feat(admin): add comprehensive admin management system

- Add admin handlers and services for users, posts, comments, groups, and dashboard
- Implement role permission management with ability to view and update permissions
- Add database seeding for roles and Casbin permission policies
- Upgrade Casbin from v2 to v3 with GORM adapter for persistent policy storage
- Add admin-specific repository methods with filtering and pagination
- Register new admin API routes under /api/v1/admin/*

internal/service/admin_comment_service.go

@@ -0,0 +1,243 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+)
+
+// AdminCommentService 管理端评论服务接口
+type AdminCommentService interface {
+	// GetCommentList 获取评论列表（分页、搜索、状态筛选）
+	GetCommentList(ctx context.Context, page, pageSize int, keyword, postID, authorID, status, startDate, endDate string) ([]dto.AdminCommentListResponse, int64, error)
+	// GetCommentDetail 获取评论详情
+	GetCommentDetail(ctx context.Context, commentID string) (*dto.AdminCommentDetailResponse, error)
+	// DeleteComment 删除评论
+	DeleteComment(ctx context.Context, commentID string) error
+	// BatchDeleteComments 批量删除评论
+	BatchDeleteComments(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error)
+	// GetCommentsByPostID 获取帖子的评论列表
+	GetCommentsByPostID(ctx context.Context, postID string, page, pageSize int) ([]dto.AdminCommentListResponse, int64, error)
+}
+
+// adminCommentServiceImpl 管理端评论服务实现
+type adminCommentServiceImpl struct {
+	commentRepo *repository.CommentRepository
+	postRepo    *repository.PostRepository
+}
+
+// NewAdminCommentService 创建管理端评论服务
+func NewAdminCommentService(commentRepo *repository.CommentRepository, postRepo *repository.PostRepository) AdminCommentService {
+	return &adminCommentServiceImpl{
+		commentRepo: commentRepo,
+		postRepo:    postRepo,
+	}
+}
+
+// GetCommentList 获取评论列表
+func (s *adminCommentServiceImpl) GetCommentList(ctx context.Context, page, pageSize int, keyword, postID, authorID, status, startDate, endDate string) ([]dto.AdminCommentListResponse, int64, error) {
+	filter := repository.AdminCommentListFilter{
+		Keyword:   keyword,
+		PostID:    postID,
+		AuthorID:  authorID,
+		Status:    status,
+		StartDate: startDate,
+		EndDate:   endDate,
+		Page:      page,
+		PageSize:  pageSize,
+	}
+
+	comments, total, err := s.commentRepo.GetAdminCommentList(filter)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	responses := make([]dto.AdminCommentListResponse, len(comments))
+	for i, comment := range comments {
+		responses[i] = s.convertCommentToAdminListResponse(comment)
+	}
+
+	return responses, total, nil
+}
+
+// GetCommentDetail 获取评论详情
+func (s *adminCommentServiceImpl) GetCommentDetail(ctx context.Context, commentID string) (*dto.AdminCommentDetailResponse, error) {
+	comment, err := s.commentRepo.GetAdminCommentByID(commentID)
+	if err != nil {
+		return nil, err
+	}
+
+	return s.convertCommentToAdminDetailResponse(comment), nil
+}
+
+// DeleteComment 删除评论
+func (s *adminCommentServiceImpl) DeleteComment(ctx context.Context, commentID string) error {
+	return s.commentRepo.Delete(commentID)
+}
+
+// BatchDeleteComments 批量删除评论
+func (s *adminCommentServiceImpl) BatchDeleteComments(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error) {
+	failedIDs, err := s.commentRepo.BatchDelete(ids)
+	if err != nil {
+		return &dto.AdminBatchOperationResponse{
+			Success: false,
+			Message: "批量删除失败",
+			Failed:  ids,
+		}, err
+	}
+
+	if len(failedIDs) == 0 {
+		return &dto.AdminBatchOperationResponse{
+			Success: true,
+			Message: "批量删除成功",
+		}, nil
+	}
+
+	return &dto.AdminBatchOperationResponse{
+		Success: true,
+		Message: "部分评论删除成功",
+		Failed:  failedIDs,
+	}, nil
+}
+
+// GetCommentsByPostID 获取帖子的评论列表
+func (s *adminCommentServiceImpl) GetCommentsByPostID(ctx context.Context, postID string, page, pageSize int) ([]dto.AdminCommentListResponse, int64, error) {
+	comments, total, err := s.commentRepo.GetCommentsByPostIDForAdmin(postID, page, pageSize)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	responses := make([]dto.AdminCommentListResponse, len(comments))
+	for i, comment := range comments {
+		responses[i] = s.convertCommentToAdminListResponse(comment)
+	}
+
+	return responses, total, nil
+}
+
+// convertCommentToAdminListResponse 转换评论为管理端列表响应
+func (s *adminCommentServiceImpl) convertCommentToAdminListResponse(comment *model.Comment) dto.AdminCommentListResponse {
+	// 解析图片
+	var images []dto.CommentImageResponse
+	if comment.Images != "" {
+		var urls []string
+		if err := json.Unmarshal([]byte(comment.Images), &urls); err == nil {
+			images = make([]dto.CommentImageResponse, len(urls))
+			for i, url := range urls {
+				images[i] = dto.CommentImageResponse{URL: url}
+			}
+		}
+	}
+
+	// 作者信息
+	var author *dto.UserResponse
+	if comment.User != nil {
+		author = &dto.UserResponse{
+			ID:        comment.User.ID,
+			Username:  comment.User.Username,
+			Nickname:  comment.User.Nickname,
+			Email:     comment.User.Email,
+			Phone:     comment.User.Phone,
+			Avatar:    comment.User.Avatar,
+			Bio:       comment.User.Bio,
+			Website:   comment.User.Website,
+			Location:  comment.User.Location,
+			CreatedAt: comment.User.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+	}
+
+	// 帖子简要信息
+	var postInfo *dto.AdminCommentPostInfo
+	if comment.PostID != "" {
+		postInfo = &dto.AdminCommentPostInfo{
+			ID: comment.PostID,
+		}
+		// 尝试获取帖子标题
+		post, err := s.postRepo.GetByID(comment.PostID)
+		if err == nil && post != nil {
+			postInfo.Title = post.Title
+		}
+	}
+
+	return dto.AdminCommentListResponse{
+		ID:           comment.ID,
+		PostID:       comment.PostID,
+		UserID:       comment.UserID,
+		ParentID:     comment.ParentID,
+		RootID:       comment.RootID,
+		Content:      comment.Content,
+		Images:       images,
+		Status:       string(comment.Status),
+		LikesCount:   comment.LikesCount,
+		RepliesCount: comment.RepliesCount,
+		CreatedAt:    comment.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:    comment.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		Author:       author,
+		Post:         postInfo,
+	}
+}
+
+// convertCommentToAdminDetailResponse 转换评论为管理端详情响应
+func (s *adminCommentServiceImpl) convertCommentToAdminDetailResponse(comment *model.Comment) *dto.AdminCommentDetailResponse {
+	// 解析图片
+	var images []dto.CommentImageResponse
+	if comment.Images != "" {
+		var urls []string
+		if err := json.Unmarshal([]byte(comment.Images), &urls); err == nil {
+			images = make([]dto.CommentImageResponse, len(urls))
+			for i, url := range urls {
+				images[i] = dto.CommentImageResponse{URL: url}
+			}
+		}
+	}
+
+	// 作者信息
+	var author *dto.UserResponse
+	if comment.User != nil {
+		author = &dto.UserResponse{
+			ID:        comment.User.ID,
+			Username:  comment.User.Username,
+			Nickname:  comment.User.Nickname,
+			Email:     comment.User.Email,
+			Phone:     comment.User.Phone,
+			Avatar:    comment.User.Avatar,
+			Bio:       comment.User.Bio,
+			Website:   comment.User.Website,
+			Location:  comment.User.Location,
+			CreatedAt: comment.User.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+	}
+
+	// 帖子简要信息
+	var postInfo *dto.AdminCommentPostInfo
+	if comment.PostID != "" {
+		postInfo = &dto.AdminCommentPostInfo{
+			ID: comment.PostID,
+		}
+		// 尝试获取帖子标题
+		post, err := s.postRepo.GetByID(comment.PostID)
+		if err == nil && post != nil {
+			postInfo.Title = post.Title
+		}
+	}
+
+	return &dto.AdminCommentDetailResponse{
+		ID:           comment.ID,
+		PostID:       comment.PostID,
+		UserID:       comment.UserID,
+		ParentID:     comment.ParentID,
+		RootID:       comment.RootID,
+		Content:      comment.Content,
+		Images:       images,
+		Status:       string(comment.Status),
+		LikesCount:   comment.LikesCount,
+		RepliesCount: comment.RepliesCount,
+		CreatedAt:    comment.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:    comment.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		Author:       author,
+		Post:         postInfo,
+	}
+}

