package com.bycrm.service.impl;

import cn.hutool.core.util.StrUtil;
import com.bycrm.common.Constants;
import com.bycrm.common.PageResult;
import com.bycrm.dto.CustomerDTO;
import com.bycrm.dto.PageQuery;
import com.bycrm.entity.Customer;
import com.bycrm.entity.User;
import com.bycrm.exception.BusinessException;
import com.bycrm.mapper.CustomerMapper;
import com.bycrm.mapper.UserMapper;
import com.bycrm.service.CustomerService;
import com.bycrm.vo.CustomerVO;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
import java.util.List;
import java.util.stream.Collectors;

/**
 * 客户服务实现
 */
@Service
public class CustomerServiceImpl implements CustomerService {

    private final CustomerMapper customerMapper;
    private final UserMapper userMapper;

    public CustomerServiceImpl(CustomerMapper customerMapper, UserMapper userMapper) {
        this.customerMapper = customerMapper;
        this.userMapper = userMapper;
    }

    @Override
    public PageResult<CustomerVO> getCustomerPage(PageQuery query, String name, String industry, Integer status) {
        // 计算偏移量
        query.setOffset((query.getCurrent() - 1) * query.getSize());

        List<Customer> customers = customerMapper.selectPage(query, name, industry, status);
        Long total = customerMapper.countPage(name, industry, status);

        List<CustomerVO> voList = customers.stream().map(customer -> {
            CustomerVO vo = convertToVO(customer);
            return vo;
        }).collect(Collectors.toList());

        return PageResult.of(total, voList, query.getCurrent(), query.getSize());
    }

    @Override
    public CustomerVO getCustomerById(Long id) {
        Customer customer = customerMapper.selectById(id);
        if (customer == null) {
            throw new BusinessException("客户不存在");
        }
        return convertToVO(customer);
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public Customer createCustomer(CustomerDTO customerDTO, Long currentUserId) {
        // 校验客户名称是否重复
        checkCustomerNameDuplicate(customerDTO.getName());

        Customer customer = new Customer();
        BeanUtils.copyProperties(customerDTO, customer);
        customer.setStatus(Constants.CUSTOMER_STATUS_AVAILABLE);
        customer.setCreatedAt(LocalDateTime.now());
        customer.setUpdatedAt(LocalDateTime.now());

        customerMapper.insert(customer);
        return customer;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void updateCustomer(Long id, CustomerDTO customerDTO, Long currentUserId) {
        Customer existingCustomer = customerMapper.selectById(id);
        if (existingCustomer == null) {
            throw new BusinessException("客户不存在");
        }

        // 如果修改了名称，需要检查新名称是否与其他客户重复
        if (!existingCustomer.getName().equals(customerDTO.getName())) {
            checkCustomerNameDuplicate(customerDTO.getName());
        }

        Customer customer = new Customer();
        BeanUtils.copyProperties(customerDTO, customer);
        customer.setId(id);
        customer.setUpdatedAt(LocalDateTime.now());

        customerMapper.update(customer);
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void deleteCustomer(Long id, Long currentUserId) {
        Customer customer = customerMapper.selectById(id);
        if (customer == null) {
            throw new BusinessException("客户不存在");
        }

        if (customer.getStatus() == Constants.CUSTOMER_STATUS_PROTECTED) {
            throw new BusinessException("客户处于保护期中，无法删除");
        }

        customerMapper.deleteById(id);
    }

    @Override
    public List<Customer> searchByName(String name) {
        return customerMapper.selectByNameLike(name);
    }

    @Override
    public void checkCustomerNameDuplicate(String name) {
        List<Customer> existingCustomers = customerMapper.selectByNameLike(name);
        if (existingCustomers.stream().anyMatch(c -> c.getName().equals(name))) {
            throw new BusinessException("客户名称已存在");
        }
    }

    /**
     * 转换为 VO
     */
    private CustomerVO convertToVO(Customer customer) {
        CustomerVO vo = new CustomerVO();
        BeanUtils.copyProperties(customer, vo);

        // 设置状态描述
        switch (customer.getStatus()) {
            case Constants.CUSTOMER_STATUS_AVAILABLE:
                vo.setStatusDesc("可报备");
                break;
            case Constants.CUSTOMER_STATUS_PROTECTED:
                vo.setStatusDesc("保护中");
                break;
            case Constants.CUSTOMER_STATUS_EXPIRED:
                vo.setStatusDesc("已失效");
                break;
            default:
                vo.setStatusDesc("未知");
        }

        return vo;
    }
}