ARCHITECTURE.md

@@ -1,396 +0,0 @@
-# 后端架构设计规范
-
-## 1. 分层架构原则
-
-### 层级定义
-```
-Handler (控制器层) → Service (业务逻辑层) → Repository (数据访问层) → Infrastructure (基础设施层)
-```
-
-### 层级职责
-
-| 层级 | 职责 | 依赖关系 |
-|------|------|----------|
-| Handler | 接收HTTP请求、参数校验、调用Service、返回响应 | 仅依赖Service |
-| Service | 实现业务逻辑、事务管理、组合多个Repository | 仅依赖Repository接口 |
-| Repository | 数据CRUD操作、数据库事务管理 | 仅依赖Model和GORM |
-| Infrastructure | 缓存、消息队列、RPC等外部服务 | 被Service调用 |
-
-### 关键约束
-- **Handler禁止直接依赖Repository或直接操作数据库**
-- **Service禁止直接依赖`gorm.DB`，必须通过Repository间接操作**
-- **所有外部依赖通过接口抽象**
-
----
-
-## 2. Repository 层规范
-
-### 2.1 接口 + 私有实现模式
-
-所有Repository必须采用接口定义 + 私有实现结构体的模式：
-
-```go
-// ✅ 正确：接口 + 私有实现
-type UserRepository interface {
-    Create(user *model.User) error
-    GetByID(id string) (*model.User, error)
-}
-
-type userRepository struct {
-    db *gorm.DB
-}
-
-func NewUserRepository(db *gorm.DB) UserRepository {
-    return &userRepository{db: db}
-}
-
-func (r *userRepository) Create(user *model.User) error {
-    return r.db.Create(user).Error
-}
-```
-
-```go
-// ❌ 错误：直接暴露结构体指针
-type UserRepository struct {
-    db *gorm.DB
-}
-
-func NewUserRepository(db *gorm.DB) *UserRepository {
-    return &UserRepository{db: db}
-}
-```
-
-### 2.2 Repository方法设计原则
-
-- 方法签名中**使用接口类型而非指针**：`func (r *userRepository) GetByID(...) (*model.User, error)`
-- **避免在Repository层直接返回指针切片**，使用值切片更安全
-- **事务操作在Repository内部封装**，Service不应直接调用`db.Transaction()`
-
-### 2.3 新增Repository流程
-
-1. 在`repository/`目录下创建`xxx_repo.go`文件
-2. 定义`XxxRepository`接口，包含所有数据访问方法
-3. 创建私有实现结构体`xxxRepository`
-4. 创建构造函数`NewXxxRepository(db *gorm.DB) XxxRepository`
-5. 在`wire/repository.go`的`RepositorySet`中注册
-
----
-
-## 3. Service 层规范
-
-### 3.1 接口 + 私有实现模式
-
-```go
-// ✅ 正确
-type UserService interface {
-    CreateUser(ctx context.Context, req *dto.CreateUserRequest) (*model.User, error)
-    GetUserByID(ctx context.Context, id string) (*model.User, error)
-}
-
-type userService struct {
-    userRepo repository.UserRepository
-    // 其他Repo都使用接口类型
-}
-
-func NewUserService(userRepo repository.UserRepository) UserService {
-    return &userService{userRepo: userRepo}
-}
-```
-
-### 3.2 Service依赖管理
-
-- **所有Repository依赖必须使用接口类型**，禁止使用`*repository.XxxRepository`指针
-- **禁止在Service中直接持有`gorm.DB`**，如有数据库操作必须下沉到Repository
-- **如需事务支持**，在Repository中封装事务方法，Service调用封装好的方法
-
-### 3.3 Service间依赖
-
-- Service之间通过接口依赖，避免循环依赖
-- 如Service A需要调用Service B的方法，确保该方法在接口中定义
-
----
-
-## 4. Handler 层规范
-
-### 4.1 Handler只依赖Service
-
-```go
-// ✅ 正确
-type UserHandler struct {
-    userService service.UserService  // 仅依赖Service接口
-}
-
-func NewUserHandler(userService service.UserService) *UserHandler {
-    return &UserHandler{userService: userService}
-}
-```
-
-```go
-// ❌ 错误：直接依赖Repository或Cache
-type UserHandler struct {
-    userRepo    *repository.UserRepository  // 禁止
-    cache       cache.Cache               // 禁止
-}
-```
-
-### 4.2 参数和类型分离
-
-- **Query参数和Filter类型**应定义在`dto/`包中，而非`repository/`包
-- Handler负责将HTTP参数转换为DTO后传递给Service
-
----
-
-## 5. DTO/Filter 类型规范
-
-### 5.1 放置位置
-
-- **所有查询参数、过滤条件、分页参数**定义在`internal/dto/`目录下
-- **禁止在`repository/`包中定义供Handler使用的Filter类型**
-
-### 5.2 文件组织
-
-```
-internal/dto/
-├── filter.go          # 通用过滤条件（LogFilter, LoginFilter等）
-├── user_converter.go  # 用户相关转换
-└── ...
-```
-
-### 5.3 Filter类型定义示例
-
-```go
-// internal/dto/filter.go
-
-type LogFilter struct {
-    UserID     string
-    Operation  string
-    TargetType string
-    StartTime  string
-    EndTime    string
-}
-
-type PaginationParams struct {
-    Page     int
-    PageSize int
-}
-```
-
----
-
-## 6. Wire 依赖注入规范
-
-### 6.1 Provider函数设计
-
-```go
-// ✅ 正确：Provider返回接口类型
-func ProvideUserService(
-    userRepo repository.UserRepository,  // 接口类型
-    cacheBackend cache.Cache,
-) service.UserService {
-    return service.NewUserService(userRepo, cacheBackend)
-}
-
-// ❌ 错误：返回指针类型
-func ProvideUserService(userRepo *repository.UserRepository) *service.UserService
-```
-
-### 6.2 NewXxxService构造函数签名
-
-- **构造函数参数使用接口类型**
-- **返回值使用接口类型**
-
-```go
-// ✅ 正确
-func NewUserService(
-    userRepo repository.UserRepository,      // 接口
-    cache cache.Cache,
-) UserService {                             // 返回接口
-    return &userService{userRepo: userRepo}
-}
-```
-
-### 6.3 禁止的直接注入
-
-- **禁止在Handler的Provider中直接注入Repository和Cache**，应仅注入Service
-- **禁止在Service的Provider中直接注入`gorm.DB`**
-
----
-
-## 7. 事务管理规范
-
-### 7.1 事务边界在Repository层
-
-```go
-// ✅ 正确：事务封装在Repository内部
-func (r *userRepository) CreateUserWithProfile(user *model.User, profile *model.Profile) error {
-    return r.db.Transaction(func(tx *gorm.DB) error {
-        if err := tx.Create(user).Error; err != nil {
-            return err
-        }
-        profile.UserID = user.ID
-        return tx.Create(profile).Error
-    })
-}
-```
-
-### 7.2 Service调用事务方法
-
-```go
-// ✅ Service通过调用Repository的封装方法使用事务
-func (s *userService) CreateUser(ctx context.Context, req *dto.CreateUserRequest) error {
-    user := &model.User{Name: req.Name}
-    profile := &model.Profile{Bio: req.Bio}
-    return s.userRepo.CreateUserWithProfile(user, profile)
-}
-```
-
----
-
-## 8. 常见错误示例
-
-### 错误1：Handler直接依赖Repository
-
-```go
-// ❌ 错误
-type PostHandler struct {
-    postRepo *repository.PostRepository
-}
-
-// ✅ 正确
-type PostHandler struct {
-    postService service.PostService
-}
-```
-
-### 错误2：Service直接使用gorm.DB
-
-```go
-// ❌ 错误
-type postService struct {
-    db *gorm.DB
-}
-
-func (s *postService) CreatePost(post *model.Post) error {
-    return s.db.Create(post).Error
-}
-
-// ✅ 正确：使用Repository
-func (s *postService) CreatePost(post *model.Post) error {
-    return s.postRepo.Create(post)
-}
-```
-
-### 错误3：Repository返回指针类型
-
-```go
-// ❌ 错误
-func NewUserRepository(db *gorm.DB) *UserRepository {
-    return &UserRepository{db: db}
-}
-
-// ✅ 正确
-func NewUserRepository(db *gorm.DB) UserRepository {
-    return &userRepository{db: db}
-}
-```
-
-### 错误4：Filter类型放在repository包
-
-```go
-// ❌ 错误：repository包不应该被handler直接引用
-package repository
-type LogFilter struct {
-    UserID string
-}
-
-// ✅ 正确：放在dto包
-package dto
-type LogFilter struct {
-    UserID string
-}
-```
-
----
-
-## 9. 新功能开发 Checklist
-
-开发新功能时，确保满足以下规范：
-
-- [ ] **Repository定义**
-  - [ ] 接口 + 私有实现结构体
-  - [ ] 构造函数返回接口类型
-  - [ ] 方法参数使用值类型而非指针
-  - [ ] 在`wire/repository.go`中注册
-
-- [ ] **Service定义**
-  - [ ] 接口 + 私有实现结构体
-  - [ ] 所有Repository依赖使用接口类型
-  - [ ] 不直接持有`gorm.DB`
-  - [ ] 事务操作下沉到Repository
-
-- [ ] **Handler定义**
-  - [ ] 仅依赖Service接口
-  - [ ] 不直接依赖Repository或Cache
-  - [ ] Query/Filter参数使用dto包类型
-
-- [ ] **Wire Provider**
-  - [ ] 参数使用接口类型
-  - [ ] 返回值使用接口类型
-  - [ ] 不直接注入`gorm.DB`到Service
-
----
-
-## 10. 相关文件位置参考
-
-| 类别 | 目录 |
-|------|------|
-| Handler | `internal/handler/` |
-| Service | `internal/service/` |
-| Repository | `internal/repository/` |
-| DTO/Filter | `internal/dto/` |
-| Model | `internal/model/` |
-| Wire | `internal/wire/` |
-| Cache | `internal/cache/` |
-
----
-
-## 11. Wire 生成的代码规范
-
-### 11.1 禁止直接修改生成的文件
-
-以下文件由 Wire 工具自动生成，**禁止直接修改**：
-
-- `cmd/server/wire_gen.go`
-- `cmd/server/wire.go` 中的 Provider 函数签名由 Wire 维护
-
-如果需要修改这些文件：
-1. **修改源文件**（如 `wire.go` 中的结构）
-2. **运行 `wire` 命令**重新生成
-
-### 11.2 正确的修改流程
-
-```bash
-# 1. 修改 wire.go 或 wire/*.go
-# 2. 运行 wire 重新生成
-go run -mod=mod github.com/google/wire/cmd/wire ./cmd/server
-```
-
-### 11.3 Provider 依赖添加
-
-新增依赖时，必须同步修改：
-
-1. `wire/service.go` 中的 Provider 函数
-2. `wire/handler.go` 中的 Handler Provider 函数
-3. `cmd/server/wire.go` 中的 `ProvideRouter` 函数
-4. `wire/repository.go`（如需新增 Repository）
-5. 重新运行 `wire ./cmd/server` 生成 `wire_gen.go`
-
-### 11.4 生成文件识别
-
-```
-// Code generated by Wire. DO NOT EDIT.
-//go:generate go run -mod=mod github.com/google/wire/cmd/wire
-//go:build !wireinject
-```
-
-带以上标记的文件均为自动生成文件。

