// 加载环境变量（必须在最开始）
require('dotenv').config();

const express = require('express');
const cors = require('cors');
const cookieParser = require('cookie-parser');
const session = require('express-session');
const svgCaptcha = require('svg-captcha');
const SftpClient = require('ssh2-sftp-client');
const multer = require('multer');
const nodemailer = require('nodemailer');
const path = require('path');
const fs = require('fs');
const { body, validationResult } = require('express-validator');
const archiver = require('archiver');
const { exec, execSync } = require('child_process');
const net = require('net');
const dns = require('dns').promises;
const util = require('util');
const execAsync = util.promisify(exec);

const { db, UserDB, ShareDB, SettingsDB, VerificationDB, PasswordResetTokenDB } = require('./database');
const { generateToken, authMiddleware, adminMiddleware } = require('./auth');

const app = express();
const PORT = process.env.PORT || 40001;
const USERNAME_REGEX = /^[A-Za-z0-9_.\u4e00-\u9fa5-]{3,20}$/u; // 允许中英文、数字、下划线、点和短横线
const ENFORCE_HTTPS = process.env.ENFORCE_HTTPS === 'true';

// 在反向代理（如 Nginx/Cloudflare）后部署时，信任代理以正确识别协议/IP/HTTPS
app.set('trust proxy', process.env.TRUST_PROXY || true);

// 配置CORS - 严格白名单模式
const allowedOrigins = process.env.ALLOWED_ORIGINS
  ? process.env.ALLOWED_ORIGINS.split(',').map(origin => origin.trim())
  : []; // 默认为空数组，不允许任何域名

const corsOptions = {
  credentials: true,
  origin: (origin, callback) => {
    // 生产环境必须配置白名单
    if (allowedOrigins.length === 0 && process.env.NODE_ENV === 'production') {
      console.error('❌ 错误: 生产环境必须配置 ALLOWED_ORIGINS 环境变量！');
      callback(new Error('CORS未配置'));
      return;
    }

    // 开发环境如果没有配置，允许 localhost
    if (allowedOrigins.length === 0) {
      const devOrigins = ['http://localhost:3000', 'http://127.0.0.1:3000'];
      if (!origin || devOrigins.some(o => origin.startsWith(o))) {
        callback(null, true);
        return;
      }
    }

    // 严格白名单模式：只允许白名单中的域名
    // 但需要允许没有Origin头的同源请求（浏览器访问时不会发送Origin）
    if (!origin) {
      // 没有Origin头的请求通常是：
      // 1. 浏览器的同源请求（不触发CORS）
      // 2. 直接的服务器请求
      // 这些都应该允许
      callback(null, true);
    } else if (allowedOrigins.includes(origin)) {
      // 白名单中的域名
      callback(null, true);
    } else {
      // 拒绝不在白名单中的跨域请求
      console.warn(`[CORS] 拒绝来自未授权来源的请求: ${origin}`);
      callback(new Error('CORS策略不允许来自该来源的访问'));
    }
  }
};

// 中间件
app.use(cors(corsOptions));
app.use(express.json());
app.use(cookieParser());

// 强制HTTPS（可通过环境变量控制，默认关闭以兼容本地环境）
app.use((req, res, next) => {
  if (!ENFORCE_HTTPS) return next();
  const proto = req.get('x-forwarded-proto') || (req.secure ? 'https' : 'http');
  if (proto !== 'https') {
    return res.status(400).json({
      success: false,
      message: '仅支持HTTPS访问，请使用HTTPS'
    });
  }
  return next();
});

// Session配置（用于验证码）
const isSecureCookie = process.env.COOKIE_SECURE === 'true';
const sameSiteMode = isSecureCookie ? 'none' : 'lax'; // HTTPS下允许跨域获取验证码
app.use(session({
  secret: process.env.SESSION_SECRET || 'your-session-secret-change-in-production',
  resave: false,
  saveUninitialized: true, // 改为true，确保验证码请求时创建session
  name: 'captcha.sid', // 自定义session cookie名称
  cookie: {
    secure: isSecureCookie,
    httpOnly: true,
    sameSite: sameSiteMode,
    maxAge: 10 * 60 * 1000 // 10分钟
  }
}));

// 安全响应头中间件
app.use((req, res, next) => {
  // 防止点击劫持
  res.setHeader('X-Frame-Options', 'SAMEORIGIN');
  // 防止MIME类型嗅探
  res.setHeader('X-Content-Type-Options', 'nosniff');
  // XSS保护
  res.setHeader('X-XSS-Protection', '1; mode=block');
  // HTTPS严格传输安全
  if (req.secure || req.headers['x-forwarded-proto'] === 'https') {
    res.setHeader('Strict-Transport-Security', 'max-age=31536000; includeSubDomains');
  }
  // 内容安全策略
  res.setHeader('Content-Security-Policy', "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline';");
  // 隐藏X-Powered-By
  res.removeHeader('X-Powered-By');
  next();
});

// XSS过滤中间件（用于用户输入）
function sanitizeInput(str) {
  if (typeof str !== 'string') return str;
  return str
    .replace(/[<>'"]/g, (char) => {
      const map = {
        '<': '&lt;',
        '>': '&gt;',
        '"': '&quot;',
        "'": '&#x27;'
      };
      return map[char];
    });
}

// HTML转义（用于模板输出）
function escapeHtml(str) {
  if (typeof str !== 'string') return str;
  return str.replace(/[&<>"']/g, char => ({
    '&': '&amp;',
    '<': '&lt;',
    '>': '&gt;',
    '"': '&quot;',
    "'": '&#x27;'
  }[char]));
}

// 规范化并校验HTTP直链前缀，只允许http/https
function sanitizeHttpBaseUrl(raw) {
  if (!raw) return null;
  try {
    const url = new URL(raw);
    if (!['http:', 'https:'].includes(url.protocol)) {
      return null;
    }
    url.search = '';
    url.hash = '';
    // 去掉多余的结尾斜杠，保持路径稳定
    url.pathname = url.pathname.replace(/\/+$/, '');
    return url.toString();
  } catch {
    return null;
  }
}

// 构建安全的下载URL，编码路径片段并拒绝非HTTP(S)前缀
function buildHttpDownloadUrl(rawBaseUrl, filePath) {
  const baseUrl = sanitizeHttpBaseUrl(rawBaseUrl);
  if (!baseUrl || !filePath) return null;

  try {
    const url = new URL(baseUrl);
    const normalizedPath = filePath.startsWith('/') ? filePath : `/${filePath}`;
    const safeSegments = normalizedPath
      .split('/')
      .filter(Boolean)
      .map(segment => encodeURIComponent(segment));
    const safePath = safeSegments.length ? '/' + safeSegments.join('/') : '';

    const basePath = url.pathname.replace(/\/+$/, '');
    const joinedPath = `${basePath}${safePath || '/'}`;
    url.pathname = joinedPath || '/';
    url.search = '';
    url.hash = '';
    return url.toString();
  } catch (err) {
    console.warn('[安全] 生成下载URL失败:', err.message);
    return null;
  }
}

// 应用XSS过滤到所有POST/PUT请求的body
app.use((req, res, next) => {
  if ((req.method === 'POST' || req.method === 'PUT') && req.body) {
    // 递归过滤所有字符串字段
    function sanitizeObject(obj) {
      if (typeof obj === 'string') {
        return sanitizeInput(obj);
      } else if (Array.isArray(obj)) {
        return obj.map(item => sanitizeObject(item));
      } else if (obj && typeof obj === 'object') {
        const sanitized = {};
        for (const [key, value] of Object.entries(obj)) {
          sanitized[key] = sanitizeObject(value);
        }
        return sanitized;
      }
      return obj;
    }
    req.body = sanitizeObject(req.body);
  }
  next();
});

// 请求日志
app.use((req, res, next) => {
  console.log(`[${new Date().toISOString()}] ${req.method} ${req.path}`);
  next();
});

// 获取正确的协议（考虑反向代理）
function getProtocol(req) {
  // 1. 检查 X-Forwarded-Proto 头（nginx 代理传递的协议）
  const forwardedProto = req.get('X-Forwarded-Proto');
  if (forwardedProto) {
    return forwardedProto.split(',')[0].trim();
  }
  
  // 2. 检查 req.protocol
  if (req.protocol) {
    return req.protocol;
  }
  
  // 3. 如果配置了SSL，默认使用https
  if (req.secure) {
    return 'https';
  }
  
  // 4. 默认使用https（因为生产环境应该都配置了SSL）
  return 'https';
}

// 文件上传配置（临时存储）
const upload = multer({
  dest: path.join(__dirname, 'uploads'),
  limits: { fileSize: 5 * 1024 * 1024 * 1024 } // 5GB限制
});

// ===== TTL缓存类 =====

// 带过期时间的缓存类
class TTLCache {
  constructor(defaultTTL = 3600000) { // 默认1小时
    this.cache = new Map();
    this.defaultTTL = defaultTTL;
    
    // 每10分钟清理一次过期缓存
    this.cleanupInterval = setInterval(() => {
      this.cleanup();
    }, 10 * 60 * 1000);
  }

  set(key, value, ttl = this.defaultTTL) {
    const expiresAt = Date.now() + ttl;
    this.cache.set(key, { value, expiresAt });
  }

  get(key) {
    const item = this.cache.get(key);
    if (!item) {
      return undefined;
    }

    // 检查是否过期
    if (Date.now() > item.expiresAt) {
      this.cache.delete(key);
      return undefined;
    }

    return item.value;
  }

  has(key) {
    const item = this.cache.get(key);
    if (!item) {
      return false;
    }

    // 检查是否过期
    if (Date.now() > item.expiresAt) {
      this.cache.delete(key);
      return false;
    }

    return true;
  }

  delete(key) {
    return this.cache.delete(key);
  }

  // 清理过期缓存
  cleanup() {
    const now = Date.now();
    let cleaned = 0;

    for (const [key, item] of this.cache.entries()) {
      if (now > item.expiresAt) {
        this.cache.delete(key);
        cleaned++;
      }
    }

    if (cleaned > 0) {
      console.log(`[缓存清理] 已清理 ${cleaned} 个过期的分享缓存`);
    }
  }

  // 获取缓存大小
  size() {
    return this.cache.size;
  }

  // 停止清理定时器
  destroy() {
    if (this.cleanupInterval) {
      clearInterval(this.cleanupInterval);
    }
  }
}

// 分享文件信息缓存（内存缓存，1小时TTL）
const shareFileCache = new TTLCache(60 * 60 * 1000);

// ===== 防爆破限流器 =====

// 防爆破限流器类
class RateLimiter {
  constructor(options = {}) {
    this.maxAttempts = options.maxAttempts || 5;
    this.windowMs = options.windowMs || 15 * 60 * 1000;
    this.blockDuration = options.blockDuration || 30 * 60 * 1000;
    this.attempts = new Map();
    this.blockedKeys = new Map();

    // 每5分钟清理一次过期记录
    this.cleanupInterval = setInterval(() => {
      this.cleanup();
    }, 5 * 60 * 1000);
  }

  // 获取客户端IP（支持反向代理）
  getClientKey(req) {
    const forwarded = req.get('X-Forwarded-For');
    if (forwarded) {
      return forwarded.split(',')[0].trim();
    }
    return req.ip || req.connection.remoteAddress || 'unknown';
  }

  // 检查是否被封锁
  isBlocked(key) {
    const blockInfo = this.blockedKeys.get(key);
    if (!blockInfo) {
      return false;
    }

    // 检查封锁是否过期
    if (Date.now() > blockInfo.expiresAt) {
      this.blockedKeys.delete(key);
      this.attempts.delete(key);
      return false;
    }

    return true;
  }

  // 记录失败尝试
  recordFailure(key) {
    const now = Date.now();

    // 如果已被封锁，返回封锁信息
    if (this.isBlocked(key)) {
      const blockInfo = this.blockedKeys.get(key);
      return {
        blocked: true,
        remainingAttempts: 0,
        resetTime: blockInfo.expiresAt,
        waitMinutes: Math.ceil((blockInfo.expiresAt - now) / 60000),
        needCaptcha: true
      };
    }

    // 获取或创建尝试记录
    let attemptInfo = this.attempts.get(key);
    if (!attemptInfo || now > attemptInfo.windowEnd) {
      attemptInfo = {
        count: 0,
        windowEnd: now + this.windowMs,
        firstAttempt: now
      };
    }

    attemptInfo.count++;
    this.attempts.set(key, attemptInfo);

