Merge main into devices: MCP, analytics, Mac view alongside several headsets

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

app/main.js

@@ -10,6 +10,7 @@ const net = require("net");
 const os = require("os");
 const path = require("path");
 const { SCHEME, parseInstallLink, linkFromArgv } = require("./install-link");
+const updater = require("./updater");
 
 const run = promisify(execFile);
 
@@ -114,7 +115,11 @@ function ping(target) {
 }
 
 async function startServer() {
+  // The version and whether this is a built app go to ui/frame_telemetry.py, which
+  // sends nothing from a source checkout.
   const env = { ...process.env, PATH: await loginPath(), FRAME_CONTROL_APP: "1",
+                FRAME_CONTROL_VERSION: app.getVersion(), FRAME_CONTROL_LOG: LOG,
+                ...(app.isPackaged ? { FRAME_CONTROL_PACKAGED: "1" } : {}),
                 ...(fs.existsSync(TOOLS) ? { FRAME_CONTROL_TOOLS: TOOLS } : {}) };
   python = await findPython(env);
   if (!python) throw new Error(`Frame Control needs Python 3.8 or later. ${PYTHON_HELP}`);
@@ -260,6 +265,9 @@ function fromUi(e) {
 
 ipcMain.handle("clipboard:read", (e) => fromUi(e) ? clipboard.readText() : "");
 ipcMain.handle("connection:setup", (e) => { if (fromUi(e)) setUpConnection(); });
+ipcMain.handle("update:get", (e) => fromUi(e) ? publicUpdate() : null);
+ipcMain.handle("update:check", (e) => fromUi(e) ? checkForUpdate({ manual: true }).then(publicUpdate) : null);
+ipcMain.handle("update:install", (e) => { if (fromUi(e)) installUpdate(); });
 
 // The page reports the headsets it knows (the server's Devices tab), so the Frame
 // menu can switch between them. Only plain names and ids go into the menu.
@@ -332,6 +340,81 @@ ipcMain.on("install-link:ready", (e) => {
   deliverLinks();
 });
 
+// ---- updates (app/updater.js, docs/releasing.md) ----
+// Checked shortly after launch and every few hours; the page shows a banner and
+// the Update button calls installUpdate.
+const UPDATE_EVERY = 6 * 3600 * 1000;
+const update = { status: "idle", current: app.getVersion(), latest: null, error: null, progress: 0, how: null };
+
+function publicUpdate() {
+  const r = update.latest;
+  return { status: update.status, current: update.current, error: update.error, progress: update.progress,
+           latest: r && { version: r.version, notes: r.notes, page: r.page },
+           canInstall: !!update.how && update.how.method !== "manual", why: update.how && update.how.why };
+}
+
+function setUpdate(fields) {
+  Object.assign(update, fields);
+  if (win && linkPage === win.webContents) win.webContents.send("update:state", publicUpdate());
+}
+
+async function checkForUpdate({ manual = false } = {}) {
+  if (["checking", "downloading", "ready"].includes(update.status)) return;
+  setUpdate({ status: "checking", error: null });
+  try {
+    const latest = await updater.latestRelease();
+    const how = updater.updateMethod({ platform: process.platform, isPackaged: app.isPackaged,
+                                       execPath: process.execPath, env: process.env,
+                                       exists: fs.existsSync, writable: updater.writable });
+    if (updater.isNewer(latest.version, update.current)) {
+      setUpdate({ status: "available", latest, how });
+      if (manual) offerUpdateDialog();
+    } else {
+      setUpdate({ status: "none", latest, how });
+      if (manual) dialog.showMessageBox(win, { type: "info", message: "Frame Control is up to date",
+                                               detail: `You have ${update.current}, the newest version.` });
+    }
+  } catch (e) {
+    // A failed check: nothing to install, and never an older release kept from before.
+    setUpdate({ status: "check-failed", error: e.message, latest: null });
+    if (manual) dialog.showMessageBox(win, { type: "warning", message: "Couldn't check for updates", detail: e.message });
+  }
+}
+
+async function offerUpdateDialog() {
+  const r = update.latest;
+  const { response } = await dialog.showMessageBox(win, {
+    type: "info", message: `Frame Control ${r.version} is available`,
+    detail: `You have ${update.current}.` + (update.how.method === "manual" ? ` Download it from the release page (${update.how.why}).` : ""),
+    buttons: [update.how.method === "manual" ? "Open Release Page" : "Update and Restart", "Later"], defaultId: 0, cancelId: 1,
+  });
+  if (response === 0) installUpdate();
+}
+
+async function installUpdate() {
+  // "error" here only ever means an install failed, so trying again is safe.
+  if (update.status !== "available" && update.status !== "error") return;
+  if (!update.latest || !updater.isNewer(update.latest.version, update.current)) return;
+  if (!update.how || update.how.method === "manual") { shell.openExternal(update.latest.page); return; }
+  setUpdate({ status: "downloading", progress: 0, error: null });
+  try {
+    const start = await updater.prepare(update.latest, update.how,
+      (done, total) => { if (total) setUpdate({ progress: done / total }); }, update.current);
+    setUpdate({ status: "ready", progress: 1 });
+    start();
+    quitting = true;
+    app.quit();
+  } catch (e) {
+    setUpdate({ status: "error", error: e.message });
+  }
+}
+
+function scheduleUpdateChecks() {
+  if (process.env.FRAME_CONTROL_NO_UPDATE_CHECK === "1") return;
+  setTimeout(checkForUpdate, 8000);
+  setInterval(checkForUpdate, UPDATE_EVERY).unref();
+}
+
 function registerScheme() {
   // A checkout runs as `electron .`, so the OS must be told the script too.
   // (macOS takes the scheme from Info.plist, which only the built app has.)
@@ -394,7 +477,11 @@ async function setUpConnection(name = activeAlias()) {
 
