feat: 搜索改为子串匹配，支持多关键词、排除词与分页加载

- 不再依赖 zhparser 分词：关键词按空格拆分，全部需在描述或语音转写中以子串出现；-词 表示排除
- 英文/数字关键词要求词首对齐，避免 ai 命中 said
- 按描述/转写命中次数打分，同分按发布时间倒序；总数随查询一并返回
- 返回结构化高亮片段（descParts / snippet），前端高亮描述与转写命中位置
- 前端显示描述/语音命中标记、真实结果总数，并支持加载更多

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/api/search/route.ts

@@ -1,36 +1,36 @@
 import { NextResponse } from "next/server";
-import { isVideoContentTag } from "@/lib/video-tags";
 import { json } from "@/lib/json";
 import { getFileUrl } from "@/lib/minio";
 import { prisma } from "@/lib/prisma";
+import {
+  buildSnippet,
+  highlightAll,
+  parseSearchQuery,
+  termToPgPattern,
+} from "@/lib/search";
+import { isVideoContentTag } from "@/lib/video-tags";
 
 type SearchRow = {
-  id: string;
   awemeId: string;
   type: "video" | "image";
-  rank: number;
-  snippet: string;
+  score: number;
+  inDesc: boolean;
+  inTranscript: boolean;
+  rawDesc: string;
+  rawTranscript: string;
   contentTags: string[];
+  total: number;
 };
 
-function sanitizeSnippetHtml(snippet: string) {
-  return snippet
-    .replaceAll("&", "&")
-    .replaceAll("<", "&lt;")
-    .replaceAll(">", "&gt;")
-    .replaceAll("&lt;mark&gt;", "<mark>")
-    .replaceAll("&lt;/mark&gt;", "</mark>");
-}
-
 export async function GET(req: Request) {
   const { searchParams } = new URL(req.url);
   const q = (searchParams.get("q") || "").trim();
   const rawTag = (searchParams.get("tag") || "").trim();
   const contentTag = rawTag && isVideoContentTag(rawTag) ? rawTag : null;
-  const page = Math.max(1, Number(searchParams.get("page") || 1));
+  const page = Math.max(1, Math.floor(Number(searchParams.get("page")) || 1));
   const limit = Math.min(
     50,
-    Math.max(1, Number(searchParams.get("limit") || 20)),
+    Math.max(1, Math.floor(Number(searchParams.get("limit")) || 20)),
   );
   const offset = (page - 1) * limit;
 
@@ -38,129 +38,85 @@ export async function GET(req: Request) {
     return NextResponse.json({ error: "Invalid tag" }, { status: 400 });
   }
 
-  if (!q && !contentTag) {
-    return NextResponse.json({ results: [], total: 0 });
+  const { terms, excludes } = parseSearchQuery(q);
+  if (terms.length === 0 && !contentTag) {
+    return json({ results: [], total: 0, page, limit, terms });
   }
 
