feat: 实现赞/踩系统（P2）

- 新增 PostLike/PostDislike 模型，复合主键 (user_id, post_id)
- Post 表新增 LikesCount/DislikesCount 冗余计数器
- Repository 层：reaction_repo.go，含 WithTx 事务支持
- Service 层：reaction_service.go，赞踩互斥逻辑（6 态切换），事务包裹
- Controller 层：reaction_controller.go，3 个 API（ToggleLike/ToggleDislike/GetReaction）
- 接口定义：controller/interfaces.go 新增 reactionUseCase，service/repository.go 新增 ReactionStore
- 路由注册 + 依赖注入 + AutoMigrate
- 前端：文章详情页赞踩按钮 + 状态查询 + 401 跳转登录
- 样式：posts.css 新增赞踩按钮样式

internal/controller/interfaces.go

@@ -103,3 +103,11 @@ type commentUseCase interface {
 	ListReplies(rootID uint) ([]model.Comment, error)
 	SearchUsers(keyword string) ([]model.UserSearchResult, error)
 }
+
+// reactionUseCase ReactionController 对 ReactionService 的最小依赖（ISP：4 个方法）
+type reactionUseCase interface {
+	ToggleLike(userID, postID uint) (bool, error)
+	ToggleDislike(userID, postID uint) (bool, error)
+	GetReaction(userID, postID uint) (service.ReactionType, error)
+	GetPostLikesCount(postID uint) (int, error)
+}

internal/controller/reaction_controller.go

@@ -0,0 +1,108 @@
+package controller
+
+import (
+	"net/http"
+	"strconv"
+
+	"metazone.cc/metalab/internal/common"
+	"metazone.cc/metalab/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ReactionController 赞/踩 API 控制器
+type ReactionController struct {
+	reactionSvc reactionUseCase
+}
+
+// NewReactionController 构造函数
+func NewReactionController(reactionSvc reactionUseCase) *ReactionController {
+	return &ReactionController{reactionSvc: reactionSvc}
+}
+
+// ToggleLike 切换点赞 POST /api/posts/:id/like
+func (rc *ReactionController) ToggleLike(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
+
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章ID")
+		return
+	}
+
+	isLiked, err := rc.reactionSvc.ToggleLike(uid, uint(postID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "操作失败")
+		return
+	}
+
+	// 获取最新点赞数
+	likesCount, _ := rc.reactionSvc.GetPostLikesCount(uint(postID))
+
+	common.Ok(c, gin.H{
+		"liked":       isLiked,
+		"likes_count": likesCount,
+	})
+}
+
+// ToggleDislike 切换踩 POST /api/posts/:id/dislike
+func (rc *ReactionController) ToggleDislike(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
+
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章ID")
+		return
+	}
+
+	isDisliked, err := rc.reactionSvc.ToggleDislike(uid, uint(postID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "操作失败")
+		return
+	}
+
+	common.Ok(c, gin.H{
+		"disliked": isDisliked,
+	})
+}
+
+// GetReaction 查询当前用户对文章的反应状态 GET /api/posts/:id/reaction
+func (rc *ReactionController) GetReaction(c *gin.Context) {
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章ID")
+		return
+	}
+
+	// 未登录用户返回 none + 公开计数
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		likesCount, _ := rc.reactionSvc.GetPostLikesCount(uint(postID))
+		common.Ok(c, gin.H{
+			"reaction":    string(service.ReactionNone),
+			"likes_count": likesCount,
+		})
+		return
+	}
+
+	reaction, err := rc.reactionSvc.GetReaction(uid, uint(postID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "查询失败")
+		return
+	}
+
+	likesCount, _ := rc.reactionSvc.GetPostLikesCount(uint(postID))
+
+	common.Ok(c, gin.H{
+		"reaction":    string(reaction),
+		"likes_count": likesCount,
+	})
+}

internal/model/post.go

@@ -22,6 +22,8 @@ type Post struct {
 	AllowComment        bool           `gorm:"default:true" json:"allow_comment"`
 	CommentsCount       int            `gorm:"default:0" json:"comments_count"`        // 评论数（冗余计数器）
 	TotalEnergyReceived int            `gorm:"default:0" json:"total_energy_received"` // 文章累计被赋能域能（乘10，冗余计数）
+	LikesCount          int            `gorm:"default:0" json:"likes_count"`           // 点赞数（冗余计数器）
+	DislikesCount       int            `gorm:"default:0" json:"dislikes_count"`        // 踩数（冗余计数器，仅后台可见）
 	DeletedAt           gorm.DeletedAt `gorm:"index" json:"-"`
 	CreatedAt           time.Time      `json:"created_at"`
 	UpdatedAt           time.Time      `json:"updated_at"`

