Add Electron desktop shell workspace

apps/desktop/src/main.ts

@@ -0,0 +1,117 @@
+import { app, BrowserWindow, shell } from "electron";
+import type { Event as ElectronEvent } from "electron";
+
+import {
+  DESKTOP_PRODUCTION_URL,
+  isSafeExternalUrl,
+  isTrustedAppUrl,
+  resolveDesktopStartUrl
+} from "./security.js";
+
+const WINDOW_BACKGROUND_COLOR = "#06080b";
+const WINDOW_TITLE = "Islandflow";
+
+let mainWindow: BrowserWindow | null = null;
+
+const canOpenExternalUrl = (sourceUrl: string, targetUrl: string): boolean => {
+  return isTrustedAppUrl(sourceUrl) && isSafeExternalUrl(targetUrl);
+};
+
+const openExternalUrl = async (sourceUrl: string, targetUrl: string): Promise<void> => {
+  if (!canOpenExternalUrl(sourceUrl, targetUrl)) {
+    return;
+  }
+
+  await shell.openExternal(targetUrl);
+};
+
+const installNavigationGuards = (window: BrowserWindow): void => {
+  const { webContents } = window;
+  const { session } = webContents;
+
+  session.setPermissionRequestHandler((_webContents, _permission, callback) => {
+    callback(false);
+  });
+
+  const handleNavigationAttempt = (event: ElectronEvent, targetUrl: string) => {
+    if (isTrustedAppUrl(targetUrl)) {
+      return;
+    }
+
+    event.preventDefault();
+    void openExternalUrl(webContents.getURL(), targetUrl);
+  };
+
+  webContents.on("will-navigate", handleNavigationAttempt);
+  webContents.on("will-redirect", handleNavigationAttempt);
+
+  webContents.setWindowOpenHandler(({ url }) => {
+    void openExternalUrl(webContents.getURL(), url);
+    return { action: "deny" };
+  });
+};
+
+const createMainWindow = (): BrowserWindow => {
+  const window = new BrowserWindow({
+    width: 1440,
+    height: 960,
+    minWidth: 1200,
+    minHeight: 800,
+    show: false,
+    title: WINDOW_TITLE,
+    backgroundColor: WINDOW_BACKGROUND_COLOR,
+    webPreferences: {
+      nodeIntegration: false,
+      contextIsolation: true,
+      sandbox: true,
+      webSecurity: true,
+      webviewTag: false
+    }
+  });
+
+  installNavigationGuards(window);
+
+  window.once("ready-to-show", () => {
+    window.show();
+  });
+
+  window.on("closed", () => {
+    if (mainWindow === window) {
+      mainWindow = null;
+    }
+  });
+
+  const startUrl = resolveDesktopStartUrl(process.env.ISLANDFLOW_DESKTOP_START_URL);
+  if (process.env.ISLANDFLOW_DESKTOP_START_URL && startUrl === DESKTOP_PRODUCTION_URL) {
+    console.warn(
+      `[desktop] Refused untrusted ISLANDFLOW_DESKTOP_START_URL; falling back to ${DESKTOP_PRODUCTION_URL}`
+    );
+  }
+
+  void window.loadURL(startUrl);
+  return window;
+};
+
+const ensureMainWindow = (): void => {
+  if (mainWindow) {
+    return;
+  }
+
+  mainWindow = createMainWindow();
+};
+
+app.whenReady().then(() => {
+  ensureMainWindow();
+
+  app.on("activate", () => {
+    if (BrowserWindow.getAllWindows().length === 0) {
+      ensureMainWindow();
+    }
+  });
+});
+
+app.on("window-all-closed", () => {
+  if (process.platform !== "darwin") {
+    app.quit();
+  }
+});