Add named layouts: save/load/delete scene+playlist profiles

server/state.js

@@ -15,7 +15,21 @@ const MODELS_SEED = path.join(DATA, 'models.json');
 const CHARS_LIVE = path.join(LIVE_DIR, 'characters.live.json');
 const LANDING_LIVE = path.join(LIVE_DIR, 'landing.live.json');
 
+/* Named layouts: each is a self-contained { name, scene, playlist } saved under
+ * layouts/<slug>.json. layouts.index.json tracks the list + which slug is active.
+ * The active layout's scene/playlist are mirrored into scene.live.json /
+ * playlist.live.json so viewers and the playlist engine need no changes. */
+const LAYOUTS_DIR = path.join(LIVE_DIR, 'layouts');
+const LAYOUTS_INDEX = path.join(LIVE_DIR, 'layouts.index.json');
+
 fs.mkdirSync(LIVE_DIR, { recursive: true });
+fs.mkdirSync(LAYOUTS_DIR, { recursive: true });
+
+function slugify(name) {
+  const s = String(name || '').toLowerCase().trim()
+    .replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '').slice(0, 60);
+  return s || 'layout';
+}
 
 function readJSON(p, fallback) {
   try { return JSON.parse(fs.readFileSync(p, 'utf8')); } catch { return fallback; }
@@ -53,6 +67,64 @@ let landing = Object.assign({}, LANDING_DEFAULTS, readJSON(LANDING_LIVE, null) |
 
 const listeners = [];
 
+/* ---------- named layouts ---------- */
+function readLayoutIndex() {
+  const idx = readJSON(LAYOUTS_INDEX, null);
+  if (idx && Array.isArray(idx.layouts)) return idx;
+  return { layouts: [], activeSlug: null };
+}
+function writeLayoutIndex(idx) { writeJSON(LAYOUTS_INDEX, idx); }
+function layoutPath(slug) { return path.join(LAYOUTS_DIR, `${slug}.json`); }
+
+function listLayouts() {
+  const idx = readLayoutIndex();
+  return { layouts: idx.layouts, activeSlug: idx.activeSlug };
+}
+
+/* Snapshot the CURRENT live scene + playlist under a name. Overwrites if the
+ * slug already exists (same name). Returns the updated index. */
+function saveLayout(name, playlistCfg) {
+  const slug = slugify(name);
+  const record = {
+    name: String(name || slug),
+    slug,
+    scene,
+    playlist: playlistCfg || readJSON(PLAYLIST_LIVE, null) || readJSON(path.join(DATA, 'playlist.json'), {}),
+    savedAt: Date.now(),
+  };
+  writeJSON(layoutPath(slug), record);
+  const idx = readLayoutIndex();
+  if (!idx.layouts.some(l => l.slug === slug)) idx.layouts.push({ slug, name: record.name });
+  else idx.layouts = idx.layouts.map(l => l.slug === slug ? { slug, name: record.name } : l);
+  idx.activeSlug = slug;
+  writeLayoutIndex(idx);
+  return listLayouts();
+}
+
+/* Make a saved layout active: mirror its scene into the live scene (so viewers
+ * update) and return its playlist so the caller can reload the engine. */
+function loadLayout(slug) {
+  const rec = readJSON(layoutPath(slug), null);
+  if (!rec) throw new Error('layout not found: ' + slug);
+  scene = validateScene(rec.scene);
+  writeJSON(LIVE, scene);
+  if (rec.playlist) writeJSON(PLAYLIST_LIVE, rec.playlist);
+  const idx = readLayoutIndex();
+  idx.activeSlug = slug;
+  writeLayoutIndex(idx);
+  listeners.forEach(f => f());
+  return { scene, playlist: rec.playlist || null };
+}
+
+function deleteLayout(slug) {
+  try { fs.unlinkSync(layoutPath(slug)); } catch {}
+  const idx = readLayoutIndex();
+  idx.layouts = idx.layouts.filter(l => l.slug !== slug);
+  if (idx.activeSlug === slug) idx.activeSlug = null;
+  writeLayoutIndex(idx);
+  return listLayouts();
+}
+
 function validateScene(s) {
   if (!s || typeof s !== 'object') throw new Error('scene must be object');
   for (const k of ['anchors', 'buildings', 'spawns']) {
@@ -122,5 +194,9 @@ module.exports = {
   },
   getPlaylistConfig: (fallback) => readJSON(PLAYLIST_LIVE, null) || readJSON(path.join(DATA, 'playlist.json'), fallback),
   putPlaylistConfig(cfg) { writeJSON(PLAYLIST_LIVE, cfg); return cfg; },
+  listLayouts,
+  saveLayout,
+  loadLayout,
+  deleteLayout,
   onChange: (f) => listeners.push(f),
 };