 function buildMenu() {
   const template = [
-    ...(IS_MAC ? [{ role: "appMenu" }] : []),
+    ...(IS_MAC ? [{ label: app.name, submenu: [
+      { role: "about" }, { label: "Check for Updates…", click: () => checkForUpdate({ manual: true }) },
+      { type: "separator" }, { role: "services" }, { type: "separator" },
+      { role: "hide" }, { role: "hideOthers" }, { role: "unhide" }, { type: "separator" }, { role: "quit" },
+    ] }] : []),
     { role: "fileMenu" },
     { role: "editMenu" },
     {
@@ -428,7 +515,15 @@ function buildMenu() {
     ...(IS_MAC ? [{ role: "windowMenu" }] : []),
     {
       role: "help",
-      submenu: [{ label: "Project on GitHub", click: () => shell.openExternal("https://github.com/saphid/steam-frame") }],
+      submenu: [
+        ...(IS_MAC ? [] : [{ label: "Check for Updates…", click: () => checkForUpdate({ manual: true }) }]),
+        { label: "Report a Problem…", click: () => {
+          if (win && url && linkPage === win.webContents) win.webContents.send("report:open");
+          else shell.openExternal("https://frame-control.pages.dev/feedback/");  // the page isn't up
+        } },
+        { label: "Release Notes", click: () => shell.openExternal(updater.RELEASES) },
+        { label: "Project on GitHub", click: () => shell.openExternal("https://github.com/saphid/steam-frame") },
+      ],
     },
   ];
   Menu.setApplicationMenu(Menu.buildFromTemplate(template));
@@ -451,6 +546,7 @@ if (!app.requestSingleInstanceLock()) {
     registerScheme();
     buildMenu();
     createWindow();
+    scheduleUpdateChecks();
   });
   app.on("activate", () => { if (!win) createWindow(); });
   app.on("window-all-closed", () => app.quit());

app/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "frame-control",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "frame-control",
-      "version": "0.3.1",
+      "version": "0.4.0",
       "license": "MIT",
       "devDependencies": {
         "electron": "^44.4.5",