    // 检查是否达到封锁阈值
    if (attemptInfo.count >= this.maxAttempts) {
      const blockExpiresAt = now + this.blockDuration;
      this.blockedKeys.set(key, {
        expiresAt: blockExpiresAt,
        blockedAt: now
      });
      console.warn(`[防爆破] 封锁Key: ${key}, 失败次数: ${attemptInfo.count}, 封锁时长: ${Math.ceil(this.blockDuration / 60000)}分钟`);
      return {
        blocked: true,
        remainingAttempts: 0,
        resetTime: blockExpiresAt,
        waitMinutes: Math.ceil(this.blockDuration / 60000),
        needCaptcha: true
      };
    }

    return {
      blocked: false,
      remainingAttempts: this.maxAttempts - attemptInfo.count,
      resetTime: attemptInfo.windowEnd,
      waitMinutes: 0,
      needCaptcha: attemptInfo.count >= 2 // 失败2次后需要验证码
    };
  }

  // 获取失败次数
  getFailureCount(key) {
    const attemptInfo = this.attempts.get(key);
    if (!attemptInfo || Date.now() > attemptInfo.windowEnd) {
      return 0;
    }
    return attemptInfo.count;
  }

  // 记录成功（清除失败记录）
  recordSuccess(key) {
    this.attempts.delete(key);
    this.blockedKeys.delete(key);
  }

  // 清理过期记录
  cleanup() {
    const now = Date.now();
    let cleanedAttempts = 0;
    let cleanedBlocks = 0;

    // 清理过期的尝试记录
    for (const [key, info] of this.attempts.entries()) {
      if (now > info.windowEnd) {
        this.attempts.delete(key);
        cleanedAttempts++;
      }
    }

    // 清理过期的封锁记录
    for (const [key, info] of this.blockedKeys.entries()) {
      if (now > info.expiresAt) {
        this.blockedKeys.delete(key);
        cleanedBlocks++;
      }
    }

    if (cleanedAttempts > 0 || cleanedBlocks > 0) {
      console.log(`[防爆破清理] 已清理 ${cleanedAttempts} 个过期尝试记录, ${cleanedBlocks} 个过期封锁记录`);
    }
  }

  // 获取统计信息
  getStats() {
    return {
      activeAttempts: this.attempts.size,
      blockedKeys: this.blockedKeys.size
    };
  }

  // 停止清理定时器
  destroy() {
    if (this.cleanupInterval) {
      clearInterval(this.cleanupInterval);
    }
  }
}

// 创建登录限流器（5次失败/15分钟，封锁30分钟）
const loginLimiter = new RateLimiter({
  maxAttempts: 5,
  windowMs: 15 * 60 * 1000,
  blockDuration: 30 * 60 * 1000
});

// 创建分享密码限流器（10次失败/10分钟，封锁20分钟）
const shareLimiter = new RateLimiter({
  maxAttempts: 10,
  windowMs: 10 * 60 * 1000,
  blockDuration: 20 * 60 * 1000
});

// 邮件发送限流（防刷）
// 半小时最多3次，超过封30分钟；全天最多10次，超过封24小时
const mailLimiter30Min = new RateLimiter({
  maxAttempts: 3,
  windowMs: 30 * 60 * 1000,
  blockDuration: 30 * 60 * 1000
});
const mailLimiterDay = new RateLimiter({
  maxAttempts: 10,
  windowMs: 24 * 60 * 60 * 1000,
  blockDuration: 24 * 60 * 60 * 1000
});

// 创建验证码获取限流器（30次请求/10分钟，封锁30分钟）
const captchaLimiter = new RateLimiter({
  maxAttempts: 30,
  windowMs: 10 * 60 * 1000,
  blockDuration: 30 * 60 * 1000
});

// 验证码最小请求间隔控制
const CAPTCHA_MIN_INTERVAL = 3000; // 3秒
const captchaLastRequest = new TTLCache(15 * 60 * 1000); // 15分钟自动清理

// 验证码防刷中间件
function captchaRateLimitMiddleware(req, res, next) {
  const clientKey = `captcha:${captchaLimiter.getClientKey(req)}`;
  const now = Date.now();

  // 最小时间间隔限制
  const lastRequest = captchaLastRequest.get(clientKey);
  if (lastRequest && (now - lastRequest) < CAPTCHA_MIN_INTERVAL) {
    return res.status(429).json({
      success: false,
      message: '验证码请求过于频繁，请稍后再试'
    });
  }
  captchaLastRequest.set(clientKey, now, 15 * 60 * 1000);

  // 窗口内总次数限流
  const result = captchaLimiter.recordFailure(clientKey);
  if (result.blocked) {
    return res.status(429).json({
      success: false,
      message: `验证码请求过多，请在 ${result.waitMinutes} 分钟后再试`,
      blocked: true,
      resetTime: result.resetTime
    });
  }

  next();
}

// 登录防爆破中间件
function loginRateLimitMiddleware(req, res, next) {
  const clientIP = loginLimiter.getClientKey(req);
  const { username } = req.body;
  const ipKey = `login:ip:${clientIP}`;

  // 检查IP是否被封锁
  if (loginLimiter.isBlocked(ipKey)) {
    const result = loginLimiter.recordFailure(ipKey);
    console.warn(`[防爆破] 拦截登录尝试 - IP: ${clientIP}, 原因: IP被封锁`);
    return res.status(429).json({
      success: false,
      message: `登录尝试过多，请在 ${result.waitMinutes} 分钟后重试`,
      blocked: true,
      resetTime: result.resetTime
    });
  }

  // 检查用户名是否被封锁
  if (username) {
    const usernameKey = `login:username:${username}`;
    if (loginLimiter.isBlocked(usernameKey)) {
      const result = loginLimiter.recordFailure(usernameKey);
      console.warn(`[防爆破] 拦截登录尝试 - 用户名: ${username}, 原因: 用户名被封锁`);
      return res.status(429).json({
        success: false,
        message: `该账号登录尝试过多，请在 ${result.waitMinutes} 分钟后重试`,
        blocked: true,
        resetTime: result.resetTime
      });
    }
  }

  // 将限流key附加到请求对象，供后续使用
  req.rateLimitKeys = {
    ipKey,
    usernameKey: username ? `login:username:${username}` : null
  };
  next();
}

// 分享密码防爆破中间件
function shareRateLimitMiddleware(req, res, next) {
  const clientIP = shareLimiter.getClientKey(req);
  const { code } = req.params;
  const key = `share:${code}:${clientIP}`;

  // 检查是否被封锁
  if (shareLimiter.isBlocked(key)) {
    const result = shareLimiter.recordFailure(key);
    console.warn(`[防爆破] 拦截分享密码尝试 - 分享码: ${code}, IP: ${clientIP}`);
    return res.status(429).json({
      success: false,
      message: `密码尝试过多，请在 ${result.waitMinutes} 分钟后重试`,
      blocked: true,
      resetTime: result.resetTime
    });
  }

  req.shareRateLimitKey = key;
  next();
}



// ===== 工具函数 =====


// 安全删除文件（不抛出异常）
function safeDeleteFile(filePath) {
  try {
    if (fs.existsSync(filePath)) {
      fs.unlinkSync(filePath);
      console.log(`[清理] 已删除临时文件: ${filePath}`);
      return true;
    }
  } catch (error) {
    console.error(`[清理] 删除临时文件失败: ${filePath}`, error.message);
    return false;
  }
}


// 验证请求路径是否在分享范围内（防止越权访问）
function isPathWithinShare(requestPath, share) {
  if (!requestPath || !share) {
    return false;
  }

  // 规范化路径（移除 ../ 等危险路径，统一分隔符）
  const normalizedRequest = path.normalize(requestPath).replace(/^(\.\.[\/\\])+/, '').replace(/\\/g, '/');
  const normalizedShare = path.normalize(share.share_path).replace(/\\/g, '/');

  if (share.share_type === 'file') {
    // 单文件分享：只允许下载该文件
    return normalizedRequest === normalizedShare;
  } else {
    // 目录分享：只允许下载该目录及其子目录下的文件
    // 确保分享路径以斜杠结尾用于前缀匹配
    const sharePrefix = normalizedShare.endsWith('/') ? normalizedShare : normalizedShare + '/';
    return normalizedRequest === normalizedShare || normalizedRequest.startsWith(sharePrefix);
  }
}
// 清理旧的临时文件（启动时执行一次）
function cleanupOldTempFiles() {
  const uploadsDir = path.join(__dirname, 'uploads');
  if (!fs.existsSync(uploadsDir)) {
    return;
  }

  try {
    const files = fs.readdirSync(uploadsDir);
    const now = Date.now();
    const maxAge = 24 * 60 * 60 * 1000; // 24小时

    let cleaned = 0;
    files.forEach(file => {
      const filePath = path.join(uploadsDir, file);
      try {
        const stats = fs.statSync(filePath);
        if (now - stats.mtimeMs > maxAge) {
          fs.unlinkSync(filePath);
          cleaned++;
        }
      } catch (err) {
        console.error(`[清理] 检查文件失败: ${filePath}`, err.message);
      }
    });

    if (cleaned > 0) {
      console.log(`[清理] 已清理 ${cleaned} 个超过24小时的临时文件`);
    }
  } catch (error) {
    console.error('[清理] 清理临时文件目录失败:', error.message);
  }
}

function isPrivateIp(ip) {
  if (!net.isIP(ip)) return false;
  return ip.startsWith('10.') ||
    ip.startsWith('192.168.') ||
    ip.startsWith('172.16.') ||
    ip.startsWith('172.17.') ||
    ip.startsWith('172.18.') ||
    ip.startsWith('172.19.') ||
    ip.startsWith('172.20.') ||
    ip.startsWith('172.21.') ||
    ip.startsWith('172.22.') ||
    ip.startsWith('172.23.') ||
    ip.startsWith('172.24.') ||
    ip.startsWith('172.25.') ||
    ip.startsWith('172.26.') ||
    ip.startsWith('172.27.') ||
    ip.startsWith('172.28.') ||
    ip.startsWith('172.29.') ||
    ip.startsWith('172.30.') ||
    ip.startsWith('172.31.') ||
    ip.startsWith('127.') ||
    ip === '0.0.0.0' ||
    ip === '::1' ||
    ip.startsWith('fe80:') ||
    ip.startsWith('fd');
}

async function validateSftpDestination(host, port) {
  if (!host || typeof host !== 'string' || host.length > 255) {
    throw new Error('无效的SFTP主机');
  }
  if (host.includes('://') || host.includes('/')) {
    throw new Error('SFTP主机不能包含协议或路径');
  }

  const portNum = parseInt(port, 10) || 22;
  if (portNum < 1 || portNum > 65535) {
    throw new Error('SFTP端口范围应为1-65535');
  }

  let resolvedIp;
  try {
    const lookup = await dns.lookup(host);
    resolvedIp = lookup.address;
  } catch (err) {
    throw new Error('无法解析SFTP主机，请检查域名或IP');
  }

  if (isPrivateIp(resolvedIp) && process.env.ALLOW_PRIVATE_SFTP !== 'true') {
    throw new Error('出于安全考虑，不允许连接内网地址');
  }

  return { host, port: portNum, resolvedIp };
}
// SFTP连接
async function connectToSFTP(config) {
  const sftp = new SftpClient();
  await sftp.connect({
    host: config.ftp_host,
    port: parseInt(config.ftp_port, 10) || 22,
    username: config.ftp_user,
    password: config.ftp_password,
    readyTimeout: parseInt(process.env.SFTP_CONNECT_TIMEOUT || '8000', 10)
  });
  return sftp;
}

// 格式化文件大小
function formatFileSize(bytes) {
  if (bytes === 0) return '0 B';
  const k = 1024;
  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  return Math.round(bytes / Math.pow(k, i) * 100) / 100 + ' ' + sizes[i];
}

// 生成随机Token
function generateRandomToken(length = 48) {
  return require('crypto').randomBytes(length).toString('hex');
}

// 获取SMTP配置
function getSmtpConfig() {
  const host = SettingsDB.get('smtp_host');
  const port = SettingsDB.get('smtp_port');
  const secure = SettingsDB.get('smtp_secure');
  const user = SettingsDB.get('smtp_user');
  const pass = SettingsDB.get('smtp_password');
  const from = SettingsDB.get('smtp_from') || user;

  if (!host || !port || !user || !pass) {
    return null;
  }

  return {
    host,
    port: parseInt(port, 10) || 465,
    secure: secure === 'true' || secure === true || port === '465',
    auth: { user, pass },
    from
  };
}

// 创建邮件传输器
function createTransport() {
  const config = getSmtpConfig();
  if (!config) return null;

  return nodemailer.createTransport({
    host: config.host,
    port: config.port,
    secure: config.secure,
    auth: config.auth
  });
}

