Version:0.0.1.dev.260202

feat: build core architecture & implement user auth modules 🚀
feat: 搭建核心架构并实现用户认证模块 🚀

Framework Migration: Switched from Hertz to Gin, providing a more idiomatic and lightweight web foundation. ⚡
框架迁移：从 Hertz 切换至 Gin，构建了更符合 Go 惯例且轻量级的 Web 基础。⚡

Architectural Overhaul: Refactored the 3-layer architecture from global-variable-based calls to Explicit Dependency Injection (DI) via New... factory functions. This significantly improves testability and decoupling. 🏗️
架构重构：将三层架构从基于“全局变量”的调用重构为通过 New... 工厂函数实现的显式依赖注入 (DI)。这大幅提升了代码的可测试性与解耦程度。🏗️

User Auth: Completed and tested Register, Login, and Token Refresh APIs with robust error handling and Bcrypt password hashing. 🔐
用户认证：完成了注册、登录与 Token 刷新接口并通过测试，包含健壮的错误处理与 Bcrypt 密码哈希加密。🔐

Config Management: Integrated Viper for centralized, environment-aware configuration management. ⚙️
配置管理：集成了 Viper，实现了中心化且具备环境感知能力的配置管理。⚙️

DevOps & Docs:
Added docker-compose.yml for seamless MySQL 8.0 & environment setup. 🐳
Updated README.md with corrections for mistakes in image quoting and formats. 📝
运维与文档：
新增 docker-compose.yml，实现 MySQL 8.0 环境的一键启动。🐳
更新 README.md，修改了一些图片引用和格式上小错误。📝

backend/service/user.go

@@ -0,0 +1,109 @@
+// Package service 业务逻辑层
+// 包含所有核心业务逻辑
+package service
+
+import (
+	"errors"
+
+	"github.com/golang-jwt/jwt/v4"
+	"github.com/smartflow/backend/auth"
+	"github.com/smartflow/backend/dao"
+	"github.com/smartflow/backend/model"
+	"github.com/smartflow/backend/respond"
+	"github.com/smartflow/backend/utils"
+	"gorm.io/gorm"
+)
+
+type UserService struct {
+	// 伸出手：准备接住 DAO
+	repo *dao.UserDAO
+}
+
+// NewUserService：组装 Service 的“工厂”
+func NewUserService(repo *dao.UserDAO) *UserService {
+	return &UserService{
+		repo: repo, // 把传进来的 DAO 揣进口袋里
+	}
+}
+
+func (sv *UserService) UserRegister(user model.UserRegisterRequest) (*model.UserRegisterResponse, error) {
+	//检查是否有空字段
+	if user.Username == "" || user.Password == "" ||
+		user.PhoneNumber == "" {
+		return nil, respond.MissingParam
+	}
+	// 检查字段长度是否超过90%
+	if len(user.Username) > 45 || len(user.Password) > 229 || len(user.PhoneNumber) > 18 {
+		return nil, respond.ParamTooLong
+	}
+	//检查用户名是否已存在
+	result, err := sv.repo.IfUsernameExists(user.Username)
+	if err != nil {
+		return nil, err
+	}
+	if result {
+		return nil, respond.InvalidName
+	}
+	hashedPwd, err := utils.HashPassword(user.Password) //调用utils层的方法
+	if err != nil {
+		return nil, err
+	}
+	user.Password = hashedPwd //将user的密码字段改为加密后的密码
+	newUser, err := sv.repo.Create(user.Username, user.PhoneNumber, user.Password)
+	if err != nil {
+		return nil, err
+	}
+	//返回注册成功的用户ID
+	return &model.UserRegisterResponse{ID: newUser.ID}, nil
+}
+
+func (sv *UserService) UserLogin(req *model.UserLoginRequest) (*model.Tokens, error) {
+	var tokens model.Tokens
+	hashedPwd, err := sv.repo.GetUserHashedPasswordByName(req.Username) //调用dao层的方法
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, respond.WrongName
+		}
+		return nil, err
+	}
+	result, err := utils.CompareHashPwdAndPwd(hashedPwd, req.Password) //比较密码是否匹配
+	if err != nil {                                                    //其他错误
+		return &tokens, err
+	} else if !result { //密码不匹配
+		return nil, respond.WrongPwd
+	}
+	id, err := sv.repo.GetUserIDByName(req.Username)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, respond.WrongName
+		}
+		return nil, err
+	}
+	tokens.AccessToken, tokens.RefreshToken, err = auth.GenerateTokens(id) //生成jwt key
+	if err != nil {                                                        //其他错误
+		return nil, err
+	}
+	return &tokens, nil
+}
+
+func (sv *UserService) RefreshTokenHandler(refreshToken string) (*model.Tokens, error) {
+	// 验证刷新令牌
+	token, err := auth.ValidateRefreshToken(refreshToken)
+	if err != nil || !token.Valid { // 刷新令牌无效
+		return nil, respond.InvalidRefreshToken
+	}
+
+	// 生成新的访问令牌和刷新令牌
+	if claims, ok := token.Claims.(jwt.MapClaims); ok {
+		userID := int(claims["user_id"].(float64))
+		newAccessToken, newRefreshToken, err := auth.GenerateTokens(userID)
+		if err != nil {
+			return nil, err
+		}
+
+		// 返回新的访问令牌和刷新令牌
+		return &model.Tokens{AccessToken: newAccessToken, RefreshToken: newRefreshToken}, nil
+	} else {
+		return nil, respond.InvalidClaims
+	}
+}