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/api/container.go

@@ -0,0 +1,5 @@
+package api
+
+type ApiHandlers struct {
+	UserHandler *UserHandler
+}

backend/api/user.go

@@ -0,0 +1,97 @@
+// Package api 定义API接口层
+// 包含所有对外暴露的HTTP接口定义
+package api
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/smartflow/backend/model"
+	"github.com/smartflow/backend/respond"
+	"github.com/smartflow/backend/service"
+)
+
+type UserHandler struct {
+	// 伸出手：准备接住 Service
+	svc *service.UserService
+}
+
+// NewUserHandler：组装 Handler 的“工厂”
+func NewUserHandler(svc *service.UserService) *UserHandler {
+	return &UserHandler{
+		svc: svc, // 把传进来的 Service 揣进口袋里
+	}
+}
+
+// UserRegister 用户注册API
+// 处理用户注册请求
+func (api *UserHandler) UserRegister(c *gin.Context) {
+	var user model.UserRegisterRequest
+	err := c.ShouldBindJSON(&user)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, respond.WrongParamType)
+		return
+	}
+
+	retUser, err := api.svc.UserRegister(user)
+	if err != nil {
+		switch {
+		case errors.Is(err, respond.InvalidName), errors.Is(err, respond.MissingParam),
+			errors.Is(err, respond.ParamTooLong): //如果是无效ID或者缺少参数的错误
+			c.JSON(http.StatusBadRequest, err)
+			return
+		default:
+			c.JSON(http.StatusInternalServerError, respond.InternalError(err))
+			return
+		}
+	}
+
+	c.JSON(http.StatusOK, respond.OKWithData(respond.Ok, retUser))
+}
+
+func (api *UserHandler) UserLogin(c *gin.Context) {
+	var req model.UserLoginRequest
+	err := c.ShouldBindJSON(&req)
+	if err != nil {
+		c.JSON(http.StatusOK, respond.WrongParamType)
+		return
+	}
+	tokens, err := api.svc.UserLogin(&req)
+	if err != nil {
+		switch {
+		case errors.Is(err, respond.WrongName), errors.Is(err, respond.WrongPwd): //如果是无效ID或者缺少参数的错误
+			c.JSON(http.StatusBadRequest, err)
+			return
+		default:
+			c.JSON(http.StatusInternalServerError, respond.InternalError(err))
+			return
+		}
+	}
+	c.JSON(http.StatusOK, respond.OKWithData(respond.Ok, tokens))
+}
+
+func (api *UserHandler) RefreshTokenHandler(c *gin.Context) {
+	var requestBody struct {
+		RefreshToken string `json:"old_refresh_token"`
+	}
+	if err := c.ShouldBindJSON(&requestBody); err != nil {
+		c.JSON(http.StatusBadRequest, respond.WrongParamType)
+		return
+	}
+	if requestBody.RefreshToken == "" {
+		c.JSON(http.StatusBadRequest, respond.MissingParam)
+	}
+	tokens, err := api.svc.RefreshTokenHandler(requestBody.RefreshToken)
+	if err != nil {
+		switch {
+		case errors.Is(err, respond.InvalidRefreshToken), errors.Is(err, respond.InvalidClaims),
+			errors.Is(err, respond.InvalidTokenSingingMethod): //如果是无效刷新令牌或者无效claims或者无效签名方法
+			c.JSON(http.StatusBadRequest, err)
+			return
+		default:
+			c.JSON(http.StatusInternalServerError, respond.InternalError(err))
+		}
+	}
+	c.JSON(http.StatusOK, respond.OKWithData(respond.Ok, tokens))
+}