// 发送邮件
async function sendMail(to, subject, html) {
  const config = getSmtpConfig();
  const transporter = createTransport();
  if (!config || !transporter) {
    throw new Error('SMTP未配置');
  }

  const from = (config.from && config.from.trim()) ? config.from.trim() : config.auth.user;

  await transporter.sendMail({
    from,
    to,
    subject,
    html
  });
}

// 检查邮件发送限流
function checkMailRateLimit(req, type = 'mail') {
  const clientKey = `${type}:${req.get('X-Forwarded-For') || req.ip || req.connection.remoteAddress || 'unknown'}`;

  const res30 = mailLimiter30Min.recordFailure(clientKey);
  if (res30.blocked) {
    const err = new Error(`请求过于频繁，30分钟内最多3次，请在 ${res30.waitMinutes} 分钟后再试`);
    err.status = 429;
    throw err;
  }

  const resDay = mailLimiterDay.recordFailure(clientKey);
  if (resDay.blocked) {
    const err = new Error(`今天的次数已用完（最多10次），请稍后再试`);
    err.status = 429;
    throw err;
  }
}

// ===== 公开API =====

// 健康检查
app.get('/api/health', (req, res) => {
  res.json({ success: true, message: 'Server is running' });
});

// 生成验证码API
app.get('/api/captcha', captchaRateLimitMiddleware, (req, res) => {
  try {
    const captcha = svgCaptcha.create({
      size: 6, // 验证码长度
      noise: 3, // 干扰线条数
      color: true, // 使用彩色
      background: '#f7f7f7', // 背景色
      width: 140,
      height: 44,
      fontSize: 52,
      charPreset: 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789' // 去掉易混淆字符，字母+数字
    });

    // 将验证码文本存储在session中
    req.session.captcha = captcha.text.toLowerCase();
    req.session.captchaTime = Date.now();

    // 保存session
    req.session.save((err) => {
      if (err) {
        console.error('[验证码] Session保存失败:', err);
      } else {
        console.log('[验证码] 生成成功, SessionID:', req.sessionID, '验证码:', captcha.text);
      }
    });

    res.type('svg');
    res.send(captcha.data);
  } catch (error) {
    console.error('生成验证码失败:', error);
    res.status(500).json({
      success: false,
      message: '生成验证码失败'
    });
  }
});

// 用户注册（简化版）
app.post('/api/register',
  [
    body('username')
      .isLength({ min: 3, max: 20 }).withMessage('用户名长度3-20个字符')
      .matches(USERNAME_REGEX).withMessage('用户名仅允许中英文、数字、下划线、点和短横线'),
    body('email').isEmail().withMessage('邮箱格式不正确'),
    body('password').isLength({ min: 6 }).withMessage('密码至少6个字符')
  ],
  async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      checkMailRateLimit(req, 'verify');
      const { username, email, password } = req.body;

      // 检查用户名是否存在
      if (UserDB.findByUsername(username)) {
        return res.status(400).json({
          success: false,
          message: '用户名已存在'
        });
      }

      // 检查邮箱是否存在
      if (UserDB.findByEmail(email)) {
        return res.status(400).json({
          success: false,
          message: '邮箱已被使用'
        });
      }

      // 检查SMTP配置
      const smtpConfig = getSmtpConfig();
      if (!smtpConfig) {
        return res.status(400).json({
          success: false,
          message: '管理员尚未配置SMTP，暂时无法注册'
        });
      }

      const verifyToken = generateRandomToken(24);
      const expiresAtMs = Date.now() + 30 * 60 * 1000; // 30分钟
      const safeUsernameForMail = escapeHtml(username);

      // 创建用户（不需要FTP配置），标记未验证
      const userId = UserDB.create({
        username,
        email,
        password,
        is_verified: 0,
        verification_token: verifyToken,
        verification_expires_at: expiresAtMs
      });

      const verifyLink = `${getProtocol(req)}://${req.get('host')}/app.html?verifyToken=${verifyToken}`;

      try {
        await sendMail(
          email,
          '邮箱验证 - 玩玩云',
          `<p>您好，${safeUsernameForMail}：</p>
           <p>请点击下面的链接验证您的邮箱，30分钟内有效：</p>
           <p><a href="${verifyLink}" target="_blank">${verifyLink}</a></p>
           <p>如果不是您本人操作，请忽略此邮件。</p>`
        );
      } catch (mailErr) {
        console.error('发送验证邮件失败:', mailErr);
        return res.status(500).json({
          success: false,
          message: '注册成功，但发送验证邮件失败，请稍后重试或联系管理员',
          needVerify: true
        });
      }

      res.json({
        success: true,
        message: '注册成功，请查收邮箱完成验证',
        user_id: userId
      });
    } catch (error) {
      console.error('注册失败:', error);
      res.status(500).json({
        success: false,
        message: '注册失败: ' + error.message
      });
    }
  }
);

// 重新发送邮箱验证邮件
app.post('/api/resend-verification', [
  body('email').optional({ checkFalsy: true }).isEmail().withMessage('邮箱格式不正确'),
  body('username')
    .optional({ checkFalsy: true })
    .isLength({ min: 3 }).withMessage('用户名格式不正确')
    .matches(USERNAME_REGEX).withMessage('用户名仅允许中英文、数字、下划线、点和短横线')
], async (req, res) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.status(400).json({ success: false, errors: errors.array() });
  }

  try {
    checkMailRateLimit(req, 'verify');

    const { email, username } = req.body;
    const user = email ? UserDB.findByEmail(email) : UserDB.findByUsername(username);

    if (!user) {
      return res.status(400).json({ success: false, message: '用户不存在' });
    }
    if (user.is_verified) {
      return res.status(400).json({ success: false, message: '该邮箱已验证，无需重复验证' });
    }

    const smtpConfig = getSmtpConfig();
    if (!smtpConfig) {
      return res.status(400).json({ success: false, message: 'SMTP未配置，无法发送邮件' });
    }

    const verifyToken = generateRandomToken(24);
    const expiresAtMs = Date.now() + 30 * 60 * 1000;
    VerificationDB.setVerification(user.id, verifyToken, expiresAtMs);

    const verifyLink = `${getProtocol(req)}://${req.get('host')}/app.html?verifyToken=${verifyToken}`;
    const safeUsernameForMail = escapeHtml(user.username);
    await sendMail(
      user.email,
      '邮箱验证 - 玩玩云',
      `<p>您好，${safeUsernameForMail}：</p>
       <p>请点击下面的链接验证您的邮箱，30分钟内有效：</p>
       <p><a href="${verifyLink}" target="_blank">${verifyLink}</a></p>
       <p>如果不是您本人操作，请忽略此邮件。</p>`
    );

    res.json({ success: true, message: '验证邮件已发送，请查收' });
  } catch (error) {
    const status = error.status || 500;
    console.error('重发验证邮件失败:', error);
    res.status(status).json({ success: false, message: error.message || '发送失败' });
  }
});

// 验证邮箱
app.get('/api/verify-email', async (req, res) => {
  const { token } = req.query;
  if (!token) {
    return res.status(400).json({ success: false, message: '缺少token' });
  }

  try {
    const user = VerificationDB.consumeVerificationToken(token);
    if (!user) {
      return res.status(400).json({ success: false, message: '无效或已过期的验证链接' });
    }
    res.json({ success: true, message: '邮箱验证成功，请登录' });
  } catch (error) {
    console.error('邮箱验证失败:', error);
    res.status(500).json({ success: false, message: '邮箱验证失败' });
  }
});

// 发起密码重置（邮件）
app.post('/api/password/forgot', [
  body('email').isEmail().withMessage('邮箱格式不正确')
], async (req, res) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.status(400).json({ success: false, errors: errors.array() });
  }

  const { email } = req.body;
  try {
    checkMailRateLimit(req, 'pwd_forgot');

    const smtpConfig = getSmtpConfig();
    if (!smtpConfig) {
      return res.status(400).json({ success: false, message: 'SMTP未配置，无法发送邮件' });
    }

    const user = UserDB.findByEmail(email);
    if (!user) {
      return res.status(400).json({ success: false, message: '邮箱未注册，无法发送重置邮件' });
    }
    if (user.is_banned || !user.is_active) {
      return res.status(403).json({ success: false, message: '账号不可用，无法重置密码' });
    }
    if (!user.is_verified) {
      return res.status(400).json({ success: false, message: '邮箱未验证，无法重置密码' });
    }

    const token = generateRandomToken(24);
    const expiresAtMs = Date.now() + 30 * 60 * 1000;
    PasswordResetTokenDB.create(user.id, token, expiresAtMs);

    const resetLink = `${getProtocol(req)}://${req.get('host')}/app.html?resetToken=${token}`;
    const safeUsernameForMail = escapeHtml(user.username);
    await sendMail(
      email,
      '密码重置 - 玩玩云',
      `<p>您好，${safeUsernameForMail}：</p>
       <p>请点击下面的链接重置密码，30分钟内有效：</p>
       <p><a href="${resetLink}" target="_blank">${resetLink}</a></p>
       <p>如果不是您本人操作，请忽略此邮件。</p>`
    );

    res.json({ success: true, message: '重置邮件已发送，请查收邮箱完成验证' });
  } catch (error) {
    const status = error.status || 500;
    console.error('发送密码重置邮件失败:', error);
    res.status(status).json({ success: false, message: error.message || '发送失败' });
  }
});

// 使用邮件Token重置密码
app.post('/api/password/reset', [
  body('token').notEmpty().withMessage('缺少token'),
  body('new_password').isLength({ min: 6 }).withMessage('新密码至少6个字符')
], async (req, res) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.status(400).json({ success: false, errors: errors.array() });
  }

  const { token, new_password } = req.body;
  try {
    const tokenRow = PasswordResetTokenDB.use(token);
    if (!tokenRow) {
      return res.status(400).json({ success: false, message: '无效或已过期的重置链接' });
    }

    const user = UserDB.findById(tokenRow.user_id);
    if (!user) {
      return res.status(404).json({ success: false, message: '用户不存在' });
    }
    if (user.is_banned || !user.is_active) {
      return res.status(403).json({ success: false, message: '账号不可用，无法重置密码' });
    }
    if (!user.is_verified) {
      return res.status(400).json({ success: false, message: '邮箱未验证，无法重置密码' });
    }

    // 更新密码
    const hashed = require('bcryptjs').hashSync(new_password, 10);
    db.prepare('UPDATE users SET password = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?')
      .run(hashed, tokenRow.user_id);

    res.json({ success: true, message: '密码重置成功，请重新登录' });
  } catch (error) {
    console.error('密码重置失败:', error);
    res.status(500).json({ success: false, message: '密码重置失败' });
  }
});

// 用户登录
app.post('/api/login',
  loginRateLimitMiddleware,
  [
    body('username').notEmpty().withMessage('用户名不能为空'),
    body('password').notEmpty().withMessage('密码不能为空')
  ],
  (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    const { username, password, captcha } = req.body;

    try {
      // 检查是否需要验证码
      const ipKey = req.rateLimitKeys?.ipKey;
      const usernameKey = req.rateLimitKeys?.usernameKey;
      const ipFailures = ipKey ? loginLimiter.getFailureCount(ipKey) : 0;
      const usernameFailures = usernameKey ? loginLimiter.getFailureCount(usernameKey) : 0;
      const needCaptcha = ipFailures >= 2 || usernameFailures >= 2;

      // 如果需要验证码，则验证验证码
      if (needCaptcha) {
        console.log('[登录验证] 需要验证码, SessionID:', req.sessionID, 'IP失败次数:', ipFailures, '用户名失败次数:', usernameFailures);

        if (!captcha) {
          return res.status(400).json({
            success: false,
            message: '请输入验证码',
            needCaptcha: true
          });
        }

        // 验证验证码
        const sessionCaptcha = req.session.captcha;
        const captchaTime = req.session.captchaTime;

        console.log('[登录验证] Session验证码:', sessionCaptcha, '输入验证码:', captcha, 'Session时间:', captchaTime);

        if (!sessionCaptcha || !captchaTime) {
          console.log('[登录验证] 验证码不存在于Session中');
          return res.status(400).json({
            success: false,
            message: '验证码已过期，请刷新验证码',
            needCaptcha: true
          });
        }

