const express = require('express');
const cors = require('cors');
const path = require('path');
const fs = require('fs');
const multer = require('multer');
const { v4: uuidv4 } = require('uuid');
const db = require('./database');

const app = express();
const PORT = process.env.PORT || 3001;

// 聊天附件存储目录
const uploadsDir = path.join(__dirname, 'uploads');
if (!fs.existsSync(uploadsDir)) {
  fs.mkdirSync(uploadsDir, { recursive: true });
}

// multer 磁盘存储：文件名用 uuid + 安全扩展名，单文件上限 100MB
const MIME_EXT = {
  'image/jpeg': '.jpg', 'image/png': '.png', 'image/gif': '.gif', 'image/webp': '.webp', 'image/bmp': '.bmp',
  'video/mp4': '.mp4', 'video/webm': '.webm', 'video/quicktime': '.mov', 'video/x-msvideo': '.avi', 'video/x-matroska': '.mkv'
};
const upload = multer({
  storage: multer.diskStorage({
    destination: (req, file, cb) => cb(null, uploadsDir),
    filename: (req, file, cb) => {
      const rawExt = path.extname(file.originalname || '').toLowerCase();
      const ext = MIME_EXT[file.mimetype] || (/^\.[a-z0-9]{1,8}$/.test(rawExt) ? rawExt : '.bin');
      cb(null, uuidv4() + ext);
    }
  }),
  limits: { fileSize: 100 * 1024 * 1024 }
});

// 内存会话存储
const sessions = new Map();
// 会话最近活跃时间（token -> 时间戳），用于判断在线状态
const sessionActivity = new Map();
// 最近活跃时间在此窗口内视为在线
const ONLINE_WINDOW_MS = 10 * 60 * 1000;

function touchSession(token) {
  sessionActivity.set(token, Date.now());
}

function dropSession(token) {
  sessions.delete(token);
  sessionActivity.delete(token);
}

// 收集当前在线用户（用户ID -> 最近活跃时间戳，取最新）
function getOnlineUserMap() {
  const now = Date.now();
  const map = new Map();
  for (const [token, sessionUser] of sessions.entries()) {
    const active = sessionActivity.get(token) || 0;
    if (now - active <= ONLINE_WINDOW_MS) {
      if (!map.has(sessionUser.id) || active > map.get(sessionUser.id)) {
        map.set(sessionUser.id, active);
      }
    }
  }
  return map;
}

function formatActive(ts) {
  const d = new Date(ts);
  const pad = (n) => String(n).padStart(2, '0');
  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}:${pad(d.getSeconds())}`;
}

// 登录验证中间件（仅对 /api 路由生效）
function authMiddleware(req, res, next) {
  const publicPaths = ['/auth/login', '/auth/logout', '/weather'];
  if (publicPaths.some(path => req.path.startsWith(path))) {
    return next();
  }
  // 优先取请求头 token；img/video/下载链接无法携带 Authorization 头，允许查询参数回退
  const token = req.headers.authorization?.replace('Bearer ', '') || req.query.token;
  if (!token || !sessions.has(token)) {
    return res.status(401).json({ success: false, message: '未登录或登录已过期' });
  }
  req.user = sessions.get(token);
  touchSession(token);
  next();
}

// 管理员权限中间件
function requireAdmin(req, res, next) {
  if (req.user && req.user.role === 'admin') {
    return next();
  }
  return res.status(403).json({ success: false, message: '权限不足，该操作仅管理员可用' });
}

app.use(cors());
app.use(express.json());

// API 认证中间件
app.use('/api', authMiddleware);

// 生产环境提供前端静态文件
const clientBuildPath = path.join(__dirname, 'client', 'dist');
app.use(express.static(clientBuildPath));

// ==================== 设备管理 API ====================

// 记录设备操作日志
function logDeviceAction(deviceId, deviceName, action, detail, operator) {
  db.prepare(`
    INSERT INTO device_logs (id, device_id, device_name, action, detail, operator)
    VALUES (?, ?, ?, ?, ?, ?)
  `).run(uuidv4(), deviceId, deviceName || '', action, detail || '', operator || '');
}

// ==================== 推送事件（客户端轮询拉取的原生推送源） ====================

// 定期清理 7 天前的推送事件
function cleanPushEvents() {
  db.prepare("DELETE FROM push_events WHERE created_at < datetime('now','localtime','-7 day')").run();
}
cleanPushEvents();
setInterval(cleanPushEvents, 6 * 60 * 60 * 1000);

// 向指定用户写入一条推送事件
function pushTo(userId, kind, title, body) {
  if (!userId) return;
  db.prepare('INSERT INTO push_events (user_id, kind, title, body) VALUES (?, ?, ?, ?)')
    .run(userId, kind, String(title || ''), String(body || '').slice(0, 200));
}

// 向多个用户推送（自动去重、跳过发送者）
function pushToMany(userIds, kind, title, body, excludeId) {
  const seen = new Set();
  for (const uid of userIds) {
    if (!uid || uid === excludeId || seen.has(uid)) continue;
    seen.add(uid);
    pushTo(uid, kind, title, body);
  }
}

// 向指定角色的全部用户推送
function pushToRole(role, kind, title, body, excludeId) {
  const rows = db.prepare('SELECT id FROM users WHERE role = ?').all(role);
  pushToMany(rows.map(r => r.id), kind, title, body, excludeId);
}

// 向全部用户推送
function pushToAll(kind, title, body, excludeId) {
  const rows = db.prepare('SELECT id FROM users').all();
  pushToMany(rows.map(r => r.id), kind, title, body, excludeId);
}

// 客户端拉取自己的新推送事件（after 游标为上次拉到的最大 id）
app.get('/api/push/events', (req, res) => {
  const after = parseInt(req.query.after) || 0;
  const rows = db.prepare('SELECT * FROM push_events WHERE user_id = ? AND id > ? ORDER BY id ASC LIMIT 50')
    .all(req.user.id, after);
  res.json({ success: true, data: rows });
});

// 写入维修记录
function addMaintenanceRecord(deviceId, deviceName, type, remark, operator) {
  db.prepare(`
    INSERT INTO maintenance_records (id, device_id, device_name, type, remark, operator)
    VALUES (?, ?, ?, ?, ?, ?)
  `).run(uuidv4(), deviceId, deviceName || '', type, remark || '', operator || '');
}

const getOperator = (req) => (req.user ? (req.user.display_name || req.user.username) : '');

// 获取所有设备
app.get('/api/devices', (req, res) => {
  const { keyword, type, status } = req.query;
  let sql = 'SELECT * FROM devices WHERE 1=1';
  const params = [];

  if (keyword) {
    sql += ' AND (name LIKE ? OR serial_number LIKE ? OR location LIKE ?)';
    params.push(`%${keyword}%`, `%${keyword}%`, `%${keyword}%`);
  }
  if (type) {
    sql += ' AND type = ?';
    params.push(type);
  }
  if (status) {
    sql += ' AND status = ?';
    params.push(status);
  }

  sql += ' ORDER BY created_at DESC';
  const devices = db.prepare(sql).all(...params);
  res.json({ success: true, data: devices });
});

