feat: export Agenda calendar snapshots (Closes #1088)

frontend/agenda-calendar.js

@@ -0,0 +1,180 @@
+(function (root) {
+  'use strict';
+
+  function escapeText(value) {
+    return String(value || '')
+      .replace(/\\/g, '\\\\')
+      .replace(/\r?\n/g, '\\n')
+      .replace(/,/g, '\\,')
+      .replace(/;/g, '\\;');
+  }
+
+  function calendarDay(value) {
+    const match = String(value || '').match(/^(\d{4})-(\d{2})-(\d{2})/);
+    return match ? match.slice(1).join('') : '';
+  }
+
+  function nextDay(day) {
+    const date = new Date(Date.UTC(
+      Number(day.slice(0, 4)), Number(day.slice(4, 6)) - 1, Number(day.slice(6, 8)) + 1
+    ));
+    return date.toISOString().slice(0, 10).replace(/-/g, '');
+  }
+
+  function uid(item) {
+    const repository = String(item.repository || '').replace(/[^a-z0-9]+/gi, '-').replace(/^-|-$/g, '').toLowerCase();
+    return `issue-${Number(item.number)}@${repository}`;
+  }
+
+  function foldLine(line) {
+    const encoder = new TextEncoder();
+    const chunks = [];
+    let chunk = '';
+    let bytes = 0;
+    let limit = 75;
+    for (const character of String(line)) {
+      const width = encoder.encode(character).length;
+      if (chunk && bytes + width > limit) {
+        chunks.push(chunk);
+        chunk = character;
+        bytes = width;
+        limit = 74;
+      } else {
+        chunk += character;
+        bytes += width;
+      }
+    }
+    chunks.push(chunk);
+    return chunks.join('\r\n ');
+  }
+
+  function serializeAgendaCalendar(items, { generatedOn } = {}) {
+    const stampDay = String(generatedOn || new Date().toISOString().slice(0, 10).replace(/-/g, ''));
+    const lines = ['BEGIN:VCALENDAR', 'VERSION:2.0', 'PRODID:-//Stackchain//Agenda Snapshot//EN',
+      'CALSCALE:GREGORIAN', 'METHOD:PUBLISH', 'X-WR-CALNAME:Stackchain Agenda'];
+    (items || []).forEach(item => {
+      const day = calendarDay(item.due_date);
+      if (!day || !Number.isInteger(Number(item.number)) || !item.repository) return;
+      lines.push(
+        'BEGIN:VEVENT',
+        `UID:${uid(item)}`,
+        `DTSTAMP:${stampDay}T000000Z`,
+        `DTSTART;VALUE=DATE:${day}`,
+        `DTEND;VALUE=DATE:${nextDay(day)}`,
+        `SUMMARY:${escapeText(item.title)}`,
+        `DESCRIPTION:${escapeText(`${item.repository}#${item.number} · Stackchain Agenda snapshot`)}`,
+        `URL:${String(item.url || '')}`,
+        'TRANSP:TRANSPARENT',
+        'END:VEVENT',
+      );
+    });
+    lines.push('END:VCALENDAR');
+    return lines.map(foldLine).join('\r\n') + '\r\n';
+  }
+
+  async function deliverCalendarSnapshot({
+    text,
+    filename,
+    navigator,
+    document,
+    urlApi,
+    FileCtor,
+  }) {
+    const file = new FileCtor([text], filename, { type: 'text/calendar;charset=utf-8' });
+    const sharePayload = { files: [file], title: 'Stackchain Agenda', text: 'Agenda calendar snapshot' };
+    if (typeof navigator?.share === 'function' && typeof navigator?.canShare === 'function' &&
+        navigator.canShare(sharePayload)) {
+      await navigator.share(sharePayload);
+      return 'shared';
+    }
+    const href = urlApi.createObjectURL(file);
+    try {
+      const anchor = document.createElement('a');
+      anchor.href = href;
+      anchor.download = filename;
+      anchor.click();
+    } finally {
+      urlApi.revokeObjectURL(href);
+    }
+    return 'downloaded';
+  }
+
+  function mountAgendaCalendarExport({
+    qs,
+    getItems,
+    escapeHtml,
+    onDone,
+    windowObject = root,
+    navigatorObject = root.navigator,
+    documentObject = root.document,
+    urlApi = root.URL,
+    FileCtor = root.File,
+  }) {
+    const sheet = qs('#agenda-export-sheet');
+    let items = [];
+    let scrollY = 0;
+    let trigger = null;
+    const selectedItems = () => Array.from(qs('#agenda-export-items').querySelectorAll('input[type="checkbox"]'))
+      .filter(checkbox => checkbox.checked)
+      .map(checkbox => items[Number(checkbox.value)])
+      .filter(Boolean);
+    const updateSelection = () => {
+      const selected = selectedItems();
+      qs('#share-agenda-export').disabled = selected.length === 0;
+      qs('#agenda-export-status').textContent = selected.length + ' of ' + items.length +
+        (items.length === 1 ? ' deadline selected.' : ' deadlines selected.');
+    };
+    const close = () => {
+      sheet.close();
+      windowObject.scrollTo({ top:scrollY, behavior:'instant' });
+      trigger?.focus();
+    };
+    qs('#open-agenda-export').addEventListener('click', event => {
+      items = getItems();
+      scrollY = windowObject.scrollY;
+      trigger = event.currentTarget;
+      qs('#agenda-export-items').innerHTML = items.map((item, index) =>
+        '<label class="agenda-export-item"><input type="checkbox" value="' + index + '" checked> ' +
+        '<span><strong>' + escapeHtml(item.title) + '</strong><small>' +
+        escapeHtml(item.repository + '#' + item.number + ' · ' + item.due_date.slice(0, 10)) +
+        '</small></span></label>'
+      ).join('');
+      qs('#agenda-export-items').querySelectorAll('input[type="checkbox"]').forEach(checkbox =>
+        checkbox.addEventListener('change', updateSelection)
+      );
+      updateSelection();
+      sheet.showModal();
+      qs('#cancel-agenda-export').focus();
+    });
+    qs('#cancel-agenda-export').addEventListener('click', close);
+    sheet.addEventListener('cancel', event => {
+      event.preventDefault();
+      close();
+    });
+    qs('#share-agenda-export').addEventListener('click', async () => {
+      const selected = selectedItems();
+      if (!selected.length) return;
+      const button = qs('#share-agenda-export');
+      button.disabled = true;
+      qs('#agenda-export-status').textContent = 'Preparing calendar snapshot…';
+      const day = new Date().toISOString().slice(0, 10);
+      try {
+        const text = serializeAgendaCalendar(selected, { generatedOn:day.replace(/-/g, '') });
+        const result = await deliverCalendarSnapshot({
+          text, filename:'stackchain-agenda-' + day + '.ics',
+          navigator:navigatorObject, document:documentObject, urlApi, FileCtor,
+        });
+        onDone(result);
+        close();
+      } catch (error) {
+        qs('#agenda-export-status').textContent = error?.name === 'AbortError' ?
+          'Share cancelled. Nothing was exported.' : 'Calendar export failed. Retry without leaving Agenda.';
+        button.disabled = false;
+      }
+    });
+  }
+
+  const api = { calendarDay, deliverCalendarSnapshot, escapeText, foldLine, mountAgendaCalendarExport, serializeAgendaCalendar };
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  else root.StackchainAgendaCalendar = api;
+})(typeof window !== 'undefined' ? window : globalThis);