cmd/server/wire_gen.go

@@ -143,7 +143,10 @@ func InitializeApp() (*App, error) {
 	setupService := wire.ProvideSetupService(userRepository, roleRepository, casbinService, config)
 	setupHandler := wire.ProvideSetupHandler(setupService)
 	wsHandler := wire.ProvideWSHandler(hub, chatService, groupService, jwtService, callService, userRepository)
-	router := ProvideRouter(userRepository, userHandler, postHandler, commentHandler, messageHandler, notificationHandler, uploadHandler, jwtService, pushHandler, systemMessageHandler, groupHandler, stickerHandler, voteHandler, channelHandler, scheduleHandler, roleHandler, adminUserHandler, adminPostHandler, adminCommentHandler, adminGroupHandler, adminDashboardHandler, adminLogHandler, qrCodeHandler, materialHandler, callHandler, reportHandler, adminReportHandler, verificationHandler, adminVerificationHandler, adminProfileAuditHandler, setupHandler, logService, userActivityService, casbinService, wsHandler)
+	tradeRepository := repository.NewTradeRepository(db)
+	tradeService := wire.ProvideTradeService(tradeRepository)
+	tradeHandler := handler.NewTradeHandler(tradeService)
+	router := ProvideRouter(userRepository, userHandler, postHandler, commentHandler, messageHandler, notificationHandler, uploadHandler, jwtService, pushHandler, systemMessageHandler, groupHandler, stickerHandler, voteHandler, channelHandler, scheduleHandler, roleHandler, adminUserHandler, adminPostHandler, adminCommentHandler, adminGroupHandler, adminDashboardHandler, adminLogHandler, qrCodeHandler, materialHandler, callHandler, reportHandler, adminReportHandler, verificationHandler, adminVerificationHandler, adminProfileAuditHandler, setupHandler, tradeHandler, logService, userActivityService, casbinService, wsHandler)
 	hotRankWorker := wire.ProvideHotRankWorker(config, postRepository, channelRepository, cache)
 	app := NewApp(config, db, router, pushService, hotRankWorker, server, logger)
 	return app, nil
@@ -184,6 +187,7 @@ func ProvideRouter(
 	adminVerificationHandler *handler.AdminVerificationHandler,
 	adminProfileAuditHandler *handler.AdminProfileAuditHandler,
 	setupHandler *handler.SetupHandler,
+	tradeHandler *handler.TradeHandler,
 	logService *service.LogService,
 	activityService service.UserActivityService,
 	casbinService service.CasbinService,
@@ -221,6 +225,7 @@ func ProvideRouter(
 		adminVerificationHandler,
 		adminProfileAuditHandler,
 		setupHandler,
+		tradeHandler,
 		logService,
 		activityService,
 		casbinService,

