const jwt = require('jsonwebtoken');
const { getConfig } = require('../db');

let cachedSecret = null;

function getSecret() {
  if (cachedSecret) return cachedSecret;
  try {
    cachedSecret = getConfig()?.jwt_secret || process.env.JWT_SECRET;
  } catch {}
  if (!cachedSecret) throw new Error('JWT_SECRET not configured');
  return cachedSecret;
}

function generateToken(user) {
  return jwt.sign({ id: user.id, username: user.username, role: user.role, game_name: user.game_name, game_uid: user.game_uid, email: user.email }, getSecret(), { expiresIn: '72h' });
}

function verifyToken(token) { return jwt.verify(token, getSecret()); }

function authenticate(req, res, next) {
  const h = req.headers.authorization;
  if (!h || !h.startsWith('Bearer ')) return res.status(401).json({ error: '请先登录' });
  try { req.user = verifyToken(h.split(' ')[1]); next(); }
  catch (e) { return res.status(401).json({ error: e.name === 'TokenExpiredError' ? '登录已过期，请重新登录' : '无效的认证信息' }); }
}

function requireRole(...roles) {
  return (req, res, next) => {
    if (!req.user) return res.status(401).json({ error: '请先登录' });
    if (!roles.includes(req.user.role)) return res.status(403).json({ error: '权限不足' });
    next();
  };
}

function optionalAuth(req, res, next) {
  const h = req.headers.authorization;
  if (h && h.startsWith('Bearer ')) { try { req.user = verifyToken(h.split(' ')[1]); } catch {} }
  next();
}

module.exports = { generateToken, verifyToken, authenticate, requireRole, optionalAuth };