/**
 * 监管任务控制器
 * @file supervisionTaskController.js
 * @description 监管任务相关的API控制器
 */
const { SupervisionTask, User } = require('../models');
const { Op } = require('sequelize');

// 获取监管任务列表
const getSupervisionTasks = async (req, res) => {
  try {
    const {
      page = 1,
      limit = 10,
      search = '',
      supervisionStatus = '',
      dateRange = '',
      sortBy = 'createdAt',
      sortOrder = 'DESC'
    } = req.query;

    const offset = (page - 1) * limit;

    // 构建查询条件
    const where = {};

    // 搜索条件
    if (search) {
      where[Op.or] = [
        { applicationNumber: { [Op.like]: `%${search}%` } },
        { contractNumber: { [Op.like]: `%${search}%` } },
        { customerName: { [Op.like]: `%${search}%` } },
        { productName: { [Op.like]: `%${search}%` } }
      ];
    }

    // 状态筛选
    if (supervisionStatus) {
      where.supervisionStatus = supervisionStatus;
    }

    // 日期范围筛选
    if (dateRange) {
      const [startDate, endDate] = dateRange.split(',');
      if (startDate && endDate) {
        where.importTime = {
          [Op.between]: [new Date(startDate), new Date(endDate)]
        };
      }
    }

    // 查询监管任务列表
    const { count, rows: tasks } = await SupervisionTask.findAndCountAll({
      where,
      include: [
        {
          model: User,
          as: 'creator',
          attributes: ['id', 'username', 'real_name']
        },
        {
          model: User,
          as: 'updater',
          attributes: ['id', 'username', 'real_name']
        }
      ],
      order: [[sortBy, sortOrder.toUpperCase()]],
      limit: parseInt(limit),
      offset: parseInt(offset)
    });

    // 计算分页信息
    const totalPages = Math.ceil(count / limit);
    const hasNextPage = page < totalPages;
    const hasPrevPage = page > 1;

    res.status(200).json({
      success: true,
      message: '监管任务列表获取成功',
      data: {
        tasks,
        pagination: {
          total: count,
          currentPage: parseInt(page),
          pageSize: parseInt(limit),
          totalPages,
          hasNextPage,
          hasPrevPage
        }
      }
    });
  } catch (error) {
    console.error('获取监管任务列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取监管任务列表失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 获取监管任务详情
const getSupervisionTaskById = async (req, res) => {
  try {
    const { id } = req.params;
    const task = await SupervisionTask.findByPk(id, {
      include: [
        {
          model: User,
          as: 'creator',
          attributes: ['id', 'username', 'real_name']
        },
        {
          model: User,
          as: 'updater',
          attributes: ['id', 'username', 'real_name']
        }
      ]
    });

    if (!task) {
      return res.status(404).json({
        success: false,
        message: '监管任务不存在'
      });
    }

    res.status(200).json({
      success: true,
      message: '监管任务详情获取成功',
      data: task
    });
  } catch (error) {
    console.error('获取监管任务详情失败:', error);
    res.status(500).json({
      success: false,
      message: '获取监管任务详情失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 创建监管任务
const createSupervisionTask = async (req, res) => {
  try {
    const {
      applicationNumber,
      contractNumber,
      productName,
      customerName,
      idType = 'id_card',
      idNumber,
      assetType = 'cattle',
      assetQuantity = 0,
      supervisionStatus = 'pending',
      startTime,
      endTime,
      loanAmount = 0,
      interestRate = 0,
      loanTerm = 12,
      supervisorName,
      supervisorPhone,
      farmAddress,
      remarks
    } = req.body;

    // 验证必填字段
    const requiredFields = ['applicationNumber', 'contractNumber', 'productName', 'customerName', 'idNumber', 'startTime', 'endTime'];
    const missingFields = requiredFields.filter(field => !req.body[field]);
    
    if (missingFields.length > 0) {
      return res.status(400).json({
        success: false,
        message: `请填写所有必填字段: ${missingFields.join(', ')}`
      });
    }

    // 验证字段长度
    if (applicationNumber.length > 50) {
      return res.status(400).json({
        success: false,
        message: '申请单号不能超过50个字符'
      });
    }

    if (contractNumber.length > 50) {
      return res.status(400).json({
        success: false,
        message: '放款合同编号不能超过50个字符'
      });
    }

    if (productName.length > 100) {
      return res.status(400).json({
        success: false,
        message: '产品名称不能超过100个字符'
      });
    }

    if (customerName.length > 50) {
      return res.status(400).json({
        success: false,
        message: '客户姓名不能超过50个字符'
      });
    }

