'use strict';

const { app, BrowserWindow, dialog, ipcMain, safeStorage, shell } = require('electron');
const http = require('node:http');
const path = require('node:path');
const { pathToFileURL } = require('node:url');
const { createSessionStore } = require('./src/session-store');
const { createAltaClient } = require('./src/alta-client');
const { createProxyManager } = require('./src/proxy-launch');
const { checkForUpdate } = require('./src/update-policy');
const {
  AppRuntime,
  PAIRING_ENVELOPE_FILENAME,
  PairingController,
  createBridgeHandler,
} = require('./src/electron-runtime');

const BRIDGE_HOST = '127.0.0.1';
const BRIDGE_PORT = 18247;

let mainWindow = null;
let bridgeServer = null;
let runtime = null;
let pairingController = null;
let firstRunPairingSecret = null;
let quitCleanupInProgress = false;
let allowConfirmedQuit = false;

function getAppDirectory() {
  return app.isPackaged
    ? path.dirname(process.env.PORTABLE_EXECUTABLE_FILE || app.getPath('exe'))
    : __dirname;
}

function sendConnectionState() {
  if (mainWindow && !mainWindow.isDestroyed() && runtime) {
    mainWindow.webContents.send('connection-state-changed', runtime.getConnectionState());
  }
}

function createWindow() {
  mainWindow = new BrowserWindow({
    width: 1400,
    height: 900,
    icon: path.join(__dirname, 'assets', 'icon.png'),
    title: 'Alta Video Camera Proxy',
    webPreferences: {
      nodeIntegration: false,
      contextIsolation: true,
      sandbox: true,
      preload: path.join(__dirname, 'preload.js'),
    },
  });

  mainWindow.webContents.setWindowOpenHandler(() => ({ action: 'deny' }));
  mainWindow.webContents.on('will-navigate', (event) => event.preventDefault());
  mainWindow.loadFile(path.join(__dirname, 'index.html'));
  if (process.argv.includes('--dev')) mainWindow.webContents.openDevTools();
}

function isTrustedSender(event) {
  if (!mainWindow || mainWindow.isDestroyed() || !event) return false;
  const webContents = mainWindow.webContents;
  const frame = event.senderFrame;
  const expectedUrl = pathToFileURL(path.join(__dirname, 'index.html')).href;
  return event.sender === webContents &&
    frame === webContents.mainFrame &&
    frame.url === expectedUrl;
}

function registerIpc(channel, handler) {
  ipcMain.handle(channel, async (event, ...args) => {
    if (!isTrustedSender(event)) throw new Error('Forbidden IPC sender');
    return handler(...args);
  });
}

function registerIpcHandlers() {
  registerIpc('get-devices', () => runtime.getDevices());
  registerIpc('get-device-sites', () => runtime.getDeviceSites());
  registerIpc('get-device-groups', () => runtime.getDeviceGroups());
  registerIpc('get-device-hierarchy', () => runtime.getDeviceHierarchy());
  registerIpc('get-auth-info', () => runtime.getAuthInfo());
  registerIpc('launch-proxy', (deviceId, username) => runtime.launchProxy(deviceId, username));
  registerIpc('stop-proxy', async (key) => {
    const result = await runtime.stopProxy(key);
    sendConnectionState();
    return result;
  });
  registerIpc('disconnect', async () => {
    const state = await runtime.disconnect();
    sendConnectionState();
    return state;
  });
  registerIpc('get-connection-state', () => runtime.getConnectionState());
  registerIpc('check-for-updates', () => runtime.checkForUpdates());
  registerIpc('open-fixed-releases-page', () => runtime.openFixedReleasesPage());
  registerIpc('rotate-pairing', () => {
    firstRunPairingSecret = null;
    return pairingController.rotate();
  });
  registerIpc('revoke-pairing', () => {
    firstRunPairingSecret = null;
    return pairingController.revoke();
  });
  registerIpc('get-pairing-status', () => {
    const result = pairingController.getStatus();
    if (firstRunPairingSecret) {
      result.secret = firstRunPairingSecret;
      firstRunPairingSecret = null;
    }
    return result;
  });
}

