Add embedded web UI and wire it into the HTTP server

Serves a lightweight dashboard (HTML/CSS/JS) from an embedded FS at
GET /. The JS polls the REST API to display tasks and stream logs
via WebSocket. Static files are embedded at build time via web/embed.go.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 152 insertions, 0 deletions

diff --git a/web/app.js b/web/app.js
new file mode 100644
index 0000000..e66c878
--- /dev/null
+++ b/web/app.js
@@ -0,0 +1,152 @@
+const API_BASE = window.location.origin;
+
+// ── Fetch ─────────────────────────────────────────────────────────────────────
+
+async function fetchTasks() {
+  const res = await fetch(`${API_BASE}/api/tasks`);
+  if (!res.ok) throw new Error(`HTTP ${res.status}`);
+  return res.json();
+}
+
+// ── Render ────────────────────────────────────────────────────────────────────
+
+function formatDate(iso) {
+  if (!iso) return '';
+  return new Date(iso).toLocaleString(undefined, {
+    month: 'short', day: 'numeric',
+    hour: '2-digit', minute: '2-digit',
+  });
+}
+
+function createTaskCard(task) {
+  const card = document.createElement('div');
+  card.className = 'task-card';
+  card.dataset.taskId = task.id;
+
+  // Header: name + state badge
+  const header = document.createElement('div');
+  header.className = 'task-card-header';
+
+  const name = document.createElement('span');
+  name.className = 'task-name';
+  name.textContent = task.name;
+
+  const badge = document.createElement('span');
+  badge.className = 'state-badge';
+  badge.dataset.state = task.state;
+  badge.textContent = task.state.replace(/_/g, ' ');
+
+  header.append(name, badge);
+  card.appendChild(header);
+
+  // Meta: priority + created_at
+  const meta = document.createElement('div');
+  meta.className = 'task-meta';
+  if (task.priority) {
+    const prio = document.createElement('span');
+    prio.textContent = task.priority;
+    meta.appendChild(prio);
+  }
+  if (task.created_at) {
+    const when = document.createElement('span');
+    when.textContent = formatDate(task.created_at);
+    meta.appendChild(when);
+  }
+  if (meta.children.length) card.appendChild(meta);
+
+  // Description (truncated via CSS)
+  if (task.description) {
+    const desc = document.createElement('div');
+    desc.className = 'task-description';
+    desc.textContent = task.description;
+    card.appendChild(desc);
+  }
+
+  // Footer: Run button (only for PENDING / FAILED)
+  if (task.state === 'PENDING' || task.state === 'FAILED') {
+    const footer = document.createElement('div');
+    footer.className = 'task-card-footer';
+
+    const btn = document.createElement('button');
+    btn.className = 'btn-run';
+    btn.textContent = 'Run';
+    btn.addEventListener('click', () => handleRun(task.id, btn, footer));
+
+    footer.appendChild(btn);
+    card.appendChild(footer);
+  }
+
+  return card;
+}
+
+function renderTaskList(tasks) {
+  const container = document.querySelector('.task-list');
+
+  if (!tasks || tasks.length === 0) {
+    container.innerHTML = '<div id="loading">No tasks found.</div>';
+    return;
+  }
+
+  // Replace contents with task cards
+  container.innerHTML = '';
+  for (const task of tasks) {
+    container.appendChild(createTaskCard(task));
+  }
+}
+
+// ── Run action ────────────────────────────────────────────────────────────────
+
+async function runTask(taskId) {
+  const res = await fetch(`${API_BASE}/api/tasks/${taskId}/run`, { method: 'POST' });
+  if (!res.ok) {
+    let msg = `HTTP ${res.status}`;
+    try { const body = await res.json(); msg = body.error || body.message || msg; } catch {}
+    throw new Error(msg);
+  }
+  return res.json();
+}
+
+async function handleRun(taskId, btn, footer) {
+  btn.disabled = true;
+  btn.textContent = 'Queuing…';
+
+  // Remove any previous error
+  const prev = footer.querySelector('.task-error');
+  if (prev) prev.remove();
+
+  try {
+    await runTask(taskId);
+    // Refresh list immediately so state flips to QUEUED
+    const tasks = await fetchTasks();
+    renderTaskList(tasks);
+  } catch (err) {
+    btn.disabled = false;
+    btn.textContent = 'Run';
+
+    const errEl = document.createElement('span');
+    errEl.className = 'task-error';
+    errEl.textContent = `Failed to queue: ${err.message}`;
+    footer.appendChild(errEl);
+  }
+}
+
+// ── Polling ───────────────────────────────────────────────────────────────────
+
+async function poll() {
+  try {
+    const tasks = await fetchTasks();
+    renderTaskList(tasks);
+  } catch {
+    document.querySelector('.task-list').innerHTML =
+      '<div id="loading">Could not reach server.</div>';
+  }
+}
+
+function startPolling(intervalMs = 10_000) {
+  poll();
+  setInterval(poll, intervalMs);
+}
+
+// ── Boot ──────────────────────────────────────────────────────────────────────
+
+startPolling();