feat: add automatic update functionality for Electron app

Closes #613

- Add electron-updater for Windows NSIS and Linux AppImage auto-update
- macOS and Linux DEB fall back to GitHub API check with download link
- Add "Check for Updates" menu item with i18n (en, zh, ja, zh-Hant)
- Fix Windows CI workflow to publish correct latest.yml after code signing
- Add update toast notifications in renderer via sonner

electron/electron.d.ts

@@ -2,6 +2,14 @@
  * Type declarations for Electron API exposed via preload script
  */
 
+/** Update status data sent from main process */
+type UpdateStatusData =
+    | { status: "available"; version: string }
+    | { status: "available-manual"; version: string; url: string }
+    | { status: "downloading"; percent: number }
+    | { status: "downloaded" }
+    | { status: "error"; message: string }
+
 /** Configuration preset interface */
 interface ConfigPreset {
     id: string
@@ -74,6 +82,12 @@ declare global {
             >
             /** Set user's preferred locale */
             setUserLocale: (locale: string) => Promise<SetUserLocaleResult>
+            /** Listen for update status events from main process */
+            onUpdateStatus: (
+                callback: (data: UpdateStatusData) => void,
+            ) => () => void
+            /** Start downloading the available update */
+            startDownload: () => Promise<void>
         }
 
         /** Settings window Electron API */

electron/main/app-menu.ts

@@ -6,6 +6,7 @@ import {
     type MenuItemConstructorOptions,
     shell,
 } from "electron"
+import { checkForUpdatesManual } from "./auto-updater"
 import {
     applyPresetToEnv,
     getAllPresets,
@@ -156,6 +157,11 @@ function getMenuTemplate(): MenuItemConstructorOptions[] {
     template.push({
         label: t.help,
         submenu: [
+            {
+                label: t.checkForUpdates,
+                click: () => checkForUpdatesManual(),
+            },
+            { type: "separator" },
             {
                 label: t.documentation,
                 click: async () => {