        // 验证码有效期5分钟
        if (Date.now() - captchaTime > 5 * 60 * 1000) {
          console.log('[登录验证] 验证码已超过5分钟');
          return res.status(400).json({
            success: false,
            message: '验证码已过期，请刷新验证码',
            needCaptcha: true
          });
        }

        if (captcha.toLowerCase() !== sessionCaptcha) {
          console.log('[登录验证] 验证码不匹配');
          return res.status(400).json({
            success: false,
            message: '验证码错误',
            needCaptcha: true
          });
        }

        console.log('[登录验证] 验证码验证通过');
        // 验证通过后清除session中的验证码
        delete req.session.captcha;
        delete req.session.captchaTime;
      }

      const user = UserDB.findByUsername(username);

      if (!user) {
        // 记录失败尝试
        if (req.rateLimitKeys) {
          const result = loginLimiter.recordFailure(req.rateLimitKeys.ipKey);
          if (req.rateLimitKeys.usernameKey) {
            loginLimiter.recordFailure(req.rateLimitKeys.usernameKey);
          }
          return res.status(401).json({
            success: false,
            message: '用户名或密码错误',
            needCaptcha: result.needCaptcha
          });
        }
        return res.status(401).json({
          success: false,
          message: '用户名或密码错误'
        });
      }

      if (user.is_banned) {
        return res.status(403).json({
          success: false,
          message: '账号已被封禁'
        });
      }

      if (!user.is_verified) {
        return res.status(403).json({
          success: false,
          message: '邮箱未验证，请查收邮件或重新发送验证邮件',
          needVerify: true,
          email: user.email
        });
      }

      if (!UserDB.verifyPassword(password, user.password)) {
        // 记录失败尝试
        if (req.rateLimitKeys) {
          const result = loginLimiter.recordFailure(req.rateLimitKeys.ipKey);
          if (req.rateLimitKeys.usernameKey) {
            loginLimiter.recordFailure(req.rateLimitKeys.usernameKey);
          }
          return res.status(401).json({
            success: false,
            message: '用户名或密码错误',
            needCaptcha: result.needCaptcha
          });
        }
        return res.status(401).json({
          success: false,
          message: '用户名或密码错误'
        });
      }

      const token = generateToken(user);

      // 清除失败记录
      if (req.rateLimitKeys) {
        loginLimiter.recordSuccess(req.rateLimitKeys.ipKey);
        if (req.rateLimitKeys.usernameKey) {
          loginLimiter.recordSuccess(req.rateLimitKeys.usernameKey);
        }
      }

      res.cookie('token', token, {
        httpOnly: true,
        secure: process.env.COOKIE_SECURE === 'true', // HTTPS环境下启用
        sameSite: 'lax', // 防止CSRF攻击
        maxAge: 7 * 24 * 60 * 60 * 1000 // 7天
      });

      res.json({
        success: true,
        message: '登录成功',
        token,
        user: {
          id: user.id,
          username: user.username,
          email: user.email,
          is_admin: user.is_admin,
          has_ftp_config: user.has_ftp_config,
          // 存储相关字段
          storage_permission: user.storage_permission || 'sftp_only',
          current_storage_type: user.current_storage_type || 'sftp',
          local_storage_quota: user.local_storage_quota || 1073741824,
          local_storage_used: user.local_storage_used || 0
        }
      });
    } catch (error) {
      console.error('登录失败:', error);
      res.status(500).json({
        success: false,
        message: '登录失败: ' + error.message
      });
    }
  }
);

// ===== 需要认证的API =====

// 获取当前用户信息
app.get('/api/user/profile', authMiddleware, (req, res) => {
  // 不返回密码明文
  const { ftp_password, password, ...safeUser } = req.user;
  safeUser.http_download_base_url = sanitizeHttpBaseUrl(safeUser.http_download_base_url);
  res.json({
    success: true,
    user: safeUser
  });
});

// 更新FTP配置
app.post('/api/user/update-ftp',
  authMiddleware,
  [
    body('ftp_host').notEmpty().withMessage('FTP主机不能为空'),
    body('ftp_port').isInt({ min: 1, max: 65535 }).withMessage('FTP端口范围1-65535'),
    body('ftp_user').notEmpty().withMessage('FTP用户名不能为空'),
    body('http_download_base_url')
      .optional({ checkFalsy: true })
      .isURL({ protocols: ['http', 'https'], require_protocol: true, require_tld: false })
      .withMessage('HTTP直链地址必须以 http/https 开头')
  ],
  async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { ftp_host, ftp_port, ftp_user, ftp_password, http_download_base_url } = req.body;
      // 调试日志：查看接收到的配置（掩码密码）
      console.log("[DEBUG] 收到SFTP配置:", {
        ftp_host,
        ftp_port,
        ftp_user,
        ftp_password: ftp_password ? "***" : "(empty)",
        http_download_base_url
      });

      const safeHttpBaseUrl = sanitizeHttpBaseUrl(http_download_base_url);
      if (http_download_base_url && !safeHttpBaseUrl) {
        return res.status(400).json({
          success: false,
          message: 'HTTP直链地址必须是合法的http/https地址，且不能包含查询或片段'
        });
      }

      // 如果用户已配置FTP且密码为空，使用现有密码
      let actualPassword = ftp_password;
      if (!ftp_password && req.user.has_ftp_config && req.user.ftp_password) {
        actualPassword = req.user.ftp_password;
      } else if (!ftp_password) {
        return res.status(400).json({
          success: false,
          message: 'FTP密码不能为空'
        });
      }

      // 主机校验与防SSRF
      const { port: safePort } = await validateSftpDestination(ftp_host, ftp_port);

      // 验证FTP连接
      try {
        const sftp = await connectToSFTP({ ftp_host, ftp_port: safePort, ftp_user, ftp_password: actualPassword });
        await sftp.end();
      } catch (error) {
        return res.status(400).json({
          success: false,
          message: 'SFTP连接失败，请检查配置: ' + error.message
        });
      }

      // 更新用户配置
      UserDB.update(req.user.id, {
        ftp_host,
        ftp_port: safePort,
        ftp_user,
        ftp_password: actualPassword,
        http_download_base_url: safeHttpBaseUrl || null,
        has_ftp_config: 1
      });

      res.json({
        success: true,
        message: 'SFTP配置已更新'
      });
    } catch (error) {
      console.error('更新配置失败:', error);
      res.status(500).json({
        success: false,
        message: '更新配置失败: ' + error.message
      });
    }
  }
);

// 修改管理员账号信息（仅管理员可修改用户名）
app.post('/api/admin/update-profile',
  authMiddleware,
  adminMiddleware,
  [
    body('username')
      .isLength({ min: 3, max: 20 }).withMessage('用户名长度3-20个字符')
      .matches(USERNAME_REGEX).withMessage('用户名仅允许中英文、数字、下划线、点和短横线')
  ],
  async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { username } = req.body;

      // 检查用户名是否被占用（排除自己）
      if (username !== req.user.username) {
        const existingUser = UserDB.findByUsername(username);
        if (existingUser && existingUser.id !== req.user.id) {
          return res.status(400).json({
            success: false,
            message: '用户名已被使用'
          });
        }

        // 更新用户名
        UserDB.update(req.user.id, { username });

        // 获取更新后的用户信息
        const updatedUser = UserDB.findById(req.user.id);

        // 生成新的token（因为用户名变了）
        const newToken = generateToken(updatedUser);

        res.json({
          success: true,
          message: '用户名已更新',
          token: newToken,
          user: {
            id: updatedUser.id,
            username: updatedUser.username,
            email: updatedUser.email,
            is_admin: updatedUser.is_admin
          }
        });
      } else {
        res.json({
          success: true,
          message: '没有需要更新的信息'
        });
      }
    } catch (error) {
      console.error('更新账号信息失败:', error);
      res.status(500).json({
        success: false,
        message: '更新失败: ' + error.message
      });
    }
  }
);

// 修改当前用户密码（需要验证当前密码）
app.post('/api/user/change-password',
  authMiddleware,
  [
    body('current_password').notEmpty().withMessage('当前密码不能为空'),
    body('new_password').isLength({ min: 6 }).withMessage('新密码至少6个字符')
  ],
  (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { current_password, new_password } = req.body;

      // 获取当前用户信息
      const user = UserDB.findById(req.user.id);
      if (!user) {
        return res.status(404).json({
          success: false,
          message: '用户不存在'
        });
      }

      // 验证当前密码
      if (!UserDB.verifyPassword(current_password, user.password)) {
        return res.status(401).json({
          success: false,
          message: '当前密码错误'
        });
      }

      // 更新密码
      UserDB.update(req.user.id, { password: new_password });

      res.json({
        success: true,
        message: '密码修改成功'
      });
    } catch (error) {
      console.error('修改密码失败:', error);
      res.status(500).json({
        success: false,
        message: '修改密码失败: ' + error.message
      });
    }
  }
);

// 修改当前用户名
app.post('/api/user/update-username',
  authMiddleware,
  [
    body('username')
      .isLength({ min: 3 }).withMessage('用户名至少3个字符')
      .matches(USERNAME_REGEX).withMessage('用户名仅允许中英文、数字、下划线、点和短横线')
  ],
  (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { username } = req.body;

      // 检查用户名是否已存在
      const existingUser = UserDB.findByUsername(username);
      if (existingUser && existingUser.id !== req.user.id) {
        return res.status(400).json({
          success: false,
          message: '用户名已存在'
        });
      }

      // 更新用户名
      UserDB.update(req.user.id, { username });

      res.json({
        success: true,
        message: '用户名修改成功'
      });
    } catch (error) {
      console.error('修改用户名失败:', error);
      res.status(500).json({
        success: false,
        message: '修改用户名失败: ' + error.message
      });
    }
  }
);

// 切换存储方式
app.post('/api/user/switch-storage',
  authMiddleware,
  [
    body('storage_type').isIn(['local', 'sftp']).withMessage('无效的存储类型')
  ],
  async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { storage_type } = req.body;

      // 检查权限
      if (req.user.storage_permission === 'local_only' && storage_type !== 'local') {
        return res.status(403).json({
          success: false,
          message: '您只能使用本地存储'
        });
      }

      if (req.user.storage_permission === 'sftp_only' && storage_type !== 'sftp') {
        return res.status(403).json({
          success: false,
          message: '您只能使用SFTP存储'
        });
      }

      // 检查SFTP配置
      if (storage_type === 'sftp' && !req.user.has_ftp_config) {
        return res.status(400).json({
          success: false,
          message: '请先配置SFTP服务器'
        });
      }

      // 更新存储类型
      UserDB.update(req.user.id, { current_storage_type: storage_type });

      res.json({
        success: true,
        message: '存储方式已切换',
        storage_type
      });
    } catch (error) {
      console.error('切换存储失败:', error);
      res.status(500).json({
        success: false,
        message: '切换存储失败: ' + error.message
      });
    }
  }
);

// 获取文件列表
app.get('/api/files', authMiddleware, async (req, res) => {
  const dirPath = req.query.path || '/';
  let storage;

  try {
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    const list = await storage.list(dirPath);

    const storageType = req.user.current_storage_type || 'sftp';
    const sanitizedHttpBase = sanitizeHttpBaseUrl(req.user.http_download_base_url);

    const formattedList = list.map(item => {
      // 构建完整的文件路径用于下载
      const httpDownloadUrl = (storageType === 'sftp' && sanitizedHttpBase && item.type !== 'd')
        ? buildHttpDownloadUrl(sanitizedHttpBase, dirPath === '/' ? `/${item.name}` : `${dirPath}/${item.name}`)
        : null;

      return {
        name: item.name,
        type: item.type === 'd' ? 'directory' : 'file',
        size: item.size,
        sizeFormatted: formatFileSize(item.size),
        modifiedAt: new Date(item.modifyTime),
        isDirectory: item.type === 'd',
        httpDownloadUrl: httpDownloadUrl
      };
    });

    formattedList.sort((a, b) => {
      if (a.isDirectory && !b.isDirectory) return -1;
      if (!a.isDirectory && b.isDirectory) return 1;
      return a.name.localeCompare(b.name);
    });

    res.json({
      success: true,
      path: dirPath,
      items: formattedList,
      storageType: storageType,
      storagePermission: req.user.storage_permission || 'sftp_only'
    });
  } catch (error) {
    console.error('获取文件列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取文件列表失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 重命名文件
app.post('/api/files/rename', authMiddleware, async (req, res) => {
  const { oldName, newName, path } = req.body;
  let storage;

  if (!oldName || !newName) {
    return res.status(400).json({
      success: false,
      message: '缺少文件名参数'
    });
  }

  try {
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    const oldPath = path === '/' ? `/${oldName}` : `${path}/${oldName}`;
    const newPath = path === '/' ? `/${newName}` : `${path}/${newName}`;

    await storage.rename(oldPath, newPath);

    res.json({
      success: true,
      message: '文件重命名成功'
    });
  } catch (error) {
    console.error('重命名文件失败:', error);
    res.status(500).json({
      success: false,
      message: '重命名文件失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 创建文件夹
app.post('/api/files/mkdir', authMiddleware, async (req, res) => {
  const { path, folderName } = req.body;
  let storage;

  // 参数验证
  if (!folderName || folderName.trim() === '') {
    return res.status(400).json({
      success: false,
      message: '文件夹名称不能为空'
    });
  }

