package com.weiwojc.service.impl;

import com.weiwojc.mapper.UserMapper;
import com.weiwojc.model.dto.UserLoginDTO;
import com.weiwojc.model.dto.UserRegisterDTO;
import com.weiwojc.model.entity.User;
import com.weiwojc.service.UserService;
import com.weiwojc.utils.JwtUtils;
import com.weiwojc.utils.PasswordUtils;
import lombok.RequiredArgsConstructor;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.LockedException;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.UUID;

@Service
@RequiredArgsConstructor
public class UserServiceImpl implements UserService {

    private final UserMapper userMapper;
    private final JwtUtils jwtUtils;

    @Override
    @Transactional
    public User register(UserRegisterDTO registerDTO) {
        // 检查账号名是否已存在
        User existingUser = userMapper.findByUsername(registerDTO.getAccountName());
        if (existingUser != null) {
            throw new RuntimeException("账号名已存在");
        }

        // 创建新用户
        User user = new User();
        user.setUuid(UUID.randomUUID().toString());
        user.setUsername(registerDTO.getAccountName());
        user.setNickname(registerDTO.getNickname());
        
        // 生成加密密码
        String salt = PasswordUtils.generateSalt();
        String hashedPassword = PasswordUtils.hashPassword(registerDTO.getPassword(), salt);
        user.setPasswordHash(hashedPassword);
        user.setPasswordSalt(salt);  // 保存盐值

        // 设置其他字段
        user.setStatus(1); // 正常状态
        user.setRegisteredAt(LocalDateTime.now());
        user.setUpdatedAt(LocalDateTime.now());

        // 保存用户
        userMapper.insert(user);
        return user;
    }

    @Override
    public String login(UserLoginDTO loginDTO) {
        User user = userMapper.findByUsername(loginDTO.getAccountName());

        if (user == null) {
            throw new BadCredentialsException("账号名或密码错误");
        }

        // 检查账户状态
        if (user.getStatus() == 0) {
            throw new LockedException("账户已被禁用");
        }

        // 检查是否被锁定
        if (isUserLocked(user.getUserId())) {
            throw new LockedException("账户已被锁定，请稍后再试");
        }

        // 验证密码
        if (!PasswordUtils.verifyPassword(loginDTO.getPassword(), user.getPasswordHash())) {
            // 增加登录失败次数
            incrementLoginAttempts(user.getUsername());
            throw new BadCredentialsException("账号名或密码错误");
        }

        // 重置登录失败次数
        resetLoginAttempts(user.getUsername());

        // 更新最后登录时间
        updateLastLogin(user.getUserId());

        // 生成JWT令牌
        return jwtUtils.generateToken(user);
    }

    @Override
    public User getUserInfo(Long userId) {
        return userMapper.findById(userId);
    }

    @Override
    public void updateLastLogin(Long userId) {
        userMapper.updateLastLogin(userId, LocalDateTime.now());
    }

    @Override
    public boolean isUserLocked(Long userId) {
        User user = userMapper.findById(userId);
        if (user == null) {
            return false;
        }

        // 检查账户锁定状态
        if (user.getLockedUntil() != null && 
            LocalDateTime.now().isBefore(user.getLockedUntil())) {
            return true;
        }

        return false;
    }

    @Override
    public void incrementLoginAttempts(String username) {
        User user = userMapper.findByUsername(username);

        if (user != null) {
            int attempts = user.getLoginAttempts() == null ? 0 : user.getLoginAttempts();
            attempts++;

            LocalDateTime lockedUntil = null;
            // 如果失败次数达到5次，锁定30分钟
            if (attempts >= 5) {
                lockedUntil = LocalDateTime.now().plusMinutes(30);
            }

            userMapper.updateLoginAttempts(user.getUserId(), attempts, lockedUntil);
        }
    }

    @Override
    public void resetLoginAttempts(String username) {
        userMapper.resetLoginAttempts(username);
    }
}