const express = require('express');
const router = express.Router();
const Joi = require('joi');

// 模拟供应商数据
let suppliers = [
  {
    id: 1,
    name: '山东优质牲畜合作社',
    code: 'SUP001',
    contact: '李经理',
    phone: '15888888888',
    address: '山东省济南市历城区牲畜养殖基地',
    businessLicense: 'SUP001_license.pdf',
    qualificationLevel: 'A',
    certifications: ['动物防疫合格证', '饲料生产许可证'],
    cattleTypes: ['肉牛', '奶牛'],
    capacity: 5000,
    rating: 4.8,
    cooperationStartDate: '2022-01-15',
    status: 'active',
    region: 'east',
    createdAt: new Date('2022-01-15'),
    updatedAt: new Date('2024-01-15')
  },
  {
    id: 2,
    name: '内蒙古草原牲畜有限公司',
    code: 'SUP002',
    contact: '王总',
    phone: '13999999999',
    address: '内蒙古呼和浩特市草原牧场',
    businessLicense: 'SUP002_license.pdf',
    qualificationLevel: 'A+',
    certifications: ['有机认证', '绿色食品认证'],
    cattleTypes: ['草原牛', '黄牛'],
    capacity: 8000,
    rating: 4.9,
    cooperationStartDate: '2021-08-20',
    status: 'active',
    region: 'north',
    createdAt: new Date('2021-08-20'),
    updatedAt: new Date('2024-01-20')
  },
  {
    id: 3,
    name: '四川高原牲畜养殖场',
    code: 'SUP003',
    contact: '张场长',
    phone: '18777777777',
    address: '四川省成都市高原养殖区',
    businessLicense: 'SUP003_license.pdf',
    qualificationLevel: 'B+',
    certifications: ['无公害产品认证'],
    cattleTypes: ['高原牛'],
    capacity: 3000,
    rating: 4.5,
    cooperationStartDate: '2022-06-10',
    status: 'active',
    region: 'southwest',
    createdAt: new Date('2022-06-10'),
    updatedAt: new Date('2024-01-10')
  }
];

// 验证schemas
const supplierCreateSchema = Joi.object({
  name: Joi.string().min(2).max(100).required(),
  code: Joi.string().min(3).max(20).required(),
  contact: Joi.string().min(2).max(50).required(),
  phone: Joi.string().pattern(/^1[3-9]\d{9}$/).required(),
  address: Joi.string().min(5).max(200).required(),
  qualificationLevel: Joi.string().valid('A+', 'A', 'B+', 'B', 'C').required(),
  cattleTypes: Joi.array().items(Joi.string()).min(1).required(),
  capacity: Joi.number().integer().min(1).required(),
  region: Joi.string().valid('north', 'south', 'east', 'west', 'northeast', 'northwest', 'southeast', 'southwest', 'central').required()
});

const supplierUpdateSchema = Joi.object({
  name: Joi.string().min(2).max(100),
  contact: Joi.string().min(2).max(50),
  phone: Joi.string().pattern(/^1[3-9]\d{9}$/),
  address: Joi.string().min(5).max(200),
  qualificationLevel: Joi.string().valid('A+', 'A', 'B+', 'B', 'C'),
  cattleTypes: Joi.array().items(Joi.string()).min(1),
  capacity: Joi.number().integer().min(1),
  region: Joi.string().valid('north', 'south', 'east', 'west', 'northeast', 'northwest', 'southeast', 'southwest', 'central'),
  status: Joi.string().valid('active', 'inactive', 'suspended')
});

// 获取供应商列表
router.get('/', (req, res) => {
  try {
    const { 
      page = 1, 
      pageSize = 20, 
      keyword, 
      region, 
      qualificationLevel, 
      status = 'active' 
    } = req.query;

    let filteredSuppliers = [...suppliers];

    // 关键词搜索
    if (keyword) {
      filteredSuppliers = filteredSuppliers.filter(supplier =>
        supplier.name.includes(keyword) ||
        supplier.code.includes(keyword) ||
        supplier.contact.includes(keyword)
      );
    }

    // 区域筛选
    if (region) {
      filteredSuppliers = filteredSuppliers.filter(supplier => supplier.region === region);
    }

    // 资质等级筛选
    if (qualificationLevel) {
      filteredSuppliers = filteredSuppliers.filter(supplier => supplier.qualificationLevel === qualificationLevel);
    }

    // 状态筛选
    if (status) {
      filteredSuppliers = filteredSuppliers.filter(supplier => supplier.status === status);
    }

    // 分页处理
    const startIndex = (page - 1) * pageSize;
    const endIndex = startIndex + parseInt(pageSize);
    const paginatedSuppliers = filteredSuppliers.slice(startIndex, endIndex);

    res.json({
      success: true,
      data: {
        list: paginatedSuppliers,
        pagination: {
          page: parseInt(page),
          pageSize: parseInt(pageSize),
          total: filteredSuppliers.length,
          totalPages: Math.ceil(filteredSuppliers.length / pageSize)
        }
      }
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '获取供应商列表失败',
      error: error.message
    });
  }
});

