const express = require('express');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const { auth } = require('../middleware/auth');

const router = express.Router();

// 模拟用户数据存储（生产环境应使用数据库）
const users = new Map();

// 用户注册
router.post('/register', async (req, res) => {
  try {
    const { email, username, password } = req.body;

    // 验证必要字段
    if (!email || !username || !password) {
      return res.status(400).json({
        success: false,
        message: '请提供邮箱、用户名和密码'
      });
    }

    // 检查邮箱格式
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    if (!emailRegex.test(email)) {
      return res.status(400).json({
        success: false,
        message: '邮箱格式不正确'
      });
    }

    // 检查密码强度
    if (password.length < 6) {
      return res.status(400).json({
        success: false,
        message: '密码长度至少6位'
      });
    }

    // 检查用户是否已存在
    for (const user of users.values()) {
      if (user.email === email) {
        return res.status(400).json({
          success: false,
          message: '邮箱已被注册'
        });
      }
      if (user.username === username) {
        return res.status(400).json({
          success: false,
          message: '用户名已被使用'
        });
      }
    }

    // 加密密码
    const hashedPassword = await bcrypt.hash(password, 12);

    // 创建用户
    const user = {
      userId: Date.now().toString(),
      email,
      username,
      password: hashedPassword,
      createdAt: new Date(),
      lastLoginAt: null,
      settings: {
        defaultOutputFormat: 'docx',
        imageQuality: 'medium',
        autoDownload: true,
        language: 'zh-CN'
      }
    };

    users.set(user.userId, user);

    // 生成JWT令牌
    const token = jwt.sign(
      { userId: user.userId, email: user.email },
      process.env.JWT_SECRET,
      { expiresIn: process.env.JWT_EXPIRES_IN || '24h' }
    );

    res.status(201).json({
      success: true,
      message: '注册成功',
      data: {
        user: {
          userId: user.userId,
          email: user.email,
          username: user.username,
          createdAt: user.createdAt
        },
        token
      }
    });

  } catch (error) {
    console.error('用户注册错误:', error);
    res.status(500).json({
      success: false,
      message: '注册失败'
    });
  }
});

// 用户登录
router.post('/login', async (req, res) => {
  try {
    const { email, password } = req.body;

    if (!email || !password) {
      return res.status(400).json({
        success: false,
        message: '请提供邮箱和密码'
      });
    }

    // 查找用户
    let foundUser = null;
    for (const user of users.values()) {
      if (user.email === email) {
        foundUser = user;
        break;
      }
    }

    if (!foundUser) {
      return res.status(401).json({
        success: false,
        message: '邮箱或密码错误'
      });
    }

    // 验证密码
    const isPasswordValid = await bcrypt.compare(password, foundUser.password);
    if (!isPasswordValid) {
      return res.status(401).json({
        success: false,
        message: '邮箱或密码错误'
      });
    }

    // 更新最后登录时间
    foundUser.lastLoginAt = new Date();
    users.set(foundUser.userId, foundUser);

    // 生成JWT令牌
    const token = jwt.sign(
      { userId: foundUser.userId, email: foundUser.email },
      process.env.JWT_SECRET,
      { expiresIn: process.env.JWT_EXPIRES_IN || '24h' }
    );

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

  } catch (error) {
    console.error('用户登录错误:', error);
    res.status(500).json({
      success: false,
      message: '登录失败'
    });
  }
});

// 获取用户信息
router.get('/profile', auth, async (req, res) => {
  try {
    const user = users.get(req.user.userId);

    if (!user) {
      return res.status(404).json({
        success: false,
        message: '用户未找到'
      });
    }

    res.json({
      success: true,
      data: {
        userId: user.userId,
        email: user.email,
        username: user.username,
        createdAt: user.createdAt,
        lastLoginAt: user.lastLoginAt,
        settings: user.settings
      }
    });

  } catch (error) {
    console.error('获取用户信息错误:', error);
    res.status(500).json({
      success: false,
      message: '获取用户信息失败'
    });
  }
});

// 更新用户设置
router.put('/settings', auth, async (req, res) => {
  try {
    const user = users.get(req.user.userId);

    if (!user) {
      return res.status(404).json({
        success: false,
        message: '用户未找到'
      });
    }

    const allowedSettings = [
      'defaultOutputFormat',
      'imageQuality',
      'autoDownload',
      'language',
      'autoDelete',
      'deleteDelay',
      'maxConcurrentTasks',
      'conversionTimeout'
    ];

    const updatedSettings = { ...user.settings };
    
    for (const [key, value] of Object.entries(req.body)) {
      if (allowedSettings.includes(key)) {
        updatedSettings[key] = value;
      }
    }

    user.settings = updatedSettings;
    users.set(user.userId, user);

    res.json({
      success: true,
      message: '设置更新成功',
      data: {
        settings: user.settings
      }
    });

  } catch (error) {
    console.error('更新用户设置错误:', error);
    res.status(500).json({
      success: false,
      message: '更新设置失败'
    });
  }
});

// 获取转换历史
router.get('/history', auth, async (req, res) => {
  try {
    const { page = 1, limit = 10, status } = req.query;
    
    // 模拟历史数据
    const mockHistory = [
      {
        taskId: 'task-1',
        fileName: '项目报告.pdf',
        outputFormat: 'docx',
        status: 'completed',
        createdAt: new Date(Date.now() - 86400000), // 1天前
        fileSize: '2.5MB'
      },
      {
        taskId: 'task-2',
        fileName: '用户手册.pdf',
        outputFormat: 'html',
        status: 'completed',
        createdAt: new Date(Date.now() - 172800000), // 2天前
        fileSize: '1.8MB'
      },
      {
        taskId: 'task-3',
        fileName: '技术文档.pdf',
        outputFormat: 'txt',
        status: 'failed',
        createdAt: new Date(Date.now() - 259200000), // 3天前
        fileSize: '3.2MB'
      }
    ];

    let filteredHistory = mockHistory;
    if (status && status !== 'all') {
      filteredHistory = mockHistory.filter(item => item.status === status);
    }

    const startIndex = (page - 1) * limit;
    const endIndex = startIndex + parseInt(limit);
    const paginatedHistory = filteredHistory.slice(startIndex, endIndex);

    res.json({
      success: true,
      data: {
        history: paginatedHistory,
        pagination: {
          page: parseInt(page),
          limit: parseInt(limit),
          total: filteredHistory.length,
          pages: Math.ceil(filteredHistory.length / limit)
        }
      }
    });

  } catch (error) {
    console.error('获取转换历史错误:', error);
    res.status(500).json({
      success: false,
      message: '获取转换历史失败'
    });
  }
});

module.exports = router;