feat(Hooks): 添加标签管理 Hooks

- 添加 useTags 全局标签统计 Hook
- 添加 useConversationTags 对话标签管理 Hook
- 添加 useTagFilter 标签筛选 Hook
- 支持标签增删改查、AI 自动生成、筛选等功能

src/hooks/useTags.ts

@@ -0,0 +1,229 @@
+'use client';
+
+import { useState, useEffect, useCallback } from 'react';
+import type { TagStats, SuggestedTag, AutoTagResponse, AllTagsResponse } from '@/types/tags';
+
+/**
+ * 全局标签管理 Hook - 获取用户所有标签统计
+ */
+export function useTags() {
+  const [tags, setTags] = useState<TagStats[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  const fetchTags = useCallback(async () => {
+    try {
+      setLoading(true);
+      setError(null);
+      const response = await fetch('/api/tags');
+      if (!response.ok) {
+        throw new Error('获取标签失败');
+      }
+      const data: AllTagsResponse = await response.json();
+      setTags(data.tags);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : '未知错误');
+    } finally {
+      setLoading(false);
+    }
+  }, []);
+
+  useEffect(() => {
+    fetchTags();
+  }, [fetchTags]);
+
+  return {
+    tags,
+    loading,
+    error,
+    refetch: fetchTags,
+  };
+}
+
+/**
+ * 对话标签管理 Hook - 管理单个对话的标签
+ */
+export function useConversationTags(conversationId: string | null) {
+  const [tags, setTags] = useState<string[]>([]);
+  const [loading, setLoading] = useState(false);
+  const [updating, setUpdating] = useState(false);
+  const [generating, setGenerating] = useState(false);
+  const [suggestedTags, setSuggestedTags] = useState<SuggestedTag[]>([]);
+  const [error, setError] = useState<string | null>(null);
+
+  // 获取对话标签
+  const fetchTags = useCallback(async () => {
+    if (!conversationId) {
+      setTags([]);
+      return;
+    }
+
+    try {
+      setLoading(true);
+      setError(null);
+      const response = await fetch(`/api/conversations/${conversationId}/tags`);
+      if (!response.ok) {
+        throw new Error('获取标签失败');
+      }
+      const data = await response.json();
+      setTags(data.tags || []);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : '未知错误');
+    } finally {
+      setLoading(false);
+    }
+  }, [conversationId]);
+
+  // 更新标签
+  const updateTags = useCallback(async (newTags: string[]) => {
+    if (!conversationId) return;
+
+    try {
+      setUpdating(true);
+      setError(null);
+      const response = await fetch(`/api/conversations/${conversationId}/tags`, {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ tags: newTags }),
+      });
+      if (!response.ok) {
+        const data = await response.json();
+        throw new Error(data.error || '更新标签失败');
+      }
+      const data = await response.json();
+      setTags(data.tags || []);
+      return data.tags;
+    } catch (err) {
+      setError(err instanceof Error ? err.message : '未知错误');
+      throw err;
+    } finally {
+      setUpdating(false);
+    }
+  }, [conversationId]);
+
+  // 添加单个标签
+  const addTag = useCallback(async (tag: string) => {
+    const trimmedTag = tag.trim();
+    if (!trimmedTag || tags.includes(trimmedTag)) return;
+    const newTags = [...tags, trimmedTag];
+    return updateTags(newTags);
+  }, [tags, updateTags]);
+
+  // 移除单个标签
+  const removeTag = useCallback(async (tag: string) => {
+    const newTags = tags.filter((t) => t !== tag);
+    return updateTags(newTags);
+  }, [tags, updateTags]);
+
+  // AI 自动生成标签
+  const generateTags = useCallback(async () => {
+    if (!conversationId) return;
+
+    try {
+      setGenerating(true);
+      setError(null);
+      setSuggestedTags([]);
+
+      const response = await fetch(`/api/conversations/${conversationId}/tags/auto`, {
+        method: 'POST',
+      });
+
+      if (!response.ok) {
+        const data = await response.json();
+        throw new Error(data.error || '生成标签失败');
+      }
+
+      const data: AutoTagResponse = await response.json();
+      setSuggestedTags(data.suggestedTags);
+      return data.suggestedTags;
+    } catch (err) {
+      setError(err instanceof Error ? err.message : '未知错误');
+      throw err;
+    } finally {
+      setGenerating(false);
+    }
+  }, [conversationId]);
+
+  // 应用选中的推荐标签
+  const applySuggestedTags = useCallback(async (selectedTags: string[]) => {
+    // 合并现有标签和选中的推荐标签，去重
+    const mergedTags = [...new Set([...tags, ...selectedTags])];
+    const result = await updateTags(mergedTags);
+    setSuggestedTags([]); // 清空推荐列表
+    return result;
+  }, [tags, updateTags]);
+
+  // 清空推荐标签
+  const clearSuggestedTags = useCallback(() => {
+    setSuggestedTags([]);
+  }, []);
+
+  useEffect(() => {
+    fetchTags();
+  }, [fetchTags]);
+
+  return {
+    tags,
+    loading,
+    updating,
+    generating,
+    suggestedTags,
+    error,
+    refetch: fetchTags,
+    updateTags,
+    addTag,
+    removeTag,
+    generateTags,
+    applySuggestedTags,
+    clearSuggestedTags,
+  };
+}
+
+/**
+ * 标签筛选 Hook - 用于侧边栏筛选对话
+ */
+export function useTagFilter() {
+  const [selectedTags, setSelectedTags] = useState<string[]>([]);
+
+  // 切换标签选中状态
+  const toggleTag = useCallback((tag: string) => {
+    setSelectedTags((prev) => {
+      if (prev.includes(tag)) {
+        return prev.filter((t) => t !== tag);
+      }
+      return [...prev, tag];
+    });
+  }, []);
+
+  // 选中单个标签（单选模式）
+  const selectTag = useCallback((tag: string) => {
+    setSelectedTags((prev) => {
+      if (prev.includes(tag) && prev.length === 1) {
+        return []; // 如果已选中且只有一个，则取消选中
+      }
+      return [tag];
+    });
+  }, []);
+
+  // 清除所有筛选
+  const clearFilter = useCallback(() => {
+    setSelectedTags([]);
+  }, []);
+
+  // 检查对话是否匹配筛选条件
+  const matchesFilter = useCallback((conversationTags: string[] | null) => {
+    if (selectedTags.length === 0) return true;
+    if (!conversationTags || conversationTags.length === 0) return false;
+    // 对话必须包含所有选中的标签
+    return selectedTags.every((tag) => conversationTags.includes(tag));
+  }, [selectedTags]);
+
+  return {
+    selectedTags,
+    isFiltering: selectedTags.length > 0,
+    toggleTag,
+    selectTag,
+    clearFilter,
+    matchesFilter,
+  };
+}