  // 文件名安全检查 - 防止路径遍历攻击
  if (folderName.includes('/') || folderName.includes('\\') || folderName.includes('..') || folderName.includes(':')) {
    return res.status(400).json({
      success: false,
      message: '文件夹名称不能包含特殊字符 (/ \\ .. :)'
    });
  }

  // 只允许本地存储创建文件夹
  if (req.user.current_storage_type !== 'local') {
    return res.status(400).json({
      success: false,
      message: '只有本地存储支持创建文件夹'
    });
  }

  try {
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    // 构造文件夹路径
    const basePath = path || '/';
    const folderPath = basePath === '/' ? `/${folderName}` : `${basePath}/${folderName}`;
    const fullPath = storage.getFullPath(folderPath);

    // 检查是否已存在
    if (fs.existsSync(fullPath)) {
      return res.status(400).json({
        success: false,
        message: '文件夹已存在'
      });
    }

    // 创建文件夹 (不使用recursive,只创建当前层级)
    fs.mkdirSync(fullPath, { mode: 0o755 });

    console.log(`[创建文件夹成功] 用户${req.user.id}: ${folderPath}`);

    res.json({
      success: true,
      message: '文件夹创建成功'
    });
  } catch (error) {
    console.error('[创建文件夹失败]', error);
    res.status(500).json({
      success: false,
      message: '创建文件夹失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 获取文件夹详情(大小统计)
app.post('/api/files/folder-info', authMiddleware, async (req, res) => {
  const { path: dirPath, folderName } = req.body;
  let storage;

  if (!folderName) {
    return res.status(400).json({
      success: false,
      message: '缺少文件夹名称参数'
    });
  }

  // 只支持本地存储
  if (req.user.current_storage_type !== 'local') {
    return res.status(400).json({
      success: false,
      message: '只有本地存储支持此功能'
    });
  }

  try {
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    // 构造文件夹路径
    const basePath = dirPath || '/';
    const folderPath = basePath === '/' ? `/${folderName}` : `${basePath}/${folderName}`;
    const fullPath = storage.getFullPath(folderPath);

    // 检查是否存在且是文件夹
    if (!fs.existsSync(fullPath)) {
      return res.status(404).json({
        success: false,
        message: '文件夹不存在'
      });
    }

    const stats = fs.statSync(fullPath);
    if (!stats.isDirectory()) {
      return res.status(400).json({
        success: false,
        message: '指定路径不是文件夹'
      });
    }

    // 计算文件夹大小
    const folderSize = storage.calculateFolderSize(fullPath);

    // 计算文件数量
    function countFiles(countDirPath) {
      let fileCount = 0;
      let folderCount = 0;

      const items = fs.readdirSync(countDirPath, { withFileTypes: true });

      for (const item of items) {
        const itemPath = path.join(countDirPath, item.name);

        if (item.isDirectory()) {
          folderCount++;
          const subCounts = countFiles(itemPath);
          fileCount += subCounts.fileCount;
          folderCount += subCounts.folderCount;
        } else {
          fileCount++;
        }
      }

      return { fileCount, folderCount };
    }

    const counts = countFiles(fullPath);

    res.json({
      success: true,
      data: {
        name: folderName,
        path: folderPath,
        size: folderSize,
        fileCount: counts.fileCount,
        folderCount: counts.folderCount
      }
    });
  } catch (error) {
    console.error('[获取文件夹详情失败]', error);
    res.status(500).json({
      success: false,
      message: '获取文件夹详情失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 删除文件
app.post('/api/files/delete', authMiddleware, async (req, res) => {
  const { fileName, path } = req.body;
  let storage;

  if (!fileName) {
    return res.status(400).json({
      success: false,
      message: '缺少文件名参数'
    });
  }

  try {
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    const filePath = path === '/' ? `/${fileName}` : `${path}/${fileName}`;

    await storage.delete(filePath);

    res.json({
      success: true,
      message: '删除成功'
    });
  } catch (error) {
    console.error('删除文件失败:', error);
    res.status(500).json({
      success: false,
      message: '删除文件失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 上传文件
app.post('/api/upload', authMiddleware, upload.single('file'), async (req, res) => {
  if (!req.file) {
    return res.status(400).json({
      success: false,
      message: '没有上传文件'
    });
  }

  // 检查文件大小限制
  const maxUploadSize = parseInt(SettingsDB.get('max_upload_size') || '10737418240');
  if (req.file.size > maxUploadSize) {
    // 删除已上传的临时文件
    if (fs.existsSync(req.file.path)) {
      safeDeleteFile(req.file.path);
    }

    return res.status(413).json({
      success: false,
      message: '文件超过上传限制',
      maxSize: maxUploadSize,
      fileSize: req.file.size
    });
  }

  const remotePath = req.body.path || '/';
  // 修复中文文件名：multer将UTF-8转为了Latin1，需要转回来
  const originalFilename = Buffer.from(req.file.originalname, 'latin1').toString('utf8');
  const remoteFilePath = remotePath === '/'
    ? `/${originalFilename}`
    : `${remotePath}/${originalFilename}`;

  let storage;

  try {
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    // storage.put() 内部已经实现了临时文件+重命名逻辑
    await storage.put(req.file.path, remoteFilePath);
    console.log(`[上传] 文件上传成功: ${remoteFilePath}`);

    // 删除本地临时文件
    safeDeleteFile(req.file.path);

    res.json({
      success: true,
      message: '文件上传成功',
      filename: originalFilename,
      path: remoteFilePath
    });
  } catch (error) {
    console.error('文件上传失败:', error);

    // 删除临时文件
    if (fs.existsSync(req.file.path)) {
      safeDeleteFile(req.file.path);
    }

    res.status(500).json({
      success: false,
      message: '文件上传失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});


// 下载文件
app.get('/api/files/download', authMiddleware, async (req, res) => {
  const filePath = req.query.path;
  let storage;

  if (!filePath) {
    return res.status(400).json({
      success: false,
      message: '缺少文件路径参数'
    });
  }

  try {
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    // 获取文件名
    const fileName = filePath.split('/').pop();

    // 先获取文件信息（获取文件大小）
    const fileStats = await storage.stat(filePath);
    const fileSize = fileStats.size;
    console.log('[下载] 文件: ' + fileName + ', 大小: ' + fileSize + ' 字节');

    // 设置响应头（包含文件大小，浏览器可显示下载进度）
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Length', fileSize);
    res.setHeader('Content-Disposition', 'attachment; filename="' + encodeURIComponent(fileName) + '"; filename*=UTF-8\'\'' + encodeURIComponent(fileName));

    // 创建文件流并传输（流式下载，服务器不保存临时文件）
    const stream = storage.createReadStream(filePath);

    stream.on('error', (error) => {
      console.error('文件流错误:', error);
      if (!res.headersSent) {
        res.status(500).json({
          success: false,
          message: '文件下载失败: ' + error.message
        });
      }
      // 发生错误时关闭存储连接
      if (storage) {
        storage.end().catch(err => console.error('关闭存储连接失败:', err));
      }
    });

    // 在传输完成后关闭存储连接
    stream.on('close', () => {
      console.log('[下载] 文件传输完成，关闭存储连接');
      if (storage) {
        storage.end().catch(err => console.error('关闭存储连接失败:', err));
      }
    });

    stream.pipe(res);




  } catch (error) {
    console.error('下载文件失败:', error);
    
    // 如果stream还未创建或发生错误，关闭storage连接
    if (storage) {
      storage.end().catch(err => console.error('关闭存储连接失败:', err));
    }
    if (!res.headersSent) {
      res.status(500).json({
        success: false,
        message: '下载文件失败: ' + error.message
      });
    }
  }
});

// 生成上传工具（生成新密钥并创建配置文件）
app.post('/api/upload/generate-tool', authMiddleware, async (req, res) => {
  try {
    // 生成新的API密钥（32位随机字符串）
    const crypto = require('crypto');
    const newApiKey = crypto.randomBytes(16).toString('hex');

    // 更新用户的upload_api_key
    UserDB.update(req.user.id, { upload_api_key: newApiKey });

    // 创建配置文件内容
    const config = {
      username: req.user.username,
      api_key: newApiKey,
      api_base_url: `${req.get('x-forwarded-proto') || req.protocol}://${req.get('host')}`
    };

    res.json({
      success: true,
      message: '上传工具已生成',
      config: config
    });
  } catch (error) {
    console.error('生成上传工具失败:', error);
    res.status(500).json({
      success: false,
      message: '生成上传工具失败: ' + error.message
    });
  }
});

// 下载上传工具（zip包含exe+config.json+README.txt）
app.get('/api/upload/download-tool', authMiddleware, async (req, res) => {
  let tempZipPath = null;

  try {
    console.log(`[上传工具] 用户 ${req.user.username} 请求下载上传工具`);

    // 生成新的API密钥
    const crypto = require('crypto');
    const newApiKey = crypto.randomBytes(16).toString('hex');

    // 更新用户的upload_api_key
    UserDB.update(req.user.id, { upload_api_key: newApiKey });

    // 创建配置文件内容
    const config = {
      username: req.user.username,
      api_key: newApiKey,
      api_base_url: `${req.get('x-forwarded-proto') || req.protocol}://${req.get('host')}`
    };
    console.log("[上传工具配置]", JSON.stringify(config, null, 2));

    // 检查exe文件是否存在
    const toolDir = path.join(__dirname, '..', 'upload-tool');
    const exePath = path.join(toolDir, 'dist', '玩玩云上传工具.exe');
    const readmePath = path.join(toolDir, 'README.txt');

    if (!fs.existsSync(exePath)) {
      console.error('[上传工具] exe文件不存在:', exePath);
      return res.status(500).json({
        success: false,
        message: '上传工具尚未打包，请联系管理员运行 upload-tool/build.bat'
      });
    }

    // 创建临时zip文件路径
    const uploadsDir = path.join(__dirname, 'uploads');
    if (!fs.existsSync(uploadsDir)) {
      fs.mkdirSync(uploadsDir, { recursive: true });
    }
    tempZipPath = path.join(uploadsDir, `tool_${req.user.username}_${Date.now()}.zip`);

    console.log('[上传工具] 开始创建zip包到临时文件:', tempZipPath);

    // 创建文件写入流
    const output = fs.createWriteStream(tempZipPath);
    const archive = archiver('zip', {
      store: true  // 使用STORE模式，不压缩，速度最快
    });

    // 等待zip文件创建完成
    await new Promise((resolve, reject) => {
      output.on('close', () => {
        console.log(`[上传工具] zip创建完成，大小: ${archive.pointer()} 字节`);
        resolve();
      });

      archive.on('error', (err) => {
        console.error('[上传工具] archiver错误:', err);
        reject(err);
      });

      // 连接archive到文件流
      archive.pipe(output);

      // 添加exe文件
      console.log('[上传工具] 添加exe文件...');
      archive.file(exePath, { name: '玩玩云上传工具.exe' });

      // 添加config.json
      console.log('[上传工具] 添加config.json...');
      archive.append(JSON.stringify(config, null, 2), { name: 'config.json' });

      // 添加README.txt
      if (fs.existsSync(readmePath)) {
        console.log('[上传工具] 添加README.txt...');
        archive.file(readmePath, { name: 'README.txt' });
      }

      // 完成打包
      console.log('[上传工具] 执行finalize...');
      archive.finalize();
    });

    // 获取文件大小
    const stats = fs.statSync(tempZipPath);
    const fileSize = stats.size;
    console.log(`[上传工具] 准备发送文件，大小: ${fileSize} 字节`);

    // 设置响应头（包含Content-Length）
    const filename = `玩玩云上传工具_${req.user.username}.zip`;
    res.setHeader('Content-Type', 'application/zip');
    res.setHeader('Content-Length', fileSize);
    res.setHeader('Content-Disposition', `attachment; filename="${encodeURIComponent(filename)}"; filename*=UTF-8''${encodeURIComponent(filename)}`);

    // 创建文件读取流并发送
    const fileStream = fs.createReadStream(tempZipPath);

    fileStream.on('end', () => {
      console.log(`[上传工具] 用户 ${req.user.username} 下载完成`);
      // 删除临时文件
      if (tempZipPath && fs.existsSync(tempZipPath)) {
        fs.unlinkSync(tempZipPath);
        console.log('[上传工具] 临时文件已删除');
      }
    });

    fileStream.on('error', (err) => {
      console.error('[上传工具] 文件流错误:', err);
      // 删除临时文件
      if (tempZipPath && fs.existsSync(tempZipPath)) {
        fs.unlinkSync(tempZipPath);
      }
    });

    fileStream.pipe(res);