// 报废设备列表（须定义在 /api/devices/:id 之前，避免路由遮蔽）
app.get('/api/devices/scrapped', (req, res) => {
  const scrapped = db.prepare(
    "SELECT * FROM devices WHERE status = '已报废' ORDER BY scrap_date DESC, updated_at DESC"
  ).all();
  res.json({ success: true, data: scrapped });
});

// 设备操作日志（管理员）
app.get('/api/devices/logs', requireAdmin, (req, res) => {
  const { device_id, keyword } = req.query;
  let sql = 'SELECT * FROM device_logs WHERE 1=1';
  const params = [];
  if (device_id) {
    sql += ' AND device_id = ?';
    params.push(device_id);
  }
  if (keyword) {
    sql += ' AND (device_name LIKE ? OR action LIKE ? OR detail LIKE ? OR operator LIKE ?)';
    params.push(`%${keyword}%`, `%${keyword}%`, `%${keyword}%`, `%${keyword}%`);
  }
  sql += ' ORDER BY created_at DESC LIMIT 500';
  res.json({ success: true, data: db.prepare(sql).all(...params) });
});

// 设备统计
app.get('/api/devices/stats/summary', (req, res) => {
  const total = db.prepare('SELECT COUNT(*) as count FROM devices').get().count;
  const normal = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='正常'").get().count;
  const repairing = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='维修中'").get().count;
  const scrapped = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='已报废'").get().count;
  const idle = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='闲置'").get().count;
  const scrappedThisMonth = db.prepare(
    "SELECT COUNT(*) as count FROM devices WHERE status='已报废' AND substr(scrap_date,1,7) = substr(date('now','localtime'),1,7)"
  ).get().count;
  const types = db.prepare('SELECT type, COUNT(*) as count FROM devices GROUP BY type').all();
  res.json({ success: true, data: { total, normal, repairing, scrapped, idle, scrappedThisMonth, types } });
});

// 获取单个设备
app.get('/api/devices/:id', (req, res) => {
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (device) {
    res.json({ success: true, data: device });
  } else {
    res.status(404).json({ success: false, message: '设备不存在' });
  }
});

// 获取设备维修/保养记录
app.get('/api/devices/:id/records', (req, res) => {
  const records = db.prepare(
    'SELECT * FROM maintenance_records WHERE device_id = ? ORDER BY created_at DESC'
  ).all(req.params.id);
  res.json({ success: true, data: records });
});

// 添加设备
app.post('/api/devices', (req, res) => {
  const { name, type, model, serial_number, status, location, purchase_date, warranty_date, responsible_person, description } = req.body;
  const id = uuidv4();
  db.prepare(`
    INSERT INTO devices (id, name, type, model, serial_number, status, location, purchase_date, warranty_date, responsible_person, description)
    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
  `).run(id, name, type, model || '', serial_number || '', status || '正常', location || '', purchase_date || '', warranty_date || '', responsible_person || '', description || '');

  logDeviceAction(id, name, '添加', '新设备入库', getOperator(req));
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(id);
  res.json({ success: true, data: device, message: '设备添加成功' });
});

// 更新设备
app.put('/api/devices/:id', requireAdmin, (req, res) => {
  const { name, type, model, serial_number, status, location, purchase_date, warranty_date, responsible_person, description } = req.body;
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  db.prepare(`
    UPDATE devices SET name=?, type=?, model=?, serial_number=?, status=?, location=?, purchase_date=?, warranty_date=?, responsible_person=?, description=?, updated_at=datetime('now','localtime')
    WHERE id=?
  `).run(name, type, model || '', serial_number || '', status, location || '', purchase_date || '', warranty_date || '', responsible_person || '', description || '', req.params.id);

  logDeviceAction(req.params.id, name, '编辑', '设备信息已更新', getOperator(req));
  const updated = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: updated, message: '设备更新成功' });
});

// 删除设备（管理员）
app.delete('/api/devices/:id', requireAdmin, (req, res) => {
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  db.prepare('DELETE FROM devices WHERE id = ?').run(req.params.id);
  db.prepare('DELETE FROM maintenance_records WHERE device_id = ?').run(req.params.id);
  db.prepare('DELETE FROM device_logs WHERE device_id = ?').run(req.params.id);
  res.json({ success: true, message: '设备删除成功' });
});

// 设备报修（普通用户+管理员）：将状态置为维修中
app.patch('/api/devices/:id/repair', (req, res) => {
  const { remark } = req.body || {};
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  if (device.status === '已报废') {
    return res.status(400).json({ success: false, message: '已报废设备不可报修' });
  }
  db.prepare(`
    UPDATE devices SET status='维修中', updated_at=datetime('now','localtime') WHERE id=?
  `).run(req.params.id);
  addMaintenanceRecord(req.params.id, device.name, '报修', remark || '', getOperator(req));
  logDeviceAction(req.params.id, device.name, '报修', remark || '设备已标记为维修中', getOperator(req));
  // 推送给全部管理员处理
  pushToRole('admin', 'repair_request', '设备报修', `${getOperator(req)} 报修：${device.name}${remark ? '（' + remark + '）' : ''}`, req.user.id);
  const updated = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: updated, message: '报修成功，设备已标记为维修中' });
});

// 修改设备维修状态（管理员）
app.patch('/api/devices/:id/status', requireAdmin, (req, res) => {
  const { status } = req.body || {};
  const allowed = ['正常', '维修中', '已报废', '闲置'];
  if (!status || !allowed.includes(status)) {
    return res.status(400).json({ success: false, message: '无效的状态值' });
  }
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  if (status === device.status) {
    return res.json({ success: true, data: device, message: '状态未发生变化' });
  }
  if (status !== '已报废') {
    // 离开报废状态时清空报废信息
    db.prepare("UPDATE devices SET status=?, scrap_reason='', scrap_date='', scrap_operator='', updated_at=datetime('now','localtime') WHERE id=?").run(status, req.params.id);
  } else {
    db.prepare("UPDATE devices SET status=?, updated_at=datetime('now','localtime') WHERE id=?").run(status, req.params.id);
  }
  if (device.status === '维修中' && status === '正常') {
    addMaintenanceRecord(req.params.id, device.name, '维修完成', '维修完成，状态恢复正常', getOperator(req));
    // 维修完成推送给全部用户
    pushToAll('repair_done', '设备维修完成', `设备「${device.name}」已维修好，状态恢复正常`, req.user.id);
  }
  logDeviceAction(req.params.id, device.name, '修改状态', `${device.status} → ${status}`, getOperator(req));
  const updated = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: updated, message: `维修状态已修改为：${status}` });
});

