feat: allow post authors to pin comments

feat: add lottery win notification

backend/src/main/java/com/openisle/controller/AdminCommentController.java

@@ -0,0 +1,29 @@
+package com.openisle.controller;
+
+import com.openisle.dto.CommentDto;
+import com.openisle.mapper.CommentMapper;
+import com.openisle.service.CommentService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
+
+/**
+ * Endpoints for administrators to manage comments.
+ */
+@RestController
+@RequestMapping("/api/admin/comments")
+@RequiredArgsConstructor
+public class AdminCommentController {
+    private final CommentService commentService;
+    private final CommentMapper commentMapper;
+
+    @PostMapping("/{id}/pin")
+    public CommentDto pin(@PathVariable Long id, Authentication auth) {
+        return commentMapper.toDto(commentService.pinComment(auth.getName(), id));
+    }
+
+    @PostMapping("/{id}/unpin")
+    public CommentDto unpin(@PathVariable Long id, Authentication auth) {
+        return commentMapper.toDto(commentService.unpinComment(auth.getName(), id));
+    }
+}

backend/src/main/java/com/openisle/controller/CommentController.java

@@ -85,4 +85,16 @@ public class CommentController {
         commentService.deleteComment(auth.getName(), id);
         log.debug("deleteComment completed for comment {}", id);
     }
+
+    @PostMapping("/comments/{id}/pin")
+    public CommentDto pinComment(@PathVariable Long id, Authentication auth) {
+        log.debug("pinComment called by user {} for comment {}", auth.getName(), id);
+        return commentMapper.toDto(commentService.pinComment(auth.getName(), id));
+    }
+
+    @PostMapping("/comments/{id}/unpin")
+    public CommentDto unpinComment(@PathVariable Long id, Authentication auth) {
+        log.debug("unpinComment called by user {} for comment {}", auth.getName(), id);
+        return commentMapper.toDto(commentService.unpinComment(auth.getName(), id));
+    }
 }

backend/src/main/java/com/openisle/dto/CommentDto.java

@@ -13,6 +13,7 @@ public class CommentDto {
     private Long id;
     private String content;
     private LocalDateTime createdAt;
+    private LocalDateTime pinnedAt;
     private AuthorDto author;
     private List<CommentDto> replies;
     private List<ReactionDto> reactions;

backend/src/main/java/com/openisle/mapper/CommentMapper.java

@@ -24,6 +24,7 @@ public class CommentMapper {
         dto.setId(comment.getId());
         dto.setContent(comment.getContent());
         dto.setCreatedAt(comment.getCreatedAt());
+        dto.setPinnedAt(comment.getPinnedAt());
         dto.setAuthor(userMapper.toAuthorDto(comment.getAuthor()));
         dto.setReward(0);
         return dto;

backend/src/main/java/com/openisle/model/Comment.java

@@ -38,4 +38,7 @@ public class Comment {
     @JoinColumn(name = "parent_id")
     private Comment parent;
 
+    @Column
+    private LocalDateTime pinnedAt;
+
 }

backend/src/main/java/com/openisle/service/CommentService.java

@@ -23,6 +23,7 @@ import java.util.List;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.transaction.annotation.Transactional;
+import java.time.LocalDateTime;
 
 @Service
 @RequiredArgsConstructor
@@ -129,13 +130,26 @@ public class CommentService {
         Post post = postRepository.findById(postId)
                 .orElseThrow(() -> new com.openisle.exception.NotFoundException("Post not found"));
         List<Comment> list = commentRepository.findByPostAndParentIsNullOrderByCreatedAtAsc(post);
-        if (sort == CommentSort.NEWEST) {
-            list.sort(java.util.Comparator.comparing(Comment::getCreatedAt).reversed());
-        } else if (sort == CommentSort.MOST_INTERACTIONS) {
-            list.sort((a, b) -> Integer.compare(interactionCount(b), interactionCount(a)));
+        java.util.List<Comment> pinned = new java.util.ArrayList<>();
+        java.util.List<Comment> others = new java.util.ArrayList<>();
+        for (Comment c : list) {
+            if (c.getPinnedAt() != null) {
+                pinned.add(c);
+            } else {
+                others.add(c);
+            }
         }
-        log.debug("getCommentsForPost returning {} comments", list.size());
-        return list;
+        pinned.sort(java.util.Comparator.comparing(Comment::getPinnedAt).reversed());
+        if (sort == CommentSort.NEWEST) {
+            others.sort(java.util.Comparator.comparing(Comment::getCreatedAt).reversed());
+        } else if (sort == CommentSort.MOST_INTERACTIONS) {
+            others.sort((a, b) -> Integer.compare(interactionCount(b), interactionCount(a)));
+        }
+        java.util.List<Comment> result = new java.util.ArrayList<>();
+        result.addAll(pinned);
+        result.addAll(others);
+        log.debug("getCommentsForPost returning {} comments", result.size());
+        return result;
     }
 
     public List<Comment> getReplies(Long parentId) {
@@ -223,6 +237,32 @@ public class CommentService {
         log.debug("deleteCommentCascade removed comment {}", comment.getId());
     }
 