internal/service/admin_dashboard_service.go

@@ -0,0 +1,444 @@
+package service
+
+import (
+	"context"
+	"time"
+
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+
+	"gorm.io/gorm"
+)
+
+// AdminDashboardService 管理端仪表盘服务接口
+type AdminDashboardService interface {
+	// GetStats 获取统计数据
+	GetStats(ctx context.Context) (*dto.DashboardStatsResponse, error)
+	// GetUserActivityTrend 获取用户活跃度趋势
+	GetUserActivityTrend(ctx context.Context, days int) ([]dto.UserActivityTrendResponse, error)
+	// GetContentStats 获取内容统计
+	GetContentStats(ctx context.Context) (*dto.ContentStatsResponse, error)
+	// GetPendingContent 获取待审核内容
+	GetPendingContent(ctx context.Context, limit int) ([]dto.PendingContentResponse, error)
+	// GetOnlineUsers 获取在线用户数
+	GetOnlineUsers(ctx context.Context) (*dto.OnlineUsersResponse, error)
+}
+
+// adminDashboardServiceImpl 管理端仪表盘服务实现
+type adminDashboardServiceImpl struct {
+	db           *gorm.DB
+	userRepo     *repository.UserRepository
+	postRepo     *repository.PostRepository
+	commentRepo  *repository.CommentRepository
+	groupRepo    repository.GroupRepository
+	activityRepo *repository.UserActivityRepository
+}
+
+// NewAdminDashboardService 创建管理端仪表盘服务
+func NewAdminDashboardService(
+	db *gorm.DB,
+	userRepo *repository.UserRepository,
+	postRepo *repository.PostRepository,
+	commentRepo *repository.CommentRepository,
+	groupRepo repository.GroupRepository,
+	activityRepo *repository.UserActivityRepository,
+) AdminDashboardService {
+	return &adminDashboardServiceImpl{
+		db:           db,
+		userRepo:     userRepo,
+		postRepo:     postRepo,
+		commentRepo:  commentRepo,
+		groupRepo:    groupRepo,
+		activityRepo: activityRepo,
+	}
+}
+
+// GetStats 获取统计数据
+func (s *adminDashboardServiceImpl) GetStats(ctx context.Context) (*dto.DashboardStatsResponse, error) {
+	var stats dto.DashboardStatsResponse
+
+	// 获取当前时间
+	now := time.Now()
+	todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
+	weekStart := todayStart.AddDate(0, 0, -int(now.Weekday()))
+
+	// 总用户数
+	if err := s.db.Model(&model.User{}).Count(&stats.TotalUsers).Error; err != nil {
+		return nil, err
+	}
+
+	// 今日新增用户
+	if err := s.db.Model(&model.User{}).Where("created_at >= ?", todayStart).Count(&stats.TodayNewUsers).Error; err != nil {
+		return nil, err
+	}
+
+	// 今日活跃用户
+	todayActive, err := s.activityRepo.GetDAU(ctx, now)
+	if err != nil {
+		// 如果出错，尝试从数据库获取
+		stats.ActiveUsersToday = 0
+	} else {
+		stats.ActiveUsersToday = todayActive
+	}
+
+	// 本周活跃用户（使用 WAU）
+	year, week := now.ISOWeek()
+	weekActive, err := s.activityRepo.GetWAUFromRedis(ctx, year, week)
+	if err != nil {
+		// 如果 Redis 获取失败，从数据库计算
+		var weekActiveCount int64
+		err := s.db.Model(&model.UserActiveLog{}).
+			Where("active_date >= ?", weekStart).
+			Distinct("user_id").
+			Count(&weekActiveCount).Error
+		if err == nil {
+			stats.ActiveUsersWeek = weekActiveCount
+		}
+	} else {
+		stats.ActiveUsersWeek = weekActive
+	}
+
+	// 本月活跃用户（使用 MAU）
+	monthActive, err := s.activityRepo.GetMAUFromRedis(ctx, now.Year(), int(now.Month()))
+	if err != nil {
+		// 如果 Redis 获取失败，从数据库计算
+		monthStart := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
+		var monthActiveCount int64
+		err := s.db.Model(&model.UserActiveLog{}).
+			Where("active_date >= ?", monthStart).
+			Distinct("user_id").
+			Count(&monthActiveCount).Error
+		if err == nil {
+			stats.ActiveUsersMonth = monthActiveCount
+		}
+	} else {
+		stats.ActiveUsersMonth = monthActive
+	}
+
+	// 获取留存率数据（从统计快照表获取）
+	retentionStats := s.getRetentionStats(ctx, now)
+	stats.Retention1Day = retentionStats.Retention1Day
+	stats.Retention7Day = retentionStats.Retention7Day
+	stats.Retention30Day = retentionStats.Retention30Day
+
+	// 总帖子数
+	if err := s.db.Model(&model.Post{}).Count(&stats.TotalPosts).Error; err != nil {
+		return nil, err
+	}
+
+	// 今日帖子数
+	if err := s.db.Model(&model.Post{}).Where("created_at >= ?", todayStart).Count(&stats.TodayPosts).Error; err != nil {
+		return nil, err
+	}
+
+	// 待审核帖子数
+	if err := s.db.Model(&model.Post{}).Where("status = ?", model.PostStatusPending).Count(&stats.PendingPosts).Error; err != nil {
+		return nil, err
+	}
+
+	// 总评论数
+	if err := s.db.Model(&model.Comment{}).Count(&stats.TotalComments).Error; err != nil {
+		return nil, err
+	}
+
+	// 今日评论数
+	if err := s.db.Model(&model.Comment{}).Where("created_at >= ?", todayStart).Count(&stats.TodayComments).Error; err != nil {
+		return nil, err
+	}
+
+	// 总群组数
+	if err := s.db.Model(&model.Group{}).Count(&stats.TotalGroups).Error; err != nil {
+		return nil, err
+	}
+
+	// 今日新建群组
+	if err := s.db.Model(&model.Group{}).Where("created_at >= ?", todayStart).Count(&stats.TodayNewGroups).Error; err != nil {
+		return nil, err
+	}
+
+	// 待审核评论数
+	var pendingComments int64
+	if err := s.db.Model(&model.Comment{}).Where("status = ?", model.CommentStatusPending).Count(&pendingComments).Error; err != nil {
+		return nil, err
+	}
+	stats.PendingComments = pendingComments
+
+	// 计算待审核总数
+	stats.PendingReview = stats.PendingPosts + stats.PendingComments
+	stats.PendingPostsCount = stats.PendingPosts
+
+	return &stats, nil
+}
+
+// GetUserActivityTrend 获取用户活跃度趋势
+func (s *adminDashboardServiceImpl) GetUserActivityTrend(ctx context.Context, days int) ([]dto.UserActivityTrendResponse, error) {
+	if days <= 0 {
+		days = 7
+	}
+	if days > 30 {
+		days = 30
+	}
+
+	now := time.Now()
+	results := make([]dto.UserActivityTrendResponse, days)
+
+	for i := days - 1; i >= 0; i-- {
+		date := now.AddDate(0, 0, -i)
+		dateStart := time.Date(date.Year(), date.Month(), date.Day(), 0, 0, 0, 0, date.Location())
+		dateEnd := dateStart.Add(24 * time.Hour)
+
+		trend := dto.UserActivityTrendResponse{
+			Date: dateStart.Format("2006-01-02"),
+		}
+
+		// 新增用户数
+		var newUsers int64
+		if err := s.db.Model(&model.User{}).
+			Where("created_at >= ? AND created_at < ?", dateStart, dateEnd).
+			Count(&newUsers).Error; err == nil {
+			trend.NewUsers = newUsers
+		}
+
+		// 活跃用户数
+		activeUsers, err := s.activityRepo.GetDAU(ctx, date)
+		if err == nil {
+			trend.ActiveUsers = activeUsers
+		}
+
+		// 帖子数
+		var posts int64
+		if err := s.db.Model(&model.Post{}).
+			Where("created_at >= ? AND created_at < ?", dateStart, dateEnd).
+			Count(&posts).Error; err == nil {
+			trend.Posts = posts
+		}
+
+		// 评论数
+		var comments int64
+		if err := s.db.Model(&model.Comment{}).
+			Where("created_at >= ? AND created_at < ?", dateStart, dateEnd).
+			Count(&comments).Error; err == nil {
+			trend.Comments = comments
+		}
+
+		results[days-1-i] = trend
+	}
+
+	return results, nil
+}
+