frontend/dashboard.css

@@ -419,6 +419,21 @@ textarea { resize: vertical; min-height: 120px; }
 .agenda-replan-actions { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:8px; margin-top:10px; }
 .agenda-replan-actions label { grid-column:1/-1; }
 .agenda-replan-actions input { box-sizing:border-box; min-height:44px; width:100%; max-width:100%; }
+.agenda-export { margin:10px 0; padding:12px; border:1px solid #2f6f9f; border-radius:12px; background:#0d2136; display:flex; align-items:center; justify-content:space-between; gap:12px; }
+.agenda-export p { margin:4px 0 0; }
+.agenda-export button { min-height:44px; flex:0 0 auto; }
+.agenda-export-sheet { box-sizing:border-box; width:min(560px,100%); max-width:none; max-height:none; height:100dvh; margin:0 0 0 auto; padding:0; border:0; color:var(--text); background:#0b1526; }
+.agenda-export-sheet::backdrop { background:rgba(5,12,21,.78); backdrop-filter:blur(4px); }
+.agenda-export-panel { box-sizing:border-box; min-height:100%; display:grid; align-content:start; gap:12px; padding:18px; padding-bottom:calc(18px + env(safe-area-inset-bottom)); overflow:auto; overflow-x:hidden; }
+.agenda-export-panel header { display:flex; align-items:flex-start; justify-content:space-between; gap:12px; }
+.agenda-export-panel h2, .agenda-export-panel header p { margin:0; }
+#agenda-export-items { min-width:0; display:grid; gap:8px; margin:0; padding:0; border:0; }
+.agenda-export-item { min-width:0; min-height:44px; display:flex; align-items:center; gap:10px; padding:10px; border:1px solid #31577f; border-radius:10px; background:#10233a; }
+.agenda-export-item input { width:22px; height:22px; flex:0 0 auto; }
+.agenda-export-item span, .agenda-export-item strong, .agenda-export-item small { min-width:0; display:block; overflow-wrap:anywhere; }
+#cancel-agenda-export, #share-agenda-export { min-height:44px; }
+#share-agenda-export { position:sticky; bottom:0; width:100%; margin-top:auto; }
+@media(max-width:430px) { .agenda-export { align-items:stretch; flex-direction:column; } .agenda-export button { width:100%; } .agenda-export-panel { padding:14px; padding-bottom:calc(14px + env(safe-area-inset-bottom)); } }
 .protect-today { margin:10px 0; padding:12px; border:1px solid #2f6f9f; border-radius:12px; background:#0d2136; display:flex; align-items:center; justify-content:space-between; gap:12px; }
 .protect-today p { margin:4px 0; }
 .protect-today button { min-height:44px; flex:0 0 auto; }

