const express = require('express');
const router = express.Router();
const bcrypt = require('bcryptjs');
const db = require('../config/database');
const { requireAuth } = require('../middleware/auth');

// Login
router.post('/login', async (req, res) => {
  try {
    const { username, password } = req.body;

    if (!username || !password) {
      return res.status(400).json({
        success: false,
        message: 'Username and password are required'
      });
    }

    // Get user from database
    const [users] = await db.query(
      'SELECT * FROM admin_users WHERE username = ?',
      [username]
    );

    if (users.length === 0) {
      return res.status(401).json({
        success: false,
        message: 'Invalid username or password'
      });
    }

    const user = users[0];

    // Verify password
    const isValidPassword = await bcrypt.compare(password, user.password);

    if (!isValidPassword) {
      return res.status(401).json({
        success: false,
        message: 'Invalid username or password'
      });
    }

    // Update last login
    await db.query(
      'UPDATE admin_users SET last_login = NOW() WHERE id = ?',
      [user.id]
    );

    // Set session
    req.session.userId = user.id;
    req.session.username = user.username;

    res.json({
      success: true,
      message: 'Login successful',
      user: {
        id: user.id,
        username: user.username,
        email: user.email
      }
    });
  } catch (error) {
    console.error('Login error:', error);
    res.status(500).json({
      success: false,
      message: 'Login failed'
    });
  }
});

// Logout
router.post('/logout', (req, res) => {
  req.session.destroy((err) => {
    if (err) {
      return res.status(500).json({
        success: false,
        message: 'Logout failed'
      });
    }
    res.json({
      success: true,
      message: 'Logout successful'
    });
  });
});

// Check auth status
router.get('/status', (req, res) => {
  if (req.session && req.session.userId) {
    res.json({
      success: true,
      authenticated: true,
      user: {
        id: req.session.userId,
        username: req.session.username
      }
    });
  } else {
    res.json({
      success: true,
      authenticated: false
    });
  }
});

// Change password
router.post('/change-password', requireAuth, async (req, res) => {
  try {
    const { current_password, new_password } = req.body;
    const userId = req.session.userId;

    if (!current_password || !new_password) {
      return res.status(400).json({
        success: false,
        message: '当前密码和新密码不能为空'
      });
    }

    if (new_password.length < 6) {
      return res.status(400).json({
        success: false,
        message: '新密码长度至少6位'
      });
    }

    // 获取当前用户信息
    const [users] = await db.query(
      'SELECT * FROM admin_users WHERE id = ?',
      [userId]
    );

    if (users.length === 0) {
      return res.status(404).json({
        success: false,
        message: '用户不存在'
      });
    }

    const user = users[0];

    // 验证当前密码
    const isValidPassword = await bcrypt.compare(current_password, user.password);

    if (!isValidPassword) {
      return res.status(401).json({
        success: false,
        message: '当前密码错误'
      });
    }

    // 生成新密码哈希
    const hashedPassword = await bcrypt.hash(new_password, 10);

    // 更新密码
    await db.query(
      'UPDATE admin_users SET password = ? WHERE id = ?',
      [hashedPassword, userId]
    );

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

module.exports = router;