app/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frame-control",
   "productName": "Frame Control",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "Desktop app for managing a Valve Steam Frame over SSH",
   "private": true,
   "main": "main.js",
@@ -9,8 +9,8 @@
   "scripts": {
     "start": "env -u ELECTRON_RUN_AS_NODE electron .",
     "icon": "env -u ELECTRON_RUN_AS_NODE electron build/make-icon.js",
-    "dist": "node build/fetch-deps.js mac arm64 && electron-builder --mac --arm64 --publish never",
-    "dist:dir": "node build/fetch-deps.js mac arm64 && electron-builder --mac --arm64 --dir",
+    "dist": "sh ../mac/frame-mac-view/build.sh && node build/fetch-deps.js mac arm64 && electron-builder --mac --arm64 --publish never",
+    "dist:dir": "sh ../mac/frame-mac-view/build.sh && node build/fetch-deps.js mac arm64 && electron-builder --mac --arm64 --dir",
     "dist:linux": "node build/fetch-deps.js linux x64 arm64 && electron-builder --linux --x64 --arm64 --publish never",
     "dist:win": "node build/fetch-deps.js win x64 && electron-builder --win --x64 --publish never"
   },
@@ -37,6 +37,7 @@
       "main.js",
       "preload.js",
       "install-link.js",
+      "updater.js",
       "package.json",
       "build/icon.png"
     ],
@@ -46,7 +47,8 @@
         "to": "ui",
         "filter": [
           "*.py",
-          "*.html"
+          "*.html",
+          "telemetry.json"
         ]
       },
       {
@@ -105,9 +107,19 @@
         "dmg",
         "zip"
       ],
+      "extraResources": [
+        {
+          "from": "../mac/bin",
+          "to": "mac/bin",
+          "filter": [
+            "frame-mac-view"
+          ]
+        }
+      ],
       "extendInfo": {
         "NSAppleEventsUsageDescription": "Frame Control opens Terminal for SSH sessions and for power actions that need the Developer Mode password.",
-        "NSLocalNetworkUsageDescription": "Frame Control connects to your Steam Frame over SSH on the local network."
+        "NSLocalNetworkUsageDescription": "Frame Control connects to your Steam Frame over SSH on the local network.",
+        "NSScreenCaptureUsageDescription": "Frame Control shows your Mac's windows and screens inside the Steam Frame when you ask it to."
       },
       "artifactName": "Frame-Control-mac-${arch}.${ext}"
     },

app/preload.js

@@ -6,6 +6,7 @@
 // Frame menu's list of headsets up to date.
 // It also receives frame-control://install links (docs/web-install.md): only
 // what the link asked for, never an install; the page asks the user first.
+// And it passes update state both ways: see app/updater.js.
 const { contextBridge, ipcRenderer, webUtils } = require("electron");
 
 contextBridge.exposeInMainWorld("frameApp", {
@@ -18,6 +19,21 @@ contextBridge.exposeInMainWorld("frameApp", {
     ipcRenderer.on("use-device", (_e, id) => cb(String(id)));
   },
   pathForFile: (file) => { try { return webUtils.getPathForFile(file) || ""; } catch { return ""; } },
+  // Updates (app/updater.js): the page shows a banner and an Update button.
+  update: {
+    get: () => ipcRenderer.invoke("update:get"),
+    check: () => ipcRenderer.invoke("update:check"),
+    install: () => ipcRenderer.invoke("update:install"),
+    onState: (cb) => {
+      ipcRenderer.removeAllListeners("update:state");
+      ipcRenderer.on("update:state", (_e, s) => cb(s));
+    },
+  },
+  // Help → Report a Problem… opens the page's report dialog (ui/frame_report.py).
+  onReportProblem: (cb) => {
+    ipcRenderer.removeAllListeners("report:open");
+    ipcRenderer.on("report:open", () => cb());
+  },
   onInstallLink: (cb) => {
     ipcRenderer.removeAllListeners("install-link");
     ipcRenderer.on("install-link", (_e, req) => cb({ kind: req.kind, target: req.target }));

