Add app version management, update checks, and periodic SW updates

- Introduced version.json and appVersionAssetPlugin for build-time version tracking.
- Enhanced settings page with update check/status UI.
- Refactored bootstrap to handle SW updates and initiate periodic checks.

src/app/bootstrap.js

@@ -9,24 +9,201 @@ import { appShell } from '../components/app-shell.js';
 import { navBar } from '../components/nav-bar.js';
 import { registerFeatureData } from '../features/register.js';
 
-async function installServiceWorker() {
-  if (!('serviceWorker' in navigator)) {
-    return;
+const APP_UPDATE_CHECK_INTERVAL_MS = 5 * 60 * 1000;
+
+function createAppUpdateManager() {
+  let registration = null;
+  let waitingWorker = null;
+
+  async function fetchServerVersion() {
+    try {
+      const response = await fetch(`/version.json?ts=${Date.now()}`, {
+        cache: 'no-store',
+        headers: {
+          'cache-control': 'no-cache',
+          pragma: 'no-cache',
+        },
+      });
+
+      if (!response.ok) {
+        throw new Error(`Version endpoint failed with HTTP ${response.status}`);
+      }
+
+      const payload = await response.json();
+      const serverVersion = String(payload?.version || '').trim();
+      const serverBuildTime = String(payload?.buildTime || '').trim();
+
+      return {
+        serverVersion: serverVersion || null,
+        serverBuildTime: serverBuildTime || null,
+      };
+    } catch (error) {
+      return {
+        serverVersion: null,
+        serverBuildTime: null,
+        error: error instanceof Error ? error.message : 'Unable to reach version endpoint.',
+      };
+    }
   }
 
-  if (import.meta.env.DEV) {
-    const registrations = await navigator.serviceWorker.getRegistrations();
-    await Promise.all(registrations.map((registration) => registration.unregister()));
-    return;
+  function syncWaitingWorker() {
+    waitingWorker = registration?.waiting || null;
   }
 
-  await navigator.serviceWorker.register('/service-worker.js');
+  function setupRegistrationHooks() {
+    if (!registration) {
+      return;
+    }
+
+    syncWaitingWorker();
+
+    registration.addEventListener('updatefound', () => {
+      const installing = registration.installing;
+      if (!installing) {
+        return;
+      }
+
+      installing.addEventListener('statechange', () => {
+        if (installing.state === 'installed' && navigator.serviceWorker.controller) {
+          waitingWorker = registration.waiting || installing;
+        }
+      });
+    });
+  }
+
+  async function installServiceWorker() {
+    if (!('serviceWorker' in navigator)) {
+      return { supported: false };
+    }
+
+    if (import.meta.env.DEV) {
+      const registrations = await navigator.serviceWorker.getRegistrations();
+      await Promise.all(registrations.map((existingRegistration) => existingRegistration.unregister()));
+      return { supported: false, development: true };
+    }
+
+    registration = await navigator.serviceWorker.register('/service-worker.js');
+    setupRegistrationHooks();
+
+    return {
+      supported: true,
+      registered: true,
+    };
+  }
+
+  async function checkForAppUpdate() {
+    if (registration) {
+      await registration.update().catch(() => {});
+      syncWaitingWorker();
+    }
+
+    const server = await fetchServerVersion();
+    const hasVersionMismatch = Boolean(server.serverVersion && server.serverVersion !== APP_VERSION);
+
+    return {
+      supported: 'serviceWorker' in navigator,
+      currentVersion: APP_VERSION,
+      serverVersion: server.serverVersion,
+      serverBuildTime: server.serverBuildTime,
+      waitingWorker: Boolean(waitingWorker),
+      updateAvailable: Boolean(waitingWorker) || hasVersionMismatch,
+      hasVersionMismatch,
+      serverError: server.error || null,
+    };
+  }
+
+  async function waitForControllerChange(previousController, timeoutMs = 4000) {
+    if (!('serviceWorker' in navigator)) {
+      return;
+    }
+
+    if (navigator.serviceWorker.controller && navigator.serviceWorker.controller !== previousController) {
+      return;
+    }
+
+    await new Promise((resolve) => {
+      let isDone = false;
+
+      const finish = () => {
+        if (isDone) {
+          return;
+        }
+
+        isDone = true;
+        navigator.serviceWorker.removeEventListener('controllerchange', onControllerChange);
+        clearTimeout(timeout);
+        resolve();
+      };
+
+      const onControllerChange = () => {
+        finish();
+      };
+
+      const timeout = setTimeout(finish, timeoutMs);
+
+      navigator.serviceWorker.addEventListener('controllerchange', onControllerChange);
+    });
+  }
+
+  async function clearAllServiceWorkerCaches() {
+    if (!('caches' in window)) {
+      return;
+    }
+
+    const keys = await caches.keys();
+    await Promise.all(keys.map((key) => caches.delete(key)));
+  }
+
+  async function applyAppUpdate() {
+    const previousController = navigator.serviceWorker?.controller || null;
+
+    if (registration) {
+      await registration.update().catch(() => {});
+      syncWaitingWorker();
+    }
+
+    if (waitingWorker) {
+      waitingWorker.postMessage({ type: 'SKIP_WAITING' });
+      await waitForControllerChange(previousController);
+    }
+
+    await clearAllServiceWorkerCaches().catch(() => {});
+
+    const nextUrl = new URL(window.location.href);
+    nextUrl.searchParams.set('app_update', String(Date.now()));
+    window.location.replace(nextUrl.toString());
+  }
+
+  function startPeriodicChecks() {
+    if (!registration) {
+      return;
+    }
+
+    window.setInterval(() => {
+      checkForAppUpdate().catch(() => {});
+    }, APP_UPDATE_CHECK_INTERVAL_MS);
+
+    document.addEventListener('visibilitychange', () => {
+      if (document.visibilityState === 'visible') {
+        checkForAppUpdate().catch(() => {});
+      }
+    });
+  }
+
+  return {
+    installServiceWorker,
+    checkForAppUpdate,
+    applyAppUpdate,
+    startPeriodicChecks,
+  };
 }
 
 export function bootstrapApp() {
   const store = createAppStore();
   Alpine.store('app', store);
 
+  const appUpdateManager = createAppUpdateManager();
+
   registerFeatureData(Alpine, store);
 
   const appRoot = document.querySelector('#app');
@@ -104,6 +281,12 @@ export function bootstrapApp() {
       renderNav();
       return result;
     },
+    async checkForAppUpdate() {
+      return appUpdateManager.checkForAppUpdate();
+    },
+    async applyAppUpdate() {
+      return appUpdateManager.applyAppUpdate();
+    },
     handleAuthFailure(error) {
       if (!store.session?.applicationKey || !store.session?.hasValidated || authFailureHandled) {
         return;
@@ -152,10 +335,13 @@ export function bootstrapApp() {
 
   renderNav();
 
-  installServiceWorker().catch(() => {
-    store.addAlert({
-      type: 'warning',
-      message: 'PWA installation support could not be initialized.',
+  appUpdateManager
+    .installServiceWorker()
+    .then(() => appUpdateManager.startPeriodicChecks())
+    .catch(() => {
+      store.addAlert({
+        type: 'warning',
+        message: 'PWA installation support could not be initialized.',
+      });
     });
-  });
 }