internal/dto/trade_converter.go

@@ -0,0 +1,101 @@
+package dto
+
+import (
+	"with_you/internal/model"
+)
+
+func ConvertTradeImageToResponse(img *model.TradeImage) TradeImageResponse {
+	if img == nil {
+		return TradeImageResponse{}
+	}
+	return TradeImageResponse{
+		ID:              img.ID,
+		URL:             img.URL,
+		ThumbnailURL:    img.ThumbnailURL,
+		PreviewURL:      img.PreviewURL,
+		PreviewURLLarge: img.PreviewURLLarge,
+		Width:           img.Width,
+		Height:          img.Height,
+	}
+}
+
+func ConvertTradeImagesToResponse(images []model.TradeImage) []TradeImageResponse {
+	result := make([]TradeImageResponse, 0, len(images))
+	for i := range images {
+		result = append(result, ConvertTradeImageToResponse(&images[i]))
+	}
+	return result
+}
+
+func ConvertTradeItemToResponse(item *model.TradeItem, isFavorited bool) *TradeItemResponse {
+	if item == nil {
+		return nil
+	}
+	resp := &TradeItemResponse{
+		ID:             item.ID,
+		UserID:         item.UserID,
+		TradeType:      string(item.TradeType),
+		Category:       string(item.Category),
+		Title:          item.Title,
+		Content:        item.Content,
+		Price:          item.Price,
+		OriginalPrice:  item.OriginalPrice,
+		Condition:      item.Condition,
+		Location:       item.Location,
+		Status:         string(item.Status),
+		ViewsCount:     item.ViewsCount,
+		FavoritesCount: item.FavoritesCount,
+		IsFavorited:    isFavorited,
+		Images:         ConvertTradeImagesToResponse(item.Images),
+		CreatedAt:      item.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:      item.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+	}
+	if len(item.Segments) > 0 {
+		resp.Segments = item.Segments
+	}
+	if item.User != nil {
+		resp.Author = ConvertUserToResponse(item.User)
+	}
+	return resp
+}
+
+func ConvertTradeItemsToResponse(items []*model.TradeItem, favoriteMap map[string]bool) []*TradeItemResponse {
+	result := make([]*TradeItemResponse, 0, len(items))
+	for _, item := range items {
+		isFav := favoriteMap[item.ID]
+		result = append(result, ConvertTradeItemToResponse(item, isFav))
+	}
+	return result
+}
+
+func ConvertTradeItemToDetailResponse(item *model.TradeItem, isFavorited bool) *TradeItemDetailResponse {
+	if item == nil {
+		return nil
+	}
+	resp := &TradeItemDetailResponse{
+		ID:             item.ID,
+		UserID:         item.UserID,
+		TradeType:      string(item.TradeType),
+		Category:       string(item.Category),
+		Title:          item.Title,
+		Content:        item.Content,
+		Price:          item.Price,
+		OriginalPrice:  item.OriginalPrice,
+		Condition:      item.Condition,
+		Location:       item.Location,
+		Status:         string(item.Status),
+		ViewsCount:     item.ViewsCount,
+		FavoritesCount: item.FavoritesCount,
+		IsFavorited:    isFavorited,
+		Images:         ConvertTradeImagesToResponse(item.Images),
+		CreatedAt:      item.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:      item.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+	}
+	if len(item.Segments) > 0 {
+		resp.Segments = item.Segments
+	}
+	if item.User != nil {
+		resp.Author = ConvertUserToResponse(item.User)
+	}
+	return resp
+}

internal/dto/trade_dto.go

@@ -0,0 +1,100 @@
+package dto
+
+import (
+	"with_you/internal/model"
+)
+
+type TradeImageResponse struct {
+	ID              string `json:"id"`
+	URL             string `json:"url"`
+	ThumbnailURL    string `json:"thumbnail_url"`
+	PreviewURL      string `json:"preview_url"`
+	PreviewURLLarge string `json:"preview_url_large"`
+	Width           int    `json:"width"`
+	Height          int    `json:"height"`
+}
+
+type TradeItemResponse struct {
+	ID              string                `json:"id"`
+	UserID          string                `json:"user_id"`
+	TradeType       string                `json:"trade_type"`
+	Category        string                `json:"category"`
+	Title           string                `json:"title"`
+	Content         string                `json:"content"`
+	Segments        model.MessageSegments `json:"segments,omitempty"`
+	Images          []TradeImageResponse   `json:"images"`
+	Price           *float64              `json:"price,omitempty"`
+	OriginalPrice   *float64              `json:"original_price,omitempty"`
+	Condition       string                `json:"condition,omitempty"`
+	Location        string                `json:"location,omitempty"`
+	Status          string                `json:"status"`
+	ViewsCount      int                   `json:"views_count"`
+	FavoritesCount  int                   `json:"favorites_count"`
+	IsFavorited     bool                  `json:"is_favorited"`
+	Author          *UserResponse         `json:"author"`
+	CreatedAt       string                `json:"created_at"`
+	UpdatedAt       string                `json:"updated_at"`
+}
+
+type TradeItemDetailResponse struct {
+	ID              string                `json:"id"`
+	UserID          string                `json:"user_id"`
+	TradeType       string                `json:"trade_type"`
+	Category        string                `json:"category"`
+	Title           string                `json:"title"`
+	Content         string                `json:"content"`
+	Segments        model.MessageSegments `json:"segments,omitempty"`
+	Images          []TradeImageResponse   `json:"images"`
+	Price           *float64              `json:"price,omitempty"`
+	OriginalPrice   *float64              `json:"original_price,omitempty"`
+	Condition       string                `json:"condition,omitempty"`
+	Location        string                `json:"location,omitempty"`
+	Status          string                `json:"status"`
+	ViewsCount      int                   `json:"views_count"`
+	FavoritesCount  int                   `json:"favorites_count"`
+	IsFavorited     bool                  `json:"is_favorited"`
+	Author          *UserResponse         `json:"author"`
+	CreatedAt       string                `json:"created_at"`
+	UpdatedAt       string                `json:"updated_at"`
+}
+
+type CreateTradeItemRequest struct {
+	TradeType     string                `json:"trade_type" binding:"required,oneof=sell buy"`
+	Category      string                `json:"category" binding:"required,oneof=digital book clothing daily cosmetics sport ticket other"`
+	Title         string                `json:"title" binding:"required,max=100"`
+	Content       string                `json:"content"`
+	Segments      model.MessageSegments `json:"segments"`
+	Images        []string              `json:"images"`
+	Price         *float64              `json:"price"`
+	OriginalPrice  *float64              `json:"original_price"`
+	Condition     string                `json:"condition" binding:"omitempty,oneof=brand_new like_new lightly_used well_used"`
+	Location      string                `json:"location" binding:"omitempty,max=100"`
+}
+
+type UpdateTradeItemRequest struct {
+	TradeType    *string               `json:"trade_type" binding:"omitempty,oneof=sell buy"`
+	Category     *string               `json:"category" binding:"omitempty,oneof=digital book clothing daily cosmetics sport ticket other"`
+	Title        *string               `json:"title" binding:"omitempty,max=100"`
+	Content      *string               `json:"content"`
+	Segments     model.MessageSegments `json:"segments"`
+	Images       []string              `json:"images"`
+	Price        *float64              `json:"price"`
+	OriginalPrice *float64              `json:"original_price"`
+	Condition    *string               `json:"condition" binding:"omitempty,oneof=brand_new like_new lightly_used well_used"`
+	Location     *string               `json:"location" binding:"omitempty,max=100"`
+}
+
+type UpdateTradeItemStatusRequest struct {
+	Status string `json:"status" binding:"required,oneof=active sold bought offline"`
+}
+
+type TradeCursorPageResponse struct {
+	Items      []*TradeItemResponse `json:"list"`
+	NextCursor string               `json:"next_cursor,omitempty"`
+	PrevCursor string               `json:"prev_cursor,omitempty"`
+	HasMore    bool                 `json:"has_more"`
+}
+
+type TradeFavoriteResponse struct {
+	Favorited bool `json:"favorited"`
+}