+  // 关键词已在 parseSearchQuery 里转为小写，这里转成正则后与 lower() 后的文本匹配
+  const patterns = terms.map(termToPgPattern);
+  const excludePatterns = excludes.map(termToPgPattern);
+
   try {
-    // 核心查询：Postgres 中文全文检索（视频转写 + 视频desc + 图文desc）+ 相关度排序 + 摘要高亮
-    // 说明：
-    // - 合并搜索来源：VideoTranscript.transcript_zh_tsv、Video.desc 与 ImagePost.desc
-    // - 使用 UNION ALL 合并视频和图文的搜索结果
-    // - rank 取两者匹配得分的最大值，snippet 优先展示转写匹配，否则展示 desc 匹配
-    const rows = q
-      ? await prisma.$queryRaw<SearchRow[]>`
-          WITH tsq AS (
-            SELECT websearch_to_tsquery('zhcfg', ${q}) AS query
-          )
-          -- 视频搜索结果
+    // 子串匹配：每个关键词都必须出现在「描述 + 语音转写」里（不区分大小写），
+    // 不依赖分词，所以输入任意片段都能搜到。数据量小，全表扫描足够快。
+    // 打分：描述命中权重更高，按出现次数累加（设上限防止长转写刷分）；同分按发布时间倒序。
+    // 没有关键词、只按标签筛选时，score 都是 0，等价于按时间排序。
+    const rows = await prisma.$queryRaw<SearchRow[]>`
+      WITH params AS (
+        SELECT ${patterns}::text[] AS terms, ${excludePatterns}::text[] AS excludes
+      ),
+      docs AS (
         SELECT
-            COALESCE(vt.id, 'desc:' || v.aweme_id) AS id,
           v.aweme_id AS "awemeId",
           'video'::text AS type,
-            GREATEST(
-              COALESCE(ts_rank(vt.transcript_zh_tsv, tsq.query), 0),
-              COALESCE(ts_rank(to_tsvector('zhcfg', v.desc), tsq.query), 0)
-            ) AS rank,
-            CASE
-              WHEN vt.transcript_zh_tsv @@ tsq.query THEN
-                ts_headline(
-                  'zhcfg',
-                  array_to_string(vt.transcript, ' '),
-                  tsq.query,
-                  'StartSel=<mark>,StopSel=</mark>,MaxFragments=2,MinWords=2,MaxWords=20'
-                )
-              ELSE
-                ts_headline(
-                  'zhcfg',
-                  v.desc,
-                  tsq.query,
-                  'StartSel=<mark>,StopSel=</mark>,MaxFragments=2,MinWords=2,MaxWords=20'
-                )
-            END AS snippet,
+          v."desc" AS "rawDesc",
+          COALESCE(array_to_string(vt.transcript, E'\n'), '') AS "rawTranscript",
+          v.created_at AS created,
           v.manual_content_tags AS "contentTags"
         FROM "Video" v
-          LEFT JOIN "VideoTranscript" vt ON vt."videoId" = v.aweme_id,
-               tsq
-          WHERE
-            (vt.transcript_zh_tsv @@ tsq.query OR to_tsvector('zhcfg', v.desc) @@ tsq.query)
-            AND CASE
-              WHEN ${contentTag}::text IS NULL THEN TRUE
-              ELSE v.manual_content_tags @> ARRAY[${contentTag}]::text[]
-            END
+        LEFT JOIN "VideoTranscript" vt ON vt."videoId" = v.aweme_id
+        WHERE ${contentTag}::text IS NULL
+           OR v.manual_content_tags @> ARRAY[${contentTag}]::text[]
 
