const express = require('express');
const path = require('path');
const crypto = require('crypto');
var app = express();
var http = require('http').Server(app);
var io = require('socket.io')(http);

// Load environment configuration
require('dotenv').config();

// Import payment system components
const DatabaseManager = require('./db/databaseManager');
const WalletRPCService = require('./payments/walletRPCService');
const PayoutRetryService = require('./payments/payoutRetryService');
const AlertService = require('./services/alertService');
const GameModeManager = require('./game/gameModeManager');
const RpcService = require('./rpc/rpcService');
const PaymentConfigManager = require('./config/paymentConfig');
const EnvironmentValidator = require('./config/environmentValidator');
const asyncHandler = require('./middleware/asyncHandler');
const createErrorMiddleware = require('./middleware/errorHandler');
const { AppError, ValidationError, NotFoundError } = require('./utils/errors');

// Import modular components
const BroadcastManager = require('./network/broadcastManager');
const DebugManager = require('./debug/debugManager');
const SocketHandlers = require('./network/socketHandlers');
const { verifyGame, hashSeed } = require('./game/provablyFair');

// Initialize payment configuration
const paymentConfigManager = new PaymentConfigManager({ logger: console });
const environmentValidator = new EnvironmentValidator({ logger: console });
environmentValidator.validate(paymentConfigManager.getConfig());
process.env.GAME_MODE = paymentConfigManager.getLegacyGameMode();

// Initialize modular components first
const broadcastManager = new BroadcastManager(io);
const debugManager = new DebugManager(broadcastManager);
broadcastManager.setDebugManager(debugManager);

// Initialize payment system components (debugManager is now available)
const databaseManager = new DatabaseManager();
const db = databaseManager; // Alias for convenience in API endpoints
const rpcService = new RpcService();
const walletRPCService = new WalletRPCService(debugManager);
const gameModeManager = new GameModeManager(databaseManager, walletRPCService, debugManager, paymentConfigManager);
// Provide io reference so GameModeManager can emit events (e.g., credits_update)
gameModeManager.io = io;

// Initialize remaining components
const activeGames = new Map(); // Maps socketId to Game objects
let alertService = null; // Initialized later when payment system starts
let payoutRetryService = null; // Initialized later when payment system starts
let batchPayoutInterval = null; // Initialized later when payment system starts
let paymentExpiryInterval = null; // Initialized later when payment system starts
const socketHandlers = new SocketHandlers(io, activeGames, broadcastManager, debugManager, gameModeManager, walletRPCService);
// Security headers (defense in depth alongside output escaping).
// CSP locks down where scripts/styles/connections may come from. Inline scripts/styles
// are still permitted ('unsafe-inline') because the current pages rely on them heavily;
// removing that is tracked as Phase 4.4 (nonce-based CSP). connect-src 'self' covers
// same-origin Socket.IO websockets under CSP Level 3.
app.use((req, res, next) => {
    res.setHeader('Content-Security-Policy', [
        "default-src 'self'",
        "script-src 'self' 'unsafe-inline' https://cdn.socket.io https://cdn.jsdelivr.net",
        "style-src 'self' 'unsafe-inline'",
        "img-src 'self' data:",
        "font-src 'self'",
        "connect-src 'self' https://smirk.cash",
        "object-src 'none'",
        "base-uri 'self'",
        "frame-ancestors 'self'",
        "form-action 'self'"
    ].join('; '));
    res.setHeader('X-Content-Type-Options', 'nosniff');
    res.setHeader('X-Frame-Options', 'SAMEORIGIN');
    res.setHeader('Referrer-Policy', 'no-referrer');
    next();
});

// Configure static file serving
const htmlPath = path.join(__dirname, '../html');
app.use(express.static(htmlPath, {
    etag: true,
    lastModified: true,
    setHeaders: (res, filePath) => {
        if (filePath.endsWith('.html') || filePath.endsWith('.js')) {
            res.setHeader('Cache-Control', 'no-cache');
        }
    }
}));
app.use(express.json()); // Parse JSON for API endpoints

// Serve main page
app.get('/', function(req, res) {
   res.sendFile('index.html', { root: htmlPath });
});

// Serve admin panel
app.get('/admin', function(req, res) {
   res.sendFile('admin.html', { root: htmlPath });
});

// Debug endpoint to receive client-side debug info
app.post('/debug', (req, res) => {
  if (debugManager.CONSOLE_LOGGING) {
    console.log('📝 CLIENT DEBUG INFO:', req.body);
  }
  res.json({ received: true, timestamp: Date.now() });
});

// Payment system API endpoints
app.post('/api/payment/create', asyncHandler(async (req, res) => {
  const { userId, gameMode } = req.body || {};
  if (!userId || !gameMode) {
    throw new ValidationError('Missing userId or gameMode', {
      safeMessage: 'userId and gameMode are required to create a payment.'
    });
  }

  throw new AppError('REST payment creation endpoint is not implemented for unified payments', {
    statusCode: 501,
    code: 'NOT_IMPLEMENTED',
    safeMessage: 'Payment creation via REST API is not available. Please use the in-game flow.'
  });
}));

const restNotImplemented = () => new AppError('Endpoint not available in unified payment system', {
  statusCode: 501,
  code: 'NOT_IMPLEMENTED',
  safeMessage: 'This API endpoint is not available. Please use the supported in-game flow.'
});

app.post('/api/payment/callback', asyncHandler(async (req, res) => {
  throw restNotImplemented();
}));

app.get('/api/payment/status/:paymentId', asyncHandler(async (req, res) => {
  throw restNotImplemented();
}));

app.get('/api/user/:socketId/credits', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  try {
    const user = await gameModeManager.getOrCreateUser(socketId);
    res.json({
      socketId,
      credits: user.credits || 0,
      totalCreditsPurchased: user.total_credits_purchased || 0
    });
  } catch (error) {
    throw new AppError('Failed to retrieve credits', {
      statusCode: 500,
      safeMessage: 'Unable to retrieve credit balance.',
      cause: error
    });
  }
}));

app.get('/api/user/:socketId/mode', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  try {
    const user = await gameModeManager.getOrCreateUser(socketId);
    res.json({
      socketId,
      preferredPaymentMode: user.preferred_payment_mode || 'direct',
      hasPayoutAddress: !!user.payout_address,
      paymentsEnabled: gameModeManager.paymentsEnabled,
      directModeEnabled: gameModeManager.directModeEnabled,
      creditsModeEnabled: gameModeManager.creditsModeEnabled
    });
  } catch (error) {
    throw new AppError('Failed to retrieve user mode', {
      statusCode: 500,
      safeMessage: 'Unable to retrieve user mode.',
      cause: error
    });
  }
}));

app.post('/api/user/:socketId/address', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  const { address } = req.body || {};

  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  if (!address || typeof address !== 'string') {
    throw new ValidationError('Missing or invalid address', {
      safeMessage: 'A valid payout address is required.'
    });
  }

  // Basic address validation (XMR/WOW addresses)
  const ADDRESS_REGEX = /((?:4|8)[1-9A-HJ-NP-Za-km-z]{90,110}|(?:Wo|WO|ww|WW)[0-9A-Za-z]{88,112}|W[0-9A-Za-z]{90,112})/;
  if (!ADDRESS_REGEX.test(address.trim())) {
    throw new ValidationError('Invalid address format', {
      safeMessage: 'The provided address does not appear to be a valid XMR/WOW address.'
    });
  }

  try {
    const success = await gameModeManager.setUserPayoutAddress(socketId, address.trim());
    if (!success) {
      throw new AppError('Failed to save address', {
        statusCode: 500,
        safeMessage: 'Unable to save payout address.'
      });
    }
    res.json({
      success: true,
      message: 'Payout address saved successfully.'
    });
  } catch (error) {
    if (error instanceof AppError || error instanceof ValidationError) {
      throw error;
    }
    throw new AppError('Failed to save address', {
      statusCode: 500,
      safeMessage: 'Unable to save payout address.',
      cause: error
    });
  }
}));

// Health check endpoint - enhanced for monitoring dashboard
app.get('/health', async (req, res) => {
  const memUsage = process.memoryUsage();

  // Get wallet balance - always attempt
  let walletBalance = null;
  let lowBalanceWarning = false;
  const lowBalanceThreshold = parseInt(process.env.LOW_BALANCE_THRESHOLD) || 100000000000; // 0.1 XMR default

  try {
    walletBalance = await walletRPCService.getBalance();
    if (walletBalance.error) {
      console.warn('Wallet balance returned error:', walletBalance.error);
    } else {
      lowBalanceWarning = walletBalance.unlocked_balance < lowBalanceThreshold;
    }
  } catch (e) {
    console.error('Failed to get wallet balance for health check:', e.message);
    walletBalance = { balance: 0, unlocked_balance: 0, error: e.message };
  }

  const health = {
    status: 'ok',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    nodeVersion: process.version,
    environment: process.env.NODE_ENV || 'development',