internal/handler/trade_handler.go

@@ -0,0 +1,220 @@
+package handler
+
+import (
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+
+	"with_you/internal/dto"
+	"with_you/internal/model"
+	"with_you/internal/pkg/response"
+	"with_you/internal/service"
+)
+
+type TradeHandler struct {
+	tradeService service.TradeService
+}
+
+func NewTradeHandler(tradeService service.TradeService) *TradeHandler {
+	return &TradeHandler{tradeService: tradeService}
+}
+
+func (h *TradeHandler) List(c *gin.Context) {
+	currentUserID := c.GetString("user_id")
+	if currentUserID == "" {
+		currentUserID = ""
+	}
+
+	var tradeType *model.TradeType
+	if v := c.Query("trade_type"); v != "" {
+		t := model.TradeType(v)
+		tradeType = &t
+	}
+
+	var category *model.TradeCategory
+	if v := c.Query("category"); v != "" {
+		cat := model.TradeCategory(v)
+		category = &cat
+	}
+
+	cursorStr := c.Query("cursor")
+	pageSize := 20
+	if v := c.Query("page_size"); v != "" {
+		if ps, err := strconv.Atoi(v); err == nil && ps > 0 && ps <= 100 {
+			pageSize = ps
+		}
+	}
+
+	keyword := c.Query("keyword")
+
+	var currentUserIDPtr *string
+	if currentUserID != "" {
+		currentUserIDPtr = &currentUserID
+	}
+
+	var resp *dto.TradeCursorPageResponse
+	var err error
+	if keyword != "" {
+		resp, err = h.tradeService.Search(c.Request.Context(), keyword, tradeType, category, cursorStr, pageSize, currentUserIDPtr)
+	} else {
+		resp, err = h.tradeService.List(c.Request.Context(), tradeType, category, cursorStr, pageSize, currentUserIDPtr)
+	}
+	if err != nil {
+		response.HandleError(c, err, "获取交易列表失败")
+		return
+	}
+	response.Success(c, resp)
+}
+
+func (h *TradeHandler) GetByID(c *gin.Context) {
+	id := c.Param("id")
+	currentUserID := c.GetString("user_id")
+
+	var currentUserIDPtr *string
+	if currentUserID != "" {
+		currentUserIDPtr = &currentUserID
+	}
+
+	resp, err := h.tradeService.GetByID(c.Request.Context(), id, currentUserIDPtr)
+	if err != nil {
+		response.HandleError(c, err, "获取交易详情失败")
+		return
+	}
+	response.Success(c, resp)
+}
+
+func (h *TradeHandler) Create(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	var req dto.CreateTradeItemRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+
+	item, err := h.tradeService.Create(c.Request.Context(), userID, req)
+	if err != nil {
+		response.HandleError(c, err, "创建交易失败")
+		return
+	}
+
+	var currentUserIDPtr *string
+	if userID != "" {
+		currentUserIDPtr = &userID
+	}
+	detail, err := h.tradeService.GetByID(c.Request.Context(), item.ID, currentUserIDPtr)
+	if err != nil {
+		response.Success(c, item)
+		return
+	}
+	response.Success(c, detail)
+}
+
+func (h *TradeHandler) Update(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	id := c.Param("id")
+
+	var req dto.UpdateTradeItemRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+
+	if err := h.tradeService.Update(c.Request.Context(), userID, id, req); err != nil {
+		response.HandleError(c, err, "更新交易失败")
+		return
+	}
+
+	var currentUserIDPtr *string
+	if userID != "" {
+		currentUserIDPtr = &userID
+	}
+	detail, err := h.tradeService.GetByID(c.Request.Context(), id, currentUserIDPtr)
+	if err != nil {
+		response.Success(c, nil)
+		return
+	}
+	response.Success(c, detail)
+}
+
+func (h *TradeHandler) Delete(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	id := c.Param("id")
+	if err := h.tradeService.Delete(c.Request.Context(), userID, id); err != nil {
+		response.HandleError(c, err, "删除交易失败")
+		return
+	}
+	response.Success(c, nil)
+}
+
+func (h *TradeHandler) UpdateStatus(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	id := c.Param("id")
+
+	var req dto.UpdateTradeItemStatusRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+
+	if err := h.tradeService.UpdateStatus(c.Request.Context(), userID, id, model.TradeItemStatus(req.Status)); err != nil {
+		response.HandleError(c, err, "更新交易状态失败")
+		return
+	}
+	response.Success(c, nil)
+}
+
+func (h *TradeHandler) RecordView(c *gin.Context) {
+	id := c.Param("id")
+	_ = h.tradeService.RecordView(c.Request.Context(), id)
+	response.Success(c, nil)
+}
+
+func (h *TradeHandler) Favorite(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	id := c.Param("id")
+	if err := h.tradeService.Favorite(c.Request.Context(), userID, id); err != nil {
+		response.HandleError(c, err, "收藏失败")
+		return
+	}
+	response.Success(c, dto.TradeFavoriteResponse{Favorited: true})
+}
+
+func (h *TradeHandler) Unfavorite(c *gin.Context) {
+	userID := c.GetString("user_id")
+	if userID == "" {
+		response.Unauthorized(c, "请先登录")
+		return
+	}
+
+	id := c.Param("id")
+	if err := h.tradeService.Unfavorite(c.Request.Context(), userID, id); err != nil {
+		response.HandleError(c, err, "取消收藏失败")
+		return
+	}
+	response.Success(c, dto.TradeFavoriteResponse{Favorited: false})
+}

internal/model/init.go

@@ -179,6 +179,11 @@ func autoMigrate(db *gorm.DB) error {
 
 		// 帖子内链引用关系
 		&PostReference{},
+
+		// 二手交易相关
+		&TradeItem{},
+		&TradeImage{},
+		&TradeFavorite{},
 	)
 	if err != nil {
 		return err