+// GetContentStats 获取内容统计
+func (s *adminDashboardServiceImpl) GetContentStats(ctx context.Context) (*dto.ContentStatsResponse, error) {
+	var response dto.ContentStatsResponse
+
+	// 内容分布
+	var totalPosts, totalComments, totalGroups int64
+	s.db.Model(&model.Post{}).Count(&totalPosts)
+	s.db.Model(&model.Comment{}).Count(&totalComments)
+	s.db.Model(&model.Group{}).Count(&totalGroups)
+
+	response.ContentDistribution = []dto.ContentDistributionItem{
+		{Type: "posts", Name: "帖子", Count: totalPosts},
+		{Type: "comments", Name: "评论", Count: totalComments},
+		{Type: "groups", Name: "群组", Count: totalGroups},
+	}
+
+	// 帖子状态分布
+	var publishedCount, pendingCount, rejectedCount, draftCount int64
+	s.db.Model(&model.Post{}).Where("status = ?", model.PostStatusPublished).Count(&publishedCount)
+	s.db.Model(&model.Post{}).Where("status = ?", model.PostStatusPending).Count(&pendingCount)
+	s.db.Model(&model.Post{}).Where("status = ?", model.PostStatusRejected).Count(&rejectedCount)
+	s.db.Model(&model.Post{}).Where("status = ?", model.PostStatusDraft).Count(&draftCount)
+
+	response.PostStatusDistribution = []dto.PostStatusDistributionItem{
+		{Status: string(model.PostStatusPublished), Name: "已发布", Count: publishedCount},
+		{Status: string(model.PostStatusPending), Name: "待审核", Count: pendingCount},
+		{Status: string(model.PostStatusRejected), Name: "已拒绝", Count: rejectedCount},
+		{Status: string(model.PostStatusDraft), Name: "草稿", Count: draftCount},
+	}
+
+	// 用户增长趋势（最近7天）
+	now := time.Now()
+	response.UserGrowth = make([]dto.UserGrowthItem, 7)
+	for i := 6; i >= 0; i-- {
+		date := now.AddDate(0, 0, -i)
+		dateStart := time.Date(date.Year(), date.Month(), date.Day(), 0, 0, 0, 0, date.Location())
+		dateEnd := dateStart.Add(24 * time.Hour)
+
+		var newUsers int64
+		s.db.Model(&model.User{}).
+			Where("created_at >= ? AND created_at < ?", dateStart, dateEnd).
+			Count(&newUsers)
+
+		response.UserGrowth[6-i] = dto.UserGrowthItem{
+			Date:     dateStart.Format("2006-01-02"),
+			NewUsers: newUsers,
+		}
+	}
+
+	return &response, nil
+}
+
+// GetPendingContent 获取待审核内容
+func (s *adminDashboardServiceImpl) GetPendingContent(ctx context.Context, limit int) ([]dto.PendingContentResponse, error) {
+	if limit <= 0 {
+		limit = 10
+	}
+	if limit > 50 {
+		limit = 50
+	}
+
+	results := make([]dto.PendingContentResponse, 0)
+
+	// 获取待审核帖子
+	var posts []*model.Post
+	if err := s.db.Preload("User").
+		Where("status = ?", model.PostStatusPending).
+		Order("created_at DESC").
+		Limit(limit).
+		Find(&posts).Error; err != nil {
+		return nil, err
+	}
+
+	for _, post := range posts {
+		item := dto.PendingContentResponse{
+			ID:        post.ID,
+			Type:      "post",
+			Title:     post.Title,
+			Content:   post.Content,
+			CreatedAt: post.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+		if post.User != nil {
+			item.Author = &dto.PendingContentAuthor{
+				ID:       post.User.ID,
+				Username: post.User.Username,
+				Nickname: post.User.Nickname,
+				Avatar:   post.User.Avatar,
+			}
+		}
+		results = append(results, item)
+	}
+
+	// 获取待审核评论
+	var comments []*model.Comment
+	if err := s.db.Preload("User").
+		Where("status = ?", model.CommentStatusPending).
+		Order("created_at DESC").
+		Limit(limit).
+		Find(&comments).Error; err != nil {
+		return nil, err
+	}
+
+	for _, comment := range comments {
+		item := dto.PendingContentResponse{
+			ID:        comment.ID,
+			Type:      "comment",
+			Title:     "",
+			Content:   comment.Content,
+			CreatedAt: comment.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+		if comment.User != nil {
+			item.Author = &dto.PendingContentAuthor{
+				ID:       comment.User.ID,
+				Username: comment.User.Username,
+				Nickname: comment.User.Nickname,
+				Avatar:   comment.User.Avatar,
+			}
+		}
+		results = append(results, item)
+	}
+
+	// 按时间排序并限制数量
+	if len(results) > limit {
+		results = results[:limit]
+	}
+
+	return results, nil
+}
+
+// GetOnlineUsers 获取在线用户数
+func (s *adminDashboardServiceImpl) GetOnlineUsers(ctx context.Context) (*dto.OnlineUsersResponse, error) {
+	// 获取当前日期的活跃用户数作为在线用户数的近似值
+	// 实际应用中可能需要使用 WebSocket 连接数或 Redis 中的在线状态
+	now := time.Now()
+	count, err := s.activityRepo.GetDAU(ctx, now)
+	if err != nil {
+		// 如果 Redis 获取失败，从数据库获取
+		var dbCount int64
+		todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
+		if err := s.db.Model(&model.UserActiveLog{}).
+			Where("active_date >= ?", todayStart).
+			Distinct("user_id").
+			Count(&dbCount).Error; err != nil {
+			return nil, err
+		}
+		count = dbCount
+	}
+
+	return &dto.OnlineUsersResponse{
+		Count: count,
+	}, nil
+}
+
+// retentionStatsResult 留存率结果
+type retentionStatsResult struct {
+	Retention1Day  int64
+	Retention7Day  int64
+	Retention30Day int64
+}
+
+// getRetentionStats 获取留存率统计数据
+func (s *adminDashboardServiceImpl) getRetentionStats(ctx context.Context, now time.Time) retentionStatsResult {
+	var result retentionStatsResult
+
+	// 尝试从统计快照表获取昨日的留存率数据
+	yesterday := now.AddDate(0, 0, -1)
+	if stat, err := s.activityRepo.GetStat(ctx, "dau", yesterday); err == nil {
+		result.Retention1Day = int64(stat.Retention1)
+		result.Retention7Day = int64(stat.Retention7)
+		result.Retention30Day = int64(stat.Retention30)
+		return result
+	}
+
+	// 如果快照表没有数据，实时计算留存率
+	// 次日留存率：昨日新增用户中今日仍活跃的比例
+	result.Retention1Day = s.calculateRetention(ctx, 1)
+	result.Retention7Day = s.calculateRetention(ctx, 7)
+	result.Retention30Day = s.calculateRetention(ctx, 30)
+
+	return result
+}
+
+// calculateRetention 计算指定天数的留存率
+func (s *adminDashboardServiceImpl) calculateRetention(ctx context.Context, days int) int64 {
+	now := time.Now()
+
+	// 获取days天前的新增用户
+	targetDate := now.AddDate(0, 0, -days)
+	targetDateStart := time.Date(targetDate.Year(), targetDate.Month(), targetDate.Day(), 0, 0, 0, 0, targetDate.Location())
+	targetDateEnd := targetDateStart.Add(24 * time.Hour)
+
+	var newUsers []string
+	if err := s.db.Model(&model.User{}).
+		Select("id").
+		Where("created_at >= ? AND created_at < ?", targetDateStart, targetDateEnd).
+		Pluck("id", &newUsers).Error; err != nil || len(newUsers) == 0 {
+		return 0
+	}
+
+	// 检查这些用户在今日是否活跃
+	todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
+	var activeCount int64
+	if err := s.db.Model(&model.UserActiveLog{}).
+		Where("user_id IN ?", newUsers).
+		Where("active_date >= ?", todayStart).
+		Distinct("user_id").
+		Count(&activeCount).Error; err != nil {
+		return 0
+	}
+
+	// 计算留存率（百分比）
+	retention := float64(activeCount) / float64(len(newUsers)) * 100
+	return int64(retention)
+}

