src/main/java/com/example/myproject/service/UserService.java

package com.example.myproject.service;
import cn.dev33.satoken.stp.StpUtil;
import com.example.myproject.entity.FriendRelation;
import com.example.myproject.entity.User;
import com.example.myproject.entity.Users;
import com.example.myproject.entity.UserInviteCode;
import com.example.myproject.repository.FriendRelationRepository;
import com.example.myproject.repository.UserRepository;
import com.example.myproject.repository.UserInviteCodeRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.time.LocalDateTime;
import java.util.*;

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private UserInviteCodeRepository userInviteCodeRepository;

    @Autowired
    private FriendRelationRepository friendRelationRepository;

    // 生成邀请码
    public Map<String, Object> generateInviteCode(Long userId) {
        // 获取用户信息
        Users user = userRepository.findById(userId).orElse(null);

        // 如果用户不存在，返回错误
        if (user == null) {
            Map<String, Object> errorResponse = new HashMap<>();
            errorResponse.put("status", "failure");
            errorResponse.put("message", "用户不存在");
            return errorResponse;
        }

        // 检查用户的邀请数量
        if (user.getInviteCount() <= 0) {
            Map<String, Object> errorResponse = new HashMap<>();
            errorResponse.put("status", "failure");
            errorResponse.put("message", "没有剩余的邀请码");
            return errorResponse;
        }

        // 生成唯一的邀请码
        String inviteCode = generateUniqueInviteCode();

        // 将邀请码保存到 `user_invite_code` 表
        UserInviteCode userInviteCode = new UserInviteCode();
        userInviteCode.setUserId(userId);
        userInviteCode.setInviteCode(inviteCode);
        userInviteCode.setCreatedAt(java.time.LocalDateTime.now());

        userInviteCodeRepository.save(userInviteCode);

        // 更新用户的 `invite_count`，减少1
        user.setInviteCount(user.getInviteCount() - 1);
        userRepository.save(user);

        // 返回成功信息
        Map<String, Object> response = new HashMap<>();
        response.put("status", "success");
        response.put("message", "邀请码生成成功");
        response.put("invite_code", inviteCode);

        return response;
    }

    // 生成唯一的邀请码，使用26个字母（大小写）
    private String generateUniqueInviteCode() {
        String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        StringBuilder inviteCode = new StringBuilder();

        Random random = new Random();
        for (int i = 0; i < 10; i++) {
            inviteCode.append(characters.charAt(random.nextInt(characters.length())));
        }

        return inviteCode.toString();
    }

    public String registerUser(String username, String email, String password, String role, String inviteCode) {
        // 检查邮箱是否已经注册
        Optional<Users> existingEmailUser = userRepository.findByEmail(email);
        if (existingEmailUser.isPresent()) {
            return "该邮箱已被注册";
        }

        // 检查用户名是否已经存在
        Optional<Users> existingUsernameUser = userRepository.findByUsername(username); // 需要根据用户名查询
        if (existingUsernameUser.isPresent()) {
            return "该用户名已被注册";
        }

        // 检查邀请码是否有效
        if (inviteCode == null || inviteCode.isEmpty()) {
            return "邀请码不能为空";
        }

        Optional<UserInviteCode> invite = userInviteCodeRepository.findByInviteCode(inviteCode);
        if (invite.isEmpty() || invite.get().getIsUsed()) {
            return "邀请码无效或已被使用";
        }

        // 设置默认等级为2（由于邀请码有效）
        Long level = 2L;

        // 设置默认头像 URL
        String avatarUrl = "https://example.com/default-avatar.jpg";  // 默认头像

        // 获取邀请码对应的用户ID
        UserInviteCode inviteEntity = invite.get();
        Long inviteUserId = inviteEntity.getUserId();

        // 创建新用户
        Users newUser = new Users();
        newUser.setUsername(username);
        newUser.setEmail(email);
        newUser.setPassword(password);
        newUser.setRole(role);
        newUser.setInviteCount(0);  // 初始邀请码数量为 0
        newUser.setLevel(level);
        newUser.setAvatarUrl(avatarUrl);  // 设置默认头像
        newUser.setRegistrationDate(new java.util.Date());  // 设置注册日期
        newUser.setCurrentExperience(0);  // 默认经验为 0
        newUser.setCurrentSeedingHours(0f);  // 默认做种时长为 0
        newUser.setRegistrationTime(new java.util.Date());  // 设置注册时间为当前时间

        // 保存用户信息
        userRepository.save(newUser);

        FriendRelation newFriendRelation  = new FriendRelation();
        newFriendRelation.setUserId(newUser.getUserId());
        newFriendRelation.setCreateTime(new Date());
        newFriendRelation.setFriendId(inviteUserId);

        FriendRelation newFriendRelations  = new FriendRelation();
        newFriendRelations.setUserId(inviteUserId);
        newFriendRelations.setCreateTime(new Date());
        newFriendRelations.setFriendId(newUser.getUserId());
        friendRelationRepository.save(newFriendRelation);
        friendRelationRepository.save(newFriendRelations);
        // 更新邀请码的使用状态
        inviteEntity.setIsUsed(true);
        userInviteCodeRepository.save(inviteEntity);

        return "用户注册成功";
    }


    public String loginUser(String username, String password) {
        // 检查用户是否存在
        Optional<Users> userOptional = userRepository.findByUsername(username);
        if (userOptional.isEmpty()) {
            return "用户名不存在";
        }