internal/model/trade.go

@@ -0,0 +1,112 @@
+package model
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+type TradeType string
+
+const (
+	TradeTypeSell TradeType = "sell"
+	TradeTypeBuy  TradeType = "buy"
+)
+
+type TradeCategory string
+
+const (
+	TradeCategoryDigital   TradeCategory = "digital"
+	TradeCategoryBook      TradeCategory = "book"
+	TradeCategoryClothing  TradeCategory = "clothing"
+	TradeCategoryDaily     TradeCategory = "daily"
+	TradeCategoryCosmetics TradeCategory = "cosmetics"
+	TradeCategorySport     TradeCategory = "sport"
+	TradeCategoryTicket    TradeCategory = "ticket"
+	TradeCategoryOther     TradeCategory = "other"
+)
+
+type TradeItemStatus string
+
+const (
+	TradeItemActive  TradeItemStatus = "active"
+	TradeItemSold    TradeItemStatus = "sold"
+	TradeItemBought  TradeItemStatus = "bought"
+	TradeItemOffline TradeItemStatus = "offline"
+)
+
+type TradeItem struct {
+	ID             string          `json:"id" gorm:"type:varchar(36);primaryKey"`
+	UserID         string          `json:"user_id" gorm:"type:varchar(36);index;not null"`
+	TradeType      TradeType       `json:"trade_type" gorm:"type:varchar(10);not null;index"`
+	Category       TradeCategory   `json:"category" gorm:"type:varchar(20);not null;index"`
+	Title          string          `json:"title" gorm:"type:varchar(100);not null"`
+	Content        string          `json:"content" gorm:"type:text"`
+	Segments       MessageSegments `json:"segments,omitempty" gorm:"type:text"`
+	User           *User           `json:"user,omitempty" gorm:"foreignKey:UserID"`
+	Images         []TradeImage    `json:"images" gorm:"foreignKey:TradeItemID"`
+	Price          *float64        `json:"price,omitempty" gorm:"type:decimal(10,2)"`
+	OriginalPrice  *float64        `json:"original_price,omitempty" gorm:"type:decimal(10,2)"`
+	Condition      string          `json:"condition,omitempty" gorm:"type:varchar(20)"`
+	Location       string          `json:"location,omitempty" gorm:"type:varchar(100)"`
+	Status         TradeItemStatus `json:"status" gorm:"type:varchar(10);not null;default:'active';index"`
+	ViewsCount     int             `json:"views_count" gorm:"default:0"`
+	FavoritesCount int             `json:"favorites_count" gorm:"default:0"`
+	DeletedAt      gorm.DeletedAt  `json:"-" gorm:"index"`
+	CreatedAt      time.Time       `json:"created_at" gorm:"autoCreateTime;index"`
+	UpdatedAt      time.Time       `json:"updated_at" gorm:"autoUpdateTime:false"`
+}
+
+func (t *TradeItem) BeforeCreate(tx *gorm.DB) error {
+	if t.ID == "" {
+		t.ID = uuid.New().String()
+	}
+	return nil
+}
+
+func (TradeItem) TableName() string {
+	return "trade_items"
+}
+
+type TradeImage struct {
+	ID              string    `json:"id" gorm:"type:varchar(36);primaryKey"`
+	TradeItemID     string    `json:"trade_item_id" gorm:"type:varchar(36);not null;index"`
+	URL             string    `json:"url" gorm:"type:text;not null"`
+	ThumbnailURL    string    `json:"thumbnail_url" gorm:"type:text"`
+	PreviewURL      string    `json:"preview_url" gorm:"type:text"`
+	PreviewURLLarge string    `json:"preview_url_large" gorm:"type:text"`
+	Width           int       `json:"width" gorm:"default:0"`
+	Height          int       `json:"height" gorm:"default:0"`
+	SortOrder       int       `json:"sort_order" gorm:"default:0"`
+	CreatedAt       time.Time `json:"created_at" gorm:"autoCreateTime"`
+}
+
+func (ti *TradeImage) BeforeCreate(tx *gorm.DB) error {
+	if ti.ID == "" {
+		ti.ID = uuid.New().String()
+	}
+	return nil
+}
+
+func (TradeImage) TableName() string {
+	return "trade_images"
+}
+
+type TradeFavorite struct {
+	ID          string    `json:"id" gorm:"type:varchar(36);primaryKey"`
+	TradeItemID string    `json:"trade_item_id" gorm:"type:varchar(36);not null;index;uniqueIndex:idx_trade_fav_item_user,priority:1"`
+	UserID      string    `json:"user_id" gorm:"type:varchar(36);not null;index;uniqueIndex:idx_trade_fav_item_user,priority:2"`
+	CreatedAt   time.Time `json:"created_at" gorm:"autoCreateTime"`
+}
+
+func (f *TradeFavorite) BeforeCreate(tx *gorm.DB) error {
+	if f.ID == "" {
+		f.ID = uuid.New().String()
+	}
+	return nil
+}
+
+func (TradeFavorite) TableName() string {
+	return "trade_favorites"
+}