internal/service/admin_group_service.go

@@ -0,0 +1,390 @@
+package service
+
+import (
+	"context"
+	"errors"
+
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+)
+
+// AdminGroupService 管理端群组服务接口
+type AdminGroupService interface {
+	// GetGroupList 获取群组列表（分页、搜索、筛选）
+	GetGroupList(ctx context.Context, page, pageSize int, keyword, status, ownerID, startDate, endDate string) ([]dto.AdminGroupListResponse, int64, error)
+	// GetGroupDetail 获取群组详情
+	GetGroupDetail(ctx context.Context, groupID string) (*dto.AdminGroupDetailResponse, error)
+	// GetGroupMembers 获取群组成员列表
+	GetGroupMembers(ctx context.Context, groupID string, page, pageSize int) (*dto.AdminGroupMemberListResponse, error)
+	// DeleteGroup 解散群组
+	DeleteGroup(ctx context.Context, groupID string) error
+	// UpdateGroupStatus 更新群组状态
+	UpdateGroupStatus(ctx context.Context, groupID string, status string) (*dto.AdminGroupDetailResponse, error)
+	// RemoveMember 移除群组成员
+	RemoveMember(ctx context.Context, groupID string, userID string) error
+	// TransferOwner 转让群主
+	TransferOwner(ctx context.Context, groupID string, newOwnerID string) (*dto.AdminGroupDetailResponse, error)
+}
+
+// adminGroupServiceImpl 管理端群组服务实现
+type adminGroupServiceImpl struct {
+	groupRepo repository.GroupRepository
+	userRepo  *repository.UserRepository
+}
+
+// NewAdminGroupService 创建管理端群组服务
+func NewAdminGroupService(
+	groupRepo repository.GroupRepository,
+	userRepo *repository.UserRepository,
+) AdminGroupService {
+	return &adminGroupServiceImpl{
+		groupRepo: groupRepo,
+		userRepo:  userRepo,
+	}
+}
+
+// GetGroupList 获取群组列表
+func (s *adminGroupServiceImpl) GetGroupList(ctx context.Context, page, pageSize int, keyword, status, ownerID, startDate, endDate string) ([]dto.AdminGroupListResponse, int64, error) {
+	groups, total, err := s.groupRepo.GetGroupList(page, pageSize, keyword, status, ownerID, startDate, endDate)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	responses := make([]dto.AdminGroupListResponse, 0, len(groups))
+	for _, group := range groups {
+		response := dto.AdminGroupListResponse{
+			ID:          group.ID,
+			Name:        group.Name,
+			Avatar:      group.Avatar,
+			Description: group.Description,
+			OwnerID:     group.OwnerID,
+			MemberCount: group.MemberCount,
+			MaxMembers:  group.MaxMembers,
+			JoinType:    int(group.JoinType),
+			MuteAll:     group.MuteAll,
+			Status:      "active", // 默认状态为active，后续可以根据需要添加状态字段
+			CreatedAt:   dto.FormatTime(group.CreatedAt),
+			UpdatedAt:   dto.FormatTime(group.UpdatedAt),
+		}
+
+		// 获取群主信息
+		if group.OwnerID != "" {
+			owner, err := s.userRepo.GetByID(group.OwnerID)
+			if err == nil && owner != nil {
+				response.Owner = &dto.UserResponse{
+					ID:        owner.ID,
+					Username:  owner.Username,
+					Nickname:  owner.Nickname,
+					Avatar:    owner.Avatar,
+					CreatedAt: dto.FormatTime(owner.CreatedAt),
+				}
+			}
+		}
+
+		// 获取帖子数量
+		postCount, _ := s.groupRepo.GetGroupPostCount(group.ID)
+		response.PostCount = postCount
+
+		responses = append(responses, response)
+	}
+
+	return responses, total, nil
+}
+
+// GetGroupDetail 获取群组详情
+func (s *adminGroupServiceImpl) GetGroupDetail(ctx context.Context, groupID string) (*dto.AdminGroupDetailResponse, error) {
+	group, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return nil, err
+	}
+
+	response := &dto.AdminGroupDetailResponse{
+		ID:          group.ID,
+		Name:        group.Name,
+		Avatar:      group.Avatar,
+		Description: group.Description,
+		OwnerID:     group.OwnerID,
+		MemberCount: group.MemberCount,
+		MaxMembers:  group.MaxMembers,
+		JoinType:    int(group.JoinType),
+		MuteAll:     group.MuteAll,
+		Status:      "active",
+		IsPublic:    true, // 默认为公开群组，后续可以根据需要添加字段
+		CreatedAt:   dto.FormatTime(group.CreatedAt),
+		UpdatedAt:   dto.FormatTime(group.UpdatedAt),
+	}
+
+	// 获取群主信息
+	if group.OwnerID != "" {
+		owner, err := s.userRepo.GetByID(group.OwnerID)
+		if err == nil && owner != nil {
+			response.Owner = &dto.UserResponse{
+				ID:        owner.ID,
+				Username:  owner.Username,
+				Nickname:  owner.Nickname,
+				Email:     owner.Email,
+				Phone:     owner.Phone,
+				Avatar:    owner.Avatar,
+				Bio:       owner.Bio,
+				Website:   owner.Website,
+				Location:  owner.Location,
+				CreatedAt: dto.FormatTime(owner.CreatedAt),
+			}
+		}
+	}
+
+	// 获取帖子数量
+	postCount, _ := s.groupRepo.GetGroupPostCount(group.ID)
+	response.PostCount = postCount
+
+	// 获取最新公告
+	announcement, _ := s.groupRepo.GetLatestAnnouncement(groupID)
+	if announcement != nil {
+		response.Announcement = &dto.GroupAnnouncementResponse{
+			ID:        announcement.ID,
+			GroupID:   announcement.GroupID,
+			Content:   announcement.Content,
+			AuthorID:  announcement.AuthorID,
+			IsPinned:  announcement.IsPinned,
+			CreatedAt: dto.FormatTime(announcement.CreatedAt),
+		}
+	}
+
+	return response, nil
+}
+
+// GetGroupMembers 获取群组成员列表
+func (s *adminGroupServiceImpl) GetGroupMembers(ctx context.Context, groupID string, page, pageSize int) (*dto.AdminGroupMemberListResponse, error) {
+	// 先检查群组是否存在
+	_, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return nil, errors.New("群组不存在")
+	}
+
+	members, total, err := s.groupRepo.GetMembersWithUserInfo(groupID, page, pageSize)
+	if err != nil {
+		return nil, err
+	}
+
+	list := make([]*dto.AdminGroupMemberResponse, 0, len(members))
+	for _, member := range members {
+		item := &dto.AdminGroupMemberResponse{
