jackboxpartypack-gamepicker/backend/utils/room-monitor.js

const db = require('../database');
const { getWebSocketManager } = require('./websocket-manager');
const { checkRoomStatus } = require('./jackbox-api');

const POLL_INTERVAL_MS = 10000;

// Active room monitors, keyed by "{sessionId}-{gameId}"
const activeMonitors = new Map();

/**
 * Broadcast game.started event when room becomes locked
 */
function broadcastGameStarted(sessionId, gameId, roomCode, maxPlayers) {
  try {
    const wsManager = getWebSocketManager();
    if (wsManager) {
      wsManager.broadcastEvent('game.started', {
        sessionId,
        gameId,
        roomCode,
        maxPlayers
      }, parseInt(sessionId));
    }
    console.log(`[Room Monitor] Broadcasted game.started for room ${roomCode} (max: ${maxPlayers})`);
  } catch (error) {
    console.error('[Room Monitor] Failed to broadcast game.started:', error.message);
  }
}

/**
 * Start monitoring a Jackbox room for game start (locked state).
 *
 * Polls the Jackbox REST API every 10 seconds. When the room becomes
 * locked, broadcasts a game.started WebSocket event and then hands off
 * to the player-count-checker to join as audience.
 */
async function startRoomMonitor(sessionId, gameId, roomCode, maxPlayers = 8) {
  const monitorKey = `${sessionId}-${gameId}`;

  if (activeMonitors.has(monitorKey)) {
    console.log(`[Room Monitor] Already monitoring ${monitorKey}`);
    return;
  }

  console.log(`[Room Monitor] Starting monitor for room ${roomCode} (${monitorKey})`);

  const onGameStarted = (realMaxPlayers) => {
    broadcastGameStarted(sessionId, gameId, roomCode, realMaxPlayers);
    // Lazy require breaks the circular dependency with player-count-checker
    const { startPlayerCountCheck } = require('./player-count-checker');
    console.log(`[Room Monitor] Room ${roomCode} locked — handing off to player count checker`);
    startPlayerCountCheck(sessionId, gameId, roomCode, realMaxPlayers);
  };

  const pollRoom = async () => {
    const game = db.prepare(`
      SELECT status FROM session_games
      WHERE session_id = ? AND id = ?
    `).get(sessionId, gameId);

    if (!game || game.status === 'skipped' || game.status === 'played') {
      console.log(`[Room Monitor] Stopping — game status changed for ${monitorKey}`);
      stopRoomMonitor(sessionId, gameId);
      return;
    }

    const roomStatus = await checkRoomStatus(roomCode);

    if (!roomStatus.exists) {
      console.log(`[Room Monitor] Room ${roomCode} does not exist — stopping`);
      stopRoomMonitor(sessionId, gameId);
      return;
    }

    if (roomStatus.locked) {
      stopRoomMonitor(sessionId, gameId);
      onGameStarted(roomStatus.maxPlayers);
      return;
    }

    if (roomStatus.full) {
      console.log(`[Room Monitor] Room ${roomCode} is full but not locked yet — waiting`);
    } else {
      console.log(`[Room Monitor] Room ${roomCode} lobby still open — waiting`);
    }
  };

  // Poll immediately, then every POLL_INTERVAL_MS
  activeMonitors.set(monitorKey, {
    sessionId,
    gameId,
    roomCode,
    interval: null
  });

  await pollRoom();

  // If the monitor was already stopped (room locked or gone on first check), bail
  if (!activeMonitors.has(monitorKey)) return;

  const interval = setInterval(() => pollRoom(), POLL_INTERVAL_MS);
  const monitor = activeMonitors.get(monitorKey);
  if (monitor) monitor.interval = interval;
}

/**
 * Stop monitoring a room
 */
function stopRoomMonitor(sessionId, gameId) {
  const monitorKey = `${sessionId}-${gameId}`;
  const monitor = activeMonitors.get(monitorKey);

  if (monitor) {
    if (monitor.interval) clearInterval(monitor.interval);
    activeMonitors.delete(monitorKey);
    console.log(`[Room Monitor] Stopped monitor for ${monitorKey}`);
  }
}

/**
 * Clean up all active monitors (for graceful shutdown)
 */
function cleanupAllMonitors() {
  for (const [, monitor] of activeMonitors.entries()) {
    if (monitor.interval) clearInterval(monitor.interval);
  }
  activeMonitors.clear();
  console.log('[Room Monitor] Cleaned up all active monitors');
}

module.exports = {
  startRoomMonitor,
  stopRoomMonitor,
  cleanupAllMonitors
};