         UNION ALL
 
-          -- 图文搜索结果
         SELECT
-            'img_desc:' || ip.aweme_id AS id,
-            ip.aweme_id AS "awemeId",
-            'image'::text AS type,
-            ts_rank(to_tsvector('zhcfg', ip.desc), tsq.query) AS rank,
-            ts_headline(
-              'zhcfg',
-              ip.desc,
-              tsq.query,
-              'StartSel=<mark>,StopSel=</mark>,MaxFragments=2,MinWords=2,MaxWords=20'
-            ) AS snippet,
-            ARRAY[]::text[] AS "contentTags"
-          FROM "ImagePost" ip, tsq
-          WHERE to_tsvector('zhcfg', ip.desc) @@ tsq.query
-            AND ${contentTag}::text IS NULL
-
-          ORDER BY rank DESC
-          OFFSET ${offset}
-          LIMIT ${limit};
-        `
-      : await prisma.$queryRaw<SearchRow[]>`
+          ip.aweme_id,
+          'image'::text,
+          ip."desc",
+          '',
+          ip.created_at,
+          ARRAY[]::text[]
+        FROM "ImagePost" ip
+        WHERE ${contentTag}::text IS NULL
+      ),
+      lowered AS (
+        SELECT docs.*, lower(docs."rawDesc") AS d, lower(docs."rawTranscript") AS t
+        FROM docs
+      ),
+      matched AS (
         SELECT
-            COALESCE(vt.id, 'tag:' || v.aweme_id) AS id,
-            v.aweme_id AS "awemeId",
-            'video'::text AS type,
-            1.0::double precision AS rank,
-            COALESCE(
-              NULLIF(array_to_string(vt.transcript[1:2], ' '), ''),
-              v.desc,
-              '标签匹配'
-            ) AS snippet,
-            v.manual_content_tags AS "contentTags"
-          FROM "Video" v
-          LEFT JOIN "VideoTranscript" vt ON vt."videoId" = v.aweme_id
-          WHERE v.manual_content_tags @> ARRAY[${contentTag}]::text[]
-          ORDER BY v.created_at DESC
-          OFFSET ${offset}
-          LIMIT ${limit};
-        `;
-
-    // 查询总数（参数化，避免注入）
-    const totalRows = q
-      ? await prisma.$queryRaw<{ count: number }[]>`
-          WITH tsq AS (
-            SELECT websearch_to_tsquery('zhcfg', ${q}) AS query
+          l.*,
+          COALESCE((
+            SELECT SUM(
+              4 * LEAST(regexp_count(l.d, term), 3)
+              + LEAST(regexp_count(l.t, term), 10)
             )
-          SELECT (
-            (SELECT COUNT(*)::int FROM "Video" v
-             LEFT JOIN "VideoTranscript" vt ON vt."videoId" = v.aweme_id
-             WHERE (vt.transcript_zh_tsv @@ tsq.query OR to_tsvector('zhcfg', v.desc) @@ tsq.query)
-               AND CASE
-                 WHEN ${contentTag}::text IS NULL THEN TRUE
-                 ELSE v.manual_content_tags @> ARRAY[${contentTag}]::text[]
-               END)
-            +
-            (SELECT COUNT(*)::int FROM "ImagePost" ip
-             WHERE to_tsvector('zhcfg', ip.desc) @@ tsq.query
-               AND ${contentTag}::text IS NULL)
-          ) AS count
-          FROM tsq;
-        `
-      : await prisma.$queryRaw<{ count: number }[]>`
-          SELECT COUNT(*)::int AS count
-          FROM "Video" v
-          LEFT JOIN "VideoTranscript" vt ON vt."videoId" = v.aweme_id
-          WHERE v.manual_content_tags @> ARRAY[${contentTag}]::text[];
+            FROM unnest(p.terms) term
+          ), 0)::float8 AS score,
+          EXISTS (SELECT 1 FROM unnest(p.terms) term WHERE l.d ~ term) AS "inDesc",
+          EXISTS (SELECT 1 FROM unnest(p.terms) term WHERE l.t ~ term) AS "inTranscript"
+        FROM lowered l, params p
+        WHERE NOT EXISTS (
+            SELECT 1 FROM unnest(p.terms) term
+            WHERE l.d !~ term AND l.t !~ term
+          )
+          AND NOT EXISTS (
+            SELECT 1 FROM unnest(p.excludes) x
+            WHERE l.d ~ x OR l.t ~ x
+          )
+      )
+      SELECT
+        "awemeId", type, score, "inDesc", "inTranscript",
+        "rawDesc", "rawTranscript", "contentTags",
+        (COUNT(*) OVER ())::int AS total
+      FROM matched
+      ORDER BY score DESC, created DESC, "awemeId"
+      OFFSET ${offset}
+      LIMIT ${limit};
     `;
 
-    // 分离视频和图文ID
     const videoIds = rows
       .filter((r) => r.type === "video")
       .map((r) => r.awemeId);
@@ -168,11 +124,9 @@ export async function GET(req: Request) {
       .filter((r) => r.type === "image")
       .map((r) => r.awemeId);
 
