package nju.seec.helper.service.impl;

import nju.seec.helper.aspect.auth.LoginUser;
import nju.seec.helper.dao.UserDAO;
import nju.seec.helper.dto.user.ResetPasswordDTO;
import nju.seec.helper.dto.user.UserDTO;
import nju.seec.helper.entity.User;
import nju.seec.helper.enums.ExceptionType;
import nju.seec.helper.enums.UserState;
import nju.seec.helper.enums.UserType;
import nju.seec.helper.exception.HelperException;
import nju.seec.helper.service.UserService;
import nju.seec.helper.util.Consts;
import nju.seec.helper.util.EncryptUtils;
import nju.seec.helper.util.cache.RedisCacheUtils;
import nju.seec.helper.vo.UserVO;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

/**
 * @author cst
 */
@Service
public class UserServiceImpl implements UserService {
    private final RedisCacheUtils cacheUtils;
    private final UserDAO userDAO;

    public UserServiceImpl(UserDAO userDAO, RedisCacheUtils cacheUtils) {
        this.userDAO = userDAO;
        this.cacheUtils = cacheUtils;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public UserVO createUser(UserDTO userDTO) {
        checkSameEmail(userDTO.getEmail());
        checkSamePhone(userDTO.getPhone());

        String email = userDTO.getEmail();
        if (!userDTO.getEmailCode().equals(cacheUtils.get(Consts.EMAIL_CACHE_NAME, email))) {
            throw HelperException.of(ExceptionType.NOT_FOUND, "邮箱或验证码错误");
        }

        String phone = userDTO.getPhone();
        if (!userDTO.getPhoneCode().equals(cacheUtils.get(Consts.PHONE_CACHE_NAME, phone))) {
            throw HelperException.of(ExceptionType.NOT_FOUND, "手机号或验证码错误");
        }

        User user = userDAO.save(new User()
                .setName(userDTO.getName())
                .setEmail(userDTO.getEmail())
                .setPhone(userDTO.getPhone())
                .setPassword(EncryptUtils.encode(userDTO.getPassword()))
                .setType(userDTO.getType())
                .setState(userDTO.getType() == UserType.TEACHER ? UserState.CHECKING : UserState.NORMAL));

        cacheUtils.remove(Consts.EMAIL_CACHE_NAME, email);
        cacheUtils.remove(Consts.PHONE_CACHE_NAME, phone);
        return new UserVO(user);
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public UserVO modifyUser(LoginUser loginUser, UserDTO userDTO) {
        User user = userDAO.findUserById(loginUser.getId());
        user.setName(userDTO.getName());
        user = userDAO.save(user);
        return new UserVO(user);
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public void resetPasswordByEmail(ResetPasswordDTO resetPasswordDTO) {
        User user = userDAO.findByEmail(resetPasswordDTO.getUsername())
                .orElseThrow(() -> HelperException.of(ExceptionType.NOT_FOUND, "该邮箱未在系统中注册"));

        if (!resetPasswordDTO.getCode().equals(cacheUtils.get(Consts.EMAIL_CACHE_NAME, resetPasswordDTO.getUsername()))) {
            throw HelperException.of(ExceptionType.NOT_FOUND, "邮箱或验证码错误");
        }

        user.setPassword(EncryptUtils.encode(resetPasswordDTO.getPassword()));
        userDAO.save(user);
        cacheUtils.remove(Consts.EMAIL_CACHE_NAME, resetPasswordDTO.getUsername());
    }

    @Transactional(readOnly = true)
    @Override
    public UserVO getUserByEmailAndPassword(String email, String password) {
        return userDAO
                .findByEmailAndPassword(email, EncryptUtils.encode(password))
                .map(UserVO::new)
                .orElseThrow(() -> HelperException.of(ExceptionType.NOT_FOUND, "邮箱或密码错误"));
    }

    @Transactional(readOnly = true)
    @Override
    public UserVO getUserById(Long userId) {
        return new UserVO(userDAO.findUserById(userId));
    }

    private void checkSameEmail(String email) {
        if (userDAO.existsByEmail(email)) {
            throw HelperException.of(ExceptionType.CONFLICT, "该邮箱已注册");
        }
    }

    private void checkSamePhone(String phone) {
        if (userDAO.existsByPhone(phone)) {
            throw HelperException.of(ExceptionType.CONFLICT, "该手机号已注册");
        }
    }
}