feat: show timed Today breaks on lock screen (Closes #1050)

frontend/service-worker.js

@@ -421,7 +421,7 @@ self.addEventListener('sync', event => {
   if (event.tag === 'stackchain-issue-outbox-v1') event.waitUntil(flushAndNotify());
 });
 
-async function updateTodayLockScreen(active, running, rawActionToken = '') {
+async function updateTodayLockScreen(active, running, rawActionToken = '', rawBreakDeadline = 0) {
   const tag = 'stackchain-today-session';
   if (!active) {
     const notifications = await self.registration.getNotifications({ tag });
@@ -429,12 +429,24 @@ async function updateTodayLockScreen(active, running, rawActionToken = '') {
     return;
   }
   const actionToken = /^[A-Za-z0-9_-]{16,128}$/.test(rawActionToken) ? rawActionToken : '';
-  await self.registration.showNotification(running ? 'Today session running' : 'Today session paused', {
-    body: running ? 'Your active Today timer is running.' : 'Your active Today timer is paused.',
+  const now = Date.now();
+  const breakDeadline = Number(rawBreakDeadline);
+  const onBreak = !running && actionToken && Number.isSafeInteger(breakDeadline) &&
+    breakDeadline > now && breakDeadline <= now + 120 * 60 * 1000;
+  const title = onBreak ? 'On a Today break' :
+    running ? 'Today session running' : 'Today session paused';
+  const body = onBreak ? 'Return at ' + new Date(breakDeadline).toLocaleTimeString([], {
+    hour:'numeric', minute:'2-digit',
+  }) : running ? 'Your active Today timer is running.' : 'Your active Today timer is paused.';
+  await self.registration.showNotification(title, {
+    body,
     tag,
     renotify:false,
     silent:true,
-    actions: [
+    actions: onBreak ? [
+      { action:'resume-today', title:'Resume now' },
+      { action:'open-today', title:'Open Today' },
+    ] : [
       { action:running ? 'pause-today' : 'resume-today', title:running ? 'Pause' : 'Resume' },
       ...(actionToken ? [{ action:'finish-today', title:'Finish current' }] : []),
     ],
@@ -464,7 +476,8 @@ self.addEventListener('message', event => {
     event.waitUntil(updateTodayLockScreen(
       event.data.active === true,
       event.data.running === true,
-      String(event.data.actionToken || '')
+      String(event.data.actionToken || ''),
+      Number(event.data.breakDeadlineAt || 0)
     ));
   }
 });
@@ -561,19 +574,20 @@ async function openCanonicalIssueUrl(rawUrl) {
 
 async function applyTodayTimerAction(action, actionToken = '') {
   if (!['pause', 'resume', 'complete'].includes(action)) return;
-  if (action === 'complete' && !/^[A-Za-z0-9_-]{16,128}$/.test(actionToken)) return;
+  if (actionToken && !/^[A-Za-z0-9_-]{16,128}$/.test(actionToken)) return;
+  if (action === 'complete' && !actionToken) return;
   const route = '#/my-work/today';
   const windows = await self.clients.matchAll({ type:'window', includeUncontrolled:true });
   const client = windows.find(candidate => candidate.url.startsWith(self.location.origin + BASE));
   if (client) {
     client.postMessage?.({
       type:'stackchain-today-timer-action', action,
-      ...(action === 'complete' ? { actionToken } : {}),
+      ...(actionToken ? { actionToken } : {}),
     });
     return client.focus?.();
   }
   const query = '?today_timer_action=' + action +
-    (action === 'complete' ? '&today_action_token=' + encodeURIComponent(actionToken) : '');
+    (actionToken ? '&today_action_token=' + encodeURIComponent(actionToken) : '');
   const target = new URL(BASE + query + route, self.location.origin).href;
   return self.clients.openWindow(target);
 }

frontend/today-lock-screen.js

@@ -21,6 +21,8 @@ function createTodayLockScreen({
   onAction = () => {},
 }) {
   let activeIdentity = '';
+  let activeActionIdentity = '';
+  let activeBreakDeadline = 0;
   const preferenceKey = () => {
     const login = String(getLogin?.() || '').trim().toLowerCase();
     return login ? 'stackchain.today-lock-screen.v1.' + encodeURIComponent(login) : '';
@@ -82,13 +84,14 @@ function createTodayLockScreen({
   };
   const consumeAction = async (action, token = '') => {
     if (!enabled() || !['pause', 'resume', 'complete'].includes(action)) return false;
-    if (action !== 'complete') {
+    const requiresToken = action === 'complete' || (action === 'resume' && activeBreakDeadline > 0);
+    if (!requiresToken) {
       onAction(action, null);
       return true;
     }
     const pending = readAction();
     if (!pending || !token || !activeIdentity || pending.token !== token ||
-        await fingerprint(token, activeIdentity) !== pending.fingerprint) return false;
+        await fingerprint(token, activeActionIdentity) !== pending.fingerprint) return false;
     if (!clearAction()) return false;
     onAction(action, activeIdentity);
     return true;
@@ -128,12 +131,17 @@ function createTodayLockScreen({
       if (!enabled() || NotificationRef?.permission !== 'granted') return false;
       const visible = Boolean(active && snapshot?.identity);
       activeIdentity = visible ? snapshot.identity : '';
-      const pending = visible ? await actionFor(activeIdentity) : null;
+      const rawBreakDeadline = Number(snapshot?.break_deadline_at);
+      activeBreakDeadline = visible && Number.isSafeInteger(rawBreakDeadline) && rawBreakDeadline > 0 ?
+        rawBreakDeadline : 0;
+      activeActionIdentity = activeIdentity + (activeBreakDeadline ? '\0break:' + activeBreakDeadline : '');
+      const pending = visible ? await actionFor(activeActionIdentity) : null;
       if (!visible) clearAction();
       await post({
         type:'stackchain-today-lock-screen',
         active:visible,
         running:visible && Boolean(snapshot.running),
+        ...(activeBreakDeadline ? { breakDeadlineAt:activeBreakDeadline } : {}),
         ...(pending?.token ? { actionToken:pending.token } : {}),
       });
       if (visible && !pending) setStatus('Finish current is unavailable because its one-time action could not be saved.');