// 设备报废（管理员）
app.post('/api/devices/:id/scrap', requireAdmin, (req, res) => {
  const { reason } = req.body || {};
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  if (device.status === '已报废') {
    return res.status(400).json({ success: false, message: '该设备已处于报废状态' });
  }
  const operator = getOperator(req);
  db.prepare(`
    UPDATE devices SET status='已报废', scrap_reason=?, scrap_date=date('now','localtime'), scrap_operator=?, updated_at=datetime('now','localtime')
    WHERE id=?
  `).run(reason || '', operator, req.params.id);

  addMaintenanceRecord(req.params.id, device.name, '报废', reason || '', operator);
  logDeviceAction(req.params.id, device.name, '报废', reason || '设备已报废', operator);
  const updated = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: updated, message: '设备已报废' });
});

// 恢复报废设备（管理员）：撤销报废，状态恢复为闲置
app.post('/api/devices/:id/restore', requireAdmin, (req, res) => {
  const device = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  if (!device) {
    return res.status(404).json({ success: false, message: '设备不存在' });
  }
  if (device.status !== '已报废') {
    return res.status(400).json({ success: false, message: '仅报废状态的设备可恢复' });
  }
  db.prepare(`
    UPDATE devices SET status='闲置', scrap_reason='', scrap_date='', scrap_operator='', updated_at=datetime('now','localtime')
    WHERE id=?
  `).run(req.params.id);

  logDeviceAction(req.params.id, device.name, '恢复', '报废已撤销，状态恢复为闲置', getOperator(req));
  const updated = db.prepare('SELECT * FROM devices WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: updated, message: '报废已撤销，设备状态恢复为闲置' });
});

// ==================== 人员管理 API ====================

// 获取所有人员（LEFT JOIN 账户信息）
app.get('/api/personnel', (req, res) => {
  const { keyword, department, status } = req.query;
  let sql = `
    SELECT p.*, u.id AS user_id, u.username AS account_username, u.role AS account_role
    FROM personnel p LEFT JOIN users u ON u.personnel_id = p.id
    WHERE 1=1
  `;
  const params = [];

  if (keyword) {
    sql += ' AND (p.name LIKE ? OR p.employee_id LIKE ? OR p.phone LIKE ?)';
    params.push(`%${keyword}%`, `%${keyword}%`, `%${keyword}%`);
  }
  if (department) {
    sql += ' AND p.department = ?';
    params.push(department);
  }
  if (status) {
    sql += ' AND p.status = ?';
    params.push(status);
  }

  sql += ' ORDER BY p.created_at DESC';
  const personnel = db.prepare(sql).all(...params);
  res.json({ success: true, data: personnel });
});

// 获取单个人员
app.get('/api/personnel/:id', (req, res) => {
  const person = db.prepare('SELECT * FROM personnel WHERE id = ?').get(req.params.id);
  if (person) {
    res.json({ success: true, data: person });
  } else {
    res.status(404).json({ success: false, message: '人员不存在' });
  }
});

// 添加人员（管理员），可同时创建登录账户
app.post('/api/personnel', requireAdmin, (req, res) => {
  const { name, employee_id, department, position, phone, email, status, entry_date, description, account } = req.body;
  const id = uuidv4();

  // 校验账户用户名唯一
  if (account && account.createAccount) {
    if (!account.username || !account.password) {
      return res.status(400).json({ success: false, message: '创建账户需填写用户名和密码' });
    }
    const exist = db.prepare('SELECT id FROM users WHERE username = ?').get(account.username);
    if (exist) {
      return res.status(400).json({ success: false, message: `用户名 ${account.username} 已存在` });
    }
  }

  db.prepare(`
    INSERT INTO personnel (id, name, employee_id, department, position, phone, email, status, entry_date, description)
    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
  `).run(id, name, employee_id || '', department || '', position || '', phone || '', email || '', status || '在职', entry_date || '', description || '');

  // 同步创建账户
  if (account && account.createAccount) {
    db.prepare(`
      INSERT INTO users (id, username, password, role, display_name, personnel_id)
      VALUES (?, ?, ?, ?, ?, ?)
    `).run(uuidv4(), account.username, account.password, account.role || 'user', name, id);
  }

  const person = db.prepare(`
    SELECT p.*, u.id AS user_id, u.username AS account_username, u.role AS account_role
    FROM personnel p LEFT JOIN users u ON u.personnel_id = p.id WHERE p.id = ?
  `).get(id);
  res.json({ success: true, data: person, message: account && account.createAccount ? '人员及账户创建成功' : '人员添加成功' });
});

// 更新人员（管理员），同步维护关联账户
app.put('/api/personnel/:id', requireAdmin, (req, res) => {
  const { name, employee_id, department, position, phone, email, status, entry_date, description, account } = req.body;
  db.prepare(`
    UPDATE personnel SET name=?, employee_id=?, department=?, position=?, phone=?, email=?, status=?, entry_date=?, description=?, updated_at=datetime('now','localtime')
    WHERE id=?
  `).run(name, employee_id, department || '', position || '', phone || '', email || '', status, entry_date || '', description || '', req.params.id);

  const existUser = db.prepare('SELECT * FROM users WHERE personnel_id = ?').get(req.params.id);

  if (account && account.createAccount) {
    // 校验用户名唯一（排除自身）
    const dup = db.prepare('SELECT id FROM users WHERE username = ? AND personnel_id != ?').get(account.username, req.params.id);
    if (dup) {
      return res.status(400).json({ success: false, message: `用户名 ${account.username} 已存在` });
    }
    if (existUser) {
      db.prepare('UPDATE users SET username=?, role=?, display_name=? WHERE personnel_id=?')
        .run(account.username, account.role || 'user', name, req.params.id);
      // 仅当提供新密码时更新密码
      if (account.password) {
        db.prepare('UPDATE users SET password=? WHERE personnel_id=?').run(account.password, req.params.id);
      }
    } else {
      if (!account.username || !account.password) {
        return res.status(400).json({ success: false, message: '创建账户需填写用户名和密码' });
      }
      db.prepare(`
        INSERT INTO users (id, username, password, role, display_name, personnel_id)
        VALUES (?, ?, ?, ?, ?, ?)
      `).run(uuidv4(), account.username, account.password, account.role || 'user', name, req.params.id);
    }
  } else if (existUser) {
    // 关闭账户：删除关联用户
    db.prepare('DELETE FROM users WHERE personnel_id = ?').run(req.params.id);
  }

  const person = db.prepare(`
    SELECT p.*, u.id AS user_id, u.username AS account_username, u.role AS account_role
    FROM personnel p LEFT JOIN users u ON u.personnel_id = p.id WHERE p.id = ?
  `).get(req.params.id);
  res.json({ success: true, data: person, message: '人员更新成功' });
});

// 删除人员（管理员），同时删除关联账户
app.delete('/api/personnel/:id', requireAdmin, (req, res) => {
  db.prepare('DELETE FROM users WHERE personnel_id = ?').run(req.params.id);
  db.prepare('DELETE FROM personnel WHERE id = ?').run(req.params.id);
  res.json({ success: true, message: '人员及关联账户删除成功' });
});