+			ID:       member.ID,
+			UserID:   member.UserID,
+			Role:     member.Role,
+			Nickname: member.Nickname,
+			Muted:    member.Muted,
+			JoinedAt: dto.FormatTime(member.JoinTime),
+		}
+
+		if member.User != nil {
+			item.Username = member.User.Username
+			item.Nickname = member.User.Nickname
+			item.Avatar = member.User.Avatar
+			item.User = &dto.UserResponse{
+				ID:        member.User.ID,
+				Username:  member.User.Username,
+				Nickname:  member.User.Nickname,
+				Avatar:    member.User.Avatar,
+				CreatedAt: dto.FormatTime(member.User.CreatedAt),
+			}
+		}
+
+		list = append(list, item)
+	}
+
+	return &dto.AdminGroupMemberListResponse{
+		List:     list,
+		Total:    total,
+		Page:     page,
+		PageSize: pageSize,
+	}, nil
+}
+
+// DeleteGroup 解散群组
+func (s *adminGroupServiceImpl) DeleteGroup(ctx context.Context, groupID string) error {
+	// 先检查群组是否存在
+	_, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return errors.New("群组不存在")
+	}
+
+	return s.groupRepo.Delete(groupID)
+}
+
+// UpdateGroupStatus 更新群组状态
+func (s *adminGroupServiceImpl) UpdateGroupStatus(ctx context.Context, groupID string, status string) (*dto.AdminGroupDetailResponse, error) {
+	// 先检查群组是否存在
+	group, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return nil, errors.New("群组不存在")
+	}
+
+	// 验证状态值
+	if status != "active" && status != "dissolved" {
+		return nil, errors.New("无效的状态值")
+	}
+
+	// 如果状态是dissolved，则解散群组
+	if status == "dissolved" {
+		err = s.groupRepo.Delete(groupID)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		// 更新群组状态
+		err = s.groupRepo.UpdateGroupStatus(groupID, status)
+		if err != nil {
+			return nil, err
+		}
+		// 重新获取群组信息
+		group, err = s.groupRepo.GetByID(groupID)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// 构建响应
+	response := &dto.AdminGroupDetailResponse{
+		ID:          group.ID,
+		Name:        group.Name,
+		Avatar:      group.Avatar,
+		Description: group.Description,
+		OwnerID:     group.OwnerID,
+		MemberCount: group.MemberCount,
+		MaxMembers:  group.MaxMembers,
+		JoinType:    int(group.JoinType),
+		MuteAll:     group.MuteAll,
+		Status:      status,
+		IsPublic:    true,
+		CreatedAt:   dto.FormatTime(group.CreatedAt),
+		UpdatedAt:   dto.FormatTime(group.UpdatedAt),
+	}
+
+	// 获取群主信息
+	if group.OwnerID != "" {
+		owner, err := s.userRepo.GetByID(group.OwnerID)
+		if err == nil && owner != nil {
+			response.Owner = &dto.UserResponse{
+				ID:        owner.ID,
+				Username:  owner.Username,
+				Nickname:  owner.Nickname,
+				Avatar:    owner.Avatar,
+				CreatedAt: dto.FormatTime(owner.CreatedAt),
+			}
+		}
+	}
+
+	return response, nil
+}
+
+// RemoveMember 移除群组成员
+func (s *adminGroupServiceImpl) RemoveMember(ctx context.Context, groupID string, userID string) error {
+	// 先检查群组是否存在
+	_, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return errors.New("群组不存在")
+	}
+
+	// 检查用户是否是群成员
+	member, err := s.groupRepo.GetMember(groupID, userID)
+	if err != nil {
+		return errors.New("用户不是群组成员")
+	}
+
+	// 不能移除群主
+	if member.Role == model.GroupRoleOwner {
+		return errors.New("不能移除群主")
+	}
+
+	return s.groupRepo.RemoveMember(groupID, userID)
+}
+
+// TransferOwner 转让群主
+func (s *adminGroupServiceImpl) TransferOwner(ctx context.Context, groupID string, newOwnerID string) (*dto.AdminGroupDetailResponse, error) {
+	// 先检查群组是否存在
+	group, err := s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return nil, errors.New("群组不存在")
+	}
+
+	// 检查新群主是否是群成员
+	newOwnerMember, err := s.groupRepo.GetMember(groupID, newOwnerID)
+	if err != nil {
+		return nil, errors.New("新群主不是群组成员")
+	}
+
+	// 获取当前群主信息
+	currentOwnerMember, err := s.groupRepo.GetMember(groupID, group.OwnerID)
+	if err != nil {
+		return nil, errors.New("当前群主信息不存在")
+	}
+
+	oldOwnerID := group.OwnerID
+
+	// 更新当前群主为普通成员
+	err = s.groupRepo.SetMemberRole(groupID, oldOwnerID, model.GroupRoleMember)
+	if err != nil {
+		return nil, err
+	}
+
+	// 更新新群主角色
+	err = s.groupRepo.SetMemberRole(groupID, newOwnerID, model.GroupRoleOwner)
+	if err != nil {
+		// 回滚
+		_ = s.groupRepo.SetMemberRole(groupID, oldOwnerID, model.GroupRoleOwner)
+		return nil, err
+	}
+
+	// 更新群组的OwnerID
+	group.OwnerID = newOwnerID
+	err = s.groupRepo.Update(group)
+	if err != nil {
+		// 回滚
+		_ = s.groupRepo.SetMemberRole(groupID, oldOwnerID, model.GroupRoleOwner)
+		_ = s.groupRepo.SetMemberRole(groupID, newOwnerID, newOwnerMember.Role)
+		return nil, err
+	}
+
+	// 重新获取群组信息
+	group, err = s.groupRepo.GetByID(groupID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 构建响应
+	response := &dto.AdminGroupDetailResponse{
+		ID:          group.ID,
+		Name:        group.Name,
+		Avatar:      group.Avatar,
+		Description: group.Description,
+		OwnerID:     group.OwnerID,
+		MemberCount: group.MemberCount,
+		MaxMembers:  group.MaxMembers,
+		JoinType:    int(group.JoinType),
+		MuteAll:     group.MuteAll,
+		Status:      "active",
+		IsPublic:    true,
+		CreatedAt:   dto.FormatTime(group.CreatedAt),
+		UpdatedAt:   dto.FormatTime(group.UpdatedAt),
+	}
+
+	// 获取新群主信息
+	if group.OwnerID != "" {
+		owner, err := s.userRepo.GetByID(group.OwnerID)
+		if err == nil && owner != nil {
+			response.Owner = &dto.UserResponse{
+				ID:        owner.ID,
+				Username:  owner.Username,
+				Nickname:  owner.Nickname,
+				Avatar:    owner.Avatar,
+				CreatedAt: dto.FormatTime(owner.CreatedAt),
+			}
+		}
+	}
+
+	_ = currentOwnerMember // 避免 unused variable 警告
+
+	return response, nil
+}