    // Memory details
    memory: {
      heapUsed: memUsage.heapUsed,
      heapTotal: memUsage.heapTotal,
      rss: memUsage.rss,
      external: memUsage.external || 0
    },

    // Game statistics
    games: {
      active: activeGames.size,
      queued: socketHandlers?.queueManager?.getQueueLength?.() || 0,
      connected: io.sockets.sockets.size || 0,
      mode: gameModeManager.gameMode
    },

    // Blockchain
    blockHeight: debugManager.getCurrentBlockHeight(),
    blockSource: process.env.BLOCK_SOURCE || 'daemon',
    network: process.env.MONERO_NETWORK || 'mainnet',

    // Wallet status
    wallet: {
      available: gameModeManager.paymentsEnabled,
      status: walletRPCService.isHealthy ? 'connected' : 'disconnected',
      endpoint: process.env.PRIMARY_WALLET_ENDPOINT ? '...' + process.env.PRIMARY_WALLET_ENDPOINT.slice(-15) : null,
      pendingPayouts: 0,
      balance: walletBalance,
      lowBalanceWarning
    },

    // Rate limiter stats (if available)
    rateLimiter: socketHandlers?.rateLimiter ? {
      trackedEntries: socketHandlers.rateLimiter.getTrackedCount?.() || 0,
      blockedCount: socketHandlers.rateLimiter.getBlockedCount?.() || 0
    } : null,

    // Limits
    limits: {
      maxGamesPerHour: parseInt(process.env.MAX_GAMES_PER_HOUR) || 60,
      maxPayoutsPerDay: parseInt(process.env.MAX_PAYOUTS_PER_DAY) || 100
    },

    // Legacy fields for compatibility
    gameMode: gameModeManager.gameMode,
    paymentsEnabled: gameModeManager.paymentsEnabled,
    directModeEnabled: gameModeManager.directModeEnabled,
    creditsModeEnabled: gameModeManager.creditsModeEnabled,
    walletHealthy: walletRPCService.isHealthy,
    activeGames: activeGames.size,
    debugMode: debugManager.getDebugStatus().debugMode
  };
  res.json(health);
});

// Get payment options for a user (mixed mode support)
app.get('/api/user/:socketId/payment-options', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  try {
    const options = await gameModeManager.getPaymentOptionsForUser(socketId);
    res.json(options);
  } catch (error) {
    throw new AppError('Failed to retrieve payment options', {
      statusCode: 500,
      safeMessage: 'Unable to retrieve payment options.',
      cause: error
    });
  }
}));

// Get payment history for a user
app.get('/api/user/:socketId/payments', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  const limit = Math.min(parseInt(req.query.limit, 10) || 20, 100);
  const offset = parseInt(req.query.offset, 10) || 0;
  
  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  try {
    const user = await gameModeManager.getOrCreateUser(socketId);
    const result = await db.query(`
      SELECT 
        id, 
        payment_type, 
        expected_amount, 
        status, 
        credits_purchased,
        created_at, 
        confirmed_at,
        description
      FROM payments 
      WHERE user_id = $1 
      ORDER BY created_at DESC 
      LIMIT $2 OFFSET $3
    `, [user.id, limit, offset]);
    
    const countResult = await db.query(
      `SELECT COUNT(*) as total, 
              COALESCE(SUM(CASE WHEN status = 'confirmed' THEN expected_amount ELSE 0 END), 0) as total_paid 
       FROM payments WHERE user_id = $1`,
      [user.id]
    );
    
    const totalPaid = parseInt(countResult.rows[0].total_paid, 10) || 0;
    
    res.json({
      payments: result.rows.map(row => ({
        id: row.id,
        type: row.payment_type,
        amount: row.expected_amount,
        amountFormatted: gameModeManager.formatAtomicHuman(row.expected_amount, 4),
        status: row.status,
        creditsReceived: row.credits_purchased || 0,
        createdAt: row.created_at,
        confirmedAt: row.confirmed_at,
        description: row.description
      })),
      total: parseInt(countResult.rows[0].total, 10),
      totalPaid: totalPaid,
      totalPaidFormatted: gameModeManager.formatAtomicHuman(totalPaid, 4),
      limit,
      offset,
      currency: gameModeManager.cryptoType
    });
  } catch (error) {
    throw new AppError('Failed to retrieve payment history', {
      statusCode: 500,
      safeMessage: 'Unable to retrieve payment history.',
      cause: error
    });
  }
}));

// Get payout history for a user
app.get('/api/user/:socketId/payouts', asyncHandler(async (req, res) => {
  const { socketId } = req.params;
  const limit = Math.min(parseInt(req.query.limit, 10) || 20, 100);
  const offset = parseInt(req.query.offset, 10) || 0;
  
  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId parameter is required.'
    });
  }

  try {
    const user = await gameModeManager.getOrCreateUser(socketId);
    const result = await db.query(`
      SELECT 
        p.id,
        p.amount,
        p.multiplier,
        p.reason,
        p.status,
        p.tx_hash,
        p.created_at,
        p.processed_at,
        g.outcome as game_outcome
      FROM payouts p
      LEFT JOIN games g ON p.game_id = g.id
      WHERE p.user_id = $1 
      ORDER BY p.created_at DESC 
      LIMIT $2 OFFSET $3
    `, [user.id, limit, offset]);
    
    const countResult = await db.query(
      `SELECT COUNT(*) as total FROM payouts WHERE user_id = $1`,
      [user.id]
    );
    
    // Calculate total received (confirmed payouts)
    const totalResult = await db.query(
      `SELECT COALESCE(SUM(amount), 0) as total_received FROM payouts WHERE user_id = $1 AND status = 'completed'`,
      [user.id]
    );
    
    res.json({
      payouts: result.rows.map(row => ({
        id: row.id,
        amount: row.amount,
        amountFormatted: gameModeManager.formatAtomicHuman(row.amount, 4),
        multiplier: parseFloat(row.multiplier) || 0,
        reason: row.reason,
        status: row.status,
        txHash: row.tx_hash,
        createdAt: row.created_at,
        processedAt: row.processed_at,
        gameOutcome: row.game_outcome
      })),
      total: parseInt(countResult.rows[0].total, 10),
      totalReceived: parseInt(totalResult.rows[0].total_received, 10),
      totalReceivedFormatted: gameModeManager.formatAtomicHuman(totalResult.rows[0].total_received, 4),
      limit,
      offset,
      currency: gameModeManager.cryptoType
    });
  } catch (error) {
    throw new AppError('Failed to retrieve payout history', {
      statusCode: 500,
      safeMessage: 'Unable to retrieve payout history.',
      cause: error
    });
  }
}));

// =============================================================================
// Smirk Wallet Authentication Endpoints
// =============================================================================
// Smirk is a browser extension wallet for Wownero/Monero.
// Disable for Monero stagenet deployments (Smirk doesn't support stagenet).
const smirkEnabled = process.env.SMIRK_ENABLED !== 'false';

if (smirkEnabled) {
/**
 * POST /api/auth/smirk/challenge
 * Generate a challenge for Smirk wallet signature verification
 * Body: { socketId: string }
 */
app.post('/api/auth/smirk/challenge', asyncHandler(async (req, res) => {
  const { socketId } = req.body || {};

  if (!socketId || typeof socketId !== 'string') {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId is required to generate a challenge.'
    });
  }

  // Generate a cryptographically secure challenge
  const challenge = crypto.randomBytes(32).toString('hex');

  // Store challenge in database (expires in 5 minutes)
  await db.query(`
    INSERT INTO smirk_challenges (challenge, socket_id)
    VALUES ($1, $2)
  `, [challenge, socketId]);

  // Clean up old/expired challenges periodically
  await db.query(`
    DELETE FROM smirk_challenges
    WHERE expires_at < NOW() OR (used = TRUE AND created_at < NOW() - INTERVAL '1 hour')
  `);

  res.json({
    challenge,
    expiresIn: 300 // 5 minutes in seconds
  });
}));

/**
 * POST /api/auth/smirk/verify
 * Verify a Smirk wallet signature and link to user session
 * Body: { socketId: string, challenge: string, publicKey: string, signature: string }
 */
app.post('/api/auth/smirk/verify', asyncHandler(async (req, res) => {
  const { socketId, challenge, publicKey, signature } = req.body || {};

  if (!socketId || !challenge || !publicKey || !signature) {
    throw new ValidationError('Missing required fields', {
      safeMessage: 'socketId, challenge, publicKey, and signature are required.'
    });
  }