internal/repository/trade_repo.go

@@ -0,0 +1,325 @@
+package repository
+
+import (
+	"context"
+
+	"with_you/internal/model"
+	"with_you/internal/pkg/cursor"
+
+	"gorm.io/gorm"
+)
+
+type TradeRepository interface {
+	Create(ctx context.Context, item *model.TradeItem, imageUrls []string) error
+	GetByID(ctx context.Context, id string) (*model.TradeItem, error)
+	Update(ctx context.Context, item *model.TradeItem) error
+	UpdateWithImages(ctx context.Context, item *model.TradeItem, imageUrls *[]string) error
+	Delete(ctx context.Context, id string) error
+	UpdateStatus(ctx context.Context, id string, status model.TradeItemStatus) error
+	ListByCursor(ctx context.Context, tradeType *model.TradeType, category *model.TradeCategory, status *model.TradeItemStatus, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error)
+	SearchByCursor(ctx context.Context, keyword string, tradeType *model.TradeType, category *model.TradeCategory, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error)
+	ListByUserByCursor(ctx context.Context, userID string, status *model.TradeItemStatus, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error)
+	IncrementViews(ctx context.Context, id string) error
+	IncrementFavorites(ctx context.Context, id string) error
+	DecrementFavorites(ctx context.Context, id string) error
+
+	CreateFavorite(ctx context.Context, tradeItemID, userID string) error
+	DeleteFavorite(ctx context.Context, tradeItemID, userID string) error
+	IsFavorited(ctx context.Context, tradeItemID, userID string) (bool, error)
+	IsFavoritedBatch(ctx context.Context, tradeItemIDs []string, userID string) (map[string]bool, error)
+}
+
+type tradeRepository struct {
+	db *gorm.DB
+}
+
+func NewTradeRepository(db *gorm.DB) TradeRepository {
+	return &tradeRepository{db: db}
+}
+
+func (r *tradeRepository) getDB(ctx context.Context) *gorm.DB {
+	if tx := GetTxFromContext(ctx); tx != nil {
+		return tx
+	}
+	return r.db
+}
+
+func (r *tradeRepository) Create(ctx context.Context, item *model.TradeItem, imageUrls []string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Create(item).Error; err != nil {
+			return err
+		}
+		for i, url := range imageUrls {
+			img := model.TradeImage{
+				TradeItemID: item.ID,
+				URL:          url,
+				SortOrder:    i,
+			}
+			if err := tx.Create(&img).Error; err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}
+
+func (r *tradeRepository) GetByID(ctx context.Context, id string) (*model.TradeItem, error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	var item model.TradeItem
+	if err := db.Preload("User").Preload("Images", func(db *gorm.DB) *gorm.DB {
+		return db.Order("sort_order ASC")
+	}).First(&item, "id = ?", id).Error; err != nil {
+		return nil, err
+	}
+	return &item, nil
+}
+
+func (r *tradeRepository) Update(ctx context.Context, item *model.TradeItem) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Save(item).Error
+}
+
+func (r *tradeRepository) UpdateWithImages(ctx context.Context, item *model.TradeItem, imageUrls *[]string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Save(item).Error; err != nil {
+			return err
+		}
+		if imageUrls != nil {
+			if err := tx.Where("trade_item_id = ?", item.ID).Delete(&model.TradeImage{}).Error; err != nil {
+				return err
+			}
+			for i, url := range *imageUrls {
+				img := model.TradeImage{
+					TradeItemID: item.ID,
+					URL:          url,
+					SortOrder:    i,
+				}
+				if err := tx.Create(&img).Error; err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+}
+
+func (r *tradeRepository) Delete(ctx context.Context, id string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Where("trade_item_id = ?", id).Delete(&model.TradeImage{}).Error; err != nil {
+			return err
+		}
+		if err := tx.Where("trade_item_id = ?", id).Delete(&model.TradeFavorite{}).Error; err != nil {
+			return err
+		}
+		return tx.Delete(&model.TradeItem{}, "id = ?", id).Error
+	})
+}
+
+func (r *tradeRepository) UpdateStatus(ctx context.Context, id string, status model.TradeItemStatus) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Model(&model.TradeItem{}).Where("id = ?", id).Update("status", status).Error
+}
+
+func (r *tradeRepository) ListByCursor(ctx context.Context, tradeType *model.TradeType, category *model.TradeCategory, status *model.TradeItemStatus, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	query := db.Model(&model.TradeItem{})
+
+	if tradeType != nil {
+		query = query.Where("trade_type = ?", *tradeType)
+	}
+	if category != nil {
+		query = query.Where("category = ?", *category)
+	}
+	defaultStatus := model.TradeItemActive
+	if status != nil {
+		defaultStatus = *status
+	}
+	query = query.Where("status = ?", defaultStatus)
+
+	builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).
+		WithCursor(req.Cursor, req.Direction).
+		WithPageSize(req.PageSize)
+
+	if builder.Error() != nil {
+		return cursor.NewCursorPageResult([]*model.TradeItem{}, "", "", false), nil
+	}
+
+	var items []*model.TradeItem
+	q := builder.Build().Preload("User").Preload("Images", func(db *gorm.DB) *gorm.DB {
+		return db.Order("sort_order ASC")
+	})
+	if err := q.Find(&items).Error; err != nil {
+		return nil, err
+	}
+
+	pageSize := builder.GetPageSize()
+	hasMore := cursor.HasMore(len(items), pageSize)
+	if hasMore {
+		items = items[:pageSize]
+	}
+
+	var nextCursor, prevCursor string
+	if len(items) > 0 {
+		if hasMore {
+			last := items[len(items)-1]
+			nextCursor = cursor.NewCursor(cursor.FormatTime(last.CreatedAt), last.ID, cursor.SortByCreatedAtDesc).Encode()
+		}
+		first := items[0]
+		prevCursor = cursor.NewCursor(cursor.FormatTime(first.CreatedAt), first.ID, cursor.SortByCreatedAtDesc).Encode()
+	}
+
+	return cursor.NewCursorPageResult(items, nextCursor, prevCursor, hasMore), nil
+}
+
+func (r *tradeRepository) SearchByCursor(ctx context.Context, keyword string, tradeType *model.TradeType, category *model.TradeCategory, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	query := db.Model(&model.TradeItem{}).Where("status = ?", model.TradeItemActive)
+
+	if tradeType != nil {
+		query = query.Where("trade_type = ?", *tradeType)
+	}
+	if category != nil {
+		query = query.Where("category = ?", *category)
+	}
+	if keyword != "" {
+		searchPattern := "%" + keyword + "%"
+		query = query.Where("title LIKE ? OR content LIKE ?", searchPattern, searchPattern)
+	}
+
+	builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).
+		WithCursor(req.Cursor, req.Direction).
+		WithPageSize(req.PageSize)
+
+	if builder.Error() != nil {
+		return cursor.NewCursorPageResult([]*model.TradeItem{}, "", "", false), nil
+	}
+
+	var items []*model.TradeItem
+	q := builder.Build().Preload("User").Preload("Images", func(db *gorm.DB) *gorm.DB {
+		return db.Order("sort_order ASC")
+	})
+	if err := q.Find(&items).Error; err != nil {
+		return nil, err
+	}
+
+	pageSize := builder.GetPageSize()
+	hasMore := cursor.HasMore(len(items), pageSize)
+	if hasMore {
+		items = items[:pageSize]
+	}
+
+	var nextCursor, prevCursor string
+	if len(items) > 0 {
+		if hasMore {
+			last := items[len(items)-1]
+			nextCursor = cursor.NewCursor(cursor.FormatTime(last.CreatedAt), last.ID, cursor.SortByCreatedAtDesc).Encode()
+		}
+		first := items[0]
+		prevCursor = cursor.NewCursor(cursor.FormatTime(first.CreatedAt), first.ID, cursor.SortByCreatedAtDesc).Encode()
+	}
+
+	return cursor.NewCursorPageResult(items, nextCursor, prevCursor, hasMore), nil
+}
+
+func (r *tradeRepository) ListByUserByCursor(ctx context.Context, userID string, status *model.TradeItemStatus, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.TradeItem], error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	query := db.Model(&model.TradeItem{}).Where("user_id = ?", userID)
+
+	if status != nil {
+		query = query.Where("status = ?", *status)
+	}
+
+	builder := cursor.NewBuilder(query, cursor.SortByCreatedAtDesc).
+		WithCursor(req.Cursor, req.Direction).
+		WithPageSize(req.PageSize)
+
+	if builder.Error() != nil {
+		return cursor.NewCursorPageResult([]*model.TradeItem{}, "", "", false), nil
+	}
+
+	var items []*model.TradeItem
+	q := builder.Build().Preload("User").Preload("Images", func(db *gorm.DB) *gorm.DB {
+		return db.Order("sort_order ASC")
+	})
+	if err := q.Find(&items).Error; err != nil {
+		return nil, err
+	}
+
+	pageSize := builder.GetPageSize()
+	hasMore := cursor.HasMore(len(items), pageSize)
+	if hasMore {
+		items = items[:pageSize]
+	}
+
+	var nextCursor, prevCursor string
+	if len(items) > 0 {
+		if hasMore {
+			last := items[len(items)-1]
+			nextCursor = cursor.NewCursor(cursor.FormatTime(last.CreatedAt), last.ID, cursor.SortByCreatedAtDesc).Encode()
+		}
+		first := items[0]
+		prevCursor = cursor.NewCursor(cursor.FormatTime(first.CreatedAt), first.ID, cursor.SortByCreatedAtDesc).Encode()
+	}
+
+	return cursor.NewCursorPageResult(items, nextCursor, prevCursor, hasMore), nil
+}
+
+func (r *tradeRepository) IncrementViews(ctx context.Context, id string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Model(&model.TradeItem{}).Where("id = ?", id).UpdateColumn("views_count", gorm.Expr("views_count + 1")).Error
+}
+
+func (r *tradeRepository) IncrementFavorites(ctx context.Context, id string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Model(&model.TradeItem{}).Where("id = ?", id).UpdateColumn("favorites_count", gorm.Expr("favorites_count + 1")).Error
+}
+
+func (r *tradeRepository) DecrementFavorites(ctx context.Context, id string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Model(&model.TradeItem{}).Where("id = ? AND favorites_count > 0", id).UpdateColumn("favorites_count", gorm.Expr("favorites_count - 1")).Error
+}
+
+func (r *tradeRepository) CreateFavorite(ctx context.Context, tradeItemID, userID string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	fav := model.TradeFavorite{
+		TradeItemID: tradeItemID,
+		UserID:      userID,
+	}
+	return db.Create(&fav).Error
+}
+
+func (r *tradeRepository) DeleteFavorite(ctx context.Context, tradeItemID, userID string) error {
+	db := r.getDB(ctx).WithContext(ctx)
+	return db.Where("trade_item_id = ? AND user_id = ?", tradeItemID, userID).Delete(&model.TradeFavorite{}).Error
+}
+
+func (r *tradeRepository) IsFavorited(ctx context.Context, tradeItemID, userID string) (bool, error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	var count int64
+	if err := db.Model(&model.TradeFavorite{}).Where("trade_item_id = ? AND user_id = ?", tradeItemID, userID).Count(&count).Error; err != nil {
+		return false, err
+	}
+	return count > 0, nil
+}
+
+func (r *tradeRepository) IsFavoritedBatch(ctx context.Context, tradeItemIDs []string, userID string) (map[string]bool, error) {
+	db := r.getDB(ctx).WithContext(ctx)
+	result := make(map[string]bool, len(tradeItemIDs))
+	if len(tradeItemIDs) == 0 {
+		return result, nil
+	}
+	for _, id := range tradeItemIDs {
+		result[id] = false
+	}
+	var favorites []model.TradeFavorite
+	if err := db.Where("trade_item_id IN ? AND user_id = ?", tradeItemIDs, userID).Find(&favorites).Error; err != nil {
+		return nil, err
+	}
+	for _, fav := range favorites {
+		result[fav.TradeItemID] = true
+	}
+	return result, nil
+}