  } catch (error) {
    console.error('[上传工具] 异常:', error);

    // 删除临时文件
    if (tempZipPath && fs.existsSync(tempZipPath)) {
      fs.unlinkSync(tempZipPath);
      console.log('[上传工具] 临时文件已删除（异常）');
    }

    if (!res.headersSent) {
      res.status(500).json({
        success: false,
        message: '下载失败: ' + error.message
      });
    }
  }
});

// 通过API密钥获取SFTP配置（供Python工具调用）
app.post('/api/upload/get-config', async (req, res) => {
  try {
    const { api_key } = req.body;

    if (!api_key) {
      return res.status(400).json({
        success: false,
        message: 'API密钥不能为空'
      });
    }

    // 查找拥有此API密钥的用户
    const user = db.prepare('SELECT * FROM users WHERE upload_api_key = ?').get(api_key);

    if (!user) {
      return res.status(401).json({
        success: false,
        message: 'API密钥无效或已过期'
      });
    }

    if (user.is_banned) {
      return res.status(403).json({
        success: false,
        message: '账号已被封禁'
      });
    }

    if (!user.has_ftp_config) {
      return res.status(400).json({
        success: false,
        message: '用户未配置SFTP服务器'
      });
    }

    // 返回SFTP配置
    res.json({
      success: true,
      sftp_config: {
        host: user.ftp_host,
        port: user.ftp_port,
        username: user.ftp_user,
        password: user.ftp_password
      }
    });
  } catch (error) {
    console.error('获取SFTP配置失败:', error);
    res.status(500).json({
      success: false,
      message: '获取SFTP配置失败: ' + error.message
    });
  }
});

// 创建分享链接
app.post('/api/share/create', authMiddleware, (req, res) => {
  try {
    const { share_type, file_path, file_name, password, expiry_days } = req.body;
    console.log("[DEBUG] 创建分享请求:", { share_type, file_path, file_name, password: password ? "***" : null, expiry_days });

    if (share_type === 'file' && !file_path) {
      return res.status(400).json({
        success: false,
        message: '文件路径不能为空'
      });
    }

    const result = ShareDB.create(req.user.id, {
      share_type: share_type || 'file',
      file_path: file_path || '',
      file_name: file_name || '',
      password: password || null,
      expiry_days: expiry_days || null
    });

    // 更新分享的存储类型
    const { db } = require('./database');
    db.prepare('UPDATE shares SET storage_type = ? WHERE id = ?')
      .run(req.user.current_storage_type || 'sftp', result.id);

    const shareUrl = `${getProtocol(req)}://${req.get('host')}/s/${result.share_code}`;

    res.json({
      success: true,
      message: '分享链接创建成功',
      share_code: result.share_code,
      share_url: shareUrl,
      share_type: result.share_type,
      expires_at: result.expires_at,
    });
  } catch (error) {
    console.error('创建分享链接失败:', error);
    res.status(500).json({
      success: false,
      message: '创建分享链接失败: ' + error.message
    });
  }
});

// 获取我的分享列表
app.get('/api/share/my', authMiddleware, (req, res) => {
  try {
    const shares = ShareDB.getUserShares(req.user.id);

    res.json({
      success: true,
      shares: shares.map(share => ({
        ...share,
        share_url: `${getProtocol(req)}://${req.get('host')}/s/${share.share_code}`
      }))
    });
  } catch (error) {
    console.error('获取分享列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取分享列表失败: ' + error.message
    });
  }
});

// 删除分享
app.delete('/api/share/:id', authMiddleware, (req, res) => {
  try {
    // 先获取分享信息以获得share_code
    const share = ShareDB.findById(req.params.id);

    if (share && share.user_id === req.user.id) {
      // 删除缓存
      if (shareFileCache.has(share.share_code)) {
        shareFileCache.delete(share.share_code);
        console.log(`[缓存清除] 分享码: ${share.share_code}`);
      }

      // 删除数据库记录
      ShareDB.delete(req.params.id, req.user.id);

      res.json({
        success: true,
        message: '分享已删除'
      });
    } else {
      res.status(404).json({
        success: false,
        message: '分享不存在或无权限'
      });
    }
  } catch (error) {
    console.error('删除分享失败:', error);
    res.status(500).json({
      success: false,
      message: '删除分享失败: ' + error.message
    });
  }
});

// ===== 分享链接访问（公开） =====

// 访问分享链接 - 验证密码（支持本地存储和SFTP）
app.post('/api/share/:code/verify', shareRateLimitMiddleware, async (req, res) => {
  const { code } = req.params;
  const { password } = req.body;
  let storage;

  try {

    // ===== 调试日志: 分享验证开始 =====
    console.log('[分享验证]', {
      timestamp: new Date().toISOString(),
      shareCode: code,
      hasPassword: !!password,
      requestIP: req.ip
    });

    const share = ShareDB.findByCode(code);


    // 调试日志: findByCode 结果
    console.log('[分享验证] findByCode结果:', {
      found: !!share,
      expires_at: share?.expires_at || null,
      current_time: new Date().toISOString(),
      is_expired: share?.expires_at ? new Date(share.expires_at) <= new Date() : false
    });

    if (!share) {
      return res.status(404).json({
        success: false,
        message: '分享不存在'
      });
    }

    // 如果设置了密码，验证密码
    if (share.share_password) {
      if (!password) {
        return res.status(401).json({
          success: false,
          message: '需要密码',
          needPassword: true
        });
      }

      if (!ShareDB.verifyPassword(password, share.share_password)) {
        // 记录密码错误
        if (req.shareRateLimitKey) {
          shareLimiter.recordFailure(req.shareRateLimitKey);
        }
        return res.status(401).json({
          success: false,
          message: '密码错误'
        });
      }
    }

    // 清除失败记录（密码验证成功）
    if (req.shareRateLimitKey) {
      shareLimiter.recordSuccess(req.shareRateLimitKey);
    }

    // 增加查看次数
    ShareDB.incrementViewCount(code);

    const sanitizedShareHttpBase = sanitizeHttpBaseUrl(share.http_download_base_url);

    // 构建返回数据
    const responseData = {
      success: true,
      share: {
        share_path: share.share_path,
        share_type: share.share_type,
        username: share.username,
        created_at: share.created_at,
        expires_at: share.expires_at  // 添加到期时间
      }
    };

    // 如果是单文件分享，查询存储获取文件信息（带缓存）
    if (share.share_type === 'file') {
      const filePath = share.share_path;
      const lastSlashIndex = filePath.lastIndexOf('/');
      const dirPath = lastSlashIndex > 0 ? filePath.substring(0, lastSlashIndex) : '/';
      const fileName = lastSlashIndex >= 0 ? filePath.substring(lastSlashIndex + 1) : filePath;

      // 检查缓存
      if (shareFileCache.has(code)) {
        console.log(`[缓存命中] 分享码: ${code}`);
        responseData.file = shareFileCache.get(code);
      } else {
        // 缓存未命中，查询存储
        try {
          // 获取分享者的用户信息
          const shareOwner = UserDB.findById(share.user_id);
          if (!shareOwner) {
            throw new Error('分享者不存在');
          }
          const storageType = shareOwner.current_storage_type || 'sftp';
          console.log(`[缓存未命中] 分享码: ${code}，存储类型: ${storageType}`);

          // 使用统一存储接口
          const { StorageInterface } = require('./storage');
          const userForStorage = {
            ...shareOwner,
            current_storage_type: storageType
          };

          const storageInterface = new StorageInterface(userForStorage);
          storage = await storageInterface.connect();

          const list = await storage.list(dirPath);
          const fileInfo = list.find(item => item.name === fileName);

          // 检查文件是否存在
          if (!fileInfo) {
            shareFileCache.delete(code);
            throw new Error("分享的文件已被删除或不存在");
          }

          if (fileInfo) {
            const normalizedFilePath = filePath.startsWith('/') ? filePath : `/${filePath}`;
            // SFTP存储才提供HTTP下载URL，本地存储使用API下载
            const httpDownloadUrl = (storageType === 'sftp')
              ? buildHttpDownloadUrl(sanitizedShareHttpBase, normalizedFilePath)
              : null;

            const fileData = {
              name: fileName,
              type: 'file',
              isDirectory: false,
              httpDownloadUrl: httpDownloadUrl,
              size: fileInfo.size,
              sizeFormatted: formatFileSize(fileInfo.size),
              modifiedAt: new Date(fileInfo.modifyTime)
            };

            // 存入缓存
            shareFileCache.set(code, fileData);
            console.log(`[缓存存储] 分享码: ${code}，文件: ${fileName}`);

            responseData.file = fileData;
          }
        } catch (storageError) {
          console.error('获取文件信息失败:', storageError);

          // 如果是文件不存在的错误，重新抛出
          if (storageError.message && storageError.message.includes("分享的文件已被删除或不存在")) {
            throw storageError;
          }
          // 存储失败时仍返回基本信息，只是没有大小
          const normalizedFilePath = filePath.startsWith('/') ? filePath : `/${filePath}`;
          const storageType = share.storage_type || 'sftp';
          const httpDownloadUrl = (storageType === 'sftp')
            ? buildHttpDownloadUrl(sanitizedShareHttpBase, normalizedFilePath)
            : null;

          responseData.file = {
            name: fileName,
            type: 'file',
            isDirectory: false,
            httpDownloadUrl: httpDownloadUrl,
            size: 0,
            sizeFormatted: '-'
          };
        }
      }
    }

    res.json(responseData);
  } catch (error) {
    console.error('验证分享失败:', error);
    res.status(500).json({
      success: false,
      message: '验证失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 获取分享的文件列表（支持本地存储和SFTP）
app.post('/api/share/:code/list', shareRateLimitMiddleware, async (req, res) => {
  const { code } = req.params;
  const { password, path: subPath } = req.body;

  let storage;

  try {

    // ===== 调试日志: 获取分享文件列表 =====
    console.log('[获取文件列表]', {
      timestamp: new Date().toISOString(),
      shareCode: code,
      subPath: subPath,
      hasPassword: !!password,
      requestIP: req.ip
    });

    const share = ShareDB.findByCode(code);


    // 调试日志: findByCode 结果
    console.log('[获取文件列表] findByCode结果:', {
      found: !!share,
      expires_at: share?.expires_at || null,
      current_time: new Date().toISOString(),
      is_expired: share?.expires_at ? new Date(share.expires_at) <= new Date() : false
    });

    if (!share) {
      return res.status(404).json({
        success: false,
        message: '分享不存在'
      });
    }

    // 验证密码
    if (share.share_password && !ShareDB.verifyPassword(password, share.share_password)) {
      // 记录密码错误
      if (req.shareRateLimitKey) {
        shareLimiter.recordFailure(req.shareRateLimitKey);
      }
      return res.status(401).json({
        success: false,
        message: '密码错误'
      });
    }

    // 清除失败记录（密码验证成功或无密码）
    if (req.shareRateLimitKey && share.share_password) {
      shareLimiter.recordSuccess(req.shareRateLimitKey);
    }

    // 获取分享者的用户信息
    const shareOwner = UserDB.findById(share.user_id);
    if (!shareOwner) {
      return res.status(404).json({
        success: false,
        message: '分享者不存在'
      });
    }

    // 使用统一存储接口，根据分享的storage_type选择存储后端
    const { StorageInterface } = require('./storage');
    const storageType = share.storage_type || 'sftp';
    console.log(`[分享列表] 存储类型: ${storageType}, 分享路径: ${share.share_path}`);

    // 临时构造用户对象以使用存储接口
    const userForStorage = {
      ...shareOwner,
      current_storage_type: storageType
    };

    const storageInterface = new StorageInterface(userForStorage);
    storage = await storageInterface.connect();

    const sanitizedShareHttpBase = sanitizeHttpBaseUrl(share.http_download_base_url);
    let formattedList = [];

    // 如果是单文件分享
    if (share.share_type === 'file') {
      // share_path 就是文件路径
      const filePath = share.share_path;

      // 提取父目录和文件名
      const lastSlashIndex = filePath.lastIndexOf('/');
      const dirPath = lastSlashIndex > 0 ? filePath.substring(0, lastSlashIndex) : '/';
      const fileName = lastSlashIndex >= 0 ? filePath.substring(lastSlashIndex + 1) : filePath;

      // 列出父目录
      const list = await storage.list(dirPath);

      // 只返回这个文件
      const fileInfo = list.find(item => item.name === fileName);

      if (fileInfo) {
        // 确保文件路径以斜杠开头
        const normalizedFilePath = filePath.startsWith('/') ? filePath : `/${filePath}`;