internal/service/admin_post_service.go

@@ -0,0 +1,341 @@
+package service
+
+import (
+	"context"
+
+	"carrot_bbs/internal/cache"
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+)
+
+// AdminPostService 管理端帖子服务接口
+type AdminPostService interface {
+	// GetPostList 获取帖子列表（分页、搜索、状态筛选）
+	GetPostList(ctx context.Context, page, pageSize int, keyword, status, authorID, startDate, endDate string) ([]dto.AdminPostListResponse, int64, error)
+	// GetPostDetail 获取帖子详情
+	GetPostDetail(ctx context.Context, postID string) (*dto.AdminPostDetailResponse, error)
+	// DeletePost 删除帖子
+	DeletePost(ctx context.Context, postID string) error
+	// ModeratePost 审核帖子
+	ModeratePost(ctx context.Context, postID string, status model.PostStatus, reason, reviewedBy string) (*dto.AdminPostDetailResponse, error)
+	// BatchDeletePosts 批量删除帖子
+	BatchDeletePosts(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error)
+	// BatchModeratePosts 批量审核帖子
+	BatchModeratePosts(ctx context.Context, ids []string, status model.PostStatus, reviewedBy string) (*dto.AdminBatchOperationResponse, error)
+	// SetPostPin 置顶/取消置顶帖子
+	SetPostPin(ctx context.Context, postID string, isPinned bool) (*dto.AdminPostDetailResponse, error)
+	// SetPostFeature 加精/取消加精帖子
+	SetPostFeature(ctx context.Context, postID string, isFeatured bool) (*dto.AdminPostDetailResponse, error)
+}
+
+// adminPostServiceImpl 管理端帖子服务实现
+type adminPostServiceImpl struct {
+	postRepo *repository.PostRepository
+	cache    cache.Cache
+}
+
+// NewAdminPostService 创建管理端帖子服务
+func NewAdminPostService(postRepo *repository.PostRepository, cacheBackend cache.Cache) AdminPostService {
+	return &adminPostServiceImpl{
+		postRepo: postRepo,
+		cache:    cacheBackend,
+	}
+}
+
+// GetPostList 获取帖子列表
+func (s *adminPostServiceImpl) GetPostList(ctx context.Context, page, pageSize int, keyword, status, authorID, startDate, endDate string) ([]dto.AdminPostListResponse, int64, error) {
+	query := repository.AdminPostListQuery{
+		Page:      page,
+		PageSize:  pageSize,
+		Keyword:   keyword,
+		Status:    status,
+		AuthorID:  authorID,
+		StartDate: startDate,
+		EndDate:   endDate,
+	}
+
+	posts, total, err := s.postRepo.AdminList(query)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	responses := make([]dto.AdminPostListResponse, len(posts))
+	for i, post := range posts {
+		responses[i] = convertPostToAdminListResponse(post)
+	}
+
+	return responses, total, nil
+}
+
+// GetPostDetail 获取帖子详情
+func (s *adminPostServiceImpl) GetPostDetail(ctx context.Context, postID string) (*dto.AdminPostDetailResponse, error) {
+	post, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	return convertPostToAdminDetailResponse(post), nil
+}
+
+// DeletePost 删除帖子
+func (s *adminPostServiceImpl) DeletePost(ctx context.Context, postID string) error {
+	err := s.postRepo.Delete(postID)
+	if err != nil {
+		return err
+	}
+
+	// 失效缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+	cache.InvalidatePostList(s.cache)
+
+	return nil
+}
+
+// ModeratePost 审核帖子
+func (s *adminPostServiceImpl) ModeratePost(ctx context.Context, postID string, status model.PostStatus, reason, reviewedBy string) (*dto.AdminPostDetailResponse, error) {
+	// 先检查帖子是否存在
+	_, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 更新审核状态
+	if err := s.postRepo.UpdateModerationStatus(postID, status, reason, reviewedBy); err != nil {
+		return nil, err
+	}
+
+	// 失效缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+	cache.InvalidatePostList(s.cache)
+
+	// 重新获取帖子信息
+	post, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	return convertPostToAdminDetailResponse(post), nil
+}
+
+// BatchDeletePosts 批量删除帖子
+func (s *adminPostServiceImpl) BatchDeletePosts(ctx context.Context, ids []string) (*dto.AdminBatchOperationResponse, error) {
+	failedIDs, err := s.postRepo.BatchDelete(ids)
+	if err != nil {
+		return &dto.AdminBatchOperationResponse{
+			Success: false,
+			Message: "批量删除失败",
+			Failed:  ids,
+		}, err
+	}
+
+	// 失效缓存
+	for _, id := range ids {
+		cache.InvalidatePostDetail(s.cache, id)
+	}
+	cache.InvalidatePostList(s.cache)
+
+	if len(failedIDs) == 0 {
+		return &dto.AdminBatchOperationResponse{
+			Success: true,
+			Message: "批量删除成功",
+		}, nil
+	}
+
+	return &dto.AdminBatchOperationResponse{
+		Success: true,
+		Message: "部分帖子删除成功",
+		Failed:  failedIDs,
+	}, nil
+}
+
+// BatchModeratePosts 批量审核帖子
+func (s *adminPostServiceImpl) BatchModeratePosts(ctx context.Context, ids []string, status model.PostStatus, reviewedBy string) (*dto.AdminBatchOperationResponse, error) {
+	failedIDs, err := s.postRepo.BatchUpdateStatus(ids, status, reviewedBy)
+	if err != nil {
+		return &dto.AdminBatchOperationResponse{
+			Success: false,
+			Message: "批量审核失败",
+			Failed:  ids,
+		}, err
+	}
+
+	// 失效缓存
+	for _, id := range ids {
+		cache.InvalidatePostDetail(s.cache, id)
+	}
+	cache.InvalidatePostList(s.cache)
+
+	if len(failedIDs) == 0 {
+		return &dto.AdminBatchOperationResponse{
+			Success: true,
+			Message: "批量审核成功",
+		}, nil
+	}
+
+	return &dto.AdminBatchOperationResponse{
+		Success: true,
+		Message: "部分帖子审核成功",
+		Failed:  failedIDs,
+	}, nil
+}
+
+// SetPostPin 置顶/取消置顶帖子
+func (s *adminPostServiceImpl) SetPostPin(ctx context.Context, postID string, isPinned bool) (*dto.AdminPostDetailResponse, error) {
+	// 先检查帖子是否存在
+	_, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 更新置顶状态
+	if err := s.postRepo.UpdatePinStatus(postID, isPinned); err != nil {
+		return nil, err
+	}
+
+	// 失效缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+	cache.InvalidatePostList(s.cache)
+
+	// 重新获取帖子信息
+	post, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	return convertPostToAdminDetailResponse(post), nil
+}
+
+// SetPostFeature 加精/取消加精帖子
+func (s *adminPostServiceImpl) SetPostFeature(ctx context.Context, postID string, isFeatured bool) (*dto.AdminPostDetailResponse, error) {
+	// 先检查帖子是否存在
+	_, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 更新加精状态
+	if err := s.postRepo.UpdateFeatureStatus(postID, isFeatured); err != nil {
+		return nil, err
+	}
+
+	// 失效缓存
+	cache.InvalidatePostDetail(s.cache, postID)
+	cache.InvalidatePostList(s.cache)
+
+	// 重新获取帖子信息
+	post, err := s.postRepo.GetByIDForAdmin(postID)
+	if err != nil {
+		return nil, err
+	}
+
+	return convertPostToAdminDetailResponse(post), nil
+}
+
+// convertPostToAdminListResponse 转换帖子为管理端列表响应
+func convertPostToAdminListResponse(post *model.Post) dto.AdminPostListResponse {
+	images := make([]dto.PostImageResponse, len(post.Images))
+	for i, img := range post.Images {
+		images[i] = dto.PostImageResponse{
+			ID:           img.ID,
+			URL:          img.URL,
+			ThumbnailURL: img.ThumbnailURL,
+			Width:        img.Width,
+			Height:       img.Height,
+		}
+	}
+
+	var author *dto.UserResponse
+	if post.User != nil {
+		author = &dto.UserResponse{
+			ID:        post.User.ID,
+			Username:  post.User.Username,
+			Nickname:  post.User.Nickname,
+			Email:     post.User.Email,
+			Phone:     post.User.Phone,
+			Avatar:    post.User.Avatar,
+			Bio:       post.User.Bio,
+			Website:   post.User.Website,
+			Location:  post.User.Location,
+			CreatedAt: post.User.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+	}
+
+	return dto.AdminPostListResponse{
+		ID:             post.ID,
+		UserID:         post.UserID,
+		Title:          post.Title,
+		Content:        post.Content,
+		Images:         images,
+		Status:         string(post.Status),
+		LikesCount:     post.LikesCount,
+		CommentsCount:  post.CommentsCount,
+		FavoritesCount: post.FavoritesCount,
+		ViewsCount:     post.ViewsCount,
+		IsPinned:       post.IsPinned,
+		IsFeatured:     post.IsFeatured,
+		IsLocked:       post.IsLocked,
+		RejectReason:   post.RejectReason,
+		ReviewedAt:     dto.FormatTimePointer(post.ReviewedAt),
+		ReviewedBy:     post.ReviewedBy,
+		CreatedAt:      post.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:      post.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		Author:         author,
+	}
+}
+
+// convertPostToAdminDetailResponse 转换帖子为管理端详情响应
+func convertPostToAdminDetailResponse(post *model.Post) *dto.AdminPostDetailResponse {
+	images := make([]dto.PostImageResponse, len(post.Images))
+	for i, img := range post.Images {
+		images[i] = dto.PostImageResponse{
+			ID:           img.ID,
+			URL:          img.URL,
+			ThumbnailURL: img.ThumbnailURL,
+			Width:        img.Width,
+			Height:       img.Height,
+		}
+	}
+
+	var author *dto.UserResponse
+	if post.User != nil {
+		author = &dto.UserResponse{
+			ID:        post.User.ID,
+			Username:  post.User.Username,
+			Nickname:  post.User.Nickname,
+			Email:     post.User.Email,
+			Phone:     post.User.Phone,
+			Avatar:    post.User.Avatar,
+			Bio:       post.User.Bio,
+			Website:   post.User.Website,
+			Location:  post.User.Location,
+			CreatedAt: post.User.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		}
+	}
+
+	return &dto.AdminPostDetailResponse{
+		ID:             post.ID,
+		UserID:         post.UserID,
+		CommunityID:    post.CommunityID,
+		Title:          post.Title,
+		Content:        post.Content,
+		Images:         images,
+		Status:         string(post.Status),
+		LikesCount:     post.LikesCount,
+		CommentsCount:  post.CommentsCount,
+		FavoritesCount: post.FavoritesCount,
+		SharesCount:    post.SharesCount,
+		ViewsCount:     post.ViewsCount,
+		HotScore:       post.HotScore,
+		IsPinned:       post.IsPinned,
+		IsFeatured:     post.IsFeatured,
+		IsLocked:       post.IsLocked,
+		IsVote:         post.IsVote,
+		RejectReason:   post.RejectReason,
+		ReviewedAt:     dto.FormatTimePointer(post.ReviewedAt),
+		ReviewedBy:     post.ReviewedBy,
+		CreatedAt:      post.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:      post.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		Author:         author,
+	}
+}