-    // 批量查询视频元信息
-    const videos =
+    const [videos, imagePosts] = await Promise.all([
       videoIds.length > 0
-        ? (
-            await prisma.video.findMany({
+        ? prisma.video.findMany({
             where: { aweme_id: { in: videoIds } },
             select: {
               aweme_id: true,
@@ -183,22 +137,9 @@ export async function GET(req: Request) {
               author: true,
             },
           })
-          ).map((v) => ({
-            ...v,
-            cover_url: getFileUrl(v.cover_url || ""),
-            author: {
-              ...v.author,
-              avatar_url: getFileUrl(v.author.avatar_url || ""),
-            },
-            video_url: getFileUrl(v.video_url || ""),
-          }))
-        : [];
-
-    // 批量查询图文元信息
-    const imagePosts =
+        : [],
       imagePostIds.length > 0
-        ? (
-            await prisma.imagePost.findMany({
+        ? prisma.imagePost.findMany({
             where: { aweme_id: { in: imagePostIds } },
             select: {
               aweme_id: true,
@@ -207,40 +148,68 @@ export async function GET(req: Request) {
               images: {
                 orderBy: { order: "asc" },
                 take: 1,
-                  select: {
-                    url: true,
-                    width: true,
-                    height: true,
-                  },
+                select: { url: true, width: true, height: true },
               },
             },
           })
-          ).map((ip) => ({
+        : [],
+    ]);
+
+    const videoMap = new Map(
+      videos.map((v) => [
+        v.aweme_id,
+        {
+          ...v,
+          cover_url: getFileUrl(v.cover_url || ""),
+          video_url: getFileUrl(v.video_url || ""),
+          author: {
+            ...v.author,
+            avatar_url: getFileUrl(v.author.avatar_url || ""),
+          },
+        },
+      ]),
+    );
+    const imagePostMap = new Map(
+      imagePosts.map((ip) => [
+        ip.aweme_id,
+        {
           ...ip,
           author: {
             ...ip.author,
             avatar_url: getFileUrl(ip.author.avatar_url || ""),
           },
           cover_url: ip.images[0] ? getFileUrl(ip.images[0].url) : null,
-          }))
-        : [];
+        },
+      ]),
+    );
 
     return json({
-      results: rows.map((r) => ({
-        ...r,
-        snippet: sanitizeSnippetHtml(r.snippet),
-        video:
-          r.type === "video"
-            ? videos.find((v) => v.aweme_id === r.awemeId)
-            : undefined,
+      results: rows.map((r) => {
+        const matchedIn: ("desc" | "transcript")[] = [];
+        if (r.inDesc) matchedIn.push("desc");
+        if (r.inTranscript) matchedIn.push("transcript");
+        return {
+          id: `${r.type}:${r.awemeId}`,
+          awemeId: r.awemeId,
+          type: r.type,
+          score: r.score,
+          matchedIn,
+          contentTags: r.contentTags,
+          descParts: highlightAll(r.rawDesc, terms),
+          // 转写命中时给出命中片段；只按标签筛选时给出转写开头作为预览
+          snippet:
+            r.inTranscript || (terms.length === 0 && r.rawTranscript)
+              ? buildSnippet(r.rawTranscript, terms)
+              : null,
+          video: r.type === "video" ? videoMap.get(r.awemeId) : undefined,
           imagePost:
-          r.type === "image"
-            ? imagePosts.find((ip) => ip.aweme_id === r.awemeId)
-            : undefined,
-      })),
-      total: totalRows?.[0]?.count ?? 0,
+            r.type === "image" ? imagePostMap.get(r.awemeId) : undefined,
+        };
+      }),
+      total: rows[0]?.total ?? 0,
       page,
       limit,
+      terms,
     });
   } catch (err) {
     console.error("Search error:", err);

app/search/SearchClient.tsx

@@ -1,19 +1,28 @@
 "use client";
 
-import { ArrowLeft, MessageSquare, Search, X } from "lucide-react";
+import { ArrowLeft, FileText, Mic, Search, X } from "lucide-react";
 import Image from "next/image";
 import Link from "next/link";
 import { useRouter, useSearchParams } from "next/navigation";
-import { type FormEvent, useCallback, useEffect, useState } from "react";
-import { VIDEO_CONTENT_TAGS, isVideoContentTag } from "@/lib/video-tags";
+import {
+  type FormEvent,
+  useCallback,
+  useEffect,
+  useRef,
+  useState,
+} from "react";
+import type { SnippetPart } from "@/lib/search";
+import { isVideoContentTag, VIDEO_CONTENT_TAGS } from "@/lib/video-tags";
 