        // SFTP存储才提供HTTP下载URL，本地存储使用API下载
        const httpDownloadUrl = (storageType === 'sftp')
          ? buildHttpDownloadUrl(sanitizedShareHttpBase, normalizedFilePath)
          : null;

        formattedList = [{
          name: fileInfo.name,
          type: 'file',
          size: fileInfo.size,
          sizeFormatted: formatFileSize(fileInfo.size),
          modifiedAt: new Date(fileInfo.modifyTime),
          isDirectory: false,
          httpDownloadUrl: httpDownloadUrl
        }];
      }
    }
    // 如果是目录分享（分享所有文件）
    else {
      const fullPath = subPath ? `${share.share_path}/${subPath}`.replace('//', '/') : share.share_path;
      const list = await storage.list(fullPath);

      formattedList = list.map(item => {
        // 构建完整的文件路径用于下载
        let httpDownloadUrl = null;
        if (storageType === 'sftp' && sanitizedShareHttpBase && item.type !== 'd') {
          const normalizedPath = fullPath.startsWith('/') ? fullPath : `/${fullPath}`;
          const filePath = normalizedPath === '/' ? `/${item.name}` : `${normalizedPath}/${item.name}`;
          httpDownloadUrl = buildHttpDownloadUrl(sanitizedShareHttpBase, filePath);
        }

        return {
          name: item.name,
          type: item.type === 'd' ? 'directory' : 'file',
          size: item.size,
          sizeFormatted: formatFileSize(item.size),
          modifiedAt: new Date(item.modifyTime),
          isDirectory: item.type === 'd',
          httpDownloadUrl: httpDownloadUrl
        };
      });

      formattedList.sort((a, b) => {
        if (a.isDirectory && !b.isDirectory) return -1;
        if (!a.isDirectory && b.isDirectory) return 1;
        return a.name.localeCompare(b.name);
      });
    }

    res.json({
      success: true,
      path: share.share_path,
      items: formattedList
    });
  } catch (error) {
    console.error('获取分享文件列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取文件列表失败: ' + error.message
    });
  } finally {
    if (storage) await storage.end();
  }
});

// 记录下载次数
app.post('/api/share/:code/download', (req, res) => {
  const { code } = req.params;

  try {
    const share = ShareDB.findByCode(code);

    if (!share) {
      return res.status(404).json({
        success: false,
        message: '分享不存在'
      });
    }

    // 增加下载次数
    ShareDB.incrementDownloadCount(code);

    res.json({
      success: true,
      message: '下载统计已记录'
    });
  } catch (error) {
    console.error('记录下载失败:', error);
    res.status(500).json({
      success: false,
      message: '记录下载失败: ' + error.message
    });
  }
});

// 分享文件下载（支持本地存储和SFTP，公开API，需要分享码和密码验证）
app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req, res) => {
  const { code } = req.params;
  const { path: filePath, password } = req.query;
  let storage;

  if (!filePath) {
    return res.status(400).json({
      success: false,
      message: '缺少文件路径参数'
    });
  }

  try {
    const share = ShareDB.findByCode(code);

    if (!share) {
      return res.status(404).json({
        success: false,
        message: '分享不存在'
      });
    }

    // 验证密码（如果需要）
    if (share.share_password) {
        // 记录密码错误
        if (req.shareRateLimitKey) {
          shareLimiter.recordFailure(req.shareRateLimitKey);
        }
      if (!password || !ShareDB.verifyPassword(password, share.share_password)) {
        return res.status(401).json({
          success: false,
          message: '密码错误或未提供密码'
        });
    // 清除失败记录（密码验证成功）
    if (req.shareRateLimitKey && share.share_password) {
      shareLimiter.recordSuccess(req.shareRateLimitKey);
    }

      }
    }

    // ✅ 安全验证：检查请求路径是否在分享范围内（防止越权访问）
    if (!isPathWithinShare(filePath, share)) {
      console.warn(`[安全] 检测到越权访问尝试 - 分享码: ${code}, 请求路径: ${filePath}, 分享路径: ${share.share_path}`);
      return res.status(403).json({
        success: false,
        message: '无权访问该文件'
      });
    }

    // 获取分享者的用户信息
    const shareOwner = UserDB.findById(share.user_id);
    if (!shareOwner) {
      return res.status(404).json({
        success: false,
        message: '分享者不存在'
      });
    }

    // 使用统一存储接口，根据分享的storage_type选择存储后端
    const { StorageInterface } = require('./storage');
    const storageType = shareOwner.current_storage_type || 'sftp';
    console.log(`[分享下载] 存储类型: ${storageType} (分享者当前), 文件路径: ${filePath}`);

    // 临时构造用户对象以使用存储接口
    const userForStorage = {
      ...shareOwner,
      current_storage_type: storageType
    };

    const storageInterface = new StorageInterface(userForStorage);
    storage = await storageInterface.connect();

    // 获取文件名
    const fileName = filePath.split('/').pop();

    // 获取文件信息（获取文件大小）
    const fileStats = await storage.stat(filePath);
    const fileSize = fileStats.size;
    console.log(`[分享下载] 文件: ${fileName}, 大小: ${fileSize} 字节`);

    // 增加下载次数
    ShareDB.incrementDownloadCount(code);

    // 设置响应头（包含文件大小，浏览器可显示下载进度）
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Length', fileSize);
    res.setHeader('Content-Disposition', `attachment; filename="${encodeURIComponent(fileName)}"; filename*=UTF-8''${encodeURIComponent(fileName)}`);

    // 创建文件流并传输（流式下载，服务器不保存临时文件）
    const stream = storage.createReadStream(filePath);

    stream.on('error', (error) => {
      console.error('文件流错误:', error);
      if (!res.headersSent) {
        res.status(500).json({
          success: false,
          message: '文件下载失败: ' + error.message
        });
      }
      // 发生错误时关闭存储连接
      if (storage) {
        storage.end().catch(err => console.error('关闭存储连接失败:', err));
      }
    });

    // 在传输完成后关闭存储连接
    stream.on('close', () => {
      console.log('[分享下载] 文件传输完成，关闭存储连接');
      if (storage) {
        storage.end().catch(err => console.error('关闭存储连接失败:', err));
      }
    });

    stream.pipe(res);

  } catch (error) {
    console.error('分享下载文件失败:', error);
    if (!res.headersSent) {
      res.status(500).json({
        success: false,
        message: '下载文件失败: ' + error.message
      });
    }
    // 如果发生错误，关闭存储连接
    if (storage) {
      storage.end().catch(err => console.error('关闭存储连接失败:', err));
    }
  }
});

// ===== 管理员API =====

// 获取系统设置
app.get('/api/admin/settings', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const maxUploadSize = parseInt(SettingsDB.get('max_upload_size') || '10737418240');
    const smtpHost = SettingsDB.get('smtp_host');
    const smtpPort = SettingsDB.get('smtp_port');
    const smtpSecure = SettingsDB.get('smtp_secure') === 'true';
    const smtpUser = SettingsDB.get('smtp_user');
    const smtpFrom = SettingsDB.get('smtp_from') || smtpUser;
    const smtpHasPassword = !!SettingsDB.get('smtp_password');

    res.json({
      success: true,
      settings: {
        max_upload_size: maxUploadSize,
        smtp: {
          host: smtpHost || '',
          port: smtpPort ? parseInt(smtpPort, 10) : 465,
          secure: smtpSecure,
          user: smtpUser || '',
          from: smtpFrom || '',
          has_password: smtpHasPassword
        }
      }
    });
  } catch (error) {
    console.error('获取系统设置失败:', error);
    res.status(500).json({
      success: false,
      message: '获取系统设置失败: ' + error.message
    });
  }
});

// 更新系统设置
app.post('/api/admin/settings', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const { max_upload_size, smtp } = req.body;

    if (max_upload_size !== undefined) {
      const size = parseInt(max_upload_size);
      if (isNaN(size) || size < 0) {
        return res.status(400).json({
          success: false,
          message: '无效的文件大小'
        });
      }
      SettingsDB.set('max_upload_size', size.toString());
    }

    if (smtp) {
      if (!smtp.host || !smtp.port || !smtp.user) {
        return res.status(400).json({ success: false, message: 'SMTP配置不完整' });
      }
      SettingsDB.set('smtp_host', smtp.host);
      SettingsDB.set('smtp_port', smtp.port);
      SettingsDB.set('smtp_secure', smtp.secure ? 'true' : 'false');
      SettingsDB.set('smtp_user', smtp.user);
      SettingsDB.set('smtp_from', smtp.from || smtp.user);
      if (smtp.password) {
        SettingsDB.set('smtp_password', smtp.password);
      }
    }

    res.json({
      success: true,
      message: '系统设置已更新'
    });
  } catch (error) {
    console.error('更新系统设置失败:', error);
    res.status(500).json({
      success: false,
      message: '更新系统设置失败: ' + error.message
    });
  }
});

// 测试SMTP
app.post('/api/admin/settings/test-smtp', authMiddleware, adminMiddleware, async (req, res) => {
  const { to } = req.body;
  try {
    const smtpConfig = getSmtpConfig();
    if (!smtpConfig) {
      return res.status(400).json({ success: false, message: 'SMTP未配置' });
    }
    const target = to || req.user.email || smtpConfig.user;
    await sendMail(
      target,
      'SMTP测试 - 玩玩云',
      `<p>您好，这是一封测试邮件，说明SMTP配置可用。</p><p>时间：${new Date().toISOString()}</p>`
    );
    res.json({ success: true, message: `测试邮件已发送至 ${target}` });
  } catch (error) {
    console.error('测试SMTP失败:', error);
    res.status(500).json({ success: false, message: '测试邮件发送失败: ' + (error.response?.message || error.message) });
  }
});

// 获取服务器存储统计信息
app.get('/api/admin/storage-stats', authMiddleware, adminMiddleware, async (req, res) => {
  try {
    // 获取本地存储目录
    const localStorageDir = path.join(__dirname, 'local-storage');
    
    // 获取磁盘信息（使用df命令）
    let totalDisk = 0;
    let usedDisk = 0;
    let availableDisk = 0;
    
    try {
      // 获取本地存储目录所在分区的磁盘信息
      const { stdout: dfOutput } = await execAsync(`df -B 1 / | tail -1`, { encoding: 'utf8' });
      const parts = dfOutput.trim().split(/\s+/);
      
      if (parts.length >= 4) {
        totalDisk = parseInt(parts[1]) || 0;  // 总大小
        usedDisk = parseInt(parts[2]) || 0;   // 已使用
        availableDisk = parseInt(parts[3]) || 0;  // 可用
      }
    } catch (dfError) {
      console.error('获取磁盘信息失败:', dfError.message);
      // 如果df命令失败，尝试使用Windows的wmic命令
      try {
        // 获取本地存储目录所在的驱动器号
        const driveLetter = localStorageDir.charAt(0);
        if (!/^[A-Za-z]$/.test(driveLetter)) {
          throw new Error('Invalid drive letter');
        }
        const { stdout: wmicOutput } = await execAsync(
          `wmic logicaldisk where "DeviceID='${driveLetter}:'" get Size,FreeSpace /value`,
          { encoding: 'utf8' }
        );
        
        const freeMatch = wmicOutput.match(/FreeSpace=(\d+)/);
        const sizeMatch = wmicOutput.match(/Size=(\d+)/);
        
        if (sizeMatch && freeMatch) {
          totalDisk = parseInt(sizeMatch[1]) || 0;
          availableDisk = parseInt(freeMatch[1]) || 0;
          usedDisk = totalDisk - availableDisk;
        }
      } catch (wmicError) {
        console.error('获取Windows磁盘信息失败:', wmicError.message);
      }
    }
    
    // 从数据库获取所有用户的本地存储配额和使用情况
    const users = UserDB.getAll();
    let totalUserQuotas = 0;
    let totalUserUsed = 0;
    
    users.forEach(user => {
      // 只统计使用本地存储的用户（local_only 或 user_choice）
      const storagePermission = user.storage_permission || 'sftp_only';
      if (storagePermission === 'local_only' || storagePermission === 'user_choice') {
        totalUserQuotas += user.local_storage_quota || 0;
        totalUserUsed += user.local_storage_used || 0;
      }
    });
    
    res.json({
      success: true,
      stats: {
        totalDisk,            // 磁盘总容量
        usedDisk,             // 磁盘已使用
        availableDisk,        // 磁盘可用空间
        totalUserQuotas,      // 用户配额总和
        totalUserUsed,        // 用户实际使用总和
        totalUsers: users.length  // 用户总数
      }
    });

