const DeviceWarning = require('../models/DeviceWarning');
const { Op, fn, col } = require('sequelize');
const { QueryTypes } = require('sequelize');

// 获取设备预警列表
exports.getDeviceWarnings = async (req, res) => {
  try {
    const { page = 1, pageSize = 20, deviceType, alertType, status, farmerName } = req.query;
    const limit = parseInt(pageSize);
    const offset = (parseInt(page) - 1) * limit;

    // 构建WHERE条件
    let whereConditions = [];
    let whereParams = {};
    
    if (deviceType) {
      whereConditions.push('deviceType = :deviceType');
      whereParams.deviceType = deviceType;
    }
    if (alertType) {
      whereConditions.push('alertType = :alertType');
      whereParams.alertType = alertType;
    }
    if (status) {
      whereConditions.push('status = :status');
      whereParams.status = status;
    }
    if (farmerName) {
      whereConditions.push('farmerName LIKE :farmerName');
      whereParams.farmerName = `%${farmerName}%`;
    }

    const whereClause = whereConditions.length > 0 ? 'WHERE ' + whereConditions.join(' AND ') : '';

    // 查询总数
    const countQuery = `SELECT COUNT(*) as count FROM device_warnings ${whereClause}`;
    const countResult = await DeviceWarning.sequelize.query(countQuery, {
      replacements: whereParams,
      type: QueryTypes.SELECT
    });
    const total = countResult[0].count;

    // 查询数据
    const dataQuery = `
      SELECT id, farmName, farmerName, phone, deviceType, deviceNumber, 
             alertType, alertLevel, alertTime, status, description, 
             location, batteryLevel, signalStrength, temperature, 
             resolvedBy, resolvedAt, remarks, createdAt, updatedAt
      FROM device_warnings 
      ${whereClause}
      ORDER BY alertTime DESC 
      LIMIT :limit OFFSET :offset
    `;
    
    const rows = await DeviceWarning.sequelize.query(dataQuery, {
      replacements: { ...whereParams, limit, offset },
      type: QueryTypes.SELECT
    });

    res.status(200).json({
      code: 200,
      message: '获取成功',
      data: {
        list: rows,
        total: total,
        page: parseInt(page),
        pageSize: limit,
      },
    });
  } catch (error) {
    console.error('获取设备预警列表失败:', error);
    res.status(500).json({ code: 500, message: '获取设备预警列表失败', error: error.message });
  }
};

// 根据ID获取单个设备预警详情
exports.getDeviceWarningById = async (req, res) => {
  try {
    const { id } = req.params;
    
    const query = `
      SELECT id, farmName, farmerName, phone, deviceType, deviceNumber, 
             alertType, alertLevel, alertTime, status, description, 
             location, batteryLevel, signalStrength, temperature, 
             resolvedBy, resolvedAt, remarks, createdAt, updatedAt
      FROM device_warnings 
      WHERE id = :id
    `;
    
    const results = await DeviceWarning.sequelize.query(query, {
      replacements: { id },
      type: QueryTypes.SELECT
    });

    if (results.length === 0) {
      return res.status(404).json({ code: 404, message: '设备预警未找到' });
    }

    res.status(200).json({ code: 200, message: '获取成功', data: results[0] });
  } catch (error) {
    console.error('获取设备预警详情失败:', error);
    res.status(500).json({ code: 500, message: '获取设备预警详情失败', error: error.message });
  }
};

// 创建新的设备预警
exports.createDeviceWarning = async (req, res) => {
  try {
    const {
      farmName, farmerName, phone, deviceType, deviceNumber,
      alertType, alertLevel = 'medium', description, location, batteryLevel,
      signalStrength, temperature, remarks
    } = req.body;

    const insertQuery = `
      INSERT INTO device_warnings 
      (farmName, farmerName, phone, deviceType, deviceNumber, alertType, alertLevel, 
       description, location, batteryLevel, signalStrength, temperature, remarks, 
       alertTime, status, createdAt, updatedAt)
      VALUES 
      (:farmName, :farmerName, :phone, :deviceType, :deviceNumber, :alertType, :alertLevel,
       :description, :location, :batteryLevel, :signalStrength, :temperature, :remarks,
       NOW(), 'active', NOW(), NOW())
    `;

    await DeviceWarning.sequelize.query(insertQuery, {
      replacements: {
        farmName, farmerName, phone, deviceType, deviceNumber,
        alertType, alertLevel, 
        description: description || null, 
        location: location || null, 
        batteryLevel: batteryLevel || null,
        signalStrength: signalStrength || null, 
        temperature: temperature || null, 
        remarks: remarks || null
      },
      type: QueryTypes.INSERT
    });

    // 获取刚插入的记录
    const selectQuery = `
      SELECT id, farmName, farmerName, phone, deviceType, deviceNumber, 
             alertType, alertLevel, alertTime, status, description, 
             location, batteryLevel, signalStrength, temperature, 
             resolvedBy, resolvedAt, remarks, createdAt, updatedAt
      FROM device_warnings 
      ORDER BY id DESC 
      LIMIT 1
    `;
    
    const results = await DeviceWarning.sequelize.query(selectQuery, {
      type: QueryTypes.SELECT
    });

    res.status(201).json({ code: 201, message: '创建成功', data: results[0] });
  } catch (error) {
    console.error('创建设备预警失败:', error);
    res.status(500).json({ code: 500, message: '创建设备预警失败', error: error.message });
  }
};