 // 匹配搜索结果类型（适配后端API）
 type SearchResultItem = {
   id: string;
   awemeId: string;
   type: "video" | "image";
-  rank: number;
-  snippet: string; // 后端返回的高亮片段，已包含<mark>标签
+  score: number;
+  matchedIn: ("desc" | "transcript")[];
+  descParts: SnippetPart[]; // 完整描述，标出命中位置
+  snippet: SnippetPart[] | null; // 语音转写的命中片段
   contentTags: string[];
   video?: {
     aweme_id: string;
@@ -38,6 +47,27 @@ type SearchResultItem = {
     };
   };
 };
+
+const PAGE_SIZE = 30;
+
+function renderParts(parts: SnippetPart[]) {
+  let offset = 0;
+  return parts.map((part) => {
+    const key = `${offset}-${part.text}`;
+    offset += part.text.length;
+    return part.hit ? (
+      <mark
+        key={key}
+        className="rounded-sm bg-yellow-400/80 px-0.5 text-zinc-950"
+      >
+        {part.text}
+      </mark>
+    ) : (
+      <span key={key}>{part.text}</span>
+    );
+  });
+}
+
 export default function SearchClient({
   initialQuery,
 }: {
@@ -48,7 +78,12 @@ export default function SearchClient({
 
   const [query, setQuery] = useState(initialQuery);
   const [results, setResults] = useState<SearchResultItem[]>([]);
+  const [total, setTotal] = useState(0);
+  const [page, setPage] = useState(1);
   const [loading, setLoading] = useState(false);
+  const [loadingMore, setLoadingMore] = useState(false);
+  // 只采用最近一次请求的结果，避免快速切换关键词时旧结果覆盖新结果
+  const requestIdRef = useRef(0);
   const [searched, setSearched] = useState(false);
   const [selectedTag, setSelectedTag] = useState<string | null>(null);
 
@@ -61,30 +96,79 @@ export default function SearchClient({
     return queryString ? `/search?${queryString}` : "/search";
   }, []);
 
-  const performSearch = useCallback(async (q: string, tag: string | null) => {
+  const fetchPage = useCallback(
+    async (q: string, tag: string | null, pageNum: number) => {
+      const params = new URLSearchParams({
+        limit: String(PAGE_SIZE),
+        page: String(pageNum),
+      });
+      if (q) params.set("q", q);
+      if (tag) params.set("tag", tag);
+      const res = await fetch(`/api/search?${params.toString()}`);
+      if (!res.ok) throw new Error("Search failed");
+      return (await res.json()) as {
+        results?: SearchResultItem[];
+        total?: number;
+      };
+    },
+    [],
+  );
+
+  const performSearch = useCallback(
+    async (q: string, tag: string | null) => {
       const trimmed = q.trim();
+      const requestId = ++requestIdRef.current;
       if (!trimmed && !tag) {
         setResults([]);
+        setTotal(0);
         setSearched(false);
         return;
       }
       setLoading(true);
       setSearched(true);
+      setPage(1);
       try {
-      const params = new URLSearchParams({ limit: "60" });
-      if (trimmed) params.set("q", trimmed);
-      if (tag) params.set("tag", tag);
-      const res = await fetch(`/api/search?${params.toString()}`);
-      if (!res.ok) throw new Error("Search failed");
-      const data = await res.json();
+        const data = await fetchPage(trimmed, tag, 1);
+        if (requestId !== requestIdRef.current) return;
         setResults(data.results || []);
+        setTotal(data.total ?? 0);
       } catch (err) {
+        if (requestId !== requestIdRef.current) return;
         console.error("Search error:", err);
         setResults([]);
+        setTotal(0);
       } finally {
-      setLoading(false);
+        if (requestId === requestIdRef.current) setLoading(false);
       }
-  }, []);
+    },
+    [fetchPage],
+  );
+
+  const loadMore = async () => {
+    const q = (searchParams.get("q") || "").trim();
+    const tagParam = searchParams.get("tag") || "";
+    const tag = tagParam && isVideoContentTag(tagParam) ? tagParam : null;
+    const requestId = requestIdRef.current;
+    const nextPage = page + 1;
+    setLoadingMore(true);
+    try {
+      const data = await fetchPage(q, tag, nextPage);
+      if (requestId !== requestIdRef.current) return;
+      setResults((prev) => {
+        const seen = new Set(prev.map((r) => r.id));
+        return [
+          ...prev,
+          ...(data.results || []).filter((r) => !seen.has(r.id)),
+        ];
+      });
+      setTotal(data.total ?? 0);
+      setPage(nextPage);
+    } catch (err) {
+      console.error("Search error:", err);
+    } finally {
+      if (requestId === requestIdRef.current) setLoadingMore(false);
+    }
+  };
 