app/test/updater.test.js

@@ -0,0 +1,59 @@
+// Run: node --test app/test/
+const test = require("node:test");
+const assert = require("node:assert");
+const { isNewer, assetName, updateMethod, macBundle } = require("../updater");
+
+test("versions compare numerically, and a release beats its pre-releases", () => {
+  assert.ok(isNewer("0.3.10", "0.3.9"));
+  assert.ok(isNewer("v1.0.0", "0.9.9"));
+  assert.ok(!isNewer("0.3.1", "0.3.1"));
+  assert.ok(!isNewer("0.3.0", "0.3.1"));
+  assert.ok(isNewer("1.0.0", "1.0.0-beta.1"));
+  assert.ok(!isNewer("1.0.0-beta.1", "1.0.0"));
+  assert.ok(!isNewer("garbage", "0.1.0"));
+});
+
+test("asset names match what electron-builder publishes", () => {
+  assert.strictEqual(assetName("darwin", "arm64", "mac-zip"), "Frame-Control-mac-arm64.zip");
+  assert.strictEqual(assetName("win32", "x64", "nsis"), "Frame-Control-Setup-x64.exe");
+  assert.strictEqual(assetName("linux", "x64", "appimage"), "Frame-Control-linux-x86_64.AppImage");
+  assert.strictEqual(assetName("linux", "arm64", "appimage"), "Frame-Control-linux-arm64.AppImage");
+});
+
+const base = { isPackaged: true, env: {}, exists: () => false, writable: () => true };
+
+test("macOS updates in place only from a writable, non-translocated location", () => {
+  const exe = "/Applications/Frame Control.app/Contents/MacOS/Frame Control";
+  assert.strictEqual(macBundle(exe), "/Applications/Frame Control.app");
+  assert.deepStrictEqual(updateMethod({ ...base, platform: "darwin", execPath: exe }),
+                         { method: "mac-zip", bundle: "/Applications/Frame Control.app" });
+  const dmg = "/Volumes/Frame Control 0.3.1/Frame Control.app/Contents/MacOS/Frame Control";
+  assert.strictEqual(updateMethod({ ...base, platform: "darwin", execPath: dmg }).method, "manual");
+  const trans = "/private/var/folders/x/AppTranslocation/ABC/d/Frame Control.app/Contents/MacOS/Frame Control";
+  assert.strictEqual(updateMethod({ ...base, platform: "darwin", execPath: trans }).method, "manual");
+  assert.strictEqual(updateMethod({ ...base, platform: "darwin", execPath: exe, writable: () => false }).method, "manual");
+});
+
+test("Windows needs the installer's copy; Linux needs an AppImage", () => {
+  const exe = "C:\\Users\\a\\AppData\\Local\\Programs\\Frame Control\\Frame Control.exe";
+  assert.strictEqual(updateMethod({ ...base, platform: "win32", execPath: exe, exists: () => true }).method, "nsis");
+  assert.strictEqual(updateMethod({ ...base, platform: "win32", execPath: exe }).method, "manual");
+  assert.strictEqual(updateMethod({ ...base, platform: "linux", execPath: "/opt/x", env: { APPIMAGE: "/home/a/F.AppImage" } }).method,
+                     "appimage");
+  assert.strictEqual(updateMethod({ ...base, platform: "linux", execPath: "/opt/Frame Control/frame-control" }).method, "manual");
+  assert.strictEqual(updateMethod({ ...base, isPackaged: false, platform: "darwin", execPath: "x" }).method, "manual");
+});
+
+test("update.json assets always download from this repository's release", () => {
+  const r = require("../updater").fromManifest({ version: "0.4.0", notes: "n", assets: [
+    { name: "Frame-Control-mac-arm64.zip", url: "https://evil.example/x.zip", digest: "sha256:" + "a".repeat(64) }] });
+  assert.strictEqual(r.assets[0].url, "https://github.com/saphid/frame-control/releases/download/v0.4.0/Frame-Control-mac-arm64.zip");
+  assert.throws(() => require("../updater").fromManifest({ version: "nope", assets: [] }));
+});
+
+test("prepare refuses a release that isn't newer (no downgrades)", async () => {
+  const { prepare } = require("../updater");
+  const release = { version: "0.3.1", assets: [] };
+  await assert.rejects(prepare(release, { method: "appimage", appImage: "/nonexistent/x" }, null, "0.4.0"), /isn't newer/);
+  await assert.rejects(prepare(release, { method: "appimage", appImage: "/nonexistent/x" }, null, "0.3.1"), /isn't newer/);
+});