// 人员统计
app.get('/api/personnel/stats/summary', (req, res) => {
  const total = db.prepare('SELECT COUNT(*) as count FROM personnel').get().count;
  const active = db.prepare("SELECT COUNT(*) as count FROM personnel WHERE status='在职'").get().count;
  const withAccount = db.prepare('SELECT COUNT(*) as count FROM personnel WHERE id IN (SELECT personnel_id FROM users WHERE personnel_id IS NOT NULL)').get().count;
  const departments = db.prepare('SELECT department, COUNT(*) as count FROM personnel GROUP BY department').all();
  res.json({ success: true, data: { total, active, withAccount, departments } });
});

// ==================== 通知管理 API ====================

// 获取所有通知
app.get('/api/notifications', (req, res) => {
  const { keyword, type, priority, is_read } = req.query;
  let sql = 'SELECT * FROM notifications WHERE 1=1';
  const params = [];

  if (keyword) {
    sql += ' AND (title LIKE ? OR content LIKE ?)';
    params.push(`%${keyword}%`, `%${keyword}%`);
  }
  if (type) {
    sql += ' AND type = ?';
    params.push(type);
  }
  if (priority) {
    sql += ' AND priority = ?';
    params.push(priority);
  }
  if (is_read !== undefined && is_read !== '') {
    sql += ' AND is_read = ?';
    params.push(parseInt(is_read));
  }

  sql += ' ORDER BY created_at DESC';
  const notifications = db.prepare(sql).all(...params);
  res.json({ success: true, data: notifications });
});

// 获取单个通知
app.get('/api/notifications/:id', (req, res) => {
  const notif = db.prepare('SELECT * FROM notifications WHERE id = ?').get(req.params.id);
  if (notif) {
    res.json({ success: true, data: notif });
  } else {
    res.status(404).json({ success: false, message: '通知不存在' });
  }
});

// 添加通知（管理员）
app.post('/api/notifications', requireAdmin, (req, res) => {
  const { title, content, type, priority, target } = req.body;
  const id = uuidv4();
  db.prepare(`
    INSERT INTO notifications (id, title, content, type, priority, is_read, target)
    VALUES (?, ?, ?, ?, ?, 0, ?)
  `).run(id, title, content, type || '普通', priority || '普通', target || '全部');

  const notif = db.prepare('SELECT * FROM notifications WHERE id = ?').get(id);
  res.json({ success: true, data: notif, message: '通知发布成功' });
});

// 更新通知（管理员）
app.put('/api/notifications/:id', requireAdmin, (req, res) => {
  const { title, content, type, priority, is_read, target } = req.body;
  db.prepare(`
    UPDATE notifications SET title=?, content=?, type=?, priority=?, is_read=?, target=?, updated_at=datetime('now','localtime')
    WHERE id=?
  `).run(title, content, type, priority, is_read ? 1 : 0, target, req.params.id);

  const notif = db.prepare('SELECT * FROM notifications WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: notif, message: '通知更新成功' });
});

// 标记已读
app.patch('/api/notifications/:id/read', (req, res) => {
  db.prepare("UPDATE notifications SET is_read=1, updated_at=datetime('now','localtime') WHERE id=?").run(req.params.id);
  const notif = db.prepare('SELECT * FROM notifications WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: notif, message: '已标记为已读' });
});

// 全部标记已读
app.patch('/api/notifications/read-all', (req, res) => {
  db.prepare("UPDATE notifications SET is_read=1, updated_at=datetime('now','localtime') WHERE is_read=0").run();
  res.json({ success: true, message: '全部已标记为已读' });
});

// 删除通知（管理员）
app.delete('/api/notifications/:id', requireAdmin, (req, res) => {
  db.prepare('DELETE FROM notifications WHERE id = ?').run(req.params.id);
  res.json({ success: true, message: '通知删除成功' });
});

// 通知统计
app.get('/api/notifications/stats/summary', (req, res) => {
  const total = db.prepare('SELECT COUNT(*) as count FROM notifications').get().count;
  const unread = db.prepare('SELECT COUNT(*) as count FROM notifications WHERE is_read=0').get().count;
  const high = db.prepare("SELECT COUNT(*) as count FROM notifications WHERE priority='高' AND is_read=0").get().count;
  res.json({ success: true, data: { total, unread, high } });
});

// 清空已读通知（管理员）
app.delete('/api/notifications/read/clear', requireAdmin, (req, res) => {
  const result = db.prepare('DELETE FROM notifications WHERE is_read = 1').run();
  res.json({ success: true, message: `已清理 ${result.changes} 条已读通知` });
});

// ==================== 账户管理 API ====================

// 记录账户操作日志
function logUserAction(username, action, detail, operator) {
  db.prepare(`
    INSERT INTO user_logs (id, username, action, detail, operator)
    VALUES (?, ?, ?, ?, ?)
  `).run(uuidv4(), username || '', action, detail || '', operator || '');
}

// 获取所有账户（管理员，含关联人员）
app.get('/api/users', requireAdmin, (req, res) => {
  const { keyword, role } = req.query;
  let sql = `
    SELECT u.id, u.username, u.role, u.display_name, u.created_at, u.last_login, u.personnel_id, p.name AS personnel_name, p.department
    FROM users u LEFT JOIN personnel p ON u.personnel_id = p.id
    WHERE 1=1
  `;
  const params = [];
  if (keyword) {
    sql += ' AND (u.username LIKE ? OR u.display_name LIKE ?)';
    params.push(`%${keyword}%`, `%${keyword}%`);
  }
  if (role) {
    sql += ' AND u.role = ?';
    params.push(role);
  }
  sql += ' ORDER BY u.created_at ASC';
  const onlineMap = getOnlineUserMap();
  const data = db.prepare(sql).all(...params).map(u => {
    const active = onlineMap.get(u.id);
    return { ...u, is_online: !!active, last_active: active ? formatActive(active) : null };
  });
  res.json({ success: true, data });
});

// 账户操作日志（管理员）
app.get('/api/users/logs', requireAdmin, (req, res) => {
  const logs = db.prepare('SELECT * FROM user_logs ORDER BY created_at DESC LIMIT 500').all();
  res.json({ success: true, data: logs });
});

// 账户统计（管理员）
app.get('/api/users/stats/summary', requireAdmin, (req, res) => {
  const total = db.prepare('SELECT COUNT(*) as count FROM users').get().count;
  const admins = db.prepare("SELECT COUNT(*) as count FROM users WHERE role='admin'").get().count;
  const users = total - admins;
  const online = getOnlineUserMap().size;
  res.json({ success: true, data: { total, admins, users, online } });
});