+    @Transactional
+    public Comment pinComment(String username, Long id) {
+        Comment c = commentRepository.findById(id)
+                .orElseThrow(() -> new com.openisle.exception.NotFoundException("Comment not found"));
+        User user = userRepository.findByUsername(username)
+                .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
+        if (!user.getId().equals(c.getPost().getAuthor().getId()) && user.getRole() != Role.ADMIN) {
+            throw new IllegalArgumentException("Unauthorized");
+        }
+        c.setPinnedAt(LocalDateTime.now());
+        return commentRepository.save(c);
+    }
+
+    @Transactional
+    public Comment unpinComment(String username, Long id) {
+        Comment c = commentRepository.findById(id)
+                .orElseThrow(() -> new com.openisle.exception.NotFoundException("Comment not found"));
+        User user = userRepository.findByUsername(username)
+                .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
+        if (!user.getId().equals(c.getPost().getAuthor().getId()) && user.getRole() != Role.ADMIN) {
+            throw new IllegalArgumentException("Unauthorized");
+        }
+        c.setPinnedAt(null);
+        return commentRepository.save(c);
+    }
+
     private int interactionCount(Comment comment) {
         int reactions = reactionRepository.findByComment(comment).size();
         int replies = commentRepository.findByParentOrderByCreatedAtAsc(comment).size();

backend/src/main/resources/db/migration/V1__add_pinned_at_to_comments.sql

@@ -0,0 +1 @@
+ALTER TABLE comments ADD COLUMN pinned_at DATETIME(6) NULL;

frontend_nuxt/components/CommentItem.vue

@@ -22,6 +22,7 @@
             :to="`/users/${comment.userId}?tab=achievements`"
             >{{ getMedalTitle(comment.medal) }}</router-link
           >
+          <i v-if="comment.pinned" class="fas fa-thumbtack pin-icon"></i>
           <span v-if="level >= 2">
             <i class="fas fa-reply reply-icon"></i>
             <span class="user-name reply-user-name">{{ comment.parentUserName }}</span>
@@ -74,6 +75,7 @@
               :comment="item"
               :level="level + 1"
               :default-show-replies="item.openReplies"
+              :post-author-id="postAuthorId"
             />
           </template>
         </BaseTimeline>
@@ -119,6 +121,10 @@ const CommentItem = {
       type: Boolean,
       default: false,
     },
+    postAuthorId: {
+      type: [Number, String],
+      required: true,
+    },
   },
   setup(props, { emit }) {
     const router = useRouter()
@@ -171,12 +177,22 @@ const CommentItem = {
     })
 
     const isAuthor = computed(() => authState.username === props.comment.userName)
+    const isPostAuthor = computed(() => Number(authState.userId) === Number(props.postAuthorId))
     const isAdmin = computed(() => authState.role === 'ADMIN')
-    const commentMenuItems = computed(() =>
-      isAuthor.value || isAdmin.value
-        ? [{ text: '删除评论', color: 'red', onClick: () => deleteComment() }]
-        : [],
-    )
+    const commentMenuItems = computed(() => {
+      const items = []
+      if (isAuthor.value || isAdmin.value) {
+        items.push({ text: '删除评论', color: 'red', onClick: () => deleteComment() })
+      }
+      if (isAdmin.value || isPostAuthor.value) {
+        if (props.comment.pinned) {
+          items.push({ text: '取消置顶', onClick: () => unpinComment() })
+        } else {
+          items.push({ text: '置顶', onClick: () => pinComment() })
+        }
+      }
+      return items
+    })
     const deleteComment = async () => {
       const token = getToken()
       if (!token) {
@@ -196,6 +212,46 @@ const CommentItem = {
         toast.error('操作失败')
       }
     }
+    const pinComment = async () => {
+      const token = getToken()
+      if (!token) {
+        toast.error('请先登录')
+        return
+      }
+      const url = isAdmin.value
+        ? `${API_BASE_URL}/api/admin/comments/${props.comment.id}/pin`
+        : `${API_BASE_URL}/api/comments/${props.comment.id}/pin`
+      const res = await fetch(url, {
+        method: 'POST',
+        headers: { Authorization: `Bearer ${token}` },
+      })
+      if (res.ok) {
+        props.comment.pinned = true
+        toast.success('已置顶')
+      } else {
+        toast.error('操作失败')
+      }
+    }
+    const unpinComment = async () => {
+      const token = getToken()
+      if (!token) {
+        toast.error('请先登录')
+        return
+      }
+      const url = isAdmin.value
+        ? `${API_BASE_URL}/api/admin/comments/${props.comment.id}/unpin`
+        : `${API_BASE_URL}/api/comments/${props.comment.id}/unpin`
+      const res = await fetch(url, {
+        method: 'POST',
+        headers: { Authorization: `Bearer ${token}` },
+      })
+      if (res.ok) {
+        props.comment.pinned = false
+        toast.success('已取消置顶')
+      } else {
+        toast.error('操作失败')
+      }
+    }
     const submitReply = async (parentUserName, text, clear) => {
       if (!text.trim()) return
       isWaitingForReply.value = true
@@ -284,6 +340,9 @@ const CommentItem = {
       isWaitingForReply,
       commentMenuItems,
       deleteComment,
+      pinComment,
+      unpinComment,
+      isPostAuthor,
       lightboxVisible,
       lightboxIndex,
       lightboxImgs,
@@ -370,6 +429,12 @@ export default CommentItem
   margin-left: 10px;
 }
 
+.pin-icon {
+  font-size: 12px;
+  margin-left: 10px;
+  opacity: 0.6;
+}
+
 @keyframes highlight {
   from {
     background-color: yellow;

frontend_nuxt/pages/posts/[id]/index.vue

@@ -195,6 +195,7 @@
               :comment="item"
               :level="0"
               :default-show-replies="item.openReplies"
+              :post-author-id="author.id"
               @deleted="onCommentDeleted"
             />
           </template>
@@ -405,6 +406,7 @@ export default {
       avatar: c.author.avatar,
       text: c.content,
       reactions: c.reactions || [],
+      pinned: !!c.pinnedAt,
       reply: (c.replies || []).map((r) => mapComment(r, c.author.username, level + 1)),
       openReplies: level === 0,
       src: c.author.avatar,