internal/model/post_dislike.go

@@ -0,0 +1,10 @@
+package model
+
+import "time"
+
+// PostDislike 踩记录（仅后台可见）
+type PostDislike struct {
+	UserID    uint      `gorm:"primaryKey;not null" json:"user_id"`
+	PostID    uint      `gorm:"primaryKey;not null" json:"post_id"`
+	CreatedAt time.Time `json:"created_at"`
+}

internal/model/post_like.go

@@ -0,0 +1,10 @@
+package model
+
+import "time"
+
+// PostLike 点赞记录
+type PostLike struct {
+	UserID    uint      `gorm:"primaryKey;not null" json:"user_id"`
+	PostID    uint      `gorm:"primaryKey;not null" json:"post_id"`
+	CreatedAt time.Time `json:"created_at"`
+}

internal/repository/reaction_repo.go

@@ -0,0 +1,77 @@
+package repository
+
+import (
+	"metazone.cc/metalab/internal/model"
+	"metazone.cc/metalab/internal/service"
+
+	"gorm.io/gorm"
+)
+
+// ReactionRepo 赞/踩数据访问
+type ReactionRepo struct {
+	db *gorm.DB
+}
+
+// NewReactionRepo 构造函数
+func NewReactionRepo(db *gorm.DB) *ReactionRepo {
+	return &ReactionRepo{db: db}
+}
+
+// WithTx 基于给定事务连接创建新的 ReactionRepo
+func (r *ReactionRepo) WithTx(tx *gorm.DB) service.ReactionStore {
+	return &ReactionRepo{db: tx}
+}
+
+// FindLike 查找点赞记录
+func (r *ReactionRepo) FindLike(userID, postID uint) (*model.PostLike, error) {
+	var like model.PostLike
+	err := r.db.Where("user_id = ? AND post_id = ?", userID, postID).First(&like).Error
+	if err != nil {
+		return nil, err
+	}
+	return &like, nil
+}
+
+// CreateLike 创建点赞记录
+func (r *ReactionRepo) CreateLike(like *model.PostLike) error {
+	return r.db.Create(like).Error
+}
+
+// DeleteLike 删除点赞记录
+func (r *ReactionRepo) DeleteLike(userID, postID uint) error {
+	return r.db.Where("user_id = ? AND post_id = ?", userID, postID).Delete(&model.PostLike{}).Error
+}
+
+// FindDislike 查找踩记录
+func (r *ReactionRepo) FindDislike(userID, postID uint) (*model.PostDislike, error) {
+	var dislike model.PostDislike
+	err := r.db.Where("user_id = ? AND post_id = ?", userID, postID).First(&dislike).Error
+	if err != nil {
+		return nil, err
+	}
+	return &dislike, nil
+}
+
+// CreateDislike 创建踩记录
+func (r *ReactionRepo) CreateDislike(dislike *model.PostDislike) error {
+	return r.db.Create(dislike).Error
+}
+
+// DeleteDislike 删除踩记录
+func (r *ReactionRepo) DeleteDislike(userID, postID uint) error {
+	return r.db.Where("user_id = ? AND post_id = ?", userID, postID).Delete(&model.PostDislike{}).Error
+}
+
+// IncrPostLikes 原子增加文章点赞数
+func (r *ReactionRepo) IncrPostLikes(postID uint, delta int) error {
+	return r.db.Model(&model.Post{}).
+		Where("id = ?", postID).
+		UpdateColumn("likes_count", gorm.Expr("likes_count + ?", delta)).Error
+}
+
+// IncrPostDislikes 原子增加文章踩数
+func (r *ReactionRepo) IncrPostDislikes(postID uint, delta int) error {
+	return r.db.Model(&model.Post{}).
+		Where("id = ?", postID).
+		UpdateColumn("dislikes_count", gorm.Expr("dislikes_count + ?", delta)).Error
+}