// 创建独立账户（管理员）
app.post('/api/users', requireAdmin, (req, res) => {
  const { username, password, role, display_name } = req.body;
  if (!username || !password) {
    return res.status(400).json({ success: false, message: '用户名和密码不能为空' });
  }
  const exist = db.prepare('SELECT id FROM users WHERE username = ?').get(username);
  if (exist) {
    return res.status(400).json({ success: false, message: `用户名 ${username} 已存在` });
  }
  const id = uuidv4();
  db.prepare(`
    INSERT INTO users (id, username, password, role, display_name)
    VALUES (?, ?, ?, ?, ?)
  `).run(id, username, password, role === 'admin' ? 'admin' : 'user', display_name || username);

  logUserAction(username, '创建', `创建账户，角色：${role === 'admin' ? '管理员' : '普通用户'}`, getOperator(req));
  const user = db.prepare('SELECT id, username, role, display_name, created_at FROM users WHERE id = ?').get(id);
  res.json({ success: true, data: user, message: '账户创建成功' });
});

// 更新账户信息（管理员：用户名/角色/显示名）
app.put('/api/users/:id', requireAdmin, (req, res) => {
  const { username, role, display_name } = req.body;
  const target = db.prepare('SELECT * FROM users WHERE id = ?').get(req.params.id);
  if (!target) {
    return res.status(404).json({ success: false, message: '账户不存在' });
  }
  // 保护最后一个管理员
  if (target.role === 'admin' && role === 'user') {
    const adminCount = db.prepare("SELECT COUNT(*) as count FROM users WHERE role='admin'").get().count;
    if (adminCount <= 1) {
      return res.status(400).json({ success: false, message: '不能降级最后一个管理员账户' });
    }
  }
  const dup = db.prepare('SELECT id FROM users WHERE username = ? AND id != ?').get(username, req.params.id);
  if (dup) {
    return res.status(400).json({ success: false, message: `用户名 ${username} 已存在` });
  }
  db.prepare('UPDATE users SET username=?, role=?, display_name=? WHERE id=?')
    .run(username, role === 'admin' ? 'admin' : 'user', display_name || username, req.params.id);

  // 同步会话中的用户信息
  for (const [token, sessionUser] of sessions.entries()) {
    if (sessionUser.id === req.params.id) {
      sessions.set(token, { id: req.params.id, username, role: role === 'admin' ? 'admin' : 'user', display_name: display_name || username });
    }
  }

  logUserAction(username, '修改', '账户信息已更新', getOperator(req));
  const user = db.prepare('SELECT id, username, role, display_name, created_at FROM users WHERE id = ?').get(req.params.id);
  res.json({ success: true, data: user, message: '账户更新成功' });
});

// 重置账户密码（管理员）
app.patch('/api/users/:id/reset-password', requireAdmin, (req, res) => {
  const { password } = req.body;
  if (!password || password.length < 6) {
    return res.status(400).json({ success: false, message: '新密码不能为空且不少于6位' });
  }
  const target = db.prepare('SELECT * FROM users WHERE id = ?').get(req.params.id);
  if (!target) {
    return res.status(404).json({ success: false, message: '账户不存在' });
  }
  db.prepare('UPDATE users SET password=? WHERE id=?').run(password, req.params.id);
  logUserAction(target.username, '重置密码', '密码已被管理员重置', getOperator(req));
  res.json({ success: true, message: `已重置 ${target.username} 的密码` });
});

// 删除账户（管理员）
app.delete('/api/users/:id', requireAdmin, (req, res) => {
  const target = db.prepare('SELECT * FROM users WHERE id = ?').get(req.params.id);
  if (!target) {
    return res.status(404).json({ success: false, message: '账户不存在' });
  }
  if (req.user && req.user.id === target.id) {
    return res.status(400).json({ success: false, message: '不能删除当前登录的账户' });
  }
  if (target.role === 'admin') {
    const adminCount = db.prepare("SELECT COUNT(*) as count FROM users WHERE role='admin'").get().count;
    if (adminCount <= 1) {
      return res.status(400).json({ success: false, message: '不能删除最后一个管理员账户' });
    }
  }
  db.prepare('DELETE FROM users WHERE id = ?').run(req.params.id);
  // 使关联的会话失效
  for (const [token, sessionUser] of sessions.entries()) {
    if (sessionUser.id === target.id) dropSession(token);
  }
  logUserAction(target.username, '删除', '账户已删除', getOperator(req));
  res.json({ success: true, message: '账户删除成功' });
});

// 账户操作日志清理（管理员）
app.delete('/api/users/logs/clear', requireAdmin, (req, res) => {
  db.prepare('DELETE FROM user_logs').run();
  res.json({ success: true, message: '账户日志已清空' });
});

// ==================== 消息对话 API ====================

// 校验当前用户是否为会话成员
function isConversationMember(convId, userId) {
  return !!db.prepare('SELECT 1 FROM conversation_members WHERE conversation_id = ? AND user_id = ?').get(convId, userId);
}

function getUserDisplayName(userId) {
  const u = db.prepare('SELECT display_name, username FROM users WHERE id = ?').get(userId);
  return u ? (u.display_name || u.username) : '';
}

// 媒体消息在会话列表的预览文案
function messagePreview(m) {
  if (m.msg_type === 'image') return '[图片]';
  if (m.msg_type === 'video') return '[视频]';
  if (m.msg_type === 'file') return '[文件] ' + (m.content || '');
  return m.content;
}

// 上传聊天附件（图片/视频/文件），返回 fileId 供发送消息时引用
app.post('/api/chat/upload', upload.single('file'), (req, res) => {
  if (!req.file) {
    return res.status(400).json({ success: false, message: '未接收到文件' });
  }
  const id = uuidv4();
  db.prepare('INSERT INTO chat_files (id, uploader_id, file_name, stored_name, file_size, file_mime) VALUES (?, ?, ?, ?, ?, ?)')
    .run(id, req.user.id, req.file.originalname, req.file.filename, req.file.size, req.file.mimetype || '');
  res.json({
    success: true,
    data: { fileId: id, fileName: req.file.originalname, fileSize: req.file.size, fileMime: req.file.mimetype || '' }
  });
});

// multer 错误处理（超大文件等）
app.use('/api/chat/upload', (err, req, res, next) => {
  if (err) {
    const msg = err.code === 'LIMIT_FILE_SIZE' ? '文件超过 100MB 限制' : '上传失败';
    return res.status(400).json({ success: false, message: msg });
  }
  next();
});

// 下载/预览聊天附件：仅上传者可访问，或所在会话的成员可访问
app.get('/api/chat/files/:id', (req, res) => {
  const file = db.prepare('SELECT * FROM chat_files WHERE id = ?').get(req.params.id);
  if (!file) {
    return res.status(404).json({ success: false, message: '文件不存在' });
  }
  if (file.uploader_id !== req.user.id) {
    const inConv = db.prepare(`
      SELECT 1 FROM conversation_members m
      WHERE m.user_id = ? AND EXISTS (
        SELECT 1 FROM messages msg WHERE msg.file_id = ? AND msg.conversation_id = m.conversation_id
      )
    `).get(req.user.id, file.id);
    if (!inConv) {
      return res.status(403).json({ success: false, message: '无权访问该文件' });
    }
  }
  const filePath = path.join(uploadsDir, file.stored_name);
  if (!fs.existsSync(filePath)) {
    return res.status(404).json({ success: false, message: '文件已丢失' });
  }
  const inline = (file.file_mime || '').startsWith('image/') || (file.file_mime || '').startsWith('video/');
  const encoded = encodeURIComponent(file.file_name);
  res.setHeader('Content-Type', file.file_mime || 'application/octet-stream');
  res.setHeader('Content-Disposition', `${inline ? 'inline' : 'attachment'}; filename*=UTF-8''${encoded}`);
  fs.createReadStream(filePath).pipe(res);
});