  // 1. Verify challenge exists, is not used, and has not expired
  const challengeResult = await db.query(`
    SELECT * FROM smirk_challenges
    WHERE challenge = $1 AND socket_id = $2 AND used = FALSE AND expires_at > NOW()
  `, [challenge, socketId]);

  if (challengeResult.rows.length === 0) {
    throw new ValidationError('Invalid or expired challenge', {
      safeMessage: 'The challenge is invalid, expired, or has already been used.'
    });
  }

  // 2. Mark challenge as used immediately (prevent replay attacks)
  await db.query(`
    UPDATE smirk_challenges SET used = TRUE WHERE id = $1
  `, [challengeResult.rows[0].id]);

  // 3. Verify signature using tweetnacl
  // Accepts both formats during transition:
  // - RFC 8032 standard: signature over raw UTF-8 message bytes (new extension)
  // - Legacy: signature over SHA256(message) (old extension, remove after 2026-07-01)
  let isValidSignature = false;
  try {
    const nacl = require('tweetnacl');
    const signatureBytes = Buffer.from(signature, 'hex');
    const publicKeyBytes = Buffer.from(publicKey, 'hex');

    // Try RFC 8032 standard first (raw message bytes)
    const challengeBytes = Buffer.from(challenge, 'utf8');
    isValidSignature = nacl.sign.detached.verify(challengeBytes, signatureBytes, publicKeyBytes);

    // Fall back to legacy SHA256 pre-hash (DEPRECATED — remove after 2026-07-01)
    if (!isValidSignature) {
      const challengeHash = crypto.createHash('sha256').update(challenge).digest();
      isValidSignature = nacl.sign.detached.verify(challengeHash, signatureBytes, publicKeyBytes);
    }
  } catch (verifyError) {
    console.error('Signature verification error:', verifyError.message);
    throw new ValidationError('Signature verification failed', {
      safeMessage: 'Unable to verify the wallet signature.'
    });
  }

  if (!isValidSignature) {
    throw new ValidationError('Invalid signature', {
      safeMessage: 'The wallet signature is invalid.'
    });
  }

  // 4. Link public key to user session
  const userResult = await db.query(`
    SELECT id FROM users WHERE socket_id = $1
  `, [socketId]);

  if (userResult.rows.length === 0) {
    throw new NotFoundError('User session not found', {
      safeMessage: 'No active session found. Please connect to the game first.'
    });
  }

  const userId = userResult.rows[0].id;

  // Check if this public key is already linked to another user
  const existingLink = await db.query(`
    SELECT id FROM users WHERE smirk_public_key = $1 AND id != $2
  `, [publicKey, userId]);

  if (existingLink.rows.length > 0) {
    throw new ValidationError('Wallet already linked', {
      safeMessage: 'This wallet is already linked to another account.'
    });
  }

  // Link the wallet to this user
  await db.query(`
    UPDATE users SET smirk_public_key = $1 WHERE id = $2
  `, [publicKey, userId]);

  res.json({
    success: true,
    linked: true,
    message: 'Smirk wallet linked successfully'
  });
}));

/**
 * GET /api/auth/smirk/status
 * Check if a session has a linked Smirk wallet
 * Query: socketId=string
 */
app.get('/api/auth/smirk/status', asyncHandler(async (req, res) => {
  const { socketId } = req.query;

  if (!socketId) {
    throw new ValidationError('Missing socketId', {
      safeMessage: 'socketId query parameter is required.'
    });
  }

  const result = await db.query(`
    SELECT smirk_public_key, payout_address FROM users WHERE socket_id = $1
  `, [socketId]);

  if (result.rows.length === 0) {
    res.json({
      linked: false,
      hasPayoutAddress: false
    });
    return;
  }

  const user = result.rows[0];
  res.json({
    linked: !!user.smirk_public_key,
    hasPayoutAddress: !!user.payout_address
  });
}));

} // End of smirkEnabled block

// =============================================================================
// Admin API Endpoints (requires ADMIN_API_KEY)
// =============================================================================

/**
 * Admin authentication middleware
 * Requires X-Admin-Key header to match ADMIN_API_KEY env variable
 */
const adminAuth = (req, res, next) => {
  const adminKey = process.env.ADMIN_API_KEY;
  if (!adminKey) {
    return res.status(503).json({
      error: 'Admin API not configured',
      message: 'Set ADMIN_API_KEY environment variable to enable admin endpoints.'
    });
  }

  // Origin check — reject cross-origin requests to admin endpoints
  // Same-origin requests (Origin matches Host) are always allowed
  const origin = req.headers.origin || req.headers.referer;
  if (origin) {
    try {
      const requestOrigin = new URL(origin).origin;
      const host = req.headers.host;
      const protocol = req.secure || req.headers['x-forwarded-proto'] === 'https' ? 'https' : 'http';
      const selfOrigin = `${protocol}://${host}`;

      // Allow same-origin requests (admin.html served from same server)
      if (requestOrigin !== selfOrigin) {
        // Check explicit allowlist for cross-origin requests
        const allowedOrigins = process.env.ALLOWED_ORIGINS
          ? process.env.ALLOWED_ORIGINS.split(',').map(o => o.trim())
          : [`http://localhost:${process.env.PORT || 3000}`, `http://127.0.0.1:${process.env.PORT || 3000}`];
        if (!allowedOrigins.includes(requestOrigin)) {
          return res.status(403).json({ error: 'Forbidden', message: 'Origin not allowed.' });
        }
      }
    } catch (e) {
      return res.status(403).json({ error: 'Forbidden', message: 'Invalid origin.' });
    }
  }

  const providedKey = req.headers['x-admin-key'];
  if (!providedKey ||
      providedKey.length !== adminKey.length ||
      !crypto.timingSafeEqual(Buffer.from(providedKey), Buffer.from(adminKey))) {
    return res.status(401).json({
      error: 'Unauthorized',
      message: 'Invalid or missing X-Admin-Key header.'
    });
  }

  next();
};

/**
 * POST /api/admin/refund/payment
 * Refund a payment - marks it as refunded and optionally sends funds back
 * Body: { paymentId: number, reason?: string, sendFunds?: boolean }
 */
app.post('/api/admin/refund/payment', adminAuth, asyncHandler(async (req, res) => {
  const { paymentId, reason, sendFunds } = req.body || {};
  
  if (!paymentId || typeof paymentId !== 'number') {
    throw new ValidationError('Invalid paymentId', {
      safeMessage: 'paymentId (number) is required.'
    });
  }
  
  // Get payment record
  const paymentResult = await db.query(`
    SELECT p.*, u.payout_address, u.socket_id
    FROM payments p
    LEFT JOIN users u ON p.user_id = u.id
    WHERE p.id = $1
  `, [paymentId]);
  
  if (paymentResult.rows.length === 0) {
    throw new NotFoundError('Payment not found', {
      safeMessage: `Payment ${paymentId} not found.`
    });
  }
  
  const payment = paymentResult.rows[0];
  
  if (payment.status === 'refunded') {
    return res.json({
      success: false,
      message: 'Payment already refunded.',
      payment: { id: payment.id, status: payment.status }
    });
  }
  
  // Begin transaction
  const client = await db.getClient();
  try {
    await client.query('BEGIN');
    
    // Mark payment as refunded
    await client.query(`
      UPDATE payments 
      SET status = 'refunded', 
          description = COALESCE(description, '') || ' | Refunded: ' || $2
      WHERE id = $1
    `, [paymentId, reason || 'Admin refund']);
    
    // If credits were purchased, deduct them
    let creditsDeducted = 0;
    if (payment.credits_purchased > 0 && payment.user_id) {
      // SECURITY: Use FOR UPDATE to lock the row and prevent race conditions
      const userResult = await client.query(`
        SELECT credits FROM users WHERE id = $1 FOR UPDATE
      `, [payment.user_id]);

      const currentCredits = userResult.rows[0]?.credits || 0;
      creditsDeducted = Math.min(payment.credits_purchased, currentCredits);

      if (creditsDeducted > 0) {
        // SECURITY: Use atomic decrement with guard to prevent negative balance
        const updateResult = await client.query(`
          UPDATE users SET credits = credits - $1 WHERE id = $2 AND credits >= $1
          RETURNING credits
        `, [creditsDeducted, payment.user_id]);

        let newBalance = updateResult.rows[0]?.credits;

