feat: add poll start/end endpoints, poll.leading WS handler, and poll state persistence

Adds POST /:id/voting/start and POST /:id/voting/end endpoints that
broadcast poll lifecycle events and persist poll state to the sessions
table. The poll.leading WebSocket message is now handled server-side
(rebroadcast + DB persist) with self-healing for polls started before
the persistence columns existed.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/database.js

@@ -63,6 +63,33 @@ function initializeDatabase() {
     // Column already exists, ignore error
   }
 
+  // Poll state columns on sessions
+  try {
+    db.exec(`ALTER TABLE sessions ADD COLUMN poll_active INTEGER DEFAULT 0`);
+  } catch (err) {
+    // Column already exists, ignore error
+  }
+  try {
+    db.exec(`ALTER TABLE sessions ADD COLUMN poll_started_at TEXT`);
+  } catch (err) {
+    // Column already exists, ignore error
+  }
+  try {
+    db.exec(`ALTER TABLE sessions ADD COLUMN poll_leading_game_id INTEGER`);
+  } catch (err) {
+    // Column already exists, ignore error
+  }
+  try {
+    db.exec(`ALTER TABLE sessions ADD COLUMN poll_leading_label TEXT`);
+  } catch (err) {
+    // Column already exists, ignore error
+  }
+  try {
+    db.exec(`ALTER TABLE sessions ADD COLUMN poll_leading_votes INTEGER`);
+  } catch (err) {
+    // Column already exists, ignore error
+  }
+
   // Session games table
   db.exec(`
     CREATE TABLE IF NOT EXISTS session_games (

backend/routes/sessions.js

@@ -327,6 +327,64 @@ router.post('/:id/close', authenticateToken, (req, res) => {
   }
 });
 
+// Start voting/polling for a session (broadcasts poll.start to subscribers)
+router.post('/:id/voting/start', authenticateToken, (req, res) => {
+  try {
+    const sessionId = parseInt(req.params.id);
+    const session = db.prepare('SELECT * FROM sessions WHERE id = ?').get(sessionId);
+
+    if (!session) {
+      return res.status(404).json({ error: 'Session not found' });
+    }
+
+    if (session.is_active === 0) {
+      return res.status(400).json({ error: 'Session is not active' });
+    }
+
+    db.prepare(
+      'UPDATE sessions SET poll_active = 1, poll_started_at = ?, poll_leading_game_id = NULL, poll_leading_label = NULL, poll_leading_votes = NULL WHERE id = ?'
+    ).run(new Date().toISOString(), sessionId);
+
+    const wsManager = getWebSocketManager();
+    if (wsManager) {
+      wsManager.broadcastEvent('poll.start', { sessionId }, sessionId);
+    }
+
+    res.json({ success: true });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
+// End voting/polling for a session (broadcasts voting.ended to subscribers)
+router.post('/:id/voting/end', authenticateToken, (req, res) => {
+  try {
+    const sessionId = parseInt(req.params.id);
+    const session = db.prepare('SELECT * FROM sessions WHERE id = ?').get(sessionId);
+
+    if (!session) {
+      return res.status(404).json({ error: 'Session not found' });
+    }
+
+    if (session.is_active === 0) {
+      return res.status(400).json({ error: 'Session is not active' });
+    }
+
+    db.prepare(
+      'UPDATE sessions SET poll_active = 0, poll_started_at = NULL WHERE id = ?'
+    ).run(sessionId);
+
+    const wsManager = getWebSocketManager();
+    if (wsManager) {
+      wsManager.broadcastEvent('voting.ended', { sessionId }, sessionId);
+    }
+
+    res.json({ success: true });
+  } catch (error) {
+    res.status(500).json({ error: error.message });
+  }
+});
+
 // Delete session (admin only)
 router.delete('/:id', authenticateToken, (req, res) => {
   try {

backend/utils/websocket-manager.js

@@ -1,6 +1,7 @@
 const { WebSocketServer } = require('ws');
 const jwt = require('jsonwebtoken');
 const { JWT_SECRET } = require('../middleware/auth');
+const db = require('../database');
 