// 全部用户简表（选择聊天对象/建群成员，含在线状态）
app.get('/api/chat/users', (req, res) => {
  const rows = db.prepare('SELECT id, username, display_name, role FROM users ORDER BY created_at ASC').all();
  const onlineMap = getOnlineUserMap();
  const data = rows.map(u => ({ ...u, is_online: onlineMap.has(u.id) }));
  res.json({ success: true, data });
});

// 当前用户的会话列表（含最后一条消息与未读数）
app.get('/api/chat/conversations', (req, res) => {
  const me = req.user.id;
  const convs = db.prepare(`
    SELECT c.id, c.type, c.name, c.creator_id, c.created_at, m.last_read_message_id
    FROM conversations c JOIN conversation_members m ON m.conversation_id = c.id
    WHERE m.user_id = ?
  `).all(me);
  const data = convs.map(c => {
    const members = db.prepare(`
      SELECT u.id, u.display_name, u.username
      FROM conversation_members m JOIN users u ON u.id = m.user_id
      WHERE m.conversation_id = ?
    `).all(c.id);
    const last = db.prepare('SELECT * FROM messages WHERE conversation_id = ? ORDER BY id DESC LIMIT 1').get(c.id);
    const unread = db.prepare('SELECT COUNT(*) as count FROM messages WHERE conversation_id = ? AND id > ? AND sender_id != ?')
      .get(c.id, c.last_read_message_id || 0, me).count;
    return {
      id: c.id,
      type: c.type,
      name: c.type === 'group' ? c.name : ((members.find(x => x.id !== me) || {}).display_name || ''),
      creator_id: c.creator_id,
      member_count: members.length,
      members,
      last_message: last ? { content: messagePreview(last), created_at: last.created_at, sender_name: getUserDisplayName(last.sender_id) } : null,
      unread
    };
  });
  // 按最后消息时间倒序（无消息的按创建时间）
  data.sort((a, b) => (b.last_message?.created_at || b.created_at || '').localeCompare(a.last_message?.created_at || a.created_at || ''));
  res.json({ success: true, data });
});

// 创建会话：单聊（type=direct + userId，已有则复用）或群聊（type=group + name + memberIds）
app.post('/api/chat/conversations', (req, res) => {
  const { type, userId, name, memberIds } = req.body;
  const me = req.user;

  if (type === 'direct') {
    if (!userId || userId === me.id) {
      return res.status(400).json({ success: false, message: '请选择对话对象' });
    }
    const target = db.prepare('SELECT id FROM users WHERE id = ?').get(userId);
    if (!target) {
      return res.status(404).json({ success: false, message: '用户不存在' });
    }
    // 复用已有的单聊会话
    const existing = db.prepare(`
      SELECT c.id FROM conversations c WHERE c.type = 'direct'
      AND EXISTS (SELECT 1 FROM conversation_members m WHERE m.conversation_id = c.id AND m.user_id = ?)
      AND EXISTS (SELECT 1 FROM conversation_members m WHERE m.conversation_id = c.id AND m.user_id = ?)
    `).get(me.id, userId);
    if (existing) {
      return res.json({ success: true, data: { id: existing.id }, message: '会话已存在' });
    }
    const id = uuidv4();
    db.prepare("INSERT INTO conversations (id, type, creator_id) VALUES (?, 'direct', ?)").run(id, me.id);
    const insMember = db.prepare('INSERT INTO conversation_members (conversation_id, user_id, role) VALUES (?, ?, ?)');
    insMember.run(id, me.id, 'member');
    insMember.run(id, userId, 'member');
    return res.json({ success: true, data: { id }, message: '会话创建成功' });
  }

  if (type === 'group') {
    if (!name || !String(name).trim()) {
      return res.status(400).json({ success: false, message: '请输入群名称' });
    }
    if (!Array.isArray(memberIds) || memberIds.filter(id => id !== me.id).length < 1) {
      return res.status(400).json({ success: false, message: '请至少选择1名其他群成员' });
    }
    const id = uuidv4();
    db.prepare("INSERT INTO conversations (id, type, name, creator_id) VALUES (?, 'group', ?, ?)").run(id, String(name).trim(), me.id);
    const insMember = db.prepare('INSERT OR IGNORE INTO conversation_members (conversation_id, user_id, role) VALUES (?, ?, ?)');
    insMember.run(id, me.id, 'owner');
    for (const uid of memberIds) {
      if (uid !== me.id && db.prepare('SELECT id FROM users WHERE id = ?').get(uid)) {
        insMember.run(id, uid, 'member');
      }
    }
    logUserAction(me.username, '创建群组', `创建群组：${String(name).trim()}`, me.display_name || me.username);
    return res.json({ success: true, data: { id }, message: '群组创建成功' });
  }

  return res.status(400).json({ success: false, message: '不支持的会话类型' });
});

// 获取会话消息（默认最新 100 条；after 游标增量拉取），同时标记已读
app.get('/api/chat/conversations/:id/messages', (req, res) => {
  const conv = db.prepare('SELECT * FROM conversations WHERE id = ?').get(req.params.id);
  if (!conv || !isConversationMember(req.params.id, req.user.id)) {
    return res.status(404).json({ success: false, message: '会话不存在' });
  }
  // 标记已读到会话最新一条（先于返回，保证本次返回的消息自带已读回执）
  const latest = db.prepare('SELECT MAX(id) as maxId FROM messages WHERE conversation_id = ?').get(req.params.id);
  if (latest && latest.maxId) {
    db.prepare('UPDATE conversation_members SET last_read_message_id = MAX(last_read_message_id, ?) WHERE conversation_id = ? AND user_id = ?')
      .run(latest.maxId, req.params.id, req.user.id);
  }
  const after = parseInt(req.query.after) || 0;
  const limit = Math.min(parseInt(req.query.limit) || 100, 200);
  let rows;
  if (after > 0) {
    rows = db.prepare('SELECT * FROM messages WHERE conversation_id = ? AND id > ? ORDER BY id ASC LIMIT ?').all(req.params.id, after, limit);
  } else {
    rows = db.prepare('SELECT * FROM messages WHERE conversation_id = ? ORDER BY id DESC LIMIT ?').all(req.params.id, limit).reverse();
  }
  const readMap = buildReadStatusMap(req.params.id, req.user.id);
  const fileCache = {};
  const senderCache = {};
  const data = rows.map(m => {
    if (!senderCache[m.sender_id]) senderCache[m.sender_id] = getUserDisplayName(m.sender_id);
    const item = { ...m, sender_name: senderCache[m.sender_id], read_status: readMap[m.id] || null };
    if (m.file_id) {
      if (!fileCache[m.file_id]) fileCache[m.file_id] = db.prepare('SELECT * FROM chat_files WHERE id = ?').get(m.file_id);
      const f = fileCache[m.file_id];
      if (f) {
        item.file_name = f.file_name;
        item.file_size = f.file_size;
        item.file_mime = f.file_mime;
        item.file_url = `/api/chat/files/${f.id}`;
      }
    }
    return item;
  });
  res.json({ success: true, data });
});