// 获取所有用户
} catch (error) {    console.error('获取存储统计失败:', error);    res.status(500).json({      success: false,      message: '获取存储统计失败: ' + error.message    });  }});
app.get('/api/admin/users', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const users = UserDB.getAll();

    res.json({
      success: true,
      users: users.map(u => ({
        id: u.id,
        username: u.username,
        email: u.email,
        is_admin: u.is_admin,
        is_active: u.is_active,
        is_banned: u.is_banned,
        has_ftp_config: u.has_ftp_config,
        created_at: u.created_at,
        // 新增：存储相关字段
        storage_permission: u.storage_permission || 'sftp_only',
        current_storage_type: u.current_storage_type || 'sftp',
        local_storage_quota: u.local_storage_quota || 1073741824,
        local_storage_used: u.local_storage_used || 0
      }))
    });
  } catch (error) {
    console.error('获取用户列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取用户列表失败: ' + error.message
    });
  }
});

// 封禁/解封用户
app.post('/api/admin/users/:id/ban', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const { id } = req.params;
    const { banned } = req.body;

    UserDB.setBanStatus(id, banned);

    res.json({
      success: true,
      message: banned ? '用户已封禁' : '用户已解封'
    });
  } catch (error) {
    console.error('操作失败:', error);
    res.status(500).json({
      success: false,
      message: '操作失败: ' + error.message
    });
  }
});

// 删除用户（级联删除文件和分享）
app.delete('/api/admin/users/:id', authMiddleware, adminMiddleware, async (req, res) => {
  try {
    const { id } = req.params;

    if (parseInt(id) === req.user.id) {
      return res.status(400).json({
        success: false,
        message: '不能删除自己的账号'
      });
    }

    // 获取用户信息
    const user = UserDB.findById(id);
    if (!user) {
      return res.status(404).json({
        success: false,
        message: '用户不存在'
      });
    }

    const deletionLog = {
      userId: id,
      username: user.username,
      deletedFiles: [],
      deletedShares: 0,
      warnings: []
    };

    // 1. 删除本地存储文件（如果用户使用了本地存储）
    const storagePermission = user.storage_permission || 'sftp_only';
    if (storagePermission === 'local_only' || storagePermission === 'user_choice') {
      const storageRoot = process.env.STORAGE_ROOT || path.join(__dirname, 'storage');
      const userStorageDir = path.join(storageRoot, `user_${id}`);

      if (fs.existsSync(userStorageDir)) {
        try {
          // 递归删除用户目录
          const deletedSize = getUserDirectorySize(userStorageDir);
          fs.rmSync(userStorageDir, { recursive: true, force: true });
          deletionLog.deletedFiles.push({
            type: 'local',
            path: userStorageDir,
            size: deletedSize
          });
          console.log(`[删除用户] 已删除本地存储目录: ${userStorageDir}`);
        } catch (error) {
          console.error(`[删除用户] 删除本地存储失败:`, error);
          deletionLog.warnings.push(`删除本地存储失败: ${error.message}`);
        }
      }
    }

    // 2. SFTP存储文件 - 只记录警告，不实际删除（安全考虑）
    if (user.has_ftp_config && (storagePermission === 'sftp_only' || storagePermission === 'user_choice')) {
      deletionLog.warnings.push(
        `用户配置了SFTP存储 (${user.ftp_host}:${user.ftp_port})，SFTP文件未自动删除，请手动处理`
      );
    }

    // 3. 删除用户的所有分享记录
    try {
      const userShares = ShareDB.getUserShares(id);
      deletionLog.deletedShares = userShares.length;

      userShares.forEach(share => {
        ShareDB.delete(share.id);
        // 清除分享缓存
        if (shareFileCache.has(share.share_code)) {
          shareFileCache.delete(share.share_code);
        }
      });

      console.log(`[删除用户] 已删除 ${deletionLog.deletedShares} 条分享记录`);
    } catch (error) {
      console.error(`[删除用户] 删除分享记录失败:`, error);
      deletionLog.warnings.push(`删除分享记录失败: ${error.message}`);
    }

    // 4. 删除用户记录
    UserDB.delete(id);

    // 构建响应消息
    let message = `用户 ${user.username} 已删除`;
    if (deletionLog.deletedFiles.length > 0) {
      const totalSize = deletionLog.deletedFiles.reduce((sum, f) => sum + f.size, 0);
      message += `，已清理本地文件 ${formatFileSize(totalSize)}`;
    }
    if (deletionLog.deletedShares > 0) {
      message += `，已删除 ${deletionLog.deletedShares} 条分享`;
    }

    res.json({
      success: true,
      message,
      details: deletionLog
    });
  } catch (error) {
    console.error('删除用户失败:', error);
    res.status(500).json({
      success: false,
      message: '删除用户失败: ' + error.message
    });
  }
});

// 辅助函数：计算目录大小
function getUserDirectorySize(dirPath) {
  let totalSize = 0;

  function calculateSize(currentPath) {
    try {
      const stats = fs.statSync(currentPath);

      if (stats.isDirectory()) {
        const files = fs.readdirSync(currentPath);
        files.forEach(file => {
          calculateSize(path.join(currentPath, file));
        });
      } else {
        totalSize += stats.size;
      }
    } catch (error) {
      console.error(`计算大小失败: ${currentPath}`, error);
    }
  }

  calculateSize(dirPath);
  return totalSize;
}

// 设置用户存储权限（管理员）
app.post('/api/admin/users/:id/storage-permission',
  authMiddleware,
  adminMiddleware,
  [
    body('storage_permission').isIn(['local_only', 'sftp_only', 'user_choice']).withMessage('无效的存储权限')
  ],
  (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({
        success: false,
        errors: errors.array()
      });
    }

    try {
      const { id } = req.params;
      const { storage_permission, local_storage_quota } = req.body;

      const updates = { storage_permission };

      // 如果提供了配额，更新配额（单位：字节）
      if (local_storage_quota !== undefined) {
        updates.local_storage_quota = parseInt(local_storage_quota);
      }

      // 根据权限设置自动调整存储类型
      const user = UserDB.findById(id);
      if (!user) {
        return res.status(404).json({
          success: false,
          message: '用户不存在'
        });
      }

      if (storage_permission === 'local_only') {
        updates.current_storage_type = 'local';
      } else if (storage_permission === 'sftp_only') {
        // 只有配置了SFTP才切换到SFTP
        if (user.has_ftp_config) {
          updates.current_storage_type = 'sftp';
        }
      }
      // user_choice 不自动切换，保持用户当前选择

      UserDB.update(id, updates);

      res.json({
        success: true,
        message: '存储权限已更新'
      });
    } catch (error) {
      console.error('设置存储权限失败:', error);
      res.status(500).json({
        success: false,
        message: '设置存储权限失败: ' + error.message
      });
    }
  }
);

// ===== 管理员文件审查功能 =====

// 查看用户文件列表（管理员，只读）
app.get('/api/admin/users/:id/files', authMiddleware, adminMiddleware, async (req, res) => {
  const { id } = req.params;
  const dirPath = req.query.path || '/';
  let sftp;

  try {
    const user = UserDB.findById(id);

    if (!user) {
      return res.status(404).json({
        success: false,
        message: '用户不存在'
      });
    }

    if (!user.has_ftp_config) {
      return res.status(400).json({
        success: false,
        message: '该用户未配置SFTP服务器'
      });
    }

    sftp = await connectToSFTP(user);
    const list = await sftp.list(dirPath);

    const formattedList = list.map(item => ({
      name: item.name,
      type: item.type === 'd' ? 'directory' : 'file',
      size: item.size,
      sizeFormatted: formatFileSize(item.size),
      modifiedAt: new Date(item.modifyTime),
      isDirectory: item.type === 'd'
    }));

    formattedList.sort((a, b) => {
      if (a.isDirectory && !b.isDirectory) return -1;
      if (!a.isDirectory && b.isDirectory) return 1;
      return a.name.localeCompare(b.name);
    });

    res.json({
      success: true,
      username: user.username,
      path: dirPath,
      items: formattedList
    });
  } catch (error) {
    console.error('管理员查看用户文件失败:', error);
    res.status(500).json({
      success: false,
      message: '获取文件列表失败: ' + error.message
    });
  } finally {
    if (sftp) await sftp.end();
  }
});

// 获取所有分享（管理员）
app.get('/api/admin/shares', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const shares = ShareDB.getAll();

    res.json({
      success: true,
      shares
    });
  } catch (error) {
    console.error('获取分享列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取分享列表失败: ' + error.message
    });
  }
});

// 删除分享（管理员）
app.delete('/api/admin/shares/:id', authMiddleware, adminMiddleware, (req, res) => {
  try {
    // 先获取分享信息以获得share_code
    const share = ShareDB.findById(req.params.id);

    if (share) {
      // 删除缓存
      if (shareFileCache.has(share.share_code)) {
        shareFileCache.delete(share.share_code);
        console.log(`[缓存清除] 分享码: ${share.share_code} (管理员操作)`);
      }

      // 删除数据库记录
      ShareDB.delete(req.params.id);

      res.json({
        success: true,
        message: '分享已删除'
      });
    } else {
      res.status(404).json({
        success: false,
        message: '分享不存在'
      });
    }
  } catch (error) {
    console.error('删除分享失败:', error);
    res.status(500).json({
      success: false,
      message: '删除分享失败: ' + error.message
    });
  }
});

// ============================================
// 管理员：上传工具管理
// ============================================

// 检查上传工具是否存在
app.get('/api/admin/check-upload-tool', authMiddleware, adminMiddleware, (req, res) => {
  try {
    const toolPath = path.join(__dirname, '..', 'upload-tool', 'dist', '玩玩云上传工具.exe');

    if (fs.existsSync(toolPath)) {
      const stats = fs.statSync(toolPath);
      const sizeMB = (stats.size / (1024 * 1024)).toFixed(2);

      res.json({
        success: true,
        exists: true,
        fileInfo: {
          path: toolPath,
          size: stats.size,
          sizeMB: sizeMB,
          modifiedAt: stats.mtime
        }
      });
    } else {
      res.json({
        success: true,
        exists: false,
        message: '上传工具不存在'
      });
    }
  } catch (error) {
    console.error('检查上传工具失败:', error);
    res.status(500).json({
      success: false,
      message: '检查失败: ' + error.message
    });
  }
});

// 上传工具文件
const uploadToolStorage = multer.diskStorage({
  destination: (req, file, cb) => {
    const uploadDir = path.join(__dirname, '..', 'upload-tool', 'dist');
    // 确保目录存在
    if (!fs.existsSync(uploadDir)) {
      fs.mkdirSync(uploadDir, { recursive: true });
    }
    cb(null, uploadDir);
  },
  filename: (req, file, cb) => {
    // 固定文件名
    cb(null, '玩玩云上传工具.exe');
  }
});

const uploadTool = multer({
  storage: uploadToolStorage,
  limits: {
    fileSize: 100 * 1024 * 1024 // 限制100MB
  },
  fileFilter: (req, file, cb) => {
    // 只允许.exe文件
    if (!file.originalname.toLowerCase().endsWith('.exe')) {
      return cb(new Error('只允许上传.exe文件'));
    }
    cb(null, true);
  }
});

app.post('/api/admin/upload-tool', authMiddleware, adminMiddleware, uploadTool.single('file'), (req, res) => {
  try {
    if (!req.file) {
      return res.status(400).json({
        success: false,
        message: '请选择要上传的文件'
      });
    }

    const fileSizeMB = (req.file.size / (1024 * 1024)).toFixed(2);

    // 验证文件大小（至少20MB，上传工具通常很大）
    if (req.file.size < 20 * 1024 * 1024) {
      // 删除上传的文件
      fs.unlinkSync(req.file.path);
      return res.status(400).json({
        success: false,
        message: '文件大小异常，上传工具通常大于20MB'
      });
    }

    console.log(`[上传工具] 管理员上传成功: ${fileSizeMB}MB`);

    res.json({
      success: true,
      message: '上传工具已上传',
      fileInfo: {
        size: req.file.size,
        sizeMB: fileSizeMB
      }
    });
  } catch (error) {
    console.error('上传工具失败:', error);
    res.status(500).json({
      success: false,
      message: '上传失败: ' + error.message
    });
  }
});

// 分享页面访问路由
app.get("/s/:code", (req, res) => {
  const shareCode = req.params.code;
  // 使用相对路径重定向，浏览器会自动使用当前的协议和host
  const frontendUrl = `/share.html?code=${shareCode}`;
  console.log(`[分享] 重定向到: ${frontendUrl}`);
  res.redirect(frontendUrl);
});

// 启动时清理旧临时文件
cleanupOldTempFiles();

// 启动服务器
app.listen(PORT, '0.0.0.0', () => {
  console.log(`\n========================================`);
  console.log(`玩玩云已启动`);
  console.log(`服务器地址: http://localhost:${PORT}`);
  console.log(`外网访问地址: http://0.0.0.0:${PORT}`);
  console.log(`========================================\n`);
});