app/updater.js

@@ -0,0 +1,250 @@
+// Update checks and self-update for the desktop app (docs/releasing.md).
+//
+// The newest version is GitHub's "latest" release of saphid/frame-control. Drafts
+// and pre-releases never count, so a build reaches people only when the
+// maintainer publishes it after testing (scripts/publish-release.sh). That
+// script attaches update.json (version, notes, each asset's SHA-256), read
+// through github.com's latest/download link: the REST API allows only 60
+// unauthenticated requests an hour per IP address, shared by everyone behind
+// the same router, so it's only the fallback.
+//
+// Every download is checked against the SHA-256 digest GitHub records for the
+// asset before anything is replaced. How the update is applied:
+//   macOS     the .zip: unpacked next to the running app, swapped in by a small
+//             script once the app has quit, then reopened.
+//   Windows   the NSIS installer, run silently over the current install; it
+//             reopens the app. A copy unpacked from the .zip is updated by hand.
+//   Linux     the AppImage replaces itself; .deb installs are updated by hand.
+// When the app can't update itself it opens the release page instead.
+const { execFile, spawn } = require("child_process");
+const crypto = require("crypto");
+const fs = require("fs");
+const https = require("https");
+const os = require("os");
+const path = require("path");
+
+const REPO = "saphid/frame-control";  // renamed from saphid/steam-frame; GitHub redirects the old name
+const LATEST = `https://api.github.com/repos/${REPO}/releases/latest`;
+const MANIFEST = `https://github.com/${REPO}/releases/latest/download/update.json`;
+const RELEASES = `https://github.com/${REPO}/releases`;
+
+// "0.3.1" or "v0.3.1" -> [0, 3, 1]; pre-release suffixes sort before the release.
+function parseVersion(v) {
+  const m = String(v || "").trim().replace(/^v/i, "").match(/^(\d+)\.(\d+)\.(\d+)(?:-([0-9A-Za-z.-]+))?$/);
+  return m ? { nums: [+m[1], +m[2], +m[3]], pre: m[4] || null } : null;
+}
+
+function isNewer(candidate, current) {
+  const a = parseVersion(candidate), b = parseVersion(current);
+  if (!a || !b) return false;
+  for (let i = 0; i < 3; i++) if (a.nums[i] !== b.nums[i]) return a.nums[i] > b.nums[i];
+  if (a.pre === b.pre) return false;
+  if (!a.pre) return true;   // 1.0.0 is newer than 1.0.0-beta
+  if (!b.pre) return false;
+  return a.pre > b.pre;
+}
+
+// The asset this copy of the app updates from, by the names electron-builder gives them.
+function assetName(platform, arch, method) {
+  if (method === "mac-zip") return `Frame-Control-mac-${arch}.zip`;
+  if (method === "nsis") return `Frame-Control-Setup-${arch}.exe`;
+  if (method === "appimage") return `Frame-Control-linux-${arch === "x64" ? "x86_64" : arch}.AppImage`;
+  return null;
+}
+
+// How this copy can update itself: mac-zip, nsis, appimage, or manual (with why).
+function updateMethod({ platform, isPackaged, execPath, env, exists, writable }) {
+  if (!isPackaged) return { method: "manual", why: "running from a source checkout" };
+  if (platform === "darwin") {
+    const bundle = macBundle(execPath);
+    if (!bundle) return { method: "manual", why: "can't find the app bundle" };
+    if (bundle.includes("/AppTranslocation/") || bundle.startsWith("/Volumes/")) {
+      return { method: "manual", why: "move Frame Control to Applications first" };
+    }
+    if (!writable(path.dirname(bundle))) return { method: "manual", why: `${path.dirname(bundle)} isn't writable` };
+    return { method: "mac-zip", bundle };
+  }
+  if (platform === "win32") {
+    // electron-builder's NSIS install puts its uninstaller next to the app.
+    const dir = path.dirname(execPath);
+    if (exists(path.join(dir, "Uninstall Frame Control.exe"))) return { method: "nsis" };
+    return { method: "manual", why: "not installed with the installer" };
+  }
+  if (platform === "linux" && env.APPIMAGE) {
+    if (!writable(path.dirname(env.APPIMAGE))) return { method: "manual", why: "the AppImage's folder isn't writable" };
+    return { method: "appimage", appImage: env.APPIMAGE };
+  }
+  return { method: "manual", why: "installed from a package" };
+}
+
+function macBundle(execPath) {
+  const i = execPath.indexOf(".app/Contents/MacOS/");
+  return i < 0 ? null : execPath.slice(0, i + 4);
+}
+