internal/router/api.go

@@ -118,4 +118,17 @@ func setupAPIRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		commentsAPI.GET("/users/search", d.commentCtrl.SearchUsers)
 		commentsAPI.POST("/comments/upload-image", d.commentCtrl.UploadImage)
 	}
+
+	// --- 赞/踩 API ---
+	// 公开：查询反应状态（未登录返回 none + 点赞数）
+	r.GET("/api/posts/:id/reaction", d.reactionCtrl.GetReaction)
+	// 需登录：切换赞/踩
+	reactionAPI := r.Group("/api/posts/:id")
+	reactionAPI.Use(d.authMdw.Required())
+	reactionAPI.Use(d.authMdw.BannedWriteGuard())
+	reactionAPI.Use(middleware.CSRF(cfg))
+	{
+		reactionAPI.POST("/like", d.reactionCtrl.ToggleLike)
+		reactionAPI.POST("/dislike", d.reactionCtrl.ToggleDislike)
+	}
 }

internal/router/deps_core.go

@@ -37,6 +37,7 @@ type dependencies struct {
 	commentCtrl     *controller.CommentController
 	commentService  *service.CommentService
 	adminCommentCtrl *adminCtrl.AdminCommentController
+	reactionCtrl    *controller.ReactionController
 }
 
 func buildDepsCore(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSettings, redisClient *redis.Client) (

internal/router/deps_extra.go

@@ -69,6 +69,11 @@ func buildDeps(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSetting
 	// 后台评论管理
 	adminCommentCtrl := adminCtrl.NewAdminCommentController(commentService)
 
+	// 赞/踩系统
+	reactionRepo := repository.NewReactionRepo(db)
+	reactionService := service.NewReactionService(db, reactionRepo)
+	reactionCtrl := controller.NewReactionController(reactionService)
+
 	// 用户空间
 	spaceService := service.NewSpaceService(userRepo, postRepo)
 	spaceCtrl := controller.NewSpaceController(spaceService)
@@ -90,5 +95,6 @@ func buildDeps(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSetting
 		commentCtrl:     commentCtrl,
 		commentService:  commentService,
 		adminCommentCtrl: adminCommentCtrl,
+		reactionCtrl:    reactionCtrl,
 	}
 }

