const express = require('express');
const router = express.Router();
const { getDB } = require('../database');
const { auth } = require('../middleware/auth');

// 获取地址标签列表（包含系统默认和用户自定义）
router.get('/', auth, async (req, res) => {
  try {
    const userId = req.user.id;
    
    const [labels] = await getDB().execute(
      `SELECT * FROM address_labels 
       WHERE user_id IS NULL OR user_id = ? 
       ORDER BY is_system DESC, created_at ASC`,
      [userId]
    );
    
    res.json({
      success: true,
      data: labels
    });
  } catch (error) {
    console.error('获取地址标签列表错误:', error);
    res.status(500).json({ message: '获取地址标签列表失败' });
  }
});

// 创建自定义地址标签
router.post('/', auth, async (req, res) => {
  try {
    const userId = req.user.id;
    const { name, color = '#1890ff' } = req.body;
    
    if (!name || name.trim() === '') {
      return res.status(400).json({ message: '标签名称不能为空' });
    }
    
    // 检查标签名称是否已存在（系统标签或用户自定义标签）
    const [existing] = await getDB().execute(
      `SELECT id FROM address_labels 
       WHERE name = ? AND (user_id IS NULL OR user_id = ?)`,
      [name.trim(), userId]
    );
    
    if (existing.length > 0) {
      return res.status(400).json({ message: '标签名称已存在' });
    }
    
    const [result] = await getDB().execute(
      `INSERT INTO address_labels (name, color, user_id, is_system, created_at, updated_at) 
       VALUES (?, ?, ?, false, NOW(), NOW())`,
      [name.trim(), color, userId]
    );
    
    res.status(201).json({
      success: true,
      message: '地址标签创建成功',
      data: { labelId: result.insertId }
    });
  } catch (error) {
    console.error('创建地址标签错误:', error);
    res.status(500).json({ message: '创建地址标签失败' });
  }
});

// 更新自定义地址标签
router.put('/:id', auth, async (req, res) => {
  try {
    const labelId = req.params.id;
    const userId = req.user.id;
    const { name, color } = req.body;
    
    // 检查标签是否存在且属于当前用户（不能修改系统标签）
    const [existing] = await getDB().execute(
      'SELECT id, is_system FROM address_labels WHERE id = ? AND user_id = ?',
      [labelId, userId]
    );
    
    if (existing.length === 0) {
      return res.status(404).json({ message: '地址标签不存在或无权限修改' });
    }
    
    if (existing[0].is_system) {
      return res.status(403).json({ message: '系统标签不能修改' });
    }
    
    if (name && name.trim() !== '') {
      // 检查新名称是否已存在
      const [nameExists] = await getDB().execute(
        `SELECT id FROM address_labels 
         WHERE name = ? AND id != ? AND (user_id IS NULL OR user_id = ?)`,
        [name.trim(), labelId, userId]
      );
      
      if (nameExists.length > 0) {
        return res.status(400).json({ message: '标签名称已存在' });
      }
    }
    
    const updateFields = [];
    const updateValues = [];
    
    if (name && name.trim() !== '') {
      updateFields.push('name = ?');
      updateValues.push(name.trim());
    }
    
    if (color) {
      updateFields.push('color = ?');
      updateValues.push(color);
    }
    
    if (updateFields.length === 0) {
      return res.status(400).json({ message: '没有需要更新的字段' });
    }
    
    updateFields.push('updated_at = NOW()');
    updateValues.push(labelId, userId);
    
    await getDB().execute(
      `UPDATE address_labels SET ${updateFields.join(', ')} WHERE id = ? AND user_id = ?`,
      updateValues
    );
    
    res.json({
      success: true,
      message: '地址标签更新成功'
    });
  } catch (error) {
    console.error('更新地址标签错误:', error);
    res.status(500).json({ message: '更新地址标签失败' });
  }
});

// 删除自定义地址标签
router.delete('/:id', auth, async (req, res) => {
  try {
    const labelId = req.params.id;
    const userId = req.user.id;
    
    // 检查标签是否存在且属于当前用户（不能删除系统标签）
    const [existing] = await getDB().execute(
      'SELECT id, is_system FROM address_labels WHERE id = ? AND user_id = ?',
      [labelId, userId]
    );
    
    if (existing.length === 0) {
      return res.status(404).json({ message: '地址标签不存在或无权限删除' });
    }
    
    if (existing[0].is_system) {
      return res.status(403).json({ message: '系统标签不能删除' });
    }
    
    // 检查是否有地址正在使用该标签
    const [addressesUsingLabel] = await getDB().execute(
      'SELECT COUNT(*) as count FROM user_addresses WHERE label_id = ? AND deleted_at IS NULL',
      [labelId]
    );
    
    if (addressesUsingLabel[0].count > 0) {
      return res.status(400).json({ message: '该标签正在被使用，无法删除' });
    }
    
    await getDB().execute(
      'DELETE FROM address_labels WHERE id = ? AND user_id = ?',
      [labelId, userId]
    );
    
    res.json({
      success: true,
      message: '地址标签删除成功'
    });
  } catch (error) {
    console.error('删除地址标签错误:', error);
    res.status(500).json({ message: '删除地址标签失败' });
  }
});

module.exports = router;