        Users user = userOptional.get();

        // 检查密码是否正确
        if (!user.getPassword().equals(password)) {
            return "密码错误";
        }
        StpUtil.login(user.getUserId());
        
        // 登录成功
        return "登录成功";
    }

    public String changePassword(Long userId, String oldPassword, String newPassword, String confirmPassword) {
        // 查找用户
        Users user = userRepository.findById(userId).orElse(null);

        if (user == null) {
            return "用户不存在";
        }

        // 检查旧密码是否正确
        if (!user.getPassword().equals(oldPassword)) {
            return "旧密码错误";
        }

        // 检查新密码和确认密码是否一致
        if (!newPassword.equals(confirmPassword)) {
            return "新密码与确认密码不一致";
        }

        // 更新密码
        user.setPassword(newPassword);
        userRepository.save(user);

        return "密码修改成功";
    }

    // 获取用户个人资料
    public Map<String, Object> getProfile(Long userId) {
        Optional<Users> userOptional = userRepository.findById(userId);

        // 如果用户不存在，返回null或者可以抛出异常
        if (userOptional.isEmpty()) {
            return null; // 可以返回 null 或者根据需要返回错误信息
        }

        Users user = userOptional.get();

        // 将需要的字段放入 Map 中
        Map<String, Object> profile = new LinkedHashMap<>();
        profile.put("avatarUrl", user.getAvatarUrl());
        profile.put("username", user.getUsername());
        profile.put("email", user.getEmail());
        profile.put("gender", user.getGender());
        profile.put("description", user.getDescription());
        profile.put("hobbies", user.getHobbies());
        profile.put("level", user.getLevel());
        profile.put("Experience", user.getCurrentExperience());
        profile.put("uploadCount", user.getUploadCount());
        profile.put("downloadCount", user.getDownloadCount());
        profile.put("shareRate", user.getShareRate());
        profile.put("registrationTime", user.getRegistrationTime());

        return profile;
    }

    // 修改用户个人资料
    public boolean editProfile(Long userId, String nickname, String gender, String description, String hobbies) {
        Optional<Users> userOptional = userRepository.findById(userId);

        // 如果用户不存在，返回false
        if (userOptional.isEmpty()) {
            return false; // 用户不存在
        }

        Users user = userOptional.get();

        // 更新用户资料，只有传入值才会更新对应字段
        if (nickname != null) {
            user.setUsername(nickname);
        }
        if (gender != null) {
            user.setGender(gender);
        }
        if (description != null) {
            user.setDescription(description);
        }
        if (hobbies != null) {
            user.setHobbies(hobbies);
        }

        // 保存更新后的用户信息
        userRepository.save(user);

        return true; // 更新成功
    }

    public Map<String, Object> calculateShareRate(Long userId) {
        // 查找用户
        Users user = userRepository.findById(userId).orElse(null);
        if (user == null) {
            return Map.of("status", "error", "message", "用户不存在");
        }

        // 获取上传量和下载量
        Float uploadCount = user.getUploadCount();
        Float downloadCount = user.getDownloadCount();

        // 计算分享率
        Float shareRate = 0f;  // 默认分享率为0
        if (downloadCount != 0) {
            shareRate = uploadCount / downloadCount;  // 分享率 = 上传量 / 下载量
        }

        // 更新用户的分享率
        user.setShareRate(shareRate);
        userRepository.save(user);

        // 返回结果
        return Map.of("status", "success", "message", "分享率计算成功", "shareRate", shareRate);
    }


    private static final String AVATAR_DIR = "uploads/avatarUrl/";

    public Map<String, Object> uploadUserAvatar(Long userId, MultipartFile file) {
        Users user = userRepository.findById(userId)
                .orElseThrow(() -> new RuntimeException("用户不存在"));

        try {
            String avatarUrl = saveAvatar(file, userId);
            user.setAvatarUrl(avatarUrl);
            userRepository.save(user);

            Map<String, Object> response = new HashMap<>();
            response.put("status", "success");
            response.put("message", "头像上传成功");
            response.put("userId", user.getUserId());
            response.put("avatarUrl", avatarUrl);
            return response;

        } catch (IOException e) {
            throw new RuntimeException("头像上传失败: " + e.getMessage());
        }
    }

    // 保存头像文件并返回可访问 URL
    public String saveAvatar(MultipartFile file, Long userId) throws IOException {
        String originalFilename = file.getOriginalFilename();
        String extension = originalFilename.substring(originalFilename.lastIndexOf('.'));
        String fileName = userId + extension;  // 以用户ID作为文件名
        Path path = Paths.get(AVATAR_DIR + fileName);
        Files.createDirectories(path.getParent());
        Files.write(path, file.getBytes());
        return "/" + AVATAR_DIR + fileName;  // 返回相对URL路径
    }



}