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/handler/admin_comment_handler.go

@@ -0,0 +1,151 @@
+package handler
+
+import (
+	"strconv"
+
+	"carrot_bbs/internal/dto"
+	"carrot_bbs/internal/model"
+	"carrot_bbs/internal/pkg/response"
+	"carrot_bbs/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// AdminCommentHandler 管理端评论处理器
+type AdminCommentHandler struct {
+	adminCommentService service.AdminCommentService
+}
+
+// NewAdminCommentHandler 创建管理端评论处理器
+func NewAdminCommentHandler(adminCommentService service.AdminCommentService) *AdminCommentHandler {
+	return &AdminCommentHandler{
+		adminCommentService: adminCommentService,
+	}
+}
+
+// GetCommentList 获取评论列表
+// GET /api/v1/admin/comments
+func (h *AdminCommentHandler) GetCommentList(c *gin.Context) {
+	// 解析分页参数
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+
+	if page <= 0 {
+		page = 1
+	}
+	if pageSize <= 0 || pageSize > 100 {
+		pageSize = 20
+	}
+
+	// 获取筛选参数
+	keyword := c.Query("keyword")
+	postID := c.Query("post_id")
+	authorID := c.Query("author_id")
+	status := c.Query("status")
+	startDate := c.Query("start_date")
+	endDate := c.Query("end_date")
+
+	// 验证状态参数
+	if status != "" && status != string(model.CommentStatusDraft) &&
+		status != string(model.CommentStatusPending) &&
+		status != string(model.CommentStatusPublished) &&
+		status != string(model.CommentStatusRejected) &&
+		status != string(model.CommentStatusDeleted) {
+		response.BadRequest(c, "invalid status value")
+		return
+	}
+
+	comments, total, err := h.adminCommentService.GetCommentList(c.Request.Context(), page, pageSize, keyword, postID, authorID, status, startDate, endDate)
+	if err != nil {
+		response.InternalServerError(c, "failed to get comment list")
+		return
+	}
+
+	response.Paginated(c, comments, total, page, pageSize)
+}
+
+// GetCommentDetail 获取评论详情
+// GET /api/v1/admin/comments/:id
+func (h *AdminCommentHandler) GetCommentDetail(c *gin.Context) {
+	commentID := c.Param("id")
+	if commentID == "" {
+		response.BadRequest(c, "comment id is required")
+		return
+	}
+
+	commentDetail, err := h.adminCommentService.GetCommentDetail(c.Request.Context(), commentID)
+	if err != nil {
+		response.NotFound(c, "comment not found")
+		return
+	}
+
+	response.Success(c, commentDetail)
+}
+
+// DeleteComment 删除评论
+// DELETE /api/v1/admin/comments/:id
+func (h *AdminCommentHandler) DeleteComment(c *gin.Context) {
+	commentID := c.Param("id")
+	if commentID == "" {
+		response.BadRequest(c, "comment id is required")
+		return
+	}
+
+	err := h.adminCommentService.DeleteComment(c.Request.Context(), commentID)
+	if err != nil {
+		response.HandleError(c, err, "failed to delete comment")
+		return
+	}
+
+	response.Success(c, dto.SuccessResponse{
+		Success: true,
+		Message: "comment deleted successfully",
+	})
+}
+
+// BatchDeleteComments 批量删除评论
+// POST /api/v1/admin/comments/batch-delete
+func (h *AdminCommentHandler) BatchDeleteComments(c *gin.Context) {
+	var req dto.AdminBatchDeleteCommentsRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "invalid request body: "+err.Error())
+		return
+	}
+
+	result, err := h.adminCommentService.BatchDeleteComments(c.Request.Context(), req.IDs)
+	if err != nil {
+		response.InternalServerError(c, "failed to batch delete comments")
+		return
+	}
+
+	response.Success(c, result)
+}
+
+// GetPostComments 获取帖子的评论列表
+// GET /api/v1/admin/posts/:postId/comments
+func (h *AdminCommentHandler) GetPostComments(c *gin.Context) {
+	postID := c.Param("postId")
+	if postID == "" {
+		response.BadRequest(c, "post id is required")
+		return
+	}
+
+	// 解析分页参数
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+
+	if page <= 0 {
+		page = 1
+	}
+	if pageSize <= 0 || pageSize > 100 {
+		pageSize = 20
+	}
+
+	comments, total, err := h.adminCommentService.GetCommentsByPostID(c.Request.Context(), postID, page, pageSize)
+	if err != nil {
+		response.InternalServerError(c, "failed to get post comments")
+		return
+	}
+
+	response.Paginated(c, comments, total, page, pageSize)
+}