+function get(url, { headers = {}, timeout = 20000, redirects = 5 } = {}) {
+  return new Promise((resolve, reject) => {
+    const req = https.get(url, { headers: { "user-agent": "FrameControl-updater", ...headers }, timeout }, (res) => {
+      if ([301, 302, 303, 307, 308].includes(res.statusCode) && res.headers.location && redirects > 0) {
+        res.resume();
+        const next = new URL(res.headers.location, url);
+        if (next.protocol !== "https:") return reject(new Error("refusing a non-HTTPS redirect"));
+        return resolve(get(next.href, { headers, timeout, redirects: redirects - 1 }));
+      }
+      if (res.statusCode !== 200) { res.resume(); return reject(new Error(`HTTP ${res.statusCode} from ${new URL(url).host}`)); }
+      resolve(res);
+    });
+    req.on("timeout", () => req.destroy(new Error("timed out")));
+    req.on("error", reject);
+  });
+}
+
+async function getJson(url, headers) {
+  const res = await get(url, { headers });
+  let body = "";
+  for await (const chunk of res) body += chunk;
+  return JSON.parse(body);
+}
+
+// update.json and the API's release both become { version, notes, page, assets }.
+function fromManifest(m) {
+  if (!parseVersion(m.version) || !Array.isArray(m.assets)) throw new Error("update.json is malformed");
+  const base = `https://github.com/${REPO}/releases/download/v${String(m.version).replace(/^v/i, "")}/`;
+  return { version: String(m.version).replace(/^v/i, ""), notes: String(m.notes || "").slice(0, 4000),
+           page: m.page || RELEASES,
+           // Assets always come from this repository's release, whatever the manifest says.
+           assets: m.assets.map((a) => ({ name: String(a.name), url: base + encodeURIComponent(String(a.name)),
+                                          size: a.size, digest: a.digest || null })) };
+}
+
+function fromApi(r) {
+  if (r.draft || r.prerelease) throw new Error("GitHub returned an unpublished release");
+  return { version: String(r.tag_name || "").replace(/^v/i, ""), notes: String(r.body || "").slice(0, 4000),
+           page: r.html_url || RELEASES,
+           assets: (r.assets || []).map((a) => ({ name: a.name, url: a.browser_download_url, size: a.size,
+                                                 digest: a.digest || null })) };
+}
+
+async function latestRelease() {
+  try {
+    return fromManifest(await getJson(MANIFEST));
+  } catch (e) {
+    if (!/HTTP 404/.test(e.message)) throw e;  // releases before update.json existed
+  }
+  return fromApi(await getJson(LATEST, { accept: "application/vnd.github+json" }));
+}
+
+async function download(asset, dest, onProgress) {
+  const m = /^sha256:([0-9a-f]{64})$/.exec(asset.digest || "");
+  if (!m) throw new Error(`GitHub has no SHA-256 for ${asset.name}, so it can't be checked`);
+  const res = await get(asset.url, { timeout: 60000 });
+  const total = +res.headers["content-length"] || asset.size || 0;
+  const hash = crypto.createHash("sha256");
+  // "wx": a new file only, never through an existing file or symlink at that path.
+  const out = fs.createWriteStream(dest, { mode: 0o755, flags: "wx" });
+  let done = 0;
+  await new Promise((resolve, reject) => {
+    res.on("data", (chunk) => { hash.update(chunk); done += chunk.length; onProgress && onProgress(done, total); });
+    res.on("error", reject);
+    out.on("error", reject);
+    out.on("finish", resolve);
+    res.pipe(out);
+  });
+  if (hash.digest("hex") !== m[1]) {
+    fs.rmSync(dest, { force: true });
+    throw new Error(`${asset.name} didn't match its SHA-256; nothing was changed`);
+  }
+}
+
+const run = (cmd, args) => new Promise((resolve, reject) =>
+  execFile(cmd, args, { timeout: 120000 }, (err, stdout, stderr) => err ? reject(new Error((stderr || err.message).trim())) : resolve(stdout)));
+
+// Waits for this process to exit, swaps the new bundle in (putting the old one
+// back if that fails), and reopens the app.
+const MAC_SWAP = `set -u
+pid="$1"; app="$2"; new="$3"; stage="$4"
+while kill -0 "$pid" 2>/dev/null; do sleep 0.2; done
+old="$stage/old.app"
+if mv "$app" "$old"; then
+  if mv "$new" "$app"; then rm -rf "$old"; else mv "$old" "$app"; fi
+fi
+xattr -dr com.apple.quarantine "$app" 2>/dev/null
+rm -rf "$stage"
+open "$app"
+`;
+
+async function applyMac(release, bundle, onProgress) {
+  const asset = release.assets.find((a) => a.name === assetName("darwin", process.arch, "mac-zip"));