    // 验证数值字段
    if (assetQuantity < 0) {
      return res.status(400).json({
        success: false,
        message: '监管生资数量不能为负数'
      });
    }

    if (loanAmount < 0) {
      return res.status(400).json({
        success: false,
        message: '贷款金额不能为负数'
      });
    }

    if (interestRate < 0 || interestRate > 1) {
      return res.status(400).json({
        success: false,
        message: '利率必须在0-1之间'
      });
    }

    if (loanTerm < 0) {
      return res.status(400).json({
        success: false,
        message: '贷款期限不能为负数'
      });
    }

    // 验证状态和类型
    if (!['pending', 'supervising', 'completed', 'suspended'].includes(supervisionStatus)) {
      return res.status(400).json({
        success: false,
        message: '监管状态无效'
      });
    }

    if (!['id_card', 'passport', 'other'].includes(idType)) {
      return res.status(400).json({
        success: false,
        message: '证件类型无效'
      });
    }

    if (!['cattle', 'sheep', 'pig', 'poultry', 'other'].includes(assetType)) {
      return res.status(400).json({
        success: false,
        message: '养殖生资种类无效'
      });
    }

    // 验证日期格式和逻辑
    const startDate = new Date(startTime);
    const endDate = new Date(endTime);
    
    if (isNaN(startDate.getTime()) || isNaN(endDate.getTime())) {
      return res.status(400).json({
        success: false,
        message: '日期格式不正确'
      });
    }

    if (startDate >= endDate) {
      return res.status(400).json({
        success: false,
        message: '监管结束时间必须晚于开始时间'
      });
    }

    // 检查申请单号和合同编号是否已存在
    const existingTask = await SupervisionTask.findOne({
      where: {
        [Op.or]: [
          { applicationNumber },
          { contractNumber }
        ]
      }
    });

    if (existingTask) {
      return res.status(400).json({
        success: false,
        message: existingTask.applicationNumber === applicationNumber ? 
          '申请单号已存在' : '放款合同编号已存在'
      });
    }

    // 创建监管任务
    const task = await SupervisionTask.create({
      applicationNumber,
      contractNumber,
      productName,
      customerName,
      idType,
      idNumber,
      assetType,
      assetQuantity: parseInt(assetQuantity),
      supervisionStatus,
      startTime,
      endTime,
      loanAmount: parseFloat(loanAmount),
      interestRate: parseFloat(interestRate),
      loanTerm: parseInt(loanTerm),
      supervisorName,
      supervisorPhone,
      farmAddress,
      remarks,
      createdBy: req.user?.userId || req.user?.id,
      updatedBy: req.user?.userId || req.user?.id
    });

    // 获取创建的任务详情（包含关联信息）
    const createdTask = await SupervisionTask.findByPk(task.id, {
      include: [
        {
          model: User,
          as: 'creator',
          attributes: ['id', 'username', 'real_name']
        },
        {
          model: User,
          as: 'updater',
          attributes: ['id', 'username', 'real_name']
        }
      ]
    });

    res.status(201).json({
      success: true,
      data: createdTask,
      message: '监管任务创建成功'
    });
  } catch (error) {
    console.error('创建监管任务失败:', error);
    
    // 处理数据库约束错误
    if (error.name === 'SequelizeValidationError') {
      const validationErrors = error.errors.map(err => err.message).join(', ');
      return res.status(400).json({
        success: false,
        message: `数据验证失败: ${validationErrors}`
      });
    }

    if (error.name === 'SequelizeUniqueConstraintError') {
      return res.status(400).json({
        success: false,
        message: '申请单号或放款合同编号已存在'
      });
    }

    res.status(500).json({
      success: false,
      message: '创建监管任务失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 更新监管任务
const updateSupervisionTask = async (req, res) => {
  try {
    const { id } = req.params;
    const updateData = req.body;

    // 验证日期
    if (updateData.startTime && updateData.endTime) {
      const startDate = new Date(updateData.startTime);
      const endDate = new Date(updateData.endTime);
      if (startDate >= endDate) {
        return res.status(400).json({
          success: false,
          message: '监管结束时间必须晚于开始时间'
        });
      }
    }

    const task = await SupervisionTask.findByPk(id);

    if (!task) {
      return res.status(404).json({
        success: false,
        message: '监管任务不存在'
      });
    }