        // If update failed (race condition changed credits), recalculate
        if (updateResult.rows.length === 0) {
          const recheckResult = await client.query(`SELECT credits FROM users WHERE id = $1 FOR UPDATE`, [payment.user_id]);
          const actualCredits = recheckResult.rows[0]?.credits || 0;
          creditsDeducted = Math.min(payment.credits_purchased, actualCredits);
          if (creditsDeducted > 0) {
            const retryResult = await client.query(`
              UPDATE users SET credits = credits - $1 WHERE id = $2 AND credits >= $1 RETURNING credits
            `, [creditsDeducted, payment.user_id]);
            newBalance = retryResult.rows[0]?.credits ?? (actualCredits - creditsDeducted);
          } else {
            newBalance = actualCredits;
          }
        }

        // Record credit transaction
        if (creditsDeducted > 0) {
          await client.query(`
            INSERT INTO credit_transactions (user_id, amount, reason, balance_after, transaction_type)
            VALUES ($1, $2, $3, $4, 'refund')
          `, [payment.user_id, -creditsDeducted, `Refund for payment ${paymentId}`, newBalance]);
        }
      }
    }
    
    await client.query('COMMIT');
    
    // Optionally send funds back via wallet RPC. Refund what the user ACTUALLY paid
    // (received_amount, recorded at confirmation) when available, falling back to the
    // expected amount for older records.
    let fundsSent = false;
    let txHash = null;
    const refundAmount = (payment.received_amount != null && Number(payment.received_amount) > 0)
      ? payment.received_amount
      : payment.expected_amount;
    if (sendFunds && payment.payout_address && Number(refundAmount) > 0) {
      try {
        // processPayout validates the address and performs the transfer; returns
        // { success, txHash, fee }. (The previous code called a nonexistent sendPayment(),
        // so refunds were silently never sent while still reporting success.)
        const result = await walletRPCService.processPayout({
          address: payment.payout_address,
          amount: refundAmount,
          userId: payment.user_id,
          description: `Refund for payment ${paymentId}`
        });
        fundsSent = !!(result && result.success);
        txHash = (result && result.txHash) || null;
      } catch (err) {
        console.error('Failed to send refund funds:', err.message);
        // Don't fail the request - refund is recorded, funds can be sent manually
      }
    }
    
    res.json({
      success: true,
      message: 'Payment refunded successfully.',
      refund: {
        paymentId,
        originalAmount: payment.expected_amount,
        originalAmountFormatted: gameModeManager.formatAtomicHuman(payment.expected_amount, 4),
        creditsDeducted,
        fundsSent,
        txHash,
        reason: reason || 'Admin refund'
      }
    });
    
  } catch (err) {
    await client.query('ROLLBACK');
    throw err;
  } finally {
    client.release();
  }
}));

/**
 * POST /api/admin/credits/adjust
 * Adjust a user's credit balance (add or subtract)
 * Body: { socketId: string, amount: number, reason?: string }
 * amount can be positive (add) or negative (subtract)
 */
app.post('/api/admin/credits/adjust', adminAuth, asyncHandler(async (req, res) => {
  const { socketId, amount, reason } = req.body || {};
  
  if (!socketId || typeof socketId !== 'string') {
    throw new ValidationError('Invalid socketId', {
      safeMessage: 'socketId (string) is required.'
    });
  }
  
  if (typeof amount !== 'number' || amount === 0) {
    throw new ValidationError('Invalid amount', {
      safeMessage: 'amount (non-zero number) is required. Positive to add, negative to subtract.'
    });
  }
  
  // Get user
  const user = await gameModeManager.getOrCreateUser(socketId);
  if (!user) {
    throw new NotFoundError('User not found', {
      safeMessage: `User with socket ${socketId} not found.`
    });
  }
  
  const currentCredits = user.credits || 0;

  // SECURITY: Use atomic UPDATE to prevent race conditions
  // For negative adjustments, ensure user has enough credits
  let updateResult;
  let actualAdjustment;
  let newBalance;

  if (amount < 0) {
    // Deduction: atomic check that credits >= amount to deduct
    const deductAmount = Math.abs(amount);
    updateResult = await db.query(`
      UPDATE users
      SET credits = credits - $1, updated_at = NOW()
      WHERE id = $2 AND credits >= $1
      RETURNING credits
    `, [deductAmount, user.id]);

    if (updateResult.rows.length === 0) {
      return res.json({
        success: false,
        message: `Cannot deduct ${deductAmount} credits - user only has ${currentCredits} credits.`,
        user: { credits: currentCredits }
      });
    }

    newBalance = updateResult.rows[0].credits;
    actualAdjustment = newBalance - currentCredits;
  } else {
    // Addition: always succeeds
    updateResult = await db.query(`
      UPDATE users
      SET credits = credits + $1, updated_at = NOW()
      WHERE id = $2
      RETURNING credits
    `, [amount, user.id]);

    newBalance = updateResult.rows[0]?.credits ?? (currentCredits + amount);
    actualAdjustment = amount;
  }

  if (actualAdjustment === 0) {
    return res.json({
      success: false,
      message: 'No adjustment made.',
      user: { credits: currentCredits }
    });
  }
  
  // Record transaction
  const transactionType = actualAdjustment > 0 ? 'admin_credit' : 'admin_debit';
  await db.query(`
    INSERT INTO credit_transactions (user_id, amount, reason, balance_after, transaction_type)
    VALUES ($1, $2, $3, $4, $5)
  `, [user.id, actualAdjustment, reason || 'Admin adjustment', newBalance, transactionType]);
  
  // Notify user if connected
  try {
    io.to(socketId).emit('credits_update', { 
      balance: newBalance,
      creditsPerGame: gameModeManager.creditsPerGameCost
    });
  } catch (_) {}
  
  res.json({
    success: true,
    message: `Credits ${actualAdjustment > 0 ? 'added' : 'deducted'} successfully.`,
    adjustment: {
      userId: user.id,
      previousBalance: currentCredits,
      adjustment: actualAdjustment,
      newBalance,
      reason: reason || 'Admin adjustment'
    }
  });
}));

/**
 * POST /api/admin/alerts/test-email
 * Send a test email to verify alert service configuration
 * Requires: X-Admin-Key header
 */
app.post('/api/admin/alerts/test-email', adminAuth, asyncHandler(async (req, res) => {
  if (!alertService) {
    return res.status(503).json({
      success: false,
      message: 'Alert service not initialized. Payment system may not be enabled.'
    });
  }

  const result = await alertService.sendAlert('test_email', {
    subject: `🧪 Wownerogue Alert Test - ${process.env.NODE_ENV || 'development'}`,
    html: `
      <h2>Alert Service Test</h2>
      <p>If you received this email, the alert notifications are working correctly!</p>
      <hr>
      <p><strong>Environment:</strong> ${process.env.NODE_ENV || 'development'}</p>
      <p><strong>Time:</strong> ${new Date().toISOString()}</p>
      <p><strong>Server:</strong> ${process.env.CRYPTO_TYPE || 'WOW'}</p>
    `
  });

  res.json({
    success: result.sent,
    message: result.sent ? 'Test email sent successfully!' : (result.reason || 'Failed to send'),
    details: result
  });
}));

// =============================================================================
// Admin Queue Management
// =============================================================================

/**
 * GET /api/admin/queue
 * Get current queue details for admin dashboard
 * Returns full queue entries (not anonymized)
 */
app.get('/api/admin/queue', adminAuth, asyncHandler(async (req, res) => {
  if (!socketHandlers?.queueManager) {
    return res.status(503).json({
      success: false,
      message: 'Queue manager not available'
    });
  }

  const queueDetails = socketHandlers.queueManager.getQueueDetailsForAdmin();

  res.json({
    success: true,
    queue: queueDetails,
    count: queueDetails.length
  });
}));

/**
 * POST /api/admin/queue/remove
 * Remove a stuck queue entry by serverId
 * Body: { serverId: string, reason?: string }
 */
app.post('/api/admin/queue/remove', adminAuth, asyncHandler(async (req, res) => {
  const { serverId, reason } = req.body || {};

  if (!serverId || typeof serverId !== 'string') {
    throw new ValidationError('Missing serverId', {
      safeMessage: 'serverId is required to remove a queue entry.'
    });
  }

  if (!socketHandlers?.queueManager) {
    return res.status(503).json({
      success: false,
      message: 'Queue manager not available'
    });
  }

  // Check if entry exists first
  const isQueued = socketHandlers.queueManager.isPlayerQueued(serverId);
  if (!isQueued) {
    return res.status(404).json({
      success: false,
      message: `No queue entry found for serverId: ${serverId}`
    });
  }