internal/router/router.go

@@ -43,6 +43,7 @@ type Router struct {
 	adminVerificationHandler *handler.AdminVerificationHandler
 	adminProfileAuditHandler *handler.AdminProfileAuditHandler
 	setupHandler            *handler.SetupHandler
+	tradeHandler            *handler.TradeHandler
 	wsHandler                *handler.WSHandler
 	logService               *service.LogService
 	jwtService               *service.JWTService
@@ -81,8 +82,9 @@ func New(
 	verificationHandler *handler.VerificationHandler,
 	adminVerificationHandler *handler.AdminVerificationHandler,
 	adminProfileAuditHandler *handler.AdminProfileAuditHandler,
-	setupHandler *handler.SetupHandler,
-	logService *service.LogService,
+	setupHandler            *handler.SetupHandler,
+	tradeHandler            *handler.TradeHandler,
+	logService               *service.LogService,
 	activityService service.UserActivityService,
 	casbinService service.CasbinService,
 	wsHandler *handler.WSHandler,
@@ -124,6 +126,7 @@ func New(
 		adminVerificationHandler: adminVerificationHandler,
 		adminProfileAuditHandler: adminProfileAuditHandler,
 		setupHandler:             setupHandler,
+		tradeHandler:             tradeHandler,
 		logService:               logService,
 		jwtService:               jwtService,
 		casbinService:            casbinService,
@@ -311,6 +314,22 @@ func (r *Router) setupRoutes() {
 			}
 		}
 
+		// 二手交易路由
+		if r.tradeHandler != nil {
+			trade := v1.Group("/trade")
+			{
+				trade.GET("", middleware.OptionalAuth(r.jwtService), r.tradeHandler.List)
+				trade.GET("/:id", middleware.OptionalAuth(r.jwtService), r.tradeHandler.GetByID)
+				trade.POST("", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.Create)
+				trade.PUT("/:id", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.Update)
+				trade.DELETE("/:id", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.Delete)
+				trade.PUT("/:id/status", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.UpdateStatus)
+				trade.POST("/:id/view", middleware.OptionalAuth(r.jwtService), r.tradeHandler.RecordView)
+				trade.POST("/:id/favorite", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.Favorite)
+				trade.DELETE("/:id/favorite", authMiddleware, middleware.RequireVerified(r.userRepo), r.tradeHandler.Unfavorite)
+			}
+		}
+
 		// 课表路由
 		if r.scheduleHandler != nil {
 			schedule := v1.Group("/schedule")

