const express = require('express');
const db = require('../db-sqlite');
const { authenticate } = require('../middleware/auth');

module.exports = function(app) {
  const router = express.Router();

  router.get('/', authenticate, async (req, res) => {
    try {
      const categoriesResult = await db.query('SELECT id, name, parent_id, created_at, updated_at FROM categories ORDER BY parent_id, name');
      const categories = categoriesResult.rows;
      res.json({ success: true, data: categories, count: categories.length });
    } catch (error) {
      console.error('获取分类列表失败:', error);
      res.status(500).json({ success: false, message: '获取分类列表失败' });
    }
  });

  router.get('/tree', authenticate, async (req, res) => {
    try {
      const categoriesResult = await db.query('SELECT id, name, parent_id, created_at, updated_at FROM categories ORDER BY parent_id, name');
      const categories = categoriesResult.rows;
      
      const categoryTree = buildCategoryTree(categories);
      res.json({ success: true, data: categoryTree });
    } catch (error) {
      console.error('获取分类树失败:', error);
      res.status(500).json({ success: false, message: '获取分类树失败' });
    }
  });

  router.get('/:id', authenticate, async (req, res) => {
    try {
      const { id } = req.params;
      const categoryResult = await db.query('SELECT id, name, parent_id, created_at, updated_at FROM categories WHERE id = ?', [id]);
      
      if (categoryResult.rows.length === 0) {
        return res.status(404).json({ success: false, message: '分类不存在' });
      }
      
      const category = categoryResult.rows[0];
      res.json({ success: true, data: category });
    } catch (error) {
      console.error('获取分类详情失败:', error);
      res.status(500).json({ success: false, message: '获取分类详情失败' });
    }
  });

  router.post('/', authenticate, async (req, res) => {
    try {
      const { name, parent_id } = req.body;
      
      if (!name) {
        return res.status(400).json({ success: false, message: '分类名称为必填项' });
      }
      
      const result = await db.query(
        'INSERT INTO categories (name, parent_id, created_at, updated_at) VALUES (?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)',
        [name, parent_id || null]
      );
      
      const newCategoryResult = await db.query('SELECT id, name, parent_id, created_at, updated_at FROM categories WHERE id = ?', [result.lastID]);
      const newCategory = newCategoryResult.rows[0];
      
      console.log(`分类 ${name} 创建成功，由 ${req.user.username} 操作`);
      res.json({ success: true, data: newCategory });
    } catch (error) {
      console.error('创建分类失败:', error);
      res.status(500).json({ success: false, message: '创建分类失败' });
    }
  });

  router.put('/:id', authenticate, async (req, res) => {
    try {
      const { id } = req.params;
      const { name, parent_id } = req.body;
      
      await db.query(
        'UPDATE categories SET name = ?, parent_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?',
        [name, parent_id, id]
      );
      
      const updatedCategoryResult = await db.query('SELECT id, name, parent_id, created_at, updated_at FROM categories WHERE id = ?', [id]);
      const updatedCategory = updatedCategoryResult.rows[0];
      
      res.json({ success: true, data: updatedCategory });
    } catch (error) {
      console.error('更新分类信息失败:', error);
      res.status(500).json({ success: false, message: '更新分类信息失败' });
    }
  });

  router.delete('/:id', authenticate, async (req, res) => {
    try {
      const { id } = req.params;
      
      const existingCategory = await db.query('SELECT id FROM categories WHERE id = ?', [id]);
      if (existingCategory.rows.length === 0) {
        return res.status(404).json({ success: false, message: '分类不存在' });
      }
      
      await db.query('DELETE FROM categories WHERE id = ?', [id]);
      
      res.json({ success: true, message: '分类删除成功' });
    } catch (error) {
      console.error('删除分类失败:', error);
      res.status(500).json({ success: false, message: '删除分类失败' });
    }
  });

  function buildCategoryTree(categories, parentId = null) {
    const tree = [];
    
    categories.forEach(category => {
      if (category.parent_id === parentId) {
        tree.push({
          id: category.id,
          name: category.name,
          children: []
        });
      }
    });
    
    const rootCategories = categories.filter(cat => !cat.parent_id);
    rootCategories.forEach(category => {
      tree.push({
        id: category.id,
        name: category.name,
        children: buildCategoryTree(categories, category.id)
      });
    });
    
    return tree;
  }

  app.use('/api/categories', router);
};