catch(() => {});
    check();
    setInterval(check, 6 * 60 * 60 * 1000);
  }
});

app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit(); });