    // 如果更新申请单号或合同编号，检查是否重复
    if (updateData.applicationNumber || updateData.contractNumber) {
      const whereCondition = { id: { [Op.ne]: id } };
      if (updateData.applicationNumber) {
        whereCondition.applicationNumber = updateData.applicationNumber;
      }
      if (updateData.contractNumber) {
        whereCondition.contractNumber = updateData.contractNumber;
      }

      const existingTask = await SupervisionTask.findOne({ where: whereCondition });
      if (existingTask) {
        return res.status(400).json({
          success: false,
          message: '申请单号或放款合同编号已存在'
        });
      }
    }

    await task.update({
      ...updateData,
      updatedBy: req.user?.userId || req.user?.id
    });

    res.status(200).json({
      success: true,
      data: task,
      message: '监管任务更新成功'
    });
  } catch (error) {
    console.error('更新监管任务失败:', error);
    res.status(500).json({
      success: false,
      message: '更新监管任务失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 删除监管任务
const deleteSupervisionTask = async (req, res) => {
  try {
    const { id } = req.params;
    const task = await SupervisionTask.findByPk(id);

    if (!task) {
      return res.status(404).json({
        success: false,
        message: '监管任务不存在'
      });
    }

    await task.destroy();

    res.status(200).json({
      success: true,
      message: '监管任务删除成功'
    });
  } catch (error) {
    console.error('删除监管任务失败:', error);
    res.status(500).json({
      success: false,
      message: '删除监管任务失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 获取监管任务统计
const getSupervisionTaskStats = async (req, res) => {
  try {
    const total = await SupervisionTask.count();
    const pending = await SupervisionTask.count({ where: { supervisionStatus: 'pending' } });
    const supervising = await SupervisionTask.count({ where: { supervisionStatus: 'supervising' } });
    const completed = await SupervisionTask.count({ where: { supervisionStatus: 'completed' } });
    const suspended = await SupervisionTask.count({ where: { supervisionStatus: 'suspended' } });

    res.status(200).json({
      success: true,
      message: '监管任务统计获取成功',
      data: {
        total,
        pending,
        supervising,
        completed,
        suspended
      }
    });
  } catch (error) {
    console.error('获取监管任务统计失败:', error);
    res.status(500).json({
      success: false,
      message: '获取监管任务统计失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 批量更新监管任务状态
const batchUpdateStatus = async (req, res) => {
  try {
    const { ids, supervisionStatus } = req.body;

    if (!Array.isArray(ids) || ids.length === 0 || !supervisionStatus) {
      return res.status(400).json({
        success: false,
        message: '请求参数无效'
      });
    }

    if (!['pending', 'supervising', 'completed', 'suspended'].includes(supervisionStatus)) {
      return res.status(400).json({
        success: false,
        message: '监管状态无效'
      });
    }

    const [updatedCount] = await SupervisionTask.update(
      { 
        supervisionStatus, 
        updatedBy: req.user?.userId || req.user?.id 
      },
      { where: { id: { [Op.in]: ids } } }
    );

    res.status(200).json({
      success: true,
      message: `成功更新 ${updatedCount} 个监管任务状态`,
      data: { updatedCount }
    });
  } catch (error) {
    console.error('批量更新监管任务状态失败:', error);
    res.status(500).json({
      success: false,
      message: '批量更新监管任务状态失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 批量删除监管任务
const batchDeleteTasks = async (req, res) => {
  try {
    const { ids } = req.body;

    if (!Array.isArray(ids) || ids.length === 0) {
      return res.status(400).json({
        success: false,
        message: '请求参数无效'
      });
    }

    const deletedCount = await SupervisionTask.destroy({
      where: { id: { [Op.in]: ids } }
    });

    res.status(200).json({
      success: true,
      message: `成功删除 ${deletedCount} 个监管任务`,
      data: { deletedCount }
    });
  } catch (error) {
    console.error('批量删除监管任务失败:', error);
    res.status(500).json({
      success: false,
      message: '批量删除监管任务失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

module.exports = {
  getSupervisionTasks,
  getSupervisionTaskById,
  createSupervisionTask,
  updateSupervisionTask,
  deleteSupervisionTask,
  getSupervisionTaskStats,
  batchUpdateStatus,
  batchDeleteTasks
};