internal/service/reaction_service.go

@@ -0,0 +1,155 @@
+package service
+
+import (
+	"fmt"
+
+	"metazone.cc/metalab/internal/common"
+	"metazone.cc/metalab/internal/model"
+
+	"gorm.io/gorm"
+)
+
+// ReactionType 反应类型
+type ReactionType string
+
+const (
+	ReactionNone    ReactionType = "none"
+	ReactionLiked   ReactionType = "liked"
+	ReactionDisliked ReactionType = "disliked"
+)
+
+// ReactionService 赞/踩业务逻辑
+type ReactionService struct {
+	db   *gorm.DB
+	repo ReactionStore
+}
+
+// NewReactionService 构造函数
+func NewReactionService(db *gorm.DB, repo ReactionStore) *ReactionService {
+	return &ReactionService{db: db, repo: repo}
+}
+
+// ToggleLike 切换点赞（含踩互斥逻辑）
+// 返回：当前是否已点赞
+func (s *ReactionService) ToggleLike(userID, postID uint) (bool, error) {
+	var isLiked bool
+
+	err := s.db.Transaction(func(tx *gorm.DB) error {
+		txRepo := s.repo.WithTx(tx)
+
+		// 查当前状态
+		_, likeErr := txRepo.FindLike(userID, postID)
+		hasLike := likeErr == nil
+
+		_, dislikeErr := txRepo.FindDislike(userID, postID)
+		hasDislike := dislikeErr == nil
+
+		if hasLike {
+			// 已赞 → 取消赞
+			if err := txRepo.DeleteLike(userID, postID); err != nil {
+				return fmt.Errorf("取消点赞失败: %w", err)
+			}
+			if err := txRepo.IncrPostLikes(postID, -1); err != nil {
+				return fmt.Errorf("更新点赞计数失败: %w", err)
+			}
+			isLiked = false
+		} else {
+			// 无赞 → 加赞（若已有踩，先移除踩）
+			if hasDislike {
+				if err := txRepo.DeleteDislike(userID, postID); err != nil {
+					return fmt.Errorf("移除踩记录失败: %w", err)
+				}
+				if err := txRepo.IncrPostDislikes(postID, -1); err != nil {
+					return fmt.Errorf("更新踩计数失败: %w", err)
+				}
+			}
+
+			if err := txRepo.CreateLike(&model.PostLike{UserID: userID, PostID: postID}); err != nil {
+				return fmt.Errorf("创建点赞记录失败: %w", err)
+			}
+			if err := txRepo.IncrPostLikes(postID, 1); err != nil {
+				return fmt.Errorf("更新点赞计数失败: %w", err)
+			}
+			isLiked = true
+		}
+		return nil
+	})
+
+	return isLiked, err
+}
+
+// ToggleDislike 切换踩（含赞互斥逻辑）
+// 返回：当前是否已踩
+func (s *ReactionService) ToggleDislike(userID, postID uint) (bool, error) {
+	var isDisliked bool
+
+	err := s.db.Transaction(func(tx *gorm.DB) error {
+		txRepo := s.repo.WithTx(tx)
+
+		// 查当前状态
+		_, likeErr := txRepo.FindLike(userID, postID)
+		hasLike := likeErr == nil
+
+		_, dislikeErr := txRepo.FindDislike(userID, postID)
+		hasDislike := dislikeErr == nil
+
+		if hasDislike {
+			// 已踩 → 取消踩
+			if err := txRepo.DeleteDislike(userID, postID); err != nil {
+				return fmt.Errorf("取消踩失败: %w", err)
+			}
+			if err := txRepo.IncrPostDislikes(postID, -1); err != nil {
+				return fmt.Errorf("更新踩计数失败: %w", err)
+			}
+			isDisliked = false
+		} else {
+			// 无踩 → 加踩（若已有赞，先移除赞）
+			if hasLike {
+				if err := txRepo.DeleteLike(userID, postID); err != nil {
+					return fmt.Errorf("移除点赞记录失败: %w", err)
+				}
+				if err := txRepo.IncrPostLikes(postID, -1); err != nil {
+					return fmt.Errorf("更新点赞计数失败: %w", err)
+				}
+			}
+
+			if err := txRepo.CreateDislike(&model.PostDislike{UserID: userID, PostID: postID}); err != nil {
+				return fmt.Errorf("创建踩记录失败: %w", err)
+			}
+			if err := txRepo.IncrPostDislikes(postID, 1); err != nil {
+				return fmt.Errorf("更新踩计数失败: %w", err)
+			}
+			isDisliked = true
+		}
+		return nil
+	})
+
+	return isDisliked, err
+}
+
+// GetReaction 查询用户对文章的反应状态
+func (s *ReactionService) GetReaction(userID, postID uint) (ReactionType, error) {
+	_, likeErr := s.repo.FindLike(userID, postID)
+	if likeErr == nil {
+		return ReactionLiked, nil
+	}
+
+	_, dislikeErr := s.repo.FindDislike(userID, postID)
+	if dislikeErr == nil {
+		return ReactionDisliked, nil
+	}
+
+	return ReactionNone, nil
+}
+
+// GetPostLikesCount 查询文章点赞数（公开展示）
+func (s *ReactionService) GetPostLikesCount(postID uint) (int, error) {
+	var post model.Post
+	if err := s.db.Select("likes_count").First(&post, postID).Error; err != nil {
+		if err == gorm.ErrRecordNotFound {
+			return 0, common.ErrPostNotFound
+		}
+		return 0, fmt.Errorf("查询文章失败: %w", err)
+	}
+	return post.LikesCount, nil
+}

internal/service/repository.go

@@ -153,3 +153,16 @@ type commentStore interface {
 type commentNotifier interface {
 	Create(userID uint, notifyType, title, content string, relatedID, commentID *uint) error
 }
+
+// ReactionStore ReactionService 所需的仓储接口（ISP）
+type ReactionStore interface {
+	FindLike(userID, postID uint) (*model.PostLike, error)
+	CreateLike(like *model.PostLike) error
+	DeleteLike(userID, postID uint) error
+	FindDislike(userID, postID uint) (*model.PostDislike, error)
+	CreateDislike(dislike *model.PostDislike) error
+	DeleteDislike(userID, postID uint) error
+	IncrPostLikes(postID uint, delta int) error
+	IncrPostDislikes(postID uint, delta int) error
+	WithTx(tx *gorm.DB) ReactionStore
+}