  // Remove the entry
  const removed = socketHandlers.queueManager.removePlayer(serverId);

  // Log admin action
  console.log(`[Admin] Queue entry removed: serverId=${serverId}, reason="${reason || 'No reason provided'}", by admin at ${new Date().toISOString()}`);

  // Optionally notify the user via socket (if still connected)
  try {
    io.to(serverId).emit('queue_cancelled', {
      reason: 'admin_removed',
      message: 'Your queue entry was removed by an administrator.'
    });
  } catch (notifyErr) {
    // Ignore errors - user may be disconnected
  }

  res.json({
    success: removed,
    message: removed ? 'Queue entry removed successfully' : 'Failed to remove queue entry',
    serverId: serverId
  });
}));

// =============================================================================
// ADMIN CHAT MODERATION ENDPOINTS
// =============================================================================

/**
 * GET /api/admin/chat
 * List recent chat messages for moderation
 * Query: ?limit=100&includeDeleted=false
 */
app.get('/api/admin/chat', adminAuth, asyncHandler(async (req, res) => {
  const limit = Math.min(parseInt(req.query.limit) || 100, 500);
  const includeDeleted = req.query.includeDeleted === 'true';

  const messages = await socketHandlers.chatHandler.chatHistory.getMessagesForAdmin(limit, includeDeleted);

  res.json({
    messages,
    count: messages.length
  });
}));

/**
 * DELETE /api/admin/chat/:id
 * Soft delete a chat message
 * Body: { reason?: string }
 */
app.delete('/api/admin/chat/:id', adminAuth, asyncHandler(async (req, res) => {
  const messageId = parseInt(req.params.id);
  const { reason } = req.body;

  if (!messageId || isNaN(messageId)) {
    throw new ValidationError('Invalid message ID');
  }

  const deleted = await socketHandlers.chatHandler.chatHistory.deleteMessage(
    messageId,
    'admin',
    reason || 'Admin deleted'
  );

  if (deleted) {
    // Broadcast deletion to all connected clients
    io.emit('chat_deleted', { messageId });
    console.log(`[Admin] Chat message deleted: id=${messageId}, reason="${reason || 'No reason provided'}"`);
  }

  res.json({
    success: deleted,
    message: deleted ? 'Message deleted' : 'Message not found or already deleted'
  });
}));

/**
 * POST /api/admin/users/:id/chat-ban
 * Ban or unban a user from chat
 * Body: { banned: boolean, reason?: string }
 */
app.post('/api/admin/users/:id/chat-ban', adminAuth, asyncHandler(async (req, res) => {
  const userId = parseInt(req.params.id);
  const { banned, reason } = req.body;

  if (!userId || isNaN(userId)) {
    throw new ValidationError('Invalid user ID');
  }

  if (typeof banned !== 'boolean') {
    throw new ValidationError('banned must be a boolean');
  }

  await db.query(`
    UPDATE users
    SET chat_banned = $2,
        chat_banned_at = CASE WHEN $2 THEN NOW() ELSE NULL END,
        chat_banned_reason = $3
    WHERE id = $1
  `, [userId, banned, reason || null]);

  console.log(`[Admin] User ${userId} chat ${banned ? 'banned' : 'unbanned'}: reason="${reason || 'No reason provided'}"`);

  res.json({
    success: true,
    userId,
    banned,
    reason: reason || null
  });
}));

/**
 * GET /api/admin/users/search
 * Search for users by socket ID prefix or payout address
 * Query: ?q=searchterm&limit=20
 */
app.get('/api/admin/users/search', adminAuth, asyncHandler(async (req, res) => {
  const { q, limit = 20 } = req.query;
  
  if (!q || q.length < 3) {
    throw new ValidationError('Invalid search query', {
      safeMessage: 'Search query must be at least 3 characters.'
    });
  }
  
  const searchLimit = Math.min(parseInt(limit, 10) || 20, 100);
  
  const result = await db.query(`
    SELECT id, socket_id, payout_address, credits, total_games_played, total_credits_purchased, created_at
    FROM users
    WHERE socket_id ILIKE $1 OR payout_address ILIKE $1
    ORDER BY created_at DESC
    LIMIT $2
  `, [`%${q}%`, searchLimit]);
  
  res.json({
    users: result.rows.map(u => ({
      id: u.id,
      socketId: u.socket_id,
      payoutAddress: u.payout_address ? `${u.payout_address.substring(0, 10)}...` : null,
      credits: u.credits || 0,
      gamesPlayed: u.total_games_played || 0,
      createdAt: u.created_at
    })),
    total: result.rows.length
  });
}));

// =============================================================================
// Admin Stats Endpoints
// =============================================================================

// GET /api/admin/stats/overview - Server-wide statistics
app.get('/api/admin/stats/overview', adminAuth, asyncHandler(async (req, res) => {
  // Get user counts
  const userStats = await db.query(`
    SELECT
      COUNT(*) as total_users,
      SUM(total_games_played) as total_games,
      SUM(total_games_won) as total_wins,
      SUM(total_amount_won) as total_payout_volume,
      COUNT(*) FILTER (WHERE created_at > NOW() - INTERVAL '24 hours') as new_users_24h
    FROM users
  `);

  // Get payout counts
  const payoutStats = await db.query(`
    SELECT
      COUNT(*) FILTER (WHERE status = 'pending') as pending_payouts,
      COUNT(*) FILTER (WHERE status = 'failed') as failed_payouts,
      COUNT(*) FILTER (WHERE status = 'completed') as completed_payouts,
      COUNT(*) FILTER (WHERE status = 'completed' AND processed_at > NOW() - INTERVAL '24 hours') as payouts_24h
    FROM payouts
  `);

  // Get game counts for last 24h
  const gameStats = await db.query(`
    SELECT
      COUNT(*) as games_24h,
      COUNT(*) FILTER (WHERE status = 'won') as wins_24h,
      COUNT(*) FILTER (WHERE status = 'lost') as losses_24h
    FROM games
    WHERE created_at > NOW() - INTERVAL '24 hours'
  `);

  // Get wallet balance - always attempt, even if isHealthy is false
  let walletBalance = null;
  try {
    walletBalance = await walletRPCService.getBalance();
    if (walletBalance.error) {
      console.warn('Wallet balance returned error:', walletBalance.error);
    }
  } catch (e) {
    console.error('Failed to get wallet balance for admin stats:', e.message);
    walletBalance = { balance: 0, unlocked_balance: 0, error: e.message };
  }

  const user = userStats.rows[0];
  const payout = payoutStats.rows[0];
  const game = gameStats.rows[0];

  const cryptoType = gameModeManager.cryptoType || process.env.CRYPTO_TYPE || 'WOW';
  const { inferCurrencyDecimals, getDecimalDivisor } = require('./game/helpers/gameModeUtils');
  const atomicDivisor = getDecimalDivisor(inferCurrencyDecimals(cryptoType));

  res.json({
    totalUsers: parseInt(user.total_users) || 0,
    totalGamesPlayed: parseInt(user.total_games) || 0,
    totalGamesWon: parseInt(user.total_wins) || 0,
    totalPayoutVolume: user.total_payout_volume || '0',
    pendingPayouts: parseInt(payout.pending_payouts) || 0,
    failedPayouts: parseInt(payout.failed_payouts) || 0,
    completedPayouts: parseInt(payout.completed_payouts) || 0,
    walletBalance: walletBalance,
    cryptoType,
    atomicDivisor,
    last24h: {
      games: parseInt(game.games_24h) || 0,
      wins: parseInt(game.wins_24h) || 0,
      losses: parseInt(game.losses_24h) || 0,
      payouts: parseInt(payout.payouts_24h) || 0,
      newUsers: parseInt(user.new_users_24h) || 0
    }
  });
}));

// GET /api/admin/stats/payouts - Payout details
app.get('/api/admin/stats/payouts', adminAuth, asyncHandler(async (req, res) => {
  const { status, limit = 50, offset = 0 } = req.query;
  const limitNum = Math.min(parseInt(limit) || 50, 200);
  const offsetNum = parseInt(offset) || 0;

  let whereClause = '';
  const params = [limitNum, offsetNum];

  if (status && ['pending', 'failed', 'completed', 'permanently_failed'].includes(status)) {
    whereClause = 'WHERE status = $3';
    params.push(status);
  }

  const result = await db.query(`
    SELECT p.id, p.game_id, p.user_id, p.amount, p.payout_address, p.status,
           p.tx_hash, p.fee, p.retry_count, p.last_error, p.created_at, p.processed_at
    FROM payouts p
    ${whereClause}
    ORDER BY p.created_at DESC
    LIMIT $1 OFFSET $2
  `, params);

