Scaffold ipswap: tray-driven Windows IP preset switcher

Implements the design in claude.md as a building skeleton: pure Go, no cgo, cross-compiles to a single Windows .exe from Linux. Architecture follows the spec's deliberate split. The fast path is native — tray icon, grouped submenus, a Win32 MessageBox showing a live before/after diff, then netsh. The slow path is an embedded web editor served on a random loopback port and opened in the default browser. Two decisions worth recording: Reads use GetAdaptersAddresses, writes use netsh. The spec left the enumeration mechanism open; parsing `netsh show config` breaks on a non-English Windows because the output is localised. DNS static-vs-DHCP origin is not exposed by that API, so it comes from one registry read. The netsh command plan is built in portable code. That puts the delete-every- existing-address step — the one that stops secondary addresses leaking across switches — under test without needing a Windows box. The editor requires the session token in a header for mutations, not just the cookie: any page in the browser can make it POST to 127.0.0.1 with the cookie attached, but it cannot set a header. The updater refuses to install a release that publishes no SHA256. Not yet done: no group picker for export (the API supports it), no single-instance guard, and internal/server/web/app.css is reconstructed from the description in claude.md rather than the canonical apointless.css. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-20 13:29:35 +10:00
commit 23dcfb393f
46 changed files with 5782 additions and 0 deletions
@@ -0,0 +1,13 @@
+//go:build !windows
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+// showFatal prints, since a development build on Linux has a console.
+func showFatal(msg string) {
+	fmt.Fprintln(os.Stderr, msg)
+}
@@ -0,0 +1,11 @@
+//go:build windows
+
+package main
+
+import "gitea.apointless.space/bsncubed/ipswap/internal/dialog"
+
+// showFatal puts a startup failure on screen. Without this the binary would
+// simply not appear: -H windowsgui means there is no console to print to.
+func showFatal(msg string) {
+	dialog.Error("ipswap", msg)
+}
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+  <assemblyIdentity
+      type="win32"
+      name="space.apointless.ipswap"
+      version="1.0.0.0"
+      processorArchitecture="*"/>
+
+  <!--
+    asInvoker, NOT requireAdministrator.
+
+    requireAdministrator would put a UAC prompt in front of every launch,
+    including the ones that start with Windows. asInvoker means zero prompts on
+    a machine with UAC relaxed or an already-elevated parent, and on a
+    locked-down machine ipswap still starts — it just offers "Relaunch as
+    administrator" in the tray and when an apply is refused.
+  -->
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges>
+        <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+  <!-- Per-monitor v2 so the confirmation MessageBox is not blurry on a scaled
+       laptop panel driving an unscaled external monitor. -->
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings>
+      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/pm</dpiAware>
+      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2, PerMonitor</dpiAwareness>
+      <activeCodePage xmlns="http://schemas.microsoft.com/SMI/2019/WindowsSettings">UTF-8</activeCodePage>
+    </windowsSettings>
+  </application>
+
+  <!-- Common Controls v6, so the message boxes use the modern theme. -->
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity
+          type="win32"
+          name="Microsoft.Windows.Common-Controls"
+          version="6.0.0.0"
+          processorArchitecture="*"
+          publicKeyToken="6595b64144ccf1df"
+          language="*"/>
+    </dependentAssembly>
+  </dependency>
+
+  <!-- Declare support through Windows 11 so version APIs do not lie to us. -->
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/> <!-- 10 / 11 -->
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/> <!-- 8.1 -->
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/> <!-- 8 -->
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/> <!-- 7 -->
+    </application>
+  </compatibility>
+</assembly>
@@ -0,0 +1,96 @@
+// Command ipswap is a tray-resident switcher for saved static-IP presets.