+  if (!asset) throw new Error(`the release has no ${assetName("darwin", process.arch, "mac-zip")}`);
+  // Staged beside the app, so the final move stays on one volume.
+  const stage = fs.mkdtempSync(path.join(path.dirname(bundle), ".frame-control-update-"));
+  try {
+    const zip = path.join(stage, asset.name);
+    await download(asset, zip, onProgress);
+    await run("/usr/bin/ditto", ["-x", "-k", zip, stage]);
+    fs.rmSync(zip, { force: true });
+    const name = fs.readdirSync(stage).find((n) => n.endsWith(".app"));
+    if (!name) throw new Error("the download has no app in it");
+    const fresh = path.join(stage, name);
+    const version = (await run("/usr/bin/plutil", ["-extract", "CFBundleShortVersionString", "raw",
+                                                   path.join(fresh, "Contents", "Info.plist")])).trim();
+    if (version !== release.version) throw new Error(`the download is version ${version}, not ${release.version}`);
+    const script = path.join(stage, "swap.sh");
+    fs.writeFileSync(script, MAC_SWAP);
+    return () => spawn("/bin/sh", [script, String(process.pid), bundle, fresh, stage],
+                       { detached: true, stdio: "ignore" }).unref();
+  } catch (e) {
+    fs.rmSync(stage, { recursive: true, force: true });
+    throw e;
+  }
+}
+
+async function applyNsis(release, onProgress) {
+  const asset = release.assets.find((a) => a.name === assetName("win32", process.arch, "nsis"));
+  if (!asset) throw new Error(`the release has no ${assetName("win32", process.arch, "nsis")}`);
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), "frame-control-update-"));
+  const exe = path.join(dir, asset.name);
+  await download(asset, exe, onProgress);
+  // /S: silent, into the existing install. --force-run: open the app afterwards.
+  return () => spawn(exe, ["--updated", "/S", "--force-run"], { detached: true, stdio: "ignore" }).unref();
+}
+
+async function applyAppImage(release, appImage, onProgress) {
+  const asset = release.assets.find((a) => a.name === assetName("linux", process.arch, "appimage"));
+  if (!asset) throw new Error(`the release has no ${assetName("linux", process.arch, "appimage")}`);
+  // A private folder beside the AppImage, so the final rename stays on one filesystem.
+  const stage = fs.mkdtempSync(path.join(path.dirname(appImage), ".frame-control-update-"));
+  try {
+    const next = path.join(stage, asset.name);
+    await download(asset, next, onProgress);
+    fs.chmodSync(next, 0o755);
+    fs.renameSync(next, appImage);  // the running copy keeps its open file
+  } finally {
+    fs.rmSync(stage, { recursive: true, force: true });
+  }
+  // Without FUSE the AppImage runs extracted (--appimage-extract-and-run, which isn't passed
+  // on to the app); a FUSE mount lives under /tmp/.mount_*. Keep the same mode on restart.
+  const extracted = process.env.APPIMAGE_EXTRACT_AND_RUN === "1" || !process.execPath.includes("/.mount_");
+  const env = { ...process.env, APPIMAGE: appImage, ...(extracted ? { APPIMAGE_EXTRACT_AND_RUN: "1" } : {}) };
+  // Started only once this process has exited, or the new copy would lose the single-instance lock.
+  return () => spawn("/bin/sh", ["-c", 'while kill -0 "$1" 2>/dev/null; do sleep 0.2; done; exec "$2"',
+                                 "sh", String(process.pid), appImage], { detached: true, stdio: "ignore", env }).unref();
+}
+
+// Downloads and prepares the update; returns a function that starts the swap,
+// to be called just before the app quits.
+async function prepare(release, how, onProgress, current) {
+  if (!isNewer(release.version, current)) throw new Error(`${release.version} isn't newer than ${current}`);
+  if (how.method === "mac-zip") return applyMac(release, how.bundle, onProgress);
+  if (how.method === "nsis") return applyNsis(release, onProgress);
+  if (how.method === "appimage") return applyAppImage(release, how.appImage, onProgress);
+  throw new Error(how.why || "this copy can't update itself");
+}
+
+function writable(dir) {
+  try { fs.accessSync(dir, fs.constants.W_OK); return true; } catch { return false; }
+}
+
+module.exports = { REPO, RELEASES, parseVersion, isNewer, assetName, updateMethod, macBundle, latestRelease,
+                   fromManifest, fromApi,
+                   download, prepare, writable };