feat(grouping): 添加删除分组功能

- 在前端增加删除分组的 API 接口和相应的方法
- 在后端实现删除分组的接口
- 修改分组实体类，使用 Snowflake算法生成 ID
- 在首页组件中添加删除分组的按钮和相关逻辑
- 删除分组时，将分组下的所有笔记移动到"未分类"目录

biji-qianduan/src/api/CommonApi.js

@@ -77,6 +77,9 @@ export const updateGroupingName = (id, newName) => {
     return axiosApi.put(`/api/groupings/${id}`, { grouping: newName });
 }
 
+// 删除分组
+export const deleteGrouping = (id) => axiosApi.delete(`/api/groupings/${id}`);
+
 // 更新Markdown文件标题
 export const updateMarkdownTitle = (id, newTitle) => {
     return axiosApi.put(`/api/markdown/${id}/title`, newTitle, {

biji-qianduan/src/components/HomePage.vue

@@ -208,9 +208,10 @@ import {
   updateMarkdown, uploadImage,
   searchMarkdown,
   updateGroupingName,
-  updateMarkdownTitle
+  updateMarkdownTitle,
+  deleteGrouping as apiDeleteGrouping
 } from '@/api/CommonApi.js'
-import { Plus, Fold, Expand, Folder, Document, Search, Edit } from "@element-plus/icons-vue";
+import { Plus, Fold, Expand, Folder, Document, Search, Edit, Delete } from "@element-plus/icons-vue";
 import { useUserStore } from '../stores/user';
 import { useRouter } from 'vue-router';
 
@@ -431,7 +432,8 @@ const renderMenu = (item) => {
       title: () => h('div', { class: 'menu-item-title', onClick: () => selectFile(item) }, [
         h(ElIcon, () => h(Folder)),
         h('span', null, item.grouping),
-        h(ElIcon, { class: 'edit-icon', onClick: (e) => { e.stopPropagation(); openRenameDialog(item, 'group'); } }, () => h(Edit))
+        h(ElIcon, { class: 'edit-icon', onClick: (e) => { e.stopPropagation(); openRenameDialog(item, 'group'); } }, () => h(Edit)),
+        h(ElIcon, { class: 'delete-icon', onClick: (e) => { e.stopPropagation(); handleDeleteGroup(item); } }, () => h(Delete))
       ]),
       default: () => item.children.map(child => renderMenu(child))
     });
@@ -440,7 +442,8 @@ const renderMenu = (item) => {
     default: () => h('div', { class: 'menu-item-title' }, [
       h(ElIcon, () => h(Folder)),
       h('span', null, item.grouping),
-      h(ElIcon, { class: 'edit-icon', onClick: (e) => { e.stopPropagation(); openRenameDialog(item, 'group'); } }, () => h(Edit))
+      h(ElIcon, { class: 'edit-icon', onClick: (e) => { e.stopPropagation(); openRenameDialog(item, 'group'); } }, () => h(Edit)),
+      h(ElIcon, { class: 'delete-icon', onClick: (e) => { e.stopPropagation(); handleDeleteGroup(item); } }, () => h(Delete))
     ])
   });
 };
@@ -757,6 +760,41 @@ const handleMoveNote = async () => {
     ElMessage.error('移动失败: ' + error.message);
   }
 };
+
+const handleDeleteGroup = async (group) => {
+  try {
+    await ElMessageBox.confirm(
+      '确定要删除这个分类吗？分类下的所有笔记将被移动到“未分类”。',
+      '警告',
+      {
+        confirmButtonText: '确定',
+        cancelButtonText: '取消',
+        type: 'warning',
+      }
+    );
+
+    const unclassifiedGroup = categoryTree.value.find(g => g.grouping === '未分类');
+    if (!unclassifiedGroup) {
+      ElMessage.error('未找到“未分类”目录，无法移动笔记。');
+      return;
+    }
+
+    const notesToMove = await markdownList(group.id);
+    if (notesToMove.data && notesToMove.data.length > 0) {
+      for (const note of notesToMove.data) {
+        await updateMarkdown({ ...note, groupingId: unclassifiedGroup.id });
+      }
+    }
+
+    await apiDeleteGrouping(group.id);
+    ElMessage.success('分类删除成功');
+    await fetchGroupings();
+  } catch (error) {
+    if (error !== 'cancel') {
+      ElMessage.error('删除失败: ' + (error.message || ''));
+    }
+  }
+};
 </script>
 
 <style>
@@ -900,19 +938,24 @@ const handleMoveNote = async () => {
   text-overflow: ellipsis;
 }
 
-.edit-icon {
+.edit-icon, .delete-icon {
   cursor: pointer;
   margin-left: 8px;
   opacity: 0;
   transition: opacity var(--transition-duration) ease;
   color: var(--text-color-secondary);
 }
+.delete-icon:hover {
+  color: var(--el-color-danger);
+}
 .edit-icon:hover {
   color: var(--primary-color);
 }
 
 .el-sub-menu__title:hover .edit-icon,
+.el-sub-menu__title:hover .delete-icon,
 .el-menu-item:hover .edit-icon,
+.el-menu-item:hover .delete-icon,
 .preview-title:hover .edit-icon {
   opacity: 1;
 }