MultiRoombaRover/server/src/services/authService/index.js

// auth Service
// Purpose: Defines the auth Service module and the helpers/state used by this service unit.
// Scope: Keeps runtime behavior unchanged while isolating responsibilities into a clear module boundary.
const bcrypt = require('bcrypt');
const io = require('../../globals/io');
const logger = require('../../globals/logger').child('authService');
const { loadConfig } = require('../../helpers/configLoader');
const { clearLockdownTimer } = require('../lockdownGuard');
const { getMode, MODES } = require('../modeManager');
const { setRole } = require('../roleService');
const { getSocketIp, isLocalNetwork } = require('../../helpers/ipResolver');
const {
  canUseExternalSpectatorAccess,
  getBandwidthSavingsPolicy,
} = require('../../helpers/bandwidthSavings');
const {
  getFeatureState,
  getUserIdForSocket,
  updateFeatureState,
} = require('../identityService');

const config = loadConfig();
const admins = config.admins || [];
const SPECTATOR_ACCESS_NAMESPACE = 'spectatorAccess';

function findAdmin(username) {
  return admins.find((admin) => admin.username === username);
}

async function authenticate(username, password) {
  const admin = findAdmin(username);
  if (!admin) {
    throw new Error('Invalid credentials');
  }
  const ok = await bcrypt.compare(password, admin.password_hash);
  if (!ok) {
    throw new Error('Invalid credentials');
  }
  return admin;
}

function isAdmin(socket) {
  return socket?.data?.role === 'admin' || socket?.data?.role === 'lockdown';
}

function isLockdownAdmin(socket) {
  return socket?.data?.role === 'lockdown';
}

function hasExternalSpectatorGrant(socket) {
  const userId = getUserIdForSocket(socket);
  if (!userId) return false;
  const state = getFeatureState(userId, SPECTATOR_ACCESS_NAMESPACE, {});
  /*
    The identity database already owns per-user feature state. Keeping the grant
    as a tiny namespaced boolean avoids a new table and lets the existing admin
    database editor grant/revoke external spectator access immediately.
  */
  return Boolean(state?.external);
}

function canBecomeSpectator(socket) {
  const ip = getSocketIp(socket);
  const local = isLocalNetwork(ip);
  return canUseExternalSpectatorAccess({
    isLocal: local,
    isAdmin: isAdmin(socket),
    isVerified: Boolean(socket?.data?.isVerified),
    hasGrant: hasExternalSpectatorGrant(socket),
  });
}

function externalSpectatorAccessError() {
  const mode = getBandwidthSavingsPolicy().externalSpectatorAccess;
  if (mode === 'verifiedOnly') {
    return 'External spectator access requires a verified identity.';
  }
  if (mode === 'admin') {
    return 'External spectator access requires admin approval for this identity.';
  }
  return 'External spectator access is disabled.';
}

function grantExternalSpectatorAccessAfterAdminLogin(socket) {
  const policy = getBandwidthSavingsPolicy();
  if (policy.externalSpectatorAccess !== 'admin') {
    return false;
  }
  const ip = getSocketIp(socket);
  if (isLocalNetwork(ip)) {
    return false;
  }
  const userId = getUserIdForSocket(socket);
  if (!userId) {
    /*
      Sockets are normally identified on connection before login, but keeping a
      guard here makes the admin grant fail closed instead of writing an orphan
      feature-state row if identity setup changes later.
    */
    logger.warn('External spectator grant skipped because socket has no identity', { socketId: socket?.id });
    return false;
  }
  updateFeatureState(
    userId,
    SPECTATOR_ACCESS_NAMESPACE,
    (current) => ({
      /*
        Preserve any future spectatorAccess settings beside `external`. The
        login flow is only approving this identity for external spectating, not
        resetting the whole namespace back to a one-field object.
      */
      ...(current || {}),
      external: true,
      grantedByAdminLoginAt: Date.now(),
      grantedByAdminUsername: socket?.data?.user?.username || null,
    }),
    {},
  );
  logger.info('External spectator access granted after admin login', {
    socketId: socket.id,
    userId,
    username: socket?.data?.user?.username || null,
  });
  return true;
}

io.on('connection', (socket) => {
  const requestedRole = socket.handshake?.query?.role;
  /*
    Role is assigned before the browser's full identity heartbeat has completed.
    For admin-gated external spectators, fail closed here; the spectator page can
    identify the socket and then retry session:setRole once the grant exists.
  */
  const initialRole = requestedRole === 'spectator' && canBecomeSpectator(socket) ? 'spectator' : 'user';
  setRole(socket, initialRole);
  logger.info('Socket connected with role', socket.id, initialRole);
  socket.emit('auth:role', { role: initialRole });
  socket.on('auth:login', async ({ username, password }, cb = () => {}) => {
    try {
      const admin = await authenticate(username, password);
      if (getMode() === MODES.LOCKDOWN && !admin.lockdown) {
        throw new Error('Lockdown admins only');
      }
      const role = admin.lockdown ? 'lockdown' : 'admin';
      socket.data.user = { username: admin.username, discordId: admin.discord_id };
      setRole(socket, role);
      /*
        In admin-gated external spectator mode, logging in from /spectate is the
        approval action for this browser identity. Persist the grant before the
        client retries switching back to spectator, otherwise the user would
        lose the admin bypass and immediately fall back into the gate.
      */
      grantExternalSpectatorAccessAfterAdminLogin(socket);
      socket.emit('auth:role', { role });
      clearLockdownTimer(socket);
      logger.info('Login success', socket.id, role);
      cb({ success: true, role: socket.data.role });
    } catch (err) {
      logger.warn('Login failed', socket.id, err.message);
      cb({ success: false, error: err.message });
    }
  });

  function handleRoleChange({ role } = {}, cb = () => {}) {
    if (role === 'spectator' || role === 'user') {
      if (role === 'spectator' && !canBecomeSpectator(socket)) {
        const error = externalSpectatorAccessError();
        logger.info('Spectator role denied by bandwidth policy', socket.id, { error });
        cb({ error });
        return;
      }
      setRole(socket, role);
      socket.emit('auth:role', { role });
      logger.info('Role changed via client request', socket.id, role);
      cb({ success: true, role });
    } else {
      cb({ error: 'Invalid role' });
    }
  }

  socket.on('role:set', handleRoleChange);
  socket.on('session:setRole', handleRoleChange);
});

module.exports = {
  isAdmin,
  isLockdownAdmin,
  authenticate,
};