electron/main/auto-updater.ts

@@ -0,0 +1,279 @@
+import https from "node:https"
+import { app, dialog, ipcMain } from "electron"
+import electronUpdater from "electron-updater"
+import { getMainWindow } from "./window-manager"
+
+const { autoUpdater } = electronUpdater
+
+const CHECK_INTERVAL = 4 * 60 * 60 * 1000 // 4 hours
+const STARTUP_DELAY = 10_000 // 10 seconds
+const GITHUB_API_URL =
+    "https://api.github.com/repos/DayuanJiang/next-ai-draw-io/releases/latest"
+
+let isChecking = false
+let updateDownloaded = false
+
+/**
+ * Whether this platform supports electron-updater auto-update.
+ * macOS: disabled because builds are ad-hoc signed (no Apple Developer cert).
+ */
+function supportsAutoUpdate(): boolean {
+    if (process.platform === "darwin") return false
+    if (process.platform === "win32" && process.env.PORTABLE_EXECUTABLE_DIR)
+        return false
+    if (process.platform === "linux" && !process.env.APPIMAGE) return false
+    return true
+}
+
+/**
+ * Compare two semver-like version strings numerically.
+ * Returns true if remote > local.
+ */
+function isNewerVersion(remote: string, local: string): boolean {
+    const r = remote.replace(/^v/, "").split(".").map(Number)
+    const l = local.replace(/^v/, "").split(".").map(Number)
+    const len = Math.max(r.length, l.length)
+    for (let i = 0; i < len; i++) {
+        const rv = r[i] || 0
+        const lv = l[i] || 0
+        if (rv > lv) return true
+        if (rv < lv) return false
+    }
+    return false
+}
+
+/**
+ * Send update status to the renderer via IPC
+ */
+function sendStatus(data: Record<string, unknown>) {
+    const win = getMainWindow()
+    if (win && !win.isDestroyed()) {
+        win.webContents.send("update-status", data)
+    }
+}
+
+/**
+ * Check GitHub API for latest release (used on macOS and Linux DEB)
+ */
+function checkGitHubRelease(manual: boolean) {
+    const req = https.get(
+        GITHUB_API_URL,
+        {
+            headers: { "User-Agent": "next-ai-draw-io" },
+            timeout: 15000,
+        },
+        (res) => {
+            if (res.statusCode !== 200) {
+                console.error(`GitHub API returned status ${res.statusCode}`)
+                if (manual) {
+                    dialog.showMessageBox({
+                        type: "error",
+                        title: "Update Check Failed",
+                        message:
+                            "Could not check for updates. Please try again later.",
+                    })
+                }
+                isChecking = false
+                return
+            }
+
+            let body = ""
+            res.on("data", (chunk: string) => {
+                body += chunk
+            })
+            res.on("end", () => {
+                try {
+                    const data = JSON.parse(body)
+                    const remoteVersion = data.tag_name || ""
+                    const localVersion = app.getVersion()
+
+                    if (isNewerVersion(remoteVersion, localVersion)) {
+                        sendStatus({
+                            status: "available-manual",
+                            version: remoteVersion.replace(/^v/, ""),
+                            url: data.html_url,
+                        })
+                    } else if (manual) {
+                        dialog.showMessageBox({
+                            type: "info",
+                            title: "No Updates",
+                            message: "You're up to date!",
+                            detail: `Version ${localVersion} is the latest version.`,
+                        })
+                    }
+                } catch (err) {
+                    console.error("Failed to parse GitHub release:", err)
+                    if (manual) {
+                        dialog.showMessageBox({
+                            type: "error",
+                            title: "Update Check Failed",
+                            message:
+                                "Could not check for updates. Please try again later.",
+                        })
+                    }
+                }
+                isChecking = false
+            })
+        },
+    )
+    req.on("timeout", () => {
+        req.destroy()
+        isChecking = false
+    })
+    req.on("error", (err) => {
+        console.error("GitHub API request failed:", err)
+        if (manual) {
+            dialog.showMessageBox({
+                type: "error",
+                title: "Update Check Failed",
+                message: "Could not check for updates. Please try again later.",
+            })
+        }
+        isChecking = false
+    })
+    req.end()
+}
+
+/**
+ * Set up electron-updater event handlers (Windows NSIS / Linux AppImage)
+ */
+function setupAutoUpdater() {
+    autoUpdater.autoDownload = false
+    autoUpdater.autoInstallOnAppQuit = true
+
+    autoUpdater.on("update-available", (info) => {
+        console.log("Update available:", info.version)
+        sendStatus({ status: "available", version: info.version })
+        isChecking = false
+    })
+
+    autoUpdater.on("update-not-available", () => {
+        console.log("No update available")
+        isChecking = false
+    })
+
+    autoUpdater.on("download-progress", (progress) => {
+        sendStatus({
+            status: "downloading",
+            percent: progress.percent,
+        })
+    })
+
+    autoUpdater.on("update-downloaded", () => {
+        updateDownloaded = true
+        console.log("Update downloaded")
+        sendStatus({ status: "downloaded" })
+        showRestartDialog()
+    })
+
+    autoUpdater.on("error", (err) => {
+        console.error("Auto-update error:", err)
+        sendStatus({ status: "error", message: String(err) })
+        isChecking = false
+    })
+
+    // IPC: renderer requests download
+    ipcMain.handle("updater:start-download", () => {
+        return autoUpdater.downloadUpdate()
+    })
+}
+
+/**
+ * Show restart dialog after update downloaded
+ */
+async function showRestartDialog() {
+    const result = await dialog.showMessageBox({
+        type: "info",
+        buttons: ["Restart Now", "Later"],
+        defaultId: 0,
+        cancelId: 1,
+        title: "Update Ready",
+        message: "A new version has been downloaded.",
+        detail: "Restart the app to install the update.",
+    })
+    if (result.response === 0) {
+        autoUpdater.quitAndInstall()
+    }
+}
+
+/**
+ * Run a single update check
+ */
+function doCheck(manual: boolean) {
+    if (isChecking) return
+    isChecking = true
+
+    // If update already downloaded, just re-show restart dialog
+    if (updateDownloaded && supportsAutoUpdate()) {
+        isChecking = false
+        showRestartDialog()
+        return
+    }
+
+    if (supportsAutoUpdate()) {
+        autoUpdater.checkForUpdates().catch((err) => {
+            console.error("checkForUpdates failed:", err)
+            isChecking = false
+        })
+        // For manual check, show "up to date" if no update found
+        if (manual) {
+            const onNotAvailable = () => {
+                dialog.showMessageBox({
+                    type: "info",
+                    title: "No Updates",
+                    message: "You're up to date!",
+                    detail: `Version ${app.getVersion()} is the latest version.`,
+                })
+                cleanup()
+            }
+            // Clean up listeners when either event fires, preventing stale listeners
+            const onAvailable = () => cleanup()
+            const onError = () => cleanup()
+            const cleanup = () => {
+                autoUpdater.off("update-not-available", onNotAvailable)
+                autoUpdater.off("update-available", onAvailable)
+                autoUpdater.off("error", onError)
+            }
+            autoUpdater.once("update-not-available", onNotAvailable)
+            autoUpdater.once("update-available", onAvailable)
+            autoUpdater.once("error", onError)
+        }
+    } else {
+        checkGitHubRelease(manual)
+    }
+}
+
+/**
+ * Initialize auto-updater. Call once after createWindow().
+ */
+export function initAutoUpdater() {
+    if (!app.isPackaged) return
+
+    if (supportsAutoUpdate()) {
+        setupAutoUpdater()
+    } else {
+        // Register no-op handler so renderer doesn't get an unhandled error
+        ipcMain.handle("updater:start-download", () => {})
+    }
+
+    // First check after startup delay
+    setTimeout(() => doCheck(false), STARTUP_DELAY)
+
+    // Periodic checks
+    setInterval(() => doCheck(false), CHECK_INTERVAL)
+}
+
+/**
+ * Manual update check from menu item
+ */
+export function checkForUpdatesManual() {
+    if (!app.isPackaged) {
+        dialog.showMessageBox({
+            type: "info",
+            title: "Development Mode",
+            message: "Auto-update is not available in development mode.",
+        })
+        return
+    }
+    doCheck(true)
+}