  // Get totals
  const totals = await db.query(`
    SELECT
      COUNT(*) FILTER (WHERE status = 'pending') as pending_count,
      COUNT(*) FILTER (WHERE status = 'failed') as failed_count,
      COUNT(*) FILTER (WHERE status = 'completed') as completed_count,
      COUNT(*) FILTER (WHERE status = 'permanently_failed') as permanently_failed_count,
      COALESCE(SUM(amount) FILTER (WHERE status = 'completed'), 0) as total_volume
    FROM payouts
  `);

  res.json({
    payouts: result.rows.map(p => ({
      id: p.id,
      gameId: p.game_id,
      userId: p.user_id,
      amount: p.amount,
      address: p.payout_address,
      status: p.status,
      txHash: p.tx_hash,
      fee: p.fee,
      retryCount: p.retry_count,
      lastError: p.last_error,
      createdAt: p.created_at,
      processedAt: p.processed_at
    })),
    totals: {
      pending: parseInt(totals.rows[0].pending_count) || 0,
      failed: parseInt(totals.rows[0].failed_count) || 0,
      completed: parseInt(totals.rows[0].completed_count) || 0,
      permanentlyFailed: parseInt(totals.rows[0].permanently_failed_count) || 0,
      totalVolume: totals.rows[0].total_volume || '0'
    }
  });
}));

// GET /api/admin/stats/games - Game statistics
app.get('/api/admin/stats/games', adminAuth, asyncHandler(async (req, res) => {
  const { period = '24h', limit = 50 } = req.query;
  const limitNum = Math.min(parseInt(limit) || 50, 200);

  // Parse period
  let interval = '24 hours';
  if (period === '7d') interval = '7 days';
  else if (period === '30d') interval = '30 days';

  // Summary stats
  const summary = await db.query(`
    SELECT
      COUNT(*) as total,
      COUNT(*) FILTER (WHERE status = 'won') as won,
      COUNT(*) FILTER (WHERE status = 'lost') as lost,
      COUNT(*) FILTER (WHERE outcome = 'escaped') as escaped,
      COUNT(*) FILTER (WHERE outcome = 'caught_by_monster') as caught,
      COUNT(*) FILTER (WHERE outcome = 'expired') as expired,
      AVG(duration_seconds) as avg_duration
    FROM games
    WHERE created_at > NOW() - INTERVAL '${interval}'
  `);

  // By game mode
  const byMode = await db.query(`
    SELECT game_mode, COUNT(*) as count
    FROM games
    WHERE created_at > NOW() - INTERVAL '${interval}'
    GROUP BY game_mode
  `);

  // Top winners
  const topWinners = await db.query(`
    SELECT u.socket_id, u.total_games_won as wins, u.total_amount_won as total_won
    FROM users u
    WHERE u.total_games_won > 0
    ORDER BY u.total_amount_won DESC
    LIMIT 10
  `);

  // Recent games
  const recentGames = await db.query(`
    SELECT g.id, g.game_mode, g.status, g.outcome, g.duration_seconds, g.created_at,
           p.amount as payout_amount
    FROM games g
    LEFT JOIN payouts p ON p.game_id = g.id AND p.status = 'completed'
    ORDER BY g.created_at DESC
    LIMIT $1
  `, [limitNum]);

  const s = summary.rows[0];
  const modeMap = {};
  byMode.rows.forEach(r => { modeMap[r.game_mode] = parseInt(r.count) || 0; });

  res.json({
    summary: {
      total: parseInt(s.total) || 0,
      won: parseInt(s.won) || 0,
      lost: parseInt(s.lost) || 0,
      escaped: parseInt(s.escaped) || 0,
      caught: parseInt(s.caught) || 0,
      expired: parseInt(s.expired) || 0
    },
    avgDuration: parseFloat(s.avg_duration) || 0,
    byMode: modeMap,
    topWinners: topWinners.rows.map(w => ({
      socketId: w.socket_id?.substring(0, 20) + '...',
      wins: parseInt(w.wins) || 0,
      totalWon: w.total_won || '0'
    })),
    recentGames: recentGames.rows.map(g => ({
      id: g.id,
      mode: g.game_mode,
      status: g.status,
      outcome: g.outcome,
      duration: g.duration_seconds,
      payoutAmount: g.payout_amount,
      createdAt: g.created_at
    }))
  });
}));

// GET /api/admin/users - Paginated user list
app.get('/api/admin/users', adminAuth, asyncHandler(async (req, res) => {
  const { search, limit = 50, offset = 0 } = req.query;
  const limitNum = Math.min(parseInt(limit) || 50, 200);
  const offsetNum = parseInt(offset) || 0;

  let whereClause = '';
  const params = [limitNum, offsetNum];

  if (search && search.length >= 3) {
    whereClause = 'WHERE socket_id ILIKE $3 OR payout_address ILIKE $3';
    params.push(`%${search}%`);
  }

  const result = await db.query(`
    SELECT id, socket_id, payout_address, credits, total_games_played, total_games_won,
           total_amount_paid, total_amount_won, total_credits_purchased, created_at
    FROM users
    ${whereClause}
    ORDER BY created_at DESC
    LIMIT $1 OFFSET $2
  `, params);

  const countResult = await db.query(`
    SELECT COUNT(*) as total FROM users ${whereClause}
  `, search && search.length >= 3 ? [`%${search}%`] : []);

  res.json({
    users: result.rows.map(u => ({
      id: u.id,
      socketId: u.socket_id,
      payoutAddress: u.payout_address ? `${u.payout_address.substring(0, 15)}...` : null,
      credits: u.credits || 0,
      gamesPlayed: parseInt(u.total_games_played) || 0,
      gamesWon: parseInt(u.total_games_won) || 0,
      totalPaid: u.total_amount_paid || '0',
      totalWon: u.total_amount_won || '0',
      creditsPurchased: parseInt(u.total_credits_purchased) || 0,
      createdAt: u.created_at
    })),
    total: parseInt(countResult.rows[0]?.total) || 0,
    limit: limitNum,
    offset: offsetNum
  });
}));

// GET /api/admin/users/:id - Detailed user info
app.get('/api/admin/users/:id', adminAuth, asyncHandler(async (req, res) => {
  const { id } = req.params;

  const userResult = await db.query(`
    SELECT * FROM users WHERE id = $1
  `, [id]);

  if (!userResult.rows.length) {
    throw new NotFoundError('User not found');
  }

  const user = userResult.rows[0];

  // Get user's games
  const gamesResult = await db.query(`
    SELECT id, game_mode, status, outcome, treasure_found, moves_made, duration_seconds, created_at
    FROM games
    WHERE user_id = $1
    ORDER BY created_at DESC
    LIMIT 50
  `, [id]);

  // Get user's payments
  const paymentsResult = await db.query(`
    SELECT id, amount, status, tx_hash, credits_purchased, created_at
    FROM payments
    WHERE user_id = $1
    ORDER BY created_at DESC
    LIMIT 50
  `, [id]);

  // Get user's payouts
  const payoutsResult = await db.query(`
    SELECT id, amount, status, tx_hash, fee, payout_address, created_at, processed_at
    FROM payouts
    WHERE user_id = $1
    ORDER BY created_at DESC
    LIMIT 50
  `, [id]);

  res.json({
    user: {
      id: user.id,
      socketId: user.socket_id,
      payoutAddress: user.payout_address,
      credits: user.credits || 0,
      gamesPlayed: parseInt(user.total_games_played) || 0,
      gamesWon: parseInt(user.total_games_won) || 0,
      totalPaid: user.total_amount_paid || '0',
      totalWon: user.total_amount_won || '0',
      creditsPurchased: parseInt(user.total_credits_purchased) || 0,
      createdAt: user.created_at
    },
    games: gamesResult.rows,
    payments: paymentsResult.rows,
    payouts: payoutsResult.rows
  });
}));

// POST /api/admin/payouts/:id/retry - Manually retry a failed payout
app.post('/api/admin/payouts/:id/retry', adminAuth, asyncHandler(async (req, res) => {
  const { id } = req.params;

  const payoutResult = await db.query(`
    SELECT * FROM payouts WHERE id = $1
  `, [id]);

  if (!payoutResult.rows.length) {
    throw new NotFoundError('Payout not found');
  }

  const payout = payoutResult.rows[0];

  if (payout.status === 'completed') {
    throw new ValidationError('Payout already completed');
  }