// 获取供应商详情
router.get('/:id', (req, res) => {
  try {
    const { id } = req.params;
    const supplier = suppliers.find(s => s.id === parseInt(id));

    if (!supplier) {
      return res.status(404).json({
        success: false,
        message: '供应商不存在'
      });
    }

    res.json({
      success: true,
      data: supplier
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '获取供应商详情失败',
      error: error.message
    });
  }
});

// 创建供应商
router.post('/', (req, res) => {
  try {
    const { error, value } = supplierCreateSchema.validate(req.body);
    if (error) {
      return res.status(400).json({
        success: false,
        message: '参数验证失败',
        errors: error.details.map(detail => detail.message)
      });
    }

    // 检查编码是否重复
    const existingSupplier = suppliers.find(s => s.code === value.code);
    if (existingSupplier) {
      return res.status(400).json({
        success: false,
        message: '供应商编码已存在'
      });
    }

    const newSupplier = {
      id: Math.max(...suppliers.map(s => s.id)) + 1,
      ...value,
      businessLicense: '',
      certifications: [],
      rating: 0,
      cooperationStartDate: new Date().toISOString().split('T')[0],
      status: 'active',
      createdAt: new Date(),
      updatedAt: new Date()
    };

    suppliers.push(newSupplier);

    res.status(201).json({
      success: true,
      message: '供应商创建成功',
      data: newSupplier
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '创建供应商失败',
      error: error.message
    });
  }
});

// 更新供应商
router.put('/:id', (req, res) => {
  try {
    const { id } = req.params;
    const { error, value } = supplierUpdateSchema.validate(req.body);

    if (error) {
      return res.status(400).json({
        success: false,
        message: '参数验证失败',
        errors: error.details.map(detail => detail.message)
      });
    }

    const supplierIndex = suppliers.findIndex(s => s.id === parseInt(id));
    if (supplierIndex === -1) {
      return res.status(404).json({
        success: false,
        message: '供应商不存在'
      });
    }

    suppliers[supplierIndex] = {
      ...suppliers[supplierIndex],
      ...value,
      updatedAt: new Date()
    };

    res.json({
      success: true,
      message: '供应商更新成功',
      data: suppliers[supplierIndex]
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '更新供应商失败',
      error: error.message
    });
  }
});

// 删除供应商
router.delete('/:id', (req, res) => {
  try {
    const { id } = req.params;
    const supplierIndex = suppliers.findIndex(s => s.id === parseInt(id));

    if (supplierIndex === -1) {
      return res.status(404).json({
        success: false,
        message: '供应商不存在'
      });
    }

    suppliers.splice(supplierIndex, 1);

    res.json({
      success: true,
      message: '供应商删除成功'
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '删除供应商失败',
      error: error.message
    });
  }
});

// 获取供应商统计信息
router.get('/stats/overview', (req, res) => {
  try {
    const totalSuppliers = suppliers.length;
    const activeSuppliers = suppliers.filter(s => s.status === 'active').length;
    const averageRating = suppliers.reduce((sum, s) => sum + s.rating, 0) / totalSuppliers;
    const totalCapacity = suppliers.reduce((sum, s) => sum + s.capacity, 0);

    // 按等级统计
    const levelStats = suppliers.reduce((stats, supplier) => {
      stats[supplier.qualificationLevel] = (stats[supplier.qualificationLevel] || 0) + 1;
      return stats;
    }, {});

    // 按区域统计
    const regionStats = suppliers.reduce((stats, supplier) => {
      stats[supplier.region] = (stats[supplier.region] || 0) + 1;
      return stats;
    }, {});

    res.json({
      success: true,
      data: {
        totalSuppliers,
        activeSuppliers,
        averageRating: Math.round(averageRating * 10) / 10,
        totalCapacity,
        levelStats,
        regionStats
      }
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '获取供应商统计信息失败',
      error: error.message
    });
  }
});

// 批量操作
router.post('/batch', (req, res) => {
  try {
    const { action, ids } = req.body;

    if (!action || !Array.isArray(ids) || ids.length === 0) {
      return res.status(400).json({
        success: false,
        message: '参数错误'
      });
    }

    let affectedCount = 0;

    switch (action) {
      case 'activate':
        suppliers.forEach(supplier => {
          if (ids.includes(supplier.id)) {
            supplier.status = 'active';
            supplier.updatedAt = new Date();
            affectedCount++;
          }
        });
        break;

      case 'deactivate':
        suppliers.forEach(supplier => {
          if (ids.includes(supplier.id)) {
            supplier.status = 'inactive';
            supplier.updatedAt = new Date();
            affectedCount++;
          }
        });
        break;

      case 'delete':
        suppliers = suppliers.filter(supplier => {
          if (ids.includes(supplier.id)) {
            affectedCount++;
            return false;
          }
          return true;
        });
        break;

      default:
        return res.status(400).json({
          success: false,
          message: '不支持的操作类型'
        });
    }

    res.json({
      success: true,
      message: `批量${action}成功`,
      data: { affectedCount }
    });
  } catch (error) {
    res.status(500).json({
      success: false,
      message: '批量操作失败',
      error: error.message
    });
  }
});

module.exports = router;