frontend/dashboard.js

@@ -597,6 +597,16 @@
     window.location.hash = '#/my-work/agenda';
     qs('#my-work-action-status').textContent = 'Overdue sweep cancelled. No remaining deadline was changed.';
   });
+
+  StackchainAgendaCalendar.mountAgendaCalendarExport({
+    qs,
+    getItems:() => agendaMyWork(activeMyWork),
+    escapeHtml,
+    onDone:result => {
+      qs('#my-work-action-status').textContent = result === 'shared' ?
+        'Agenda calendar snapshot shared.' : 'Agenda calendar snapshot downloaded.';
+    },
+  });
   let searchReplyAttachmentTarget = null;
   let searchReplyRestoreGeneration = 0;
   let restoringSearchReplyPhotos = false;
@@ -3513,6 +3523,14 @@
       qs('#start-agenda-replan').textContent = 'Replan overdue (' + overdue.length + ')';
       qs('#agenda-replan-controls').hidden = true;
     }
+    const agendaExport = qs('#agenda-export');
+    const agendaExportButton = qs('#open-agenda-export');
+    agendaExport.hidden = selectedWorkFilter !== 'agenda';
+    agendaExportButton.disabled = queueItems.length === 0;
+    qs('#agenda-export-empty').textContent = queueItems.length ?
+      'Review ' + queueItems.length + (queueItems.length === 1 ? ' deadline' : ' deadlines') +
+        ' before sharing a calendar snapshot.' :
+      'No deadlines are available to export from this Agenda.';
     const incomplete = activeWorkStreams().some(stream => workPagination[stream]?.has_more);
     const visible = findQueueItems(queueItems, queueFindQuery);
     const emptyWorkStart = qs('#empty-work-start');

frontend/index.html

@@ -277,6 +277,13 @@
         </div>
       </div>
     </section>
+    <section class="agenda-export" id="agenda-export" aria-labelledby="agenda-export-heading" hidden>
+      <div>
+        <strong id="agenda-export-heading">Take deadlines with you</strong>
+        <p class="small muted" id="agenda-export-empty">Review this Agenda before sharing a calendar snapshot.</p>
+      </div>
+      <button id="open-agenda-export" type="button">Export to calendar</button>
+    </section>
     <section class="protect-today" id="protect-today-panel" aria-labelledby="protect-today-heading" hidden>
       <div>
         <strong id="protect-today-heading">Deadlines need a plan</strong>
@@ -312,6 +319,19 @@
       </div>
     </div>
   </section>
+  <dialog class="agenda-export-sheet" id="agenda-export-sheet" aria-labelledby="agenda-export-title">
+    <section class="agenda-export-panel">
+      <header>
+        <div><p class="small muted">Calendar handoff</p><h2 id="agenda-export-title">Review Agenda export</h2></div>
+        <button id="cancel-agenda-export" type="button">Cancel</button>
+      </header>
+      <p>This exports a snapshot, not ongoing synchronization. Only checked deadline details leave Stackchain.</p>
+      <fieldset id="agenda-export-items" aria-describedby="agenda-export-privacy"></fieldset>
+      <p class="small muted" id="agenda-export-privacy">Your issue titles, repositories, dates, and forge links are included in the calendar file.</p>
+      <p class="small" id="agenda-export-status" role="status" aria-live="polite"></p>
+      <button id="share-agenda-export" type="button">Share calendar file</button>
+    </section>
+  </dialog>
   <section class="insights-shell" id="insights-sheet" aria-labelledby="insights-heading">
     <div class="insights-header">
       <div><h2 id="insights-heading">Insights</h2><p class="small muted">Context, activity, live signals, and workspace tools.</p></div>
@@ -1780,6 +1800,7 @@
 <script src="static/offline-today.js"></script>
 <script src="static/my-work.js"></script>
 <script src="static/agenda-replan.js"></script>
+<script src="static/agenda-calendar.js"></script>
 <script src="static/protect-today.js"></script>
 <script src="static/notification-undo.js"></script>
 <script src="static/card-planning.js"></script>

frontend/service-worker.js

@@ -45,6 +45,7 @@ const SHELL = [
   BASE + 'static/offline-today.js',
   BASE + 'static/my-work.js',
   BASE + 'static/agenda-replan.js',
+  BASE + 'static/agenda-calendar.js',
   BASE + 'static/protect-today.js',
   BASE + 'static/notification-undo.js',
   BASE + 'static/card-planning.js',