feat: add proxy settings to Settings dialog (Desktop only) (#537)

* feat: add proxy settings to Settings dialog (Desktop only)

Fixes #535 - Desktop app now respects HTTP/HTTPS proxy configuration.

- Add proxy-manager.ts to handle proxy config storage (JSON file in userData)
- Load proxy settings on app startup before Next.js server starts
- Add IPC handlers for get-proxy and set-proxy
- Add proxy settings UI in Settings dialog (Electron only)
- Add translations for en/zh/ja

* fix: improve proxy settings reliability and simplify UI

- Fix server restart race condition (wait for process exit before starting new server)
- Add URL validation (must include http:// or https:// prefix)
- Enable Node.js built-in proxy support (NODE_USE_ENV_PROXY=1)
- Remove "Proxy Exceptions" field (unnecessary for this app)
- Add debug logging for proxy env vars

* refactor: remove duplicate ProxyConfig interface, import from electron.d.ts

electron/main/index.ts

@@ -4,6 +4,7 @@ import { getCurrentPresetEnv } from "./config-manager"
 import { loadEnvFile } from "./env-loader"
 import { registerIpcHandlers } from "./ipc-handlers"
 import { startNextServer, stopNextServer } from "./next-server"
+import { applyProxyToEnv } from "./proxy-manager"
 import { registerSettingsWindowHandlers } from "./settings-window"
 import { createWindow, getMainWindow } from "./window-manager"
 
@@ -24,6 +25,9 @@ if (!gotTheLock) {
     // Load environment variables from .env files
     loadEnvFile()
 
+    // Apply proxy settings from saved config
+    applyProxyToEnv()
+
     // Apply saved preset environment variables (overrides .env)
     const presetEnv = getCurrentPresetEnv()
     for (const [key, value] of Object.entries(presetEnv)) {

electron/main/ipc-handlers.ts

@@ -11,6 +11,12 @@ import {
     updatePreset,
 } from "./config-manager"
 import { restartNextServer } from "./next-server"
+import {
+    applyProxyToEnv,
+    getProxyConfig,
+    type ProxyConfig,
+    saveProxyConfig,
+} from "./proxy-manager"
 
 /**
  * Allowed configuration keys for presets
@@ -209,4 +215,40 @@ export function registerIpcHandlers(): void {
             return setCurrentPreset(id)
         },
     )
+
+    // ==================== Proxy Settings ====================
+
+    ipcMain.handle("get-proxy", () => {
+        return getProxyConfig()
+    })
+
+    ipcMain.handle("set-proxy", async (_event, config: ProxyConfig) => {
+        try {
+            // Save config to file
+            saveProxyConfig(config)
+
+            // Apply to current process environment
+            applyProxyToEnv()
+
+            const isDev = process.env.NODE_ENV === "development"
+
+            if (isDev) {
+                // In development, env vars are already applied
+                // Next.js dev server may need manual restart
+                return { success: true, devMode: true }
+            }
+
+            // Production: restart Next.js server to pick up new env vars
+            await restartNextServer()
+            return { success: true }
+        } catch (error) {
+            return {
+                success: false,
+                error:
+                    error instanceof Error
+                        ? error.message
+                        : "Failed to apply proxy settings",
+            }
+        }
+    })
 }

electron/main/next-server.ts

@@ -69,6 +69,8 @@ export async function startNextServer(): Promise<string> {
         NODE_ENV: "production",
         PORT: String(port),
         HOSTNAME: "localhost",
+        // Enable Node.js built-in proxy support for fetch (Node.js 24+)
+        NODE_USE_ENV_PROXY: "1",
     }
 
     // Set cache directory to a writable location (user's app data folder)
@@ -85,6 +87,13 @@ export async function startNextServer(): Promise<string> {
         }
     }
 