function startBridgeServer() {
  if (!pairingController.bridgeAuth) return;
  const handler = createBridgeHandler({
    bridgeAuth: pairingController.bridgeAuth,
    sessionStore: runtime.sessionStore,
    onConnectionStateChanged: () => {
      runtime.onSessionChanged();
      sendConnectionState();
    },
  });
  bridgeServer = http.createServer((request, response) => {
    handler(request, response).catch(() => {
      if (!response.writableEnded) {
        response.writeHead(500, { 'Content-Type': 'application/json', 'Cache-Control': 'no-store' });
        response.end(JSON.stringify({ success: false, message: 'Bridge request failed' }));
      }
    });
  });
  bridgeServer.on('clientError', (_error, socket) => socket.destroy());
  bridgeServer.on('error', (error) => {
    console.error(`Bridge server unavailable (${error.code || 'UNKNOWN'}).`);
  });
  bridgeServer.listen(BRIDGE_PORT, BRIDGE_HOST);
}

app.whenReady().then(() => {
  const sessionStore = createSessionStore();
  const altaClient = createAltaClient({ sessionStore });
  const proxyManager = createProxyManager({ appDirectory: getAppDirectory() });
  const secureStorageAvailable = safeStorage && safeStorage.isEncryptionAvailable();
  pairingController = new PairingController({
    envelopePath: path.join(app.getPath('userData'), PAIRING_ENVELOPE_FILENAME),
    protect: secureStorageAvailable ? (value) => safeStorage.encryptString(value) : undefined,
    unprotect: secureStorageAvailable ? (value) => safeStorage.decryptString(value) : undefined,
  });
  const pairingState = pairingController.initialize();
  firstRunPairingSecret = pairingState.secret || null;
  runtime = new AppRuntime({
    sessionStore,
    altaClient,
    proxyManager,
    checkForUpdate,
    currentVersion: app.getVersion(),
    openExternal: (url) => shell.openExternal(url),
  });

  registerIpcHandlers();
  createWindow();
  startBridgeServer();
});

function closeBridgeServer() {
  if (!bridgeServer) return Promise.resolve();
  const server = bridgeServer;
  return new Promise((resolve, reject) => {
    const finish = (error) => {
      if (!error || error.code === 'ERR_SERVER_NOT_RUNNING') {
        if (bridgeServer === server) bridgeServer = null;
        resolve();
        return;
      }
      reject(error);
    };
    try { server.close(finish); } catch (error) { finish(error); }
  });
}

async function notifyQuitBlocked(state) {
  sendConnectionState();
  const activeCount = state && Array.isArray(state.activeProxies) ? state.activeProxies.length : 0;
  const activeProxiesRemain = activeCount > 0;
  const processDetail = activeProxiesRemain
    ? `${activeCount} app-owned proxy process${activeCount === 1 ? '' : 'es'} remain active.`
    : 'No app-owned proxy process remains active.';
  const sessionDetail = state && state.connected
    ? ' The Alta session is still connected; resolve the process error and try quitting again.'
    : ' Resolve the shutdown error and try quitting again.';
  await dialog.showMessageBox({
    type: 'error',
    title: activeProxiesRemain ? 'Alta Camera Proxy is still running' : 'Alta Camera Proxy could not close',
    message: activeProxiesRemain
      ? 'The app could not confirm that every proxy process exited.'
      : 'The app could not complete shutdown safely.',
    detail: `${processDetail}${sessionDetail}`,
    buttons: ['OK'],
    noLink: true,
  });
}

app.on('before-quit', (event) => {
  if (allowConfirmedQuit) return;
  event.preventDefault();
  if (quitCleanupInProgress) return;
  quitCleanupInProgress = true;

  (async () => {
    try {
      const state = runtime
        ? await runtime.disconnect()
        : { success: true, connected: false, activeProxies: [] };
      if (!state.success || state.activeProxies.length > 0) {
        await notifyQuitBlocked(state);
        return;
      }
      await closeBridgeServer();
      if (runtime) runtime.sessionStore.dispose();
      allowConfirmedQuit = true;
      app.quit();
    } catch {
      const state = runtime
        ? runtime.getConnectionState()
        : { connected: false, activeProxies: [] };
      await notifyQuitBlocked(state);
    } finally {
      quitCleanupInProgress = false;
    }
  })();
});

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

app.on('activate', () => {
  if (BrowserWindow.getAllWindows().length === 0 && runtime) createWindow();
});