// 更新设备预警
exports.updateDeviceWarning = async (req, res) => {
  try {
    const { id } = req.params;
    const updateFields = [];
    const replacements = { id };

    // 动态构建更新字段
    const allowedFields = [
      'farmName', 'farmerName', 'phone', 'deviceType', 'deviceNumber',
      'alertType', 'alertLevel', 'description', 'location', 'batteryLevel',
      'signalStrength', 'temperature', 'remarks', 'status', 'resolvedBy', 'resolvedAt'
    ];

    for (const field of allowedFields) {
      if (req.body[field] !== undefined) {
        updateFields.push(`${field} = :${field}`);
        replacements[field] = req.body[field];
      }
    }

    if (updateFields.length === 0) {
      return res.status(400).json({ code: 400, message: '没有需要更新的字段' });
    }

    updateFields.push('updatedAt = NOW()');

    const updateQuery = `
      UPDATE device_warnings 
      SET ${updateFields.join(', ')}
      WHERE id = :id
    `;

    const [result] = await DeviceWarning.sequelize.query(updateQuery, {
      replacements,
      type: QueryTypes.UPDATE
    });

    if (result === 0) {
      return res.status(404).json({ code: 404, message: '设备预警未找到或无更新' });
    }

    // 获取更新后的记录
    const selectQuery = `
      SELECT id, farmName, farmerName, phone, deviceType, deviceNumber, 
             alertType, alertLevel, alertTime, status, description, 
             location, batteryLevel, signalStrength, temperature, 
             resolvedBy, resolvedAt, remarks, createdAt, updatedAt
      FROM device_warnings 
      WHERE id = :id
    `;
    
    const results = await DeviceWarning.sequelize.query(selectQuery, {
      replacements: { id },
      type: QueryTypes.SELECT
    });

    res.status(200).json({ code: 200, message: '更新成功', data: results[0] });
  } catch (error) {
    console.error('更新设备预警失败:', error);
    res.status(500).json({ code: 500, message: '更新设备预警失败', error: error.message });
  }
};

// 删除设备预警
exports.deleteDeviceWarning = async (req, res) => {
  try {
    const { id } = req.params;
    
    const deleteQuery = 'DELETE FROM device_warnings WHERE id = :id';
    const [result] = await DeviceWarning.sequelize.query(deleteQuery, {
      replacements: { id },
      type: QueryTypes.DELETE
    });

    if (result === 0) {
      return res.status(404).json({ code: 404, message: '设备预警未找到' });
    }

    res.status(200).json({ code: 200, message: '删除成功' });
  } catch (error) {
    console.error('删除设备预警失败:', error);
    res.status(500).json({ code: 500, message: '删除设备预警失败', error: error.message });
  }
};

// 更新预警状态
exports.updateWarningStatus = async (req, res) => {
  try {
    const { id } = req.params;
    const { status, resolvedBy } = req.body;

    const warning = await DeviceWarning.findByPk(id);
    if (!warning) {
      return res.status(404).json({ code: 404, message: '设备预警未找到' });
    }

    warning.status = status;
    if (status === 'resolved') {
      warning.resolvedBy = resolvedBy;
      warning.resolvedAt = new Date();
    }
    await warning.save();

    res.status(200).json({ code: 200, message: '状态更新成功', data: warning });
  } catch (error) {
    console.error('更新预警状态失败:', error);
    res.status(500).json({ code: 500, message: '更新预警状态失败', error: error.message });
  }
};

// 获取预警统计
exports.getWarningStats = async (req, res) => {
  try {
    // 使用原始SQL查询每种设备类型的活跃预警数量
    const earTagQuery = 'SELECT COUNT(*) as count FROM device_warnings WHERE deviceType = :deviceType AND status = :status';
    const earTagResult = await DeviceWarning.sequelize.query(earTagQuery, {
      replacements: { deviceType: '智能耳标', status: 'active' },
      type: QueryTypes.SELECT
    });

    const neckbandResult = await DeviceWarning.sequelize.query(earTagQuery, {
      replacements: { deviceType: '智能项圈', status: 'active' },
      type: QueryTypes.SELECT
    });

    const hostResult = await DeviceWarning.sequelize.query(earTagQuery, {
      replacements: { deviceType: '智能主机', status: 'active' },
      type: QueryTypes.SELECT
    });

    const result = {
      earTag: earTagResult[0].count,
      neckband: neckbandResult[0].count,
      host: hostResult[0].count
    };

    res.status(200).json({ code: 200, message: '获取成功', data: result });
  } catch (error) {
    console.error('获取预警统计失败:', error);
    res.status(500).json({ code: 500, message: '获取预警统计失败', error: error.message });
  }
};