// 计算会话内各消息的已读回执：read_count=已读的其他成员数，total_others=其他成员总数，unread_users=未读成员名单
function buildReadStatusMap(convId, meId) {
  const members = db.prepare('SELECT user_id, last_read_message_id FROM conversation_members WHERE conversation_id = ?').all(convId);
  const others = members.filter(m => m.user_id !== meId);
  const msgs = db.prepare('SELECT id, sender_id FROM messages WHERE conversation_id = ?').all(convId);
  const nameCache = {};
  const map = {};
  for (const m of msgs) {
    const unreadUsers = others
      .filter(o => (o.last_read_message_id || 0) < m.id)
      .map(o => {
        if (!nameCache[o.user_id]) nameCache[o.user_id] = getUserDisplayName(o.user_id);
        return { id: o.user_id, name: nameCache[o.user_id] };
      });
    map[m.id] = {
      read_count: others.length - unreadUsers.length,
      total_others: others.length,
      unread_users: unreadUsers
    };
  }
  return map;
}

// 轻量已读回执轮询（不标记已读，仅返回各消息的已读进度）
app.get('/api/chat/conversations/:id/read-status', (req, res) => {
  const conv = db.prepare('SELECT * FROM conversations WHERE id = ?').get(req.params.id);
  if (!conv || !isConversationMember(req.params.id, req.user.id)) {
    return res.status(404).json({ success: false, message: '会话不存在' });
  }
  res.json({ success: true, data: buildReadStatusMap(req.params.id, req.user.id) });
});

// 发送消息：文本（content）或媒体（type=image/video/file + fileId，引用已上传附件）
app.post('/api/chat/conversations/:id/messages', (req, res) => {
  const msgType = ['text', 'image', 'video', 'file'].includes(req.body.type) ? req.body.type : 'text';
  const content = String(req.body.content || '').trim();
  const conv = db.prepare('SELECT * FROM conversations WHERE id = ?').get(req.params.id);
  if (!conv || !isConversationMember(req.params.id, req.user.id)) {
    return res.status(404).json({ success: false, message: '会话不存在' });
  }
  let fileId = '';
  let finalContent = content;
  if (msgType !== 'text') {
    const file = db.prepare('SELECT * FROM chat_files WHERE id = ?').get(req.body.fileId);
    if (!file || file.uploader_id !== req.user.id) {
      return res.status(400).json({ success: false, message: '附件不存在，请重新上传' });
    }
    fileId = file.id;
    if (!finalContent) finalContent = file.file_name;
  } else if (!content) {
    return res.status(400).json({ success: false, message: '消息不能为空' });
  }
  if (finalContent.length > 2000) {
    return res.status(400).json({ success: false, message: '消息过长（最多 2000 字）' });
  }
  const result = db.prepare('INSERT INTO messages (conversation_id, sender_id, content, msg_type, file_id) VALUES (?, ?, ?, ?, ?)')
    .run(req.params.id, req.user.id, finalContent, msgType, fileId);
  const msg = db.prepare('SELECT * FROM messages WHERE id = ?').get(result.lastInsertRowid);
  // 自己发送的消息直接标记已读
  db.prepare('UPDATE conversation_members SET last_read_message_id = ? WHERE conversation_id = ? AND user_id = ?')
    .run(msg.id, req.params.id, req.user.id);
  const data = { ...msg, sender_name: req.user.display_name || req.user.username };
  if (fileId) {
    const f = db.prepare('SELECT * FROM chat_files WHERE id = ?').get(fileId);
    data.file_name = f.file_name;
    data.file_size = f.file_size;
    data.file_mime = f.file_mime;
    data.file_url = `/api/chat/files/${f.id}`;
  }
  // 推送给会话其他成员（群聊标题=群名，单聊标题=发送者）
  const memberRows = db.prepare('SELECT user_id FROM conversation_members WHERE conversation_id = ?').all(req.params.id);
  const senderName = req.user.display_name || req.user.username;
  const pushTitle = conv.type === 'group' ? (conv.name || '群聊消息') : senderName;
  pushToMany(memberRows.map(m => m.user_id), 'chat', pushTitle, `${senderName}：${messagePreview(msg)}`, req.user.id);
  res.json({ success: true, data });
});

// 删除/解散会话（群聊仅群主可解散，单聊任一方可删除）
app.delete('/api/chat/conversations/:id', (req, res) => {
  const conv = db.prepare('SELECT * FROM conversations WHERE id = ?').get(req.params.id);
  if (!conv) {
    return res.status(404).json({ success: false, message: '会话不存在' });
  }
  if (!isConversationMember(req.params.id, req.user.id)) {
    return res.status(403).json({ success: false, message: '您不是该会话的成员' });
  }
  if (conv.type === 'group' && conv.creator_id !== req.user.id) {
    return res.status(403).json({ success: false, message: '只有群主可以解散群组' });
  }
  // 清理会话内附件的磁盘文件与记录
  const fileRows = db.prepare(`
    SELECT f.id, f.stored_name FROM chat_files f
    WHERE f.id IN (SELECT file_id FROM messages WHERE conversation_id = ? AND file_id != '')
    AND NOT EXISTS (SELECT 1 FROM messages m2 WHERE m2.file_id = f.id AND m2.conversation_id != ?)
  `).all(req.params.id, req.params.id);
  for (const f of fileRows) {
    const p = path.join(uploadsDir, f.stored_name);
    if (fs.existsSync(p)) fs.unlinkSync(p);
  }
  if (fileRows.length) {
    db.prepare(`DELETE FROM chat_files WHERE id IN (SELECT file_id FROM messages WHERE conversation_id = ? AND file_id != '')`).run(req.params.id);
  }
  db.prepare('DELETE FROM messages WHERE conversation_id = ?').run(req.params.id);
  db.prepare('DELETE FROM conversation_members WHERE conversation_id = ?').run(req.params.id);
  db.prepare('DELETE FROM conversations WHERE id = ?').run(req.params.id);
  res.json({ success: true, message: conv.type === 'group' ? '群组已解散' : '会话已删除' });
});