electron/main/index.ts

@@ -1,5 +1,6 @@
 import { app, BrowserWindow, dialog, shell } from "electron"
 import { buildAppMenu } from "./app-menu"
+import { initAutoUpdater } from "./auto-updater"
 import { getCurrentPresetEnv } from "./config-manager"
 import { loadEnvFile } from "./env-loader"
 import { registerIpcHandlers } from "./ipc-handlers"
@@ -58,6 +59,11 @@ if (!gotTheLock) {
 
             // Create main window
             createWindow(serverUrl)
+
+            // Initialize auto-updater (production only)
+            if (!isDev) {
+                initAutoUpdater()
+            }
         } catch (error) {
             console.error("Failed to start application:", error)
             dialog.showErrorBox(

electron/main/menu-i18n.ts

@@ -33,6 +33,7 @@ export interface MenuTranslations {
     help: string
     documentation: string
     reportIssue: string
+    checkForUpdates: string
 }
 
 const translations: Record<MenuLocale, MenuTranslations> = {
@@ -62,6 +63,7 @@ const translations: Record<MenuLocale, MenuTranslations> = {
         help: "Help",
         documentation: "Documentation",
         reportIssue: "Report Issue",
+        checkForUpdates: "Check for Updates...",
     },
 
     zh: {
@@ -90,6 +92,7 @@ const translations: Record<MenuLocale, MenuTranslations> = {
         help: "帮助",
         documentation: "文档",
         reportIssue: "报告问题",
+        checkForUpdates: "检查更新...",
     },
 
     ja: {
@@ -118,6 +121,7 @@ const translations: Record<MenuLocale, MenuTranslations> = {
         help: "ヘルプ",
         documentation: "ドキュメント",
         reportIssue: "問題を報告",
+        checkForUpdates: "アップデートを確認...",
     },
 
     "zh-Hant": {
@@ -146,6 +150,7 @@ const translations: Record<MenuLocale, MenuTranslations> = {
         help: "說明",
         documentation: "文件",
         reportIssue: "回報問題",
+        checkForUpdates: "檢查更新...",
     },
 }
 

electron/preload/index.ts

@@ -1,4 +1,4 @@
-import { contextBridge, ipcRenderer } from "electron"
+import { contextBridge, type IpcRendererEvent, ipcRenderer } from "electron"
 
 /**
  * Expose safe APIs to the renderer process
@@ -31,4 +31,13 @@ contextBridge.exposeInMainWorld("electronAPI", {
     getUserLocale: () => ipcRenderer.invoke("get-user-locale"),
     setUserLocale: (locale: string) =>
         ipcRenderer.invoke("set-user-locale", locale),
+
+    // Auto-update
+    onUpdateStatus: (callback: (data: UpdateStatusData) => void) => {
+        const handler = (_event: IpcRendererEvent, data: UpdateStatusData) =>
+            callback(data)
+        ipcRenderer.on("update-status", handler)
+        return () => ipcRenderer.removeListener("update-status", handler)
+    },
+    startDownload: () => ipcRenderer.invoke("updater:start-download"),
 })