internal/service/admin_user_service.go

@@ -0,0 +1,145 @@
+package service
+
+import (
+	"context"
+
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/repository"
+)
+
+// AdminUserService 管理端用户服务接口
+type AdminUserService interface {
+	// GetUserList 获取用户列表（分页、搜索、状态筛选）
+	GetUserList(ctx context.Context, page, pageSize int, keyword, status string) ([]dto.AdminUserListResponse, int64, error)
+	// GetUserDetail 获取用户详情（含统计信息）
+	GetUserDetail(ctx context.Context, userID string) (*dto.AdminUserDetailResponse, error)
+	// UpdateUserStatus 更新用户状态
+	UpdateUserStatus(ctx context.Context, userID string, status model.UserStatus) (*dto.AdminUserDetailResponse, error)
+}
+
+// adminUserServiceImpl 管理端用户服务实现
+type adminUserServiceImpl struct {
+	userRepo *repository.UserRepository
+}
+
+// NewAdminUserService 创建管理端用户服务
+func NewAdminUserService(userRepo *repository.UserRepository) AdminUserService {
+	return &adminUserServiceImpl{
+		userRepo: userRepo,
+	}
+}
+
+// GetUserList 获取用户列表
+func (s *adminUserServiceImpl) GetUserList(ctx context.Context, page, pageSize int, keyword, status string) ([]dto.AdminUserListResponse, int64, error) {
+	users, total, err := s.userRepo.AdminList(page, pageSize, keyword, status)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	responses := make([]dto.AdminUserListResponse, len(users))
+	for i, user := range users {
+		responses[i] = convertUserToAdminListResponse(user)
+	}
+
+	return responses, total, nil
+}
+
+// GetUserDetail 获取用户详情
+func (s *adminUserServiceImpl) GetUserDetail(ctx context.Context, userID string) (*dto.AdminUserDetailResponse, error) {
+	user, err := s.userRepo.GetByID(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 获取帖子数
+	postsCount, _ := s.userRepo.GetPostsCount(userID)
+
+	// 获取评论数
+	commentsCount, _ := s.userRepo.GetCommentsCount(userID)
+
+	return convertUserToAdminDetailResponse(user, postsCount, commentsCount), nil
+}
+
+// UpdateUserStatus 更新用户状态
+func (s *adminUserServiceImpl) UpdateUserStatus(ctx context.Context, userID string, status model.UserStatus) (*dto.AdminUserDetailResponse, error) {
+	// 先检查用户是否存在
+	user, err := s.userRepo.GetByID(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 更新状态
+	if err := s.userRepo.UpdateStatus(userID, status); err != nil {
+		return nil, err
+	}
+
+	// 重新获取用户信息
+	user, err = s.userRepo.GetByID(userID)
+	if err != nil {
+		return nil, err
+	}
+
+	// 获取统计信息
+	postsCount, _ := s.userRepo.GetPostsCount(userID)
+	commentsCount, _ := s.userRepo.GetCommentsCount(userID)
+
+	return convertUserToAdminDetailResponse(user, postsCount, commentsCount), nil
+}
+
+// convertUserToAdminListResponse 转换用户为管理端列表响应
+func convertUserToAdminListResponse(user *model.User) dto.AdminUserListResponse {
+	var lastLoginAt string
+	if user.LastLoginAt != nil {
+		lastLoginAt = user.LastLoginAt.Format("2006-01-02 15:04:05")
+	}
+
+	return dto.AdminUserListResponse{
+		ID:             user.ID,
+		Username:       user.Username,
+		Nickname:       user.Nickname,
+		Email:          user.Email,
+		Phone:          user.Phone,
+		EmailVerified:  user.EmailVerified,
+		Avatar:         user.Avatar,
+		Status:         string(user.Status),
+		PostsCount:     user.PostsCount,
+		FollowersCount: user.FollowersCount,
+		FollowingCount: user.FollowingCount,
+		LastLoginAt:    lastLoginAt,
+		LastLoginIP:    user.LastLoginIP,
+		CreatedAt:      user.CreatedAt.Format("2006-01-02 15:04:05"),
+	}
+}
+
+// convertUserToAdminDetailResponse 转换用户为管理端详情响应
+func convertUserToAdminDetailResponse(user *model.User, postsCount, commentsCount int64) *dto.AdminUserDetailResponse {
+	var lastLoginAt string
+	if user.LastLoginAt != nil {
+		lastLoginAt = user.LastLoginAt.Format("2006-01-02 15:04:05")
+	}
+
+	return &dto.AdminUserDetailResponse{
+		ID:             user.ID,
+		Username:       user.Username,
+		Nickname:       user.Nickname,
+		Email:          user.Email,
+		Phone:          user.Phone,
+		EmailVerified:  user.EmailVerified,
+		Avatar:         user.Avatar,
+		CoverURL:       user.CoverURL,
+		Bio:            user.Bio,
+		Website:        user.Website,
+		Location:       user.Location,
+		IsVerified:     user.IsVerified,
+		Status:         string(user.Status),
+		PostsCount:     int(postsCount),
+		CommentsCount:  commentsCount,
+		FollowersCount: user.FollowersCount,
+		FollowingCount: user.FollowingCount,
+		LastLoginAt:    lastLoginAt,
+		LastLoginIP:    user.LastLoginIP,
+		CreatedAt:      user.CreatedAt.Format("2006-01-02 15:04:05"),
+		UpdatedAt:      user.UpdatedAt.Format("2006-01-02 15:04:05"),
+	}
+}

internal/service/casbin_service.go

@@ -9,7 +9,7 @@ import (
 	"carrot_bbs/internal/config"
 	"carrot_bbs/internal/repository"
 