internal/service/trade_service.go

@@ -0,0 +1,230 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	"with_you/internal/dto"
+	"with_you/internal/model"
+	"with_you/internal/pkg/cursor"
+	"with_you/internal/repository"
+
+	"gorm.io/gorm"
+)
+
+type TradeService interface {
+	Create(ctx context.Context, userID string, req dto.CreateTradeItemRequest) (*model.TradeItem, error)
+	GetByID(ctx context.Context, id string, currentUserID *string) (*dto.TradeItemDetailResponse, error)
+	Update(ctx context.Context, userID string, id string, req dto.UpdateTradeItemRequest) error
+	Delete(ctx context.Context, userID string, id string) error
+	UpdateStatus(ctx context.Context, userID string, id string, status model.TradeItemStatus) error
+	List(ctx context.Context, tradeType *model.TradeType, category *model.TradeCategory, cursorStr string, pageSize int, currentUserID *string) (*dto.TradeCursorPageResponse, error)
+	Search(ctx context.Context, keyword string, tradeType *model.TradeType, category *model.TradeCategory, cursorStr string, pageSize int, currentUserID *string) (*dto.TradeCursorPageResponse, error)
+	RecordView(ctx context.Context, id string) error
+	Favorite(ctx context.Context, userID string, id string) error
+	Unfavorite(ctx context.Context, userID string, id string) error
+}
+
+type tradeService struct {
+	tradeRepo repository.TradeRepository
+}
+
+func NewTradeService(tradeRepo repository.TradeRepository) TradeService {
+	return &tradeService{tradeRepo: tradeRepo}
+}
+
+func (s *tradeService) Create(ctx context.Context, userID string, req dto.CreateTradeItemRequest) (*model.TradeItem, error) {
+	item := &model.TradeItem{
+		UserID:     userID,
+		TradeType:  model.TradeType(req.TradeType),
+		Category:   model.TradeCategory(req.Category),
+		Title:      req.Title,
+		Content:    req.Content,
+		Segments:   req.Segments,
+		Price:      req.Price,
+		OriginalPrice: req.OriginalPrice,
+		Condition:  req.Condition,
+		Location:   req.Location,
+		Status:     model.TradeItemActive,
+	}
+	if item.Content == "" {
+		item.Content = item.Title
+	}
+
+	images := req.Images
+	if images == nil {
+		images = []string{}
+	}
+	if err := s.tradeRepo.Create(ctx, item, images); err != nil {
+		return nil, fmt.Errorf("create trade item: %w", err)
+	}
+	return item, nil
+}
+
+func (s *tradeService) GetByID(ctx context.Context, id string, currentUserID *string) (*dto.TradeItemDetailResponse, error) {
+	item, err := s.tradeRepo.GetByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, fmt.Errorf("trade item not found")
+		}
+		return nil, err
+	}
+
+	isFavorited := false
+	if currentUserID != nil {
+		fav, err := s.tradeRepo.IsFavorited(ctx, id, *currentUserID)
+		if err == nil {
+			isFavorited = fav
+		}
+	}
+
+	_ = s.tradeRepo.IncrementViews(ctx, id)
+
+	return dto.ConvertTradeItemToDetailResponse(item, isFavorited), nil
+}
+
+func (s *tradeService) Update(ctx context.Context, userID string, id string, req dto.UpdateTradeItemRequest) error {
+	item, err := s.tradeRepo.GetByID(ctx, id)
+	if err != nil {
+		return fmt.Errorf("trade item not found")
+	}
+	if item.UserID != userID {
+		return fmt.Errorf("not authorized")
+	}
+
+	if req.TradeType != nil {
+		item.TradeType = model.TradeType(*req.TradeType)
+	}
+	if req.Category != nil {
+		item.Category = model.TradeCategory(*req.Category)
+	}
+	if req.Title != nil {
+		item.Title = *req.Title
+	}
+	if req.Content != nil {
+		item.Content = *req.Content
+	}
+	if req.Segments != nil {
+		item.Segments = req.Segments
+	}
+	if req.Price != nil {
+		item.Price = req.Price
+	}
+	if req.OriginalPrice != nil {
+		item.OriginalPrice = req.OriginalPrice
+	}
+	if req.Condition != nil {
+		item.Condition = *req.Condition
+	}
+	if req.Location != nil {
+		item.Location = *req.Location
+	}
+	item.UpdatedAt = time.Now()
+
+	if req.Images != nil {
+		return s.tradeRepo.UpdateWithImages(ctx, item, &req.Images)
+	}
+	return s.tradeRepo.Update(ctx, item)
+}
+
+func (s *tradeService) Delete(ctx context.Context, userID string, id string) error {
+	item, err := s.tradeRepo.GetByID(ctx, id)
+	if err != nil {
+		return fmt.Errorf("trade item not found")
+	}
+	if item.UserID != userID {
+		return fmt.Errorf("not authorized")
+	}
+	return s.tradeRepo.Delete(ctx, id)
+}
+
+func (s *tradeService) UpdateStatus(ctx context.Context, userID string, id string, status model.TradeItemStatus) error {
+	item, err := s.tradeRepo.GetByID(ctx, id)
+	if err != nil {
+		return fmt.Errorf("trade item not found")
+	}
+	if item.UserID != userID {
+		return fmt.Errorf("not authorized")
+	}
+	return s.tradeRepo.UpdateStatus(ctx, id, status)
+}
+
+func (s *tradeService) List(ctx context.Context, tradeType *model.TradeType, category *model.TradeCategory, cursorStr string, pageSize int, currentUserID *string) (*dto.TradeCursorPageResponse, error) {
+	req := cursor.NewPageRequest(cursorStr, cursor.Forward, pageSize)
+	result, err := s.tradeRepo.ListByCursor(ctx, tradeType, category, nil, req)
+	if err != nil {
+		return nil, err
+	}
+	return s.buildCursorResponse(ctx, result, currentUserID)
+}
+
+func (s *tradeService) Search(ctx context.Context, keyword string, tradeType *model.TradeType, category *model.TradeCategory, cursorStr string, pageSize int, currentUserID *string) (*dto.TradeCursorPageResponse, error) {
+	req := cursor.NewPageRequest(cursorStr, cursor.Forward, pageSize)
+	result, err := s.tradeRepo.SearchByCursor(ctx, keyword, tradeType, category, req)
+	if err != nil {
+		return nil, err
+	}
+	return s.buildCursorResponse(ctx, result, currentUserID)
+}
+
+func (s *tradeService) buildCursorResponse(ctx context.Context, result *cursor.CursorPageResult[*model.TradeItem], currentUserID *string) (*dto.TradeCursorPageResponse, error) {
+	favoriteMap := make(map[string]bool)
+	if currentUserID != nil && len(result.Items) > 0 {
+		ids := make([]string, 0, len(result.Items))
+		for _, item := range result.Items {
+			ids = append(ids, item.ID)
+		}
+		fm, err := s.tradeRepo.IsFavoritedBatch(ctx, ids, *currentUserID)
+		if err == nil {
+			favoriteMap = fm
+		}
+	}
+
+	resp := &dto.TradeCursorPageResponse{
+		Items:      dto.ConvertTradeItemsToResponse(result.Items, favoriteMap),
+		NextCursor: result.NextCursor,
+		PrevCursor: result.PrevCursor,
+		HasMore:    result.HasMore,
+	}
+	return resp, nil
+}
+
+func (s *tradeService) RecordView(ctx context.Context, id string) error {
+	return s.tradeRepo.IncrementViews(ctx, id)
+}
+
+func (s *tradeService) Favorite(ctx context.Context, userID string, id string) error {
+	_, err := s.tradeRepo.GetByID(ctx, id)
+	if err != nil {
+		return fmt.Errorf("trade item not found")
+	}
+	exists, err := s.tradeRepo.IsFavorited(ctx, id, userID)
+	if err != nil {
+		return err
+	}
+	if exists {
+		return nil
+	}
+	if err := s.tradeRepo.CreateFavorite(ctx, id, userID); err != nil {
+		return err
+	}
+	_ = s.tradeRepo.IncrementFavorites(ctx, id)
+	return nil
+}
+
+func (s *tradeService) Unfavorite(ctx context.Context, userID string, id string) error {
+	exists, err := s.tradeRepo.IsFavorited(ctx, id, userID)
+	if err != nil {
+		return err
+	}
+	if !exists {
+		return nil
+	}
+	if err := s.tradeRepo.DeleteFavorite(ctx, id, userID); err != nil {
+		return err
+	}
+	_ = s.tradeRepo.DecrementFavorites(ctx, id)
+	return nil
+}

internal/wire/handler.go

@@ -34,6 +34,7 @@ var HandlerSet = wire.NewSet(
 	handler.NewVerificationHandler,
 	handler.NewAdminProfileAuditHandler,
 	handler.NewPostHandler,
+	handler.NewTradeHandler,
 
 	// 需要特殊处理的 Handler
 	ProvideUserHandler,

internal/wire/repository.go

@@ -46,6 +46,9 @@ var RepositorySet = wire.NewSet(
 
 	// 帖子内链引用关系
 	repository.NewPostRefRepository,
+
+	// 二手交易相关
+	repository.NewTradeRepository,
 )
 
 // ProvideUserActivityRepository 提供用户活跃数据仓储

internal/wire/service.go

@@ -68,6 +68,9 @@ var ServiceSet = wire.NewSet(
 	// 帖子内链引用
 	ProvidePostRefService,
 
+	// 二手交易
+	ProvideTradeService,
+
 	// 日志服务
 	ProvideAsyncLogManager,
 	ProvideOperationLogService,
@@ -496,3 +499,7 @@ func ProvidePostRefService(
 ) service.PostRefService {
 	return service.NewPostRefService(refRepo, postRepo)
 }
+
+func ProvideTradeService(tradeRepo repository.TradeRepository) service.TradeService {
+	return service.NewTradeService(tradeRepo)
+}