  // Reset status to pending for retry
  await db.query(`
    UPDATE payouts SET status = 'pending', last_error = 'Manual retry requested' WHERE id = $1
  `, [id]);

  res.json({
    success: true,
    message: 'Payout queued for retry',
    payoutId: id
  });
}));

// =============================================================================
// LEADERBOARD
// =============================================================================
app.get('/api/leaderboard', asyncHandler(async (req, res) => {
  const period = req.query.period || 'all';
  const limit = Math.min(parseInt(req.query.limit) || 20, 50);

  let timeFilter = '';
  if (period === 'week') timeFilter = "AND g.completed_at > NOW() - INTERVAL '7 days'";
  else if (period === 'month') timeFilter = "AND g.completed_at > NOW() - INTERVAL '30 days'";

  const result = await db.query(`
    SELECT
      u.id,
      COALESCE(u.display_name,
        CASE WHEN u.payout_address IS NOT NULL
          THEN LEFT(u.payout_address, 4) || '...' || RIGHT(u.payout_address, 4)
          ELSE 'Anon#' || u.id
        END
      ) as name,
      MAX(g.score) as best_score,
      COUNT(*) FILTER (WHERE g.status = 'won') as wins,
      COUNT(*) as games_played
    FROM games g
    JOIN users u ON g.user_id = u.id
    WHERE g.status IN ('won', 'lost') AND g.score > 0 ${timeFilter}
    GROUP BY u.id, u.display_name, u.payout_address
    ORDER BY best_score DESC
    LIMIT $1
  `, [limit]);

  res.json({ leaderboard: result.rows, period });
}));

app.get('/api/game-modes', (req, res) => {
  const config = paymentConfigManager.getConfig();
  const decimals = Number(config.currency?.decimals ?? 12);
  const divisor = Number.isFinite(decimals) ? Math.pow(10, decimals) : 1;
  const toDisplay = (value) => {
    if (value === null || value === undefined) {
      return 0;
    }
    const numeric = typeof value === 'bigint' ? Number(value) : Number(value);
    return Number.isFinite(numeric) ? numeric / divisor : 0;
  };

  const directMode = config.modes.direct;
  const creditsMode = config.modes.credits;

  // Include hosted by info if configured
  let hostedBy = null;
  if (process.env.HOSTED_BY) {
    let hostname = process.env.HOSTED_BY_NAME;
    if (!hostname) {
      try {
        hostname = new URL(process.env.HOSTED_BY).hostname;
      } catch (e) {
        hostname = process.env.HOSTED_BY; // Use raw value if URL parsing fails
      }
    }
    hostedBy = {
      url: process.env.HOSTED_BY,
      name: hostname
    };
  }

  res.json({
    FREE: {
      name: 'Free Play',
      cost: 0,
      payoutMultiplier: 0,
      enabled: !config.paymentsEnabled
    },
    PAID_SINGLE: {
      name: 'Paid Single Game',
      cost: toDisplay(directMode.price),
      enabled: !!directMode.enabled,
      payoutMultiplier: config.payouts.rules.direct.multipliers
    },
    PAID_CREDITS: {
      name: 'Credits Package',
      cost: toDisplay(creditsMode.packages?.[0]?.price ?? 0),
      credits: creditsMode.packages?.[0]?.credits ?? creditsMode.creditsPerGame,
      enabled: !!creditsMode.enabled,
      payoutMultiplier: creditsMode.enabled && config.payouts.rules.credits.enabled
        ? config.payouts.rules.credits.multipliers
        : 0
    },
    hostedBy
  });
});

// ============================================================================
// Provably Fair Verification Endpoint
// ============================================================================

/**
 * Verify a game's fairness by checking if the seed matches the commitment hash
 * 
 * GET /verify/:gameId - Returns HTML verification page
 * GET /api/verify - Verify seed and commitment (query params: seed, commitment)
 */
app.get('/verify/:gameId', asyncHandler(async (req, res) => {
  const { gameId } = req.params;
  
  // Try to look up the game in the database
  let gameRecord = null;
  try {
    const result = await databaseManager.query(
      'SELECT dungeon_seed, status, treasure_found, moves_made, duration_seconds, created_at FROM games WHERE dungeon_seed = $1',
      [gameId]
    );
    if (result.rows.length > 0) {
      gameRecord = result.rows[0];
    }
  } catch (err) {
    // Database lookup failed, continue without game record
  }
  
  // Return a simple HTML verification page
  res.send(`
<!DOCTYPE html>
<html>
<head>
  <title>Wownerogue - Game Verification</title>
  <style>
    body { background: #0a0a0a; color: #0f0; font-family: monospace; padding: 20px; max-width: 800px; margin: 0 auto; }
    h1 { color: #0ff; }
    .box { background: #001a00; border: 1px solid #0f0; padding: 15px; margin: 10px 0; border-radius: 5px; }
    input, button { font-family: monospace; padding: 8px; margin: 5px 0; }
    input { background: #001a00; color: #0f0; border: 1px solid #0f0; width: 100%; box-sizing: border-box; }
    button { background: #0a5c0a; color: #ff0; border: 2px solid #0f0; cursor: pointer; }
    button:hover { background: #0f0; color: #000; }
    .success { color: #4ade80; }
    .error { color: #f00; }
    #result { margin-top: 15px; padding: 10px; }
    code { background: #002200; padding: 2px 6px; border-radius: 3px; }
    .info { color: #888; font-size: 12px; }
  </style>
</head>
<body>
  <h1>🔐 Wownerogue Provably Fair Verification</h1>
  
  <div class="box">
    <h3>How it works:</h3>
    <ol>
      <li>Before game start, you received a <strong>commitment hash</strong> (SHA-256)</li>
      <li>After the game, you received the <strong>seed</strong></li>
      <li>This page verifies: <code>SHA256(seed) === commitment</code></li>
      <li>The seed deterministically generated your dungeon layout</li>
    </ol>
  </div>
  
  <div class="box">
    <h3>Verify Game</h3>
    <label>Game Seed (revealed after game):</label>
    <input type="text" id="seed" placeholder="64 character hex string">
    
    <label>Commitment Hash (shown before game):</label>
    <input type="text" id="commitment" placeholder="64 character hex string">
    
    <button onclick="verify()">🔍 Verify</button>
    
    <div id="result"></div>
  </div>
  
  ${gameRecord ? `
  <div class="box">
    <h3>Game Record</h3>
    <p><strong>Game ID:</strong> ${gameId}</p>
    <p><strong>Status:</strong> ${gameRecord.status}</p>
    <p><strong>Treasure Found:</strong> ${gameRecord.treasure_found ? 'Yes' : 'No'}</p>
    <p><strong>Moves:</strong> ${gameRecord.moves_made || 'N/A'}</p>
    <p><strong>Duration:</strong> ${gameRecord.duration_seconds ? gameRecord.duration_seconds + 's' : 'N/A'}</p>
    <p><strong>Created:</strong> ${gameRecord.created_at}</p>
  </div>
  ` : ''}
  
  <div class="box info">
    <p>For technical verification, you can also use the API:</p>
    <code>GET /api/verify?seed=YOUR_SEED&commitment=YOUR_COMMITMENT</code>
  </div>
  
  <script>
    async function verify() {
      const seed = document.getElementById('seed').value.trim();
      const commitment = document.getElementById('commitment').value.trim();
      const result = document.getElementById('result');
      
      if (!seed || !commitment) {
        result.innerHTML = '<p class="error">Please enter both seed and commitment.</p>';
        return;
      }
      
      try {
        const response = await fetch('/api/verify?seed=' + encodeURIComponent(seed) + '&commitment=' + encodeURIComponent(commitment));
        const data = await response.json();
        
        if (data.valid) {
          result.innerHTML = '<p class="success">✅ ' + data.message + '</p>' +
            '<p>Computed hash: <code>' + data.computedHash + '</code></p>';
        } else {
          result.innerHTML = '<p class="error">❌ ' + data.message + '</p>' +
            '<p>Expected: <code>' + data.expectedCommitment + '</code></p>' +
            '<p>Got: <code>' + data.computedHash + '</code></p>';
        }
      } catch (err) {
        result.innerHTML = '<p class="error">Error: ' + err.message + '</p>';
      }
    }
  </script>
</body>
</html>
  `);
}));

// API endpoint for programmatic verification
app.get('/api/verify', (req, res) => {
  const { seed, commitment } = req.query;
  
  if (!seed || !commitment) {
    return res.status(400).json({
      valid: false,
      error: 'Missing required parameters: seed and commitment'
    });
  }
  
  const result = verifyGame(seed, commitment);