// 移除群成员（群主可移除任意成员，群主本人不可被移除）
app.delete('/api/chat/conversations/:id/members/:userId', (req, res) => {
  const conv = db.prepare('SELECT * FROM conversations WHERE id = ?').get(req.params.id);
  if (!conv || conv.type !== 'group') {
    return res.status(404).json({ success: false, message: '群聊不存在' });
  }
  if (!isConversationMember(conv.id, req.user.id)) {
    return res.status(403).json({ success: false, message: '您不是该群聊的成员' });
  }
  const targetId = req.params.userId;
  if (targetId === conv.creator_id) {
    return res.status(400).json({ success: false, message: '群主不能被移除' });
  }
  if (!isConversationMember(conv.id, targetId)) {
    return res.status(404).json({ success: false, message: '该用户不在群聊中' });
  }
  if (req.user.id !== conv.creator_id) {
    return res.status(403).json({ success: false, message: '只有群主可以移除群成员' });
  }
  db.prepare('DELETE FROM conversation_members WHERE conversation_id = ? AND user_id = ?').run(conv.id, targetId);
  res.json({ success: true, message: '已将该成员移出群聊' });
});

// ==================== 认证 API ====================

// 登录
app.post('/api/auth/login', (req, res) => {
  const { username, password } = req.body;
  if (!username || !password) {
    return res.status(400).json({ success: false, message: '用户名和密码不能为空' });
  }

  const user = db.prepare('SELECT id, username, role, display_name FROM users WHERE username = ? AND password = ?').get(username, password);
  if (!user) {
    return res.status(401).json({ success: false, message: '用户名或密码错误' });
  }

  const token = uuidv4();
  sessions.set(token, user);
  touchSession(token);
  // 记录最后登录时间
  db.prepare("UPDATE users SET last_login=datetime('now','localtime') WHERE id=?").run(user.id);

  res.json({
    success: true,
    message: '登录成功',
    data: { ...user, token }
  });
});

// 获取当前登录用户
app.get('/api/auth/me', (req, res) => {
  const token = req.headers.authorization?.replace('Bearer ', '');
  if (!token || !sessions.has(token)) {
    return res.status(401).json({ success: false, message: '未登录' });
  }
  res.json({ success: true, data: sessions.get(token) });
});

// 登出
app.post('/api/auth/logout', (req, res) => {
  const token = req.headers.authorization?.replace('Bearer ', '');
  if (token) dropSession(token);
  res.json({ success: true, message: '登出成功' });
});

// 修改自己的密码（已登录用户）
app.patch('/api/auth/password', (req, res) => {
  const { oldPassword, newPassword } = req.body;
  if (!oldPassword || !newPassword || newPassword.length < 6) {
    return res.status(400).json({ success: false, message: '请输入原密码，且新密码不少于6位' });
  }
  const dbUser = db.prepare('SELECT * FROM users WHERE id = ?').get(req.user.id);
  if (!dbUser || dbUser.password !== oldPassword) {
    return res.status(400).json({ success: false, message: '原密码不正确' });
  }
  db.prepare('UPDATE users SET password=? WHERE id=?').run(newPassword, req.user.id);
  logUserAction(dbUser.username, '修改密码', '用户自行修改密码', dbUser.display_name || dbUser.username);
  // 修改成功后使当前会话失效，要求用新密码重新登录
  const token = req.headers.authorization?.replace('Bearer ', '');
  if (token) dropSession(token);
  res.json({ success: true, message: '密码修改成功，请使用新密码重新登录' });
});

// ==================== 天气 API ====================

function getWeatherDesc(code) {
  const map = {
    0: '晴朗', 1: '多云', 2: '多云', 3: '阴天',
    45: '雾', 48: '雾凇',
    51: '毛毛雨', 53: '毛毛雨', 55: '毛毛雨',
    56: '冻雨', 57: '冻雨',
    61: '小雨', 63: '中雨', 65: '大雨',
    66: '冻雨', 67: '冻雨',
    71: '小雪', 73: '中雪', 75: '大雪', 77: '雪粒',
    80: '阵雨', 81: '阵雨', 82: '强阵雨',
    85: '阵雪', 86: '强阵雪',
    95: '雷雨', 96: '雷雨伴冰雹', 99: '强雷雨伴冰雹'
  };
  return map[code] || '未知';
}

app.get('/api/weather/current', async (req, res) => {
  try {
    const city = req.query.city || 'beijing';

    // 地理编码
    const geoRes = await fetch(`https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(city)}&count=1&language=zh&format=json`);
    const geoData = await geoRes.json();

    if (!geoData.results || geoData.results.length === 0) {
      return res.status(404).json({ success: false, message: '未找到该城市' });
    }

    const { latitude, longitude, name, country } = geoData.results[0];

    // 获取天气
    const weatherRes = await fetch(
      `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&current=temperature_2m,relative_humidity_2m,weather_code,wind_speed_10m&daily=temperature_2m_max,temperature_2m_min,weather_code&timezone=Asia/Shanghai&forecast_days=1`
    );
    const weatherData = await weatherRes.json();

    const current = weatherData.current;
    const daily = weatherData.daily;

    res.json({
      success: true,
      data: {
        city: name,
        country,
        current: {
          temp: current.temperature_2m,
          humidity: current.relative_humidity_2m,
          windSpeed: current.wind_speed_10m,
          weather: getWeatherDesc(current.weather_code),
          code: current.weather_code
        },
        daily: {
          maxTemp: daily.temperature_2m_max[0],
          minTemp: daily.temperature_2m_min[0],
          weather: getWeatherDesc(daily.weather_code[0]),
          code: daily.weather_code[0]
        }
      }
    });
  } catch (err) {
    console.error('获取天气失败:', err);
    res.status(500).json({ success: false, message: '获取天气失败' });
  }
});

// ==================== 全局统计 API ====================
app.get('/api/dashboard/stats', (req, res) => {
  const deviceTotal = db.prepare('SELECT COUNT(*) as count FROM devices').get().count;
  const deviceNormal = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='正常'").get().count;
  const deviceRepairing = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='维修中'").get().count;
  const deviceScrapped = db.prepare("SELECT COUNT(*) as count FROM devices WHERE status='已报废'").get().count;
  const personnelTotal = db.prepare('SELECT COUNT(*) as count FROM personnel').get().count;
  const personnelActive = db.prepare("SELECT COUNT(*) as count FROM personnel WHERE status='在职'").get().count;
  const notifTotal = db.prepare('SELECT COUNT(*) as count FROM notifications').get().count;
  const notifUnread = db.prepare('SELECT COUNT(*) as count FROM notifications WHERE is_read=0').get().count;

  res.json({
    success: true,
    data: {
      deviceTotal, deviceNormal, deviceRepairing, deviceScrapped,
      personnelTotal, personnelActive,
      notifTotal, notifUnread
    }
  });
});

// SPA 路由回退 - 所有未匹配的请求返回前端
app.get('*', (req, res) => {
  res.sendFile(path.join(clientBuildPath, 'index.html'));
});

app.listen(PORT, '0.0.0.0', () => {
  console.log(`\n╔══════════════════════════════════════════╗`);
  console.log(`║       设备管理系统 已启动                 ║`);
  console.log(`║  地址: http://localhost:${PORT}            ║`);
  console.log(`║  按 Ctrl+C 停止服务                      ║`);
  console.log(`╚══════════════════════════════════════════╝\n`);
});