-	"github.com/casbin/casbin/v2"
+	"github.com/casbin/casbin/v3"
 )
 
 // CasbinService Casbin 权限服务接口
@@ -43,6 +43,15 @@ type CasbinService interface {
 
 	// ClearCache 清除权限缓存
 	ClearCache(ctx context.Context) error
+
+	// GetPermissionsForRole 获取角色的所有权限
+	GetPermissionsForRole(ctx context.Context, role string) ([][]string, error)
+
+	// UpdatePermissionsForRole 更新角色的权限（先删除所有权限，再添加新权限）
+	UpdatePermissionsForRole(ctx context.Context, role string, permissions [][]string) error
+
+	// GetAllPermissions 获取系统中所有权限定义
+	GetAllPermissions(ctx context.Context) [][]string
 }
 
 type casbinService struct {
@@ -223,3 +232,34 @@ func (s *casbinService) clearUserCache(ctx context.Context, userID string) error
 	}
 	return nil
 }
+
+func (s *casbinService) GetPermissionsForRole(ctx context.Context, role string) ([][]string, error) {
+	return s.enforcer.GetPermissionsForUser(role)
+}
+
+func (s *casbinService) UpdatePermissionsForRole(ctx context.Context, role string, permissions [][]string) error {
+	// 先删除该角色的所有权限
+	_, err := s.enforcer.DeletePermissionsForUser(role)
+	if err != nil {
+		return err
+	}
+
+	// 添加新权限
+	for _, perm := range permissions {
+		if len(perm) >= 2 {
+			resource := perm[0]
+			action := perm[1]
+			if _, err := s.enforcer.AddPolicy(role, resource, action); err != nil {
+				return err
+			}
+		}
+	}
+
+	// 清除缓存
+	return s.ClearCache(ctx)
+}
+
+func (s *casbinService) GetAllPermissions(ctx context.Context) [][]string {
+	permissions, _ := s.enforcer.GetPolicy()
+	return permissions
+}

internal/service/role_service.go

@@ -24,6 +24,37 @@ type RoleService interface {
 
 	// GetRole 获取角色详情
 	GetRole(ctx context.Context, name string) (*model.Role, error)
+
+	// GetRoleDetail 获取角色详情（包含用户数量和权限）
+	GetRoleDetail(ctx context.Context, name string) (*RoleDetail, error)
+
+	// GetRolePermissions 获取角色的权限列表
+	GetRolePermissions(ctx context.Context, name string) ([]Permission, error)
+
+	// GetAllPermissions 获取系统中所有权限定义
+	GetAllPermissions(ctx context.Context) ([]Permission, error)
+
+	// UpdateRolePermissions 更新角色权限
+	UpdateRolePermissions(ctx context.Context, roleName string, permissions []Permission) error
+}
+
+// Permission 权限定义
+type Permission struct {
+	Resource string `json:"resource"`
+	Action   string `json:"action"`
+}
+
+// RoleDetail 角色详情
+type RoleDetail struct {
+	Name        string       `json:"name"`
+	DisplayName string       `json:"display_name"`
+	Description string       `json:"description"`
+	ParentRole  *string      `json:"parent_role"`
+	Priority    int          `json:"priority"`
+	UserCount   int64        `json:"user_count"`
+	Permissions []Permission `json:"permissions"`
+	CreatedAt   string       `json:"created_at"`
+	UpdatedAt   string       `json:"updated_at"`
 }
 
 type roleService struct {
@@ -114,3 +145,106 @@ func (s *roleService) GetAllRoles(ctx context.Context) ([]model.Role, error) {
 func (s *roleService) GetRole(ctx context.Context, name string) (*model.Role, error) {
 	return s.roleRepo.GetRole(ctx, name)
 }
+
+func (s *roleService) GetRoleDetail(ctx context.Context, name string) (*RoleDetail, error) {
+	role, err := s.roleRepo.GetRole(ctx, name)
+	if err != nil {
+		return nil, apperrors.ErrRoleNotFound
+	}
+
+	// 获取用户数量
+	userCount, err := s.roleRepo.GetRoleUserCount(ctx, name)
+	if err != nil {
+		userCount = 0
+	}
+
+	// 获取权限
+	permissions, err := s.casbinSvc.GetPermissionsForRole(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	perms := make([]Permission, 0)
+	for _, p := range permissions {
+		if len(p) >= 2 {
+			perms = append(perms, Permission{
+				Resource: p[0],
+				Action:   p[1],
+			})
+		}
+	}
+
+	return &RoleDetail{
+		Name:        role.Name,
+		DisplayName: role.DisplayName,
+		Description: role.Description,
+		ParentRole:  role.ParentRole,
+		Priority:    role.Priority,
+		UserCount:   userCount,
+		Permissions: perms,
+		CreatedAt:   role.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
+		UpdatedAt:   role.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
+	}, nil
+}
+
+func (s *roleService) GetRolePermissions(ctx context.Context, name string) ([]Permission, error) {
+	// 检查角色是否存在
+	_, err := s.roleRepo.GetRole(ctx, name)
+	if err != nil {
+		return nil, apperrors.ErrRoleNotFound
+	}
+
+	permissions, err := s.casbinSvc.GetPermissionsForRole(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	// 初始化为空数组，避免 JSON 序列化为 null
+	perms := make([]Permission, 0)
+	for _, p := range permissions {
+		if len(p) >= 2 {
+			perms = append(perms, Permission{
+				Resource: p[0],
+				Action:   p[1],
+			})
+		}
+	}
+	return perms, nil
+}
+
+func (s *roleService) GetAllPermissions(ctx context.Context) ([]Permission, error) {
+	permissions := s.casbinSvc.GetAllPermissions(ctx)
+
+	perms := make([]Permission, 0)
+	for _, p := range permissions {
+		if len(p) >= 3 {
+			// p[0] 是角色名，p[1] 是资源，p[2] 是操作
+			perms = append(perms, Permission{
+				Resource: p[1],
+				Action:   p[2],
+			})
+		}
+	}
+	return perms, nil
+}
+
+func (s *roleService) UpdateRolePermissions(ctx context.Context, roleName string, permissions []Permission) error {
+	// 检查角色是否存在
+	_, err := s.roleRepo.GetRole(ctx, roleName)
+	if err != nil {
+		return apperrors.ErrRoleNotFound
+	}
+
+	// 不能修改超级管理员权限
+	if roleName == model.RoleSuperAdmin {
+		return apperrors.ErrCannotModifySuperAdmin
+	}
+
+	// 转换权限格式
+	var perms [][]string
+	for _, p := range permissions {
+		perms = append(perms, []string{p.Resource, p.Action})
+	}
+
+	return s.casbinSvc.UpdatePermissionsForRole(ctx, roleName, perms)
+}