+    // Debug: log proxy-related env vars
+    console.log("Proxy env vars being passed to server:", {
+        HTTP_PROXY: env.HTTP_PROXY || env.http_proxy || "not set",
+        HTTPS_PROXY: env.HTTPS_PROXY || env.https_proxy || "not set",
+        NODE_USE_ENV_PROXY: env.NODE_USE_ENV_PROXY || "not set",
+    })
+
     // Use Electron's utilityProcess API for running Node.js in background
     // This is the recommended way to run Node.js code in Electron
     serverProcess = utilityProcess.fork(serverPath, [], {
@@ -114,13 +123,41 @@ export async function startNextServer(): Promise<string> {
 }
 
 /**
- * Stop the Next.js server process
+ * Stop the Next.js server process and wait for it to exit
  */
-export function stopNextServer(): void {
+export async function stopNextServer(): Promise<void> {
     if (serverProcess) {
         console.log("Stopping Next.js server...")
+
+        // Create a promise that resolves when the process exits
+        const exitPromise = new Promise<void>((resolve) => {
+            const proc = serverProcess
+            if (!proc) {
+                resolve()
+                return
+            }
+
+            const onExit = () => {
+                resolve()
+            }
+
+            proc.once("exit", onExit)
+
+            // Timeout after 5 seconds
+            setTimeout(() => {
+                proc.removeListener("exit", onExit)
+                resolve()
+            }, 5000)
+        })
+
         serverProcess.kill()
         serverProcess = null
+
+        // Wait for process to exit
+        await exitPromise
+
+        // Additional wait for OS to release port
+        await new Promise((resolve) => setTimeout(resolve, 500))
     }
 }
 
@@ -150,8 +187,8 @@ async function waitForServerStop(timeout = 5000): Promise<void> {
 export async function restartNextServer(): Promise<string> {
     console.log("Restarting Next.js server...")
 
-    // Stop the current server
-    stopNextServer()
+    // Stop the current server and wait for it to exit
+    await stopNextServer()
 
     // Wait for the port to be released
     await waitForServerStop()

electron/main/proxy-manager.ts

@@ -0,0 +1,75 @@
+import { app } from "electron"
+import * as fs from "fs"
+import * as path from "path"
+import type { ProxyConfig } from "../electron.d"
+
+export type { ProxyConfig }
+
+const CONFIG_FILE = "proxy-config.json"
+
+function getConfigPath(): string {
+    return path.join(app.getPath("userData"), CONFIG_FILE)
+}
+
+/**
+ * Load proxy configuration from JSON file
+ */
+export function loadProxyConfig(): ProxyConfig {
+    try {
+        const configPath = getConfigPath()
+        if (fs.existsSync(configPath)) {
+            const data = fs.readFileSync(configPath, "utf-8")
+            return JSON.parse(data) as ProxyConfig
+        }
+    } catch (error) {
+        console.error("Failed to load proxy config:", error)
+    }
+    return {}
+}
+
+/**
+ * Save proxy configuration to JSON file
+ */
+export function saveProxyConfig(config: ProxyConfig): void {
+    try {
+        const configPath = getConfigPath()
+        fs.writeFileSync(configPath, JSON.stringify(config, null, 2), "utf-8")
+    } catch (error) {
+        console.error("Failed to save proxy config:", error)
+        throw error
+    }
+}
+
+/**
+ * Apply proxy configuration to process.env
+ * Must be called BEFORE starting the Next.js server
+ */
+export function applyProxyToEnv(): void {
+    const config = loadProxyConfig()
+
+    if (config.httpProxy) {
+        process.env.HTTP_PROXY = config.httpProxy
+        process.env.http_proxy = config.httpProxy
+    } else {
+        delete process.env.HTTP_PROXY
+        delete process.env.http_proxy
+    }
+
+    if (config.httpsProxy) {
+        process.env.HTTPS_PROXY = config.httpsProxy
+        process.env.https_proxy = config.httpsProxy
+    } else {
+        delete process.env.HTTPS_PROXY
+        delete process.env.https_proxy
+    }
+}
+
+/**
+ * Get current proxy configuration (from process.env)
+ */
+export function getProxyConfig(): ProxyConfig {
+    return {
+        httpProxy: process.env.HTTP_PROXY || process.env.http_proxy || "",
+        httpsProxy: process.env.HTTPS_PROXY || process.env.https_proxy || "",
+    }
+}