const { Project, User } = require('../models');
const { Op } = require('sequelize');

// 获取项目列表
const getProjects = async (req, res) => {
  try {
    const {
      page = 1,
      limit = 10,
      search = '',
      status = '',
      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] = [
        { name: { [Op.like]: `%${search}%` } },
        { farmName: { [Op.like]: `%${search}%` } },
        { loanOfficer: { [Op.like]: `%${search}%` } }
      ];
    }
    
    // 状态筛选
    if (status) {
      where.status = status;
    }

    // 查询项目列表
    const { count, rows: projects } = await Project.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.json({
      success: true,
      data: {
        projects,
        pagination: {
          current: parseInt(page),
          pageSize: parseInt(limit),
          total: count,
          totalPages,
          hasNextPage,
          hasPrevPage
        }
      },
      message: '获取项目列表成功'
    });
  } catch (error) {
    console.error('获取项目列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目列表失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 获取项目详情
const getProjectById = async (req, res) => {
  try {
    const { id } = req.params;

    const project = await Project.findByPk(id, {
      include: [
        {
          model: User,
          as: 'creator',
          attributes: ['id', 'username', 'real_name']
        },
        {
          model: User,
          as: 'updater',
          attributes: ['id', 'username', 'real_name']
        }
      ]
    });

    if (!project) {
      return res.status(404).json({
        success: false,
        message: '项目不存在'
      });
    }

    res.json({
      success: true,
      data: project,
      message: '获取项目详情成功'
    });
  } catch (error) {
    console.error('获取项目详情失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目详情失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 创建项目
const createProject = async (req, res) => {
  try {
    const {
      name,
      status = 'supervision',
      farmName,
      supervisionObject,
      supervisionQuantity = 0,
      supervisionPeriod,
      supervisionAmount = 0.00,
      startTime,
      endTime,
      earTag = 0,
      collar = 0,
      host = 0,
      loanOfficer,
      description
    } = req.body;

    // 验证必填字段
    const requiredFields = ['name', 'farmName', 'supervisionObject', 'supervisionPeriod', '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 (name.length > 100) {
      return res.status(400).json({
        success: false,
        message: '项目名称不能超过100个字符'
      });
    }

    if (farmName.length > 200) {
      return res.status(400).json({
        success: false,
        message: '养殖场名称不能超过200个字符'
      });
    }

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

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

    if (earTag < 0 || collar < 0 || host < 0) {
      return res.status(400).json({
        success: false,
        message: '设备数量不能为负数'
      });
    }

    // 验证状态
    if (!['supervision', 'completed'].includes(status)) {
      return res.status(400).json({
        success: false,
        message: '项目状态只能是 supervision 或 completed'
      });
    }

    // 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: '结束时间必须晚于开始时间'
      });
    }

    // 检查项目名称是否已存在
    const existingProject = await Project.findOne({
      where: { name }
    });

    if (existingProject) {
      return res.status(400).json({
        success: false,
        message: '项目名称已存在，请使用其他名称'
      });
    }

    // 创建项目
    const project = await Project.create({
      name,
      status,
      farmName,
      supervisionObject,
      supervisionQuantity: parseInt(supervisionQuantity),
      supervisionPeriod,
      supervisionAmount: parseFloat(supervisionAmount),
      startTime,
      endTime,
      earTag: parseInt(earTag),
      collar: parseInt(collar),
      host: parseInt(host),
      loanOfficer,
      description,
      createdBy: req.user?.userId || req.user?.id,
      updatedBy: req.user?.userId || req.user?.id
    });

    // 获取创建的项目详情（包含关联信息）
    const createdProject = await Project.findByPk(project.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: createdProject,
      message: '创建项目成功'
    });
  } catch (error) {
    console.error('创建项目失败:', 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: '项目名称已存在，请使用其他名称'
      });
    }

    res.status(500).json({
      success: false,
      message: '创建项目失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 更新项目
const updateProject = async (req, res) => {
  try {
    const { id } = req.params;
    const updateData = req.body;

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

    const project = await Project.findByPk(id);
    if (!project) {
      return res.status(404).json({
        success: false,
        message: '项目不存在'
      });
    }

    // 更新项目
    await project.update({
      ...updateData,
      updatedBy: req.user?.id
    });

    res.json({
      success: true,
      data: project,
      message: '更新项目成功'
    });
  } catch (error) {
    console.error('更新项目失败:', error);
    res.status(500).json({
      success: false,
      message: '更新项目失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 删除项目
const deleteProject = async (req, res) => {
  try {
    const { id } = req.params;

    const project = await Project.findByPk(id);
    if (!project) {
      return res.status(404).json({
        success: false,
        message: '项目不存在'
      });
    }

    await project.destroy();

    res.json({
      success: true,
      message: '删除项目成功'
    });
  } catch (error) {
    console.error('删除项目失败:', error);
    res.status(500).json({
      success: false,
      message: '删除项目失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 获取项目统计
const getProjectStats = async (req, res) => {
  try {
    const totalProjects = await Project.count();
    const supervisionProjects = await Project.count({ where: { status: 'supervision' } });
    const completedProjects = await Project.count({ where: { status: 'completed' } });
    
    // 计算总监管金额
    const totalAmount = await Project.sum('supervisionAmount');
    
    // 计算总监管数量
    const totalQuantity = await Project.sum('supervisionQuantity');

    res.json({
      success: true,
      data: {
        total: totalProjects,
        supervision: supervisionProjects,
        completed: completedProjects,
        totalAmount: totalAmount || 0,
        totalQuantity: totalQuantity || 0
      },
      message: '获取项目统计成功'
    });
  } catch (error) {
    console.error('获取项目统计失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目统计失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

// 批量更新项目状态
const batchUpdateStatus = async (req, res) => {
  try {
    const { projectIds, status } = req.body;

    if (!projectIds || !Array.isArray(projectIds) || projectIds.length === 0) {
      return res.status(400).json({
        success: false,
        message: '请选择要更新的项目'
      });
    }

    if (!['supervision', 'completed'].includes(status)) {
      return res.status(400).json({
        success: false,
        message: '无效的项目状态'
      });
    }

    await Project.update(
      { 
        status,
        updatedBy: req.user?.id
      },
      { 
        where: { id: { [Op.in]: projectIds } }
      }
    );

    res.json({
      success: true,
      message: `成功更新 ${projectIds.length} 个项目的状态`
    });
  } catch (error) {
    console.error('批量更新项目状态失败:', error);
    res.status(500).json({
      success: false,
      message: '批量更新项目状态失败',
      error: process.env.NODE_ENV === 'development' ? error.message : undefined
    });
  }
};

module.exports = {
  getProjects,
  getProjectById,
  createProject,
  updateProject,
  deleteProject,
  getProjectStats,
  batchUpdateStatus
};