 /**
  * WebSocket Manager for handling real-time session events
@@ -112,6 +113,35 @@ class WebSocketManager {
         this.broadcastPresence();
         break;
 
+      case 'poll.leading':
+        if (!clientInfo.authenticated) {
+          this.sendError(ws, 'Not authenticated');
+          return;
+        }
+        if (message.sessionId) {
+          this.broadcastEvent('poll.leading', {
+            sessionId: message.sessionId,
+            gameId: message.gameId,
+            label: message.label,
+            votes: message.votes
+          }, message.sessionId);
+          try {
+            const result = db.prepare(
+              'UPDATE sessions SET poll_leading_game_id = ?, poll_leading_label = ?, poll_leading_votes = ? WHERE id = ? AND poll_active = 1'
+            ).run(message.gameId, message.label, message.votes, message.sessionId);
+            if (result.changes === 0) {
+              // Self-heal: poll.leading arrived but poll_active is 0 (poll started before persistence fix)
+              db.prepare(
+                'UPDATE sessions SET poll_active = 1, poll_started_at = ?, poll_leading_game_id = ?, poll_leading_label = ?, poll_leading_votes = ? WHERE id = ? AND is_active = 1'
+              ).run(new Date().toISOString(), message.gameId, message.label, message.votes, message.sessionId);
+              console.log(`[WebSocket] Self-healed poll state for session ${message.sessionId}`);
+            }
+          } catch (err) {
+            console.error('[WebSocket] Failed to persist poll.leading:', err.message);
+          }
+        }
+        break;
+        
       default:
         this.sendError(ws, `Unknown message type: ${message.type}`);
     }

docs/api/websocket.md

@@ -90,6 +90,7 @@ Obtain a JWT by calling `POST /api/auth/login` with your admin key.
 | `subscribe` | `sessionId`     | Subscribe to a session's events      |
 | `unsubscribe`| `sessionId`    | Unsubscribe from a session           |
 | `ping`      | —               | Heartbeat; server responds with `pong` |
+| `poll.leading` | `sessionId`, `gameId`, `label`, `votes` | Report current poll leader (rebroadcast to subscribers) |
 
 ### auth
 ```json
@@ -139,6 +140,9 @@ Must be authenticated.
 | `game.status` | Periodic game state heartbeat every 20s (broadcast to subscribers) |
 | `player-count.updated` | Manual player count override (broadcast to subscribers) |
 | `vote.received`        | Live vote recorded (broadcast to subscribers)   |
+| `voting.ended`         | Host ended the voting/polling period (broadcast to subscribers) |
+| `poll.start`           | Host started a new poll (broadcast to subscribers) |
+| `poll.leading`         | Current poll leader updated (broadcast to subscribers) |
 
 ---
 
@@ -384,6 +388,45 @@ Possible `reason` values: `room_closed`, `room_not_found`, `connection_failed`,
 }
 ```
 
+### voting.ended
+
+- **Broadcast to:** Clients subscribed to the session
+- **Triggered by:** `POST /api/sessions/:id/voting/end` (host ends the voting/polling period)
+
+**Data:**
+```json
+{
+  "sessionId": 3
+}
+```
+
+### poll.start
+
+- **Broadcast to:** Clients subscribed to the session
+- **Triggered by:** `POST /api/sessions/:id/voting/start` (host starts a new poll)
+
+**Data:**
+```json
+{
+  "sessionId": 3
+}
+```
+
+### poll.leading
+
+- **Broadcast to:** Clients subscribed to the session
+- **Triggered by:** Downstream voting client sends `poll.leading` message (rebroadcast to all session subscribers)
+
+**Data:**
+```json
+{
+  "sessionId": 3,
+  "gameId": 42,
+  "label": "Quiplash 3",
+  "votes": 7
+}
+```
+
 ---
 
 ## 7. Error Handling