+//
+// Build for Windows with:
+//
+//	GOOS=windows GOARCH=amd64 go build -ldflags "-H windowsgui -X main.version=1.0.0" ./cmd/ipswap
+//
+// -H windowsgui is what stops a console window appearing behind the tray icon.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"runtime"
+
+	"gitea.apointless.space/bsncubed/ipswap/internal/applog"
+	"gitea.apointless.space/bsncubed/ipswap/internal/config"
+	"gitea.apointless.space/bsncubed/ipswap/internal/desktop"
+	"gitea.apointless.space/bsncubed/ipswap/internal/elevate"
+	"gitea.apointless.space/bsncubed/ipswap/internal/netcfg"
+	"gitea.apointless.space/bsncubed/ipswap/internal/preset"
+	"gitea.apointless.space/bsncubed/ipswap/internal/server"
+	"gitea.apointless.space/bsncubed/ipswap/internal/tray"
+)
+
+// version is set at link time with -X main.version=...
+var version = "dev"
+
+func main() {
+	showVersion := flag.Bool("version", false, "print the version and exit")
+	flag.Parse()
+
+	if *showVersion {
+		fmt.Printf("%s %s\n", config.AppName, version)
+		return
+	}
+
+	if err := run(); err != nil {
+		// With -H windowsgui there is no stderr to read, so anything fatal has
+		// to be shown rather than printed.
+		fatal(err)
+	}
+}
+
+func run() error {
+	paths, err := config.ResolvePaths()
+	if err != nil {
+		return err
+	}
+
+	// The log is the only diagnostic available on a customer site, so it is
+	// set up before anything that could fail interestingly.
+	logw, err := applog.Setup(paths.Log, runtime.GOOS != "windows")
+	if err != nil {
+		return err
+	}
+	defer logw.Close()
+
+	log.Printf("--- %s %s starting (elevated=%v) ---", config.AppName, version, elevate.IsElevated())
+
+	settings, err := config.Load(paths.Config)
+	if err != nil {
+		// Settings are conveniences; a broken config.json must not stop the
+		// app from starting with defaults.
+		log.Printf("using default settings: %v", err)
+	}
+
+	store, err := preset.NewStore(paths.Presets)
+	if err != nil {
+		return fmt.Errorf("loading presets: %w", err)
+	}
+	log.Printf("loaded %d preset(s) from %s", len(store.All()), paths.Presets)
+
+	// Keep the Run key in step with the setting: the user may have removed the
+	// entry by other means, or copied config.json onto a new machine.
+	if desktop.RunAtLogin() != settings.StartWithWindows {
+		if err := desktop.SetRunAtLogin(settings.StartWithWindows); err != nil {
+			log.Printf("could not update the start-with-Windows entry: %v", err)
+		}
+	}
+
+	mgr := netcfg.New()
+	srv := server.New(store, mgr, paths, settings)
+	app := tray.New(store, mgr, srv, paths, settings, version)
+
+	// systray.Run takes over this goroutine and does not return until Exit.
+	app.Run()
+	return nil
+}
+
+func fatal(err error) {
+	log.Printf("fatal: %v", err)
+	showFatal(fmt.Sprintf("%s could not start.\n\n%v", config.AppName, err))
+	os.Exit(1)
+}
@@ -0,0 +1,25 @@
+{
+  "FixedFileInfo": {
+    "FileVersion": { "Major": 0, "Minor": 1, "Patch": 0, "Build": 0 },
+    "ProductVersion": { "Major": 0, "Minor": 1, "Patch": 0, "Build": 0 },
+    "FileFlagsMask": "3f",
+    "FileFlags": "00",
+    "FileOS": "040004",
+    "FileType": "01",
+    "FileSubType": "00"
+  },
+  "StringFileInfo": {
+    "CompanyName": "apointless.space",
+    "FileDescription": "ipswap — network preset switcher",
+    "InternalName": "ipswap",
+    "LegalCopyright": "",
+    "OriginalFilename": "ipswap.exe",
+    "ProductName": "ipswap",
+    "ProductVersion": "0.1.0"
+  },
+  "VarFileInfo": {
+    "Translation": { "LangID": "0409", "CharsetID": "04B0" }
+  },
+  "IconPath": "../../internal/tray/icon.ico",
+  "ManifestPath": "ipswap.manifest"
+}