package com.njuzr.eaibackend.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.njuzr.eaibackend.dto.user.PasswordChangeDTO;
import com.njuzr.eaibackend.dto.user.UserDTO;
import com.njuzr.eaibackend.dto.user.UserRegisterDTO;
import com.njuzr.eaibackend.dto.user.UserUpdateDTO;
import com.njuzr.eaibackend.enums.Role;
import com.njuzr.eaibackend.exception.MyException;
import com.njuzr.eaibackend.mapper.UserMapper;
import com.njuzr.eaibackend.po.User;
import com.njuzr.eaibackend.service.UserService;
import com.njuzr.eaibackend.utils.ModelMapperUtil;
import com.njuzr.eaibackend.utils.PageMapperUtil;
import com.njuzr.eaibackend.vo.UserVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.HttpStatus;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;


@Slf4j
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Autowired
    private RedisTemplate<String, Object> redisTemplate;
    private final PasswordEncoder passwordEncoder = new BCryptPasswordEncoder();


    @Override
    public IPage<UserVO> searchUsers(Page<User> page, Long id, String name, String officialNumber, Role role) {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>(); // 设置查询条件
        // 禁止访问查询ADMIN用户
        if (role == Role.ADMIN) {
            throw new MyException(HttpStatus.FORBIDDEN.value(), HttpStatus.FORBIDDEN.getReasonPhrase() + "：" + "被拒绝");
        }
        queryWrapper
                .eq(Objects.nonNull(id), "id", id)
                .like(StringUtils.isNotBlank(name), "name", name)
                .eq(StringUtils.isNotBlank(officialNumber), "official_number", officialNumber)
                .eq(Objects.nonNull(role), "role", role);

        IPage<User> targets = userMapper.selectPage(page, queryWrapper); // selectPage是内置的方法

        // targets.total如果为0，则说明没有符合条件的用户，但是不报错，由前端自行处理异常。
        return PageMapperUtil.convert(targets, record -> ModelMapperUtil.map(record, UserVO.class));
    }


    @Override
    public UserVO createUser(UserRegisterDTO userDTO) {
        // 从Redis中获取验证码
        final String key = "registerVerifyCode:" + userDTO.getOfficialEmail();
        String storedCode = (String) redisTemplate.opsForValue().get(key);

        if (storedCode == null) {
            throw new MyException(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase() + "：" + "验证码已过期");
        }
        // 验证码校验
        if (storedCode.equals(userDTO.getVerifyCode())) {
            // 检查邮箱和学号是否已存在
            if (!isOfficialNumberNotExists(userDTO.getOfficialNumber())) {
                throw new MyException(HttpStatus.BAD_REQUEST.value(), "学号已注册");
            }

            if (!isEmailNotExists(userDTO.getOfficialEmail())) {
                throw new MyException(HttpStatus.BAD_REQUEST.value(), "邮箱已注册");
            }
            User targetUser = ModelMapperUtil.map(userDTO, User.class);
            targetUser.setPassword(new BCryptPasswordEncoder().encode(targetUser.getPassword())); // 密码加密存储
            targetUser.setCreateTime(new Date()); // 设置创建时间

            int state = userMapper.insert(targetUser);
            log.info("state: {}", state);
            log.info("User创建完毕，User对象如下：" + targetUser);

            redisTemplate.delete(key); //注册成功后删除验证码

            return ModelMapperUtil.map(targetUser, UserVO.class);

        }
        else {
            throw new MyException(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase() + "：" + "验证码错误");
        }
    }


    @Override
    public UserVO createUserByPortal(UserRegisterDTO userDTO) {
        User targetUser = ModelMapperUtil.map(userDTO, User.class);
        targetUser.setCreateTime(new Date()); // 设置创建时间
        int state = userMapper.insert(targetUser);
        log.info("state: {}", state);
        log.info("User创建完毕，User对象如下：" + targetUser);
        return ModelMapperUtil.map(targetUser, UserVO.class);