  // PROVABLY FAIR (Phase 0.2): when the seed matches the commitment, regenerate the
  // dungeon from the seed and return a layout fingerprint so the player can confirm
  // the layout is a deterministic function of the committed seed (not crafted after payment).
  if (result.valid) {
    try {
      const DungeonGenerator = require('./game/dungeon');
      const dungeon = DungeonGenerator.regenerateFromSeed(seed, process.env.CRYPTO_TYPE || 'WOW');
      result.layoutFingerprint = DungeonGenerator.layoutFingerprint(dungeon);
      result.dungeonSize = { width: dungeon.map[0].length, height: dungeon.map.length };
      result.entrance = dungeon.entrance;
      result.exit = dungeon.exit;
      result.treasure = dungeon.treasure;
    } catch (e) {
      // Regeneration is best-effort; the hash check above is the primary verification.
    }
  }

  res.json(result);
});

// Initialize debug manager with new block callbacks
debugManager.onNewBlockCallback((blockHeight) => {
    // Start games for waiting players when new block detected
    socketHandlers.startGamesForWaiting(blockHeight);
    // Check active games for timeout
    socketHandlers.checkGamesTimeout(blockHeight);
    // Flush any pending payouts (safety net for batch timer)
    gameModeManager._processPendingPayouts().catch(err => {
        console.error('❌ Block-triggered payout processing error:', err.message);
    });
});

// Initialize payment system
async function initializePaymentSystem() {
    try {
        console.log('🔧 Initializing payment system...');
        const walletInitialized = await walletRPCService.initialize();
        if (!walletInitialized) {
            console.log('⚠️ Wallet RPC not available - falling back to FREE mode');
            process.env.GAME_MODE = 'FREE';
      paymentConfigManager.refresh();
      gameModeManager.setLegacyGameMode('FREE');
      gameModeManager.paymentsEnabled = false;
      gameModeManager.directModeEnabled = false;
      gameModeManager.creditsModeEnabled = false;
        }
        
        // Initialize database connection and run migrations
        await databaseManager.initialize();
        console.log('✅ Database initialized successfully');
        
        // Test RPC service connectivity
        const rpcHealth = await rpcService.healthCheck();
        console.log(`✅ RPC Service: ${rpcHealth.healthy ? 'Connected' : 'Warning - using fallback'}`);
        
        console.log('🚀 Payment system ready!');
        return true;
    } catch (error) {
        console.error('❌ Failed to initialize payment system:', error);
        console.log('⚠️  Server will continue in FREE mode only');
        return false;
    }
}

// Start the debug/production system
debugManager.initialize();

// Debug function for registered users
function debugRegisteredUsers() {
    if (debugManager.CONSOLE_LOGGING) {
        console.log("📊 REGISTERED USERS DEBUG:");
        const allUsers = require('./db/user').getAllUsers();
        console.log(`Total registered users: ${allUsers.length}`);
        allUsers.forEach(u => {
            // u.id is the socket/server id; there is no separate socketId property on User
            console.log(`  - User ID: ${u.id}, Socket: ${u.id}, Client: ${u.clientId}`);
        });
        console.log(`Active games: ${activeGames.size}`);
    }
}

// Regular debug logging
setInterval(debugRegisteredUsers, 10000);

// Start server
async function startServer() {
    try {
        // Initialize payment system first
        const paymentSystemReady = await initializePaymentSystem();
        
        // Socket.io connection handler - ONLY after payment system is ready
        io.on('connection', function(socket) {
            socketHandlers.handleConnection(socket);
        });
        
        // Start HTTP server
        const PORT = process.env.PORT || 3000;
        http.listen(PORT, function() {
            console.log(`🚀 Wownerogue server listening on *:${PORT}`);
            console.log(`🐛 Debug mode: ${debugManager.getDebugStatus().debugMode ? 'ENABLED' : 'DISABLED'}`);
            console.log(`💰 Payment system: ${paymentSystemReady ? 'ENABLED' : 'FREE MODE ONLY'}`);
            const summary = paymentConfigManager.summarize();
            const enabledModes = [];
            if (!summary.paymentsEnabled || !paymentSystemReady) {
                enabledModes.push('FREE');
            }
            if (summary.directEnabled && paymentSystemReady) {
                enabledModes.push('PAID_SINGLE');
            }
            if (summary.creditsEnabled && paymentSystemReady) {
                enabledModes.push('PAID_CREDITS');
            }
            if (enabledModes.length === 0) {
                enabledModes.push(summary.legacyMode || 'FREE');
            }
            console.log(`🎮 Available game modes: ${enabledModes.join(', ')}`);
        });
        
        // Start batch payout processing if payment system is ready
        if (paymentSystemReady) {
            const payoutConfig = paymentConfigManager.getConfig().payouts?.processing || {};
            const payoutIntervalSeconds = Math.max(1, Number(payoutConfig.batchInterval || 300));
            const payoutIntervalMs = payoutIntervalSeconds * 1000;
            batchPayoutInterval = setInterval(async () => {
                try {
                    await gameModeManager._processPendingPayouts();
                } catch (error) {
                    console.error('Error in batch payout processing:', error);
                }
            }, payoutIntervalMs);

            // Start payout retry service for failed/stuck payouts
            const maxRetries = Number(process.env.PAYOUT_MAX_RETRIES) || 3;
            const retryIntervalMs = Number(process.env.PAYOUT_RETRY_INTERVAL_MS) || 300000; // 5 minutes
            // Initialize alert service for email notifications
            alertService = new AlertService({
                walletService: walletRPCService,
                db: databaseManager,
                debugManager
            });

            // Make alertService available to gameModeManager/paymentHandlers for balance checks
            gameModeManager.alertService = alertService;

            payoutRetryService = new PayoutRetryService({
                db: databaseManager,
                walletService: walletRPCService,
                debugManager,
                maxRetries,
                retryIntervalMs,
                alertService // Pass alert service for failure notifications
            });
            payoutRetryService.start();

            // Start periodic alert checks (every 5 minutes)
            alertService.startPeriodicChecks(300000);
        }

        // Periodic job: expire old pending payments (every 5 minutes)
        paymentExpiryInterval = setInterval(async () => {
            try {
                const result = await databaseManager.query(`
                    UPDATE payments SET status = 'expired'
                    WHERE status = 'pending' AND expires_at < NOW()
                    RETURNING id, subaddress
                `);
                if (result.rows.length > 0) {
                    for (const row of result.rows) {
                        walletRPCService.stopPaymentMonitoring(row.subaddress);
                        walletRPCService.addressToUser.delete(row.subaddress);
                        walletRPCService.addressToSocket.delete(row.subaddress);
                    }
                    console.log(`[PaymentExpiry] Expired ${result.rows.length} stale payment(s)`);
                }
            } catch (e) {
                console.error('[PaymentExpiry] Error:', e.message);
            }
        }, 5 * 60 * 1000);
        
    } catch (error) {
        console.error('❌ Failed to start server:', error);
        process.exit(1);
    }
}

// Attach 404 and error handlers last
app.use((req, res, next) => {
  next(new NotFoundError(`Route not found: ${req.method} ${req.originalUrl}`, {
    safeMessage: 'The requested resource was not found.'
  }));
});

app.use(createErrorMiddleware({ logger: console }));

startServer();

// Graceful shutdown — clean up timers, wait for in-flight payouts, close DB pool
async function gracefulShutdown(signal) {
    console.log(`\n${signal} received. Shutting down gracefully...`);

    // Stop accepting new connections
    http.close();

    // Stop scheduled timers
    if (batchPayoutInterval) clearInterval(batchPayoutInterval);
    if (paymentExpiryInterval) clearInterval(paymentExpiryInterval);
    if (gameModeManager._batchPayoutTimer) clearTimeout(gameModeManager._batchPayoutTimer);
    if (payoutRetryService) payoutRetryService.stop();
    if (alertService) alertService.stopPeriodicChecks?.();

    // Wait for in-flight batch processing to finish (up to 10 seconds)
    let waitMs = 0;
    while (gameModeManager._isBatchProcessing && waitMs < 10000) {
        await new Promise(r => setTimeout(r, 500));
        waitMs += 500;
    }
    if (waitMs > 0) {
        console.log(`  Waited ${waitMs}ms for in-flight payout processing`);
    }

    // Close database pool
    try {
        await databaseManager.close();
        console.log('  Database pool closed');
    } catch (err) {
        console.error('  Error closing database pool:', err.message);
    }

    console.log('Shutdown complete.');
    process.exit(0);
}

process.on('SIGTERM', () => gracefulShutdown('SIGTERM'));
process.on('SIGINT', () => gracefulShutdown('SIGINT'));