const express = require('express');
const router = express.Router();
const { Op } = require('sequelize');
const FaultCategory = require('../models/FaultCategory');

router.get('/', async (req, res) => {
  try {
    const { isActive } = req.query;
    const where = {};

    if (isActive !== undefined) {
      where.isActive = isActive === 'true';
    }

    const categories = await FaultCategory.findAll({
      where,
      order: [
        ['priority', 'ASC'],
        ['name', 'ASC'],
      ],
    });

    res.json(categories);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

router.get('/stats', async (req, res) => {
  try {
    const Ticket = require('../models/Ticket');
    const { startDate, endDate } = req.query;

    const where = {};
    if (startDate || endDate) {
      where.createdAt = {};
      if (startDate) {
        where.createdAt[Op.gte] = new Date(startDate);
      }
      if (endDate) {
        where.createdAt[Op.lte] = new Date(endDate + ' 23:59:59');
      }
    }

    const stats = await Ticket.findAll({
      where,
      attributes: [
        'faultCategory',
        [require('sequelize').fn('COUNT', '*'), 'totalCount'],
        [
          require('sequelize').sum(
            require('sequelize').case(
              {
                when: { status: 'completed' },
                then: 1,
              },
              0
            )
          ),
          'completedCount',
        ],
        [
          require('sequelize').sum(
            require('sequelize').case(
              {
                when: { status: { [Op.ne]: 'completed' } },
                then: 1,
              },
              0
            )
          ),
          'pendingCount',
        ],
      ],
      group: ['faultCategory'],
    });

    res.json(stats);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

router.get('/:categoryId', async (req, res) => {
  try {
    const category = await FaultCategory.findByPk(req.params.categoryId);
    if (!category) {
      return res.status(404).json({ error: '分类不存在' });
    }
    res.json(category);
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

router.post('/', async (req, res) => {
  try {
    const { name, description, priority, defaultPriority, expectedDuration, solutions, isActive } =
      req.body;

    const existing = await FaultCategory.findOne({ where: { name } });
    if (existing) {
      return res.status(400).json({ error: '分类名称已存在' });
    }

    const categoryId = `CAT${Date.now().toString(36).toUpperCase()}`;

    const category = await FaultCategory.create({
      categoryId,
      name,
      description,
      priority: priority || 99,
      defaultPriority: defaultPriority || 'medium',
      expectedDuration: expectedDuration ? parseInt(expectedDuration) : null,
      solutions: solutions || [],
      isSystem: false,
      isActive: isActive !== false,
    });

    res.status(201).json(category);
  } catch (error) {
    res.status(400).json({ error: error.message });
  }
});

router.post('/init', async (req, res) => {
  try {
    const defaultCategories = [
      {
        name: '系统故障',
        description: '操作系统、应用程序等系统软件的故障问题',
        priority: 1,
        defaultPriority: 'high',
      },
      {
        name: '硬件故障',
        description: '物理设备、服务器、存储等硬件设备的故障问题',
        priority: 2,
        defaultPriority: 'high',
      },
      {
        name: '网络故障',
        description: '网络连接、交换机、路由器等网络相关故障',
        priority: 3,
        defaultPriority: 'high',
      },
      {
        name: '软件故障',
        description: '应用程序错误、软件兼容性等问题',
        priority: 4,
        defaultPriority: 'medium',
      },
      {
        name: '安全事件',
        description: '安全漏洞、入侵检测、权限异常等安全问题',
        priority: 5,
        defaultPriority: 'urgent',
      },
      {
        name: '性能问题',
        description: '系统响应慢、资源利用率高等性能问题',
        priority: 6,
        defaultPriority: 'medium',
      },
      {
        name: '配置变更',
        description: '系统配置、软件配置等变更需求',
        priority: 7,
        defaultPriority: 'low',
      },
      {
        name: '例行维护',
        description: '定期维护、巡检、更新等计划性工作',
        priority: 8,
        defaultPriority: 'low',
      },
      {
        name: '数据问题',
        description: '数据错误、数据丢失、数据同步等数据相关问题',
        priority: 9,
        defaultPriority: 'high',
      },
      {
        name: '其他问题',
        description: '无法归类的其他问题',
        priority: 99,
        defaultPriority: 'medium',
      },
    ];

    for (const cat of defaultCategories) {
      const existing = await FaultCategory.findOne({ where: { name: cat.name } });
      if (!existing) {
        const categoryId = `CAT${Date.now().toString(36).toUpperCase()}${Math.random().toString(36).substr(2, 4).toUpperCase()}`;
        await FaultCategory.create({
          categoryId,
          ...cat,
          expectedDuration: 120,
          solutions: [],
          isSystem: true,
          isActive: true,
        });
      }
    }

    res.json({ message: '分类初始化成功' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

router.put('/:categoryId', async (req, res) => {
  try {
    const category = await FaultCategory.findByPk(req.params.categoryId);
    if (!category) {
      return res.status(404).json({ error: '分类不存在' });
    }

    await category.update(req.body);
    res.json(category);
  } catch (error) {
    res.status(400).json({ error: error.message });
  }
});

router.delete('/:categoryId', async (req, res) => {
  try {
    const category = await FaultCategory.findByPk(req.params.categoryId);
    if (!category) {
      return res.status(404).json({ error: '分类不存在' });
    }

    const Ticket = require('../models/Ticket');
    const ticketCount = await Ticket.count({ where: { faultCategory: category.name } });
    if (ticketCount > 0) {
      return res.status(400).json({ error: `该分类下有 ${ticketCount} 个工单，无法删除` });
    }

    await category.destroy();
    res.json({ message: '分类已删除' });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

router.patch('/:categoryId/toggle', async (req, res) => {
  try {
    const category = await FaultCategory.findByPk(req.params.categoryId);
    if (!category) {
      return res.status(404).json({ error: '分类不存在' });
    }

    await category.update({ isActive: !category.isActive });
    res.json(category);
  } catch (error) {
    res.status(400).json({ error: error.message });
  }
});

module.exports = router;