    }





    /**
     * 更新用户信息
     *
     * @param userDTO
     * @return
     */
    @Override
    public UserVO updateUser(Long id, UserUpdateDTO userDTO) {
        UserDTO opeUser = ModelMapperUtil.map(userDTO, UserDTO.class);
        User user = ModelMapperUtil.map(userDTO, User.class);
        user.setId(id);
        try {
            int status = userMapper.updateUser(user);
            if (status > 0) {
                return ModelMapperUtil.map(userMapper.selectById(user.getId()), UserVO.class);
            }
        } catch (Exception e) {
            log.error("数据库更新错误，错误如下：" + e.getMessage());
            throw new MyException(HttpStatus.INTERNAL_SERVER_ERROR.value(), HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase() + "：" + "数据库更新失败");
        }
        return null;
    }

    @Override
    public UserVO updateUserByPid(Integer pid, UserUpdateDTO userDTO) {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("pid", pid);
        User user = userMapper.selectOne(queryWrapper);
        return this.updateUser(user.getId(), userDTO);
    }


    /**
     * 更新密码
     */
    @Override
    public void updatePassword(PasswordChangeDTO passwordChangeDTO) throws MyException {
        User user = userMapper.selectByOfficialEmail(passwordChangeDTO.getOfficialEmail());
        if (user == null) {
            log.error("用户不存在");
            throw new MyException(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase() + "：" + "找不到用户");
        }

        // 从Redis中获取验证码
        final String key = "passwordChangeVerifyCode:" + passwordChangeDTO.getOfficialEmail();
        String storedCode = (String) redisTemplate.opsForValue().get(key);

        if (storedCode == null) {
            throw new MyException(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase() + "：" + "验证码已过期");
        }
        // 验证码校验
        if (storedCode.equals(passwordChangeDTO.getVerifyCode())) {
            String encodedNewPassword = passwordEncoder.encode(passwordChangeDTO.getPassword());
            int code = userMapper.updatePassword(user.getId(), encodedNewPassword);
            if (code == 1) {
                log.info("用户更新成功");
            }
            redisTemplate.delete(key); //成功后删除验证码
        } else {
            throw new MyException(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase() + "：" + "验证码错误");
        }
    }

    @Override
    public boolean userExists(Integer pid) {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("pid", pid);
        return userMapper.exists(queryWrapper);
    }

    /**
     * 查看学号是否不存在
     *
     * @param officialNumber 学号
     * @return true表示不存在，false表示存在
     */
    private boolean isOfficialNumberNotExists(String officialNumber) throws MyException {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("official_number", officialNumber);
        User existingUser = userMapper.selectOne(queryWrapper);
        if (existingUser != null) {
            log.error("用户已存在，学号{}重复", officialNumber);
            throw new MyException(400, "用户已存在，请检查学号信息");
        }
        return true;
    }


    /**
     * 查看邮箱是否不存在
     *
     * @param email 邮箱
     * @return true表示不存在，false表示存在
     */
    private boolean isEmailNotExists(String email) throws MyException {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("official_email", email);
        User existingUser = userMapper.selectOne(queryWrapper);
        if (existingUser != null) {
            log.error("用户已存在，邮箱{}重复", email);
            throw new MyException(400, "用户已存在，请检查邮箱信息");
        }
        return true;
    }

    @Override
    public String getNameById(Long id) {
        if (id == null) return null;
        try {
            return userMapper.selectNameById(id);
        } catch (Exception e) {
            return null;
        }
    }

    @Override
    public Map<Long, String> getNamesByIds(Collection<Long> ids) {
        if (ids == null || ids.isEmpty()) return Collections.emptyMap();
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.in("id", ids);
        List<User> users = userMapper.selectList(wrapper);
        if (users == null || users.isEmpty()) return Collections.emptyMap();
        return users.stream().collect(Collectors.toMap(User::getId, User::getName, (a,b)->a));
    }

}