   // 初始 & URL 变化时同步（用 searchParams 订阅 URL 更稳妥）
   useEffect(() => {
@@ -96,7 +180,9 @@ export default function SearchClient({
     if (q || tag) {
       performSearch(q, tag);
     } else {
+      requestIdRef.current++;
       setResults([]);
+      setTotal(0);
       setSearched(false);
     }
   }, [searchParams, performSearch]);
@@ -118,28 +204,11 @@ export default function SearchClient({
     setQuery("");
     setSelectedTag(null);
     setResults([]);
+    setTotal(0);
     setSearched(false);
     router.push("/search");
   };
 
-  const renderSnippet = (snippet: string) => {
-    let highlighted = false;
-    let offset = 0;
-    return snippet.split(/(<mark>|<\/mark>)/g).map((part) => {
-      offset += part.length;
-      if (part === "<mark>") {
-        highlighted = true;
-        return null;
-      }
-      if (part === "</mark>") {
-        highlighted = false;
-        return null;
-      }
-      if (!part) return null;
-      return highlighted ? <mark key={`${offset}-${part}`}>{part}</mark> : part;
-    });
-  };
-
   return (
     <div className="min-h-screen bg-zinc-950 text-white">
       {/* 顶部搜索栏 */}
@@ -234,7 +303,7 @@ export default function SearchClient({
             <Search size={64} className="mb-4 opacity-20" />
             <p className="text-xl">输入关键词开始搜索</p>
             <p className="text-sm mt-2">
-              支持搜索视频描述、图文描述及语音转写内容
+              按原文匹配描述和语音转写，多个关键词用空格分隔，以 - 开头表示排除
             </p>
           </div>
         )}
@@ -243,10 +312,7 @@ export default function SearchClient({
           <div>
             <div className="mb-6 flex items-center justify-between">
               <h2 className="text-lg text-white/80">
-                找到{" "}
-                <span className="text-white font-semibold">
-                  {results.length}
-                </span>{" "}
+                找到 <span className="text-white font-semibold">{total}</span>{" "}
                 个结果
               </h2>
             </div>
@@ -260,7 +326,7 @@ export default function SearchClient({
 
                 return (
                   <div
-                    key={item.awemeId}
+                    key={item.id}
                     className="bg-white/5 backdrop-blur-sm border border-white/10 rounded-2xl overflow-hidden hover:border-white/20 transition-all hover:-translate-y-1"
                   >
                     {/* 主内容区 */}
@@ -298,10 +364,18 @@ export default function SearchClient({
                           >
                             {item.type === "video" ? "视频" : "图文"}
                           </span>
+                          {item.matchedIn.includes("desc") && (
                             <span className="flex items-center gap-1 px-2 py-0.5 bg-green-600/20 text-green-300 text-xs rounded">
-                            <MessageSquare size={12} />
-                            匹配度: {(item.rank * 100).toFixed(1)}%
+                              <FileText size={12} />
+                              描述命中
                             </span>
+                          )}
+                          {item.matchedIn.includes("transcript") && (
+                            <span className="flex items-center gap-1 px-2 py-0.5 bg-green-600/20 text-green-300 text-xs rounded">
+                              <Mic size={12} />
+                              语音命中
+                            </span>
+                          )}
                           {item.contentTags.map((tag) => (
                             <span
                               key={tag}
@@ -317,8 +391,10 @@ export default function SearchClient({
                           href={`/aweme/${content.aweme_id}`}
                           target="_blank"
                         >
-                          <p className="text-white/90 text-sm sm:text-base line-clamp-2 mb-3 hover:text-white transition-colors">
-                            {content.desc || "无描述"}
+                          <p className="text-white/90 text-sm sm:text-base line-clamp-3 mb-3 hover:text-white transition-colors">
+                            {item.descParts.length > 0
+                              ? renderParts(item.descParts)
+                              : "无描述"}
                           </p>
                         </Link>
 
@@ -341,29 +417,44 @@ export default function SearchClient({
                           </span>
                         </div>
 
-                        {/* 匹配详情：展示后端返回的snippet（已包含<mark>标签） */}
-                        <div className="space-y-3">
+                        {/* 语音转写片段：命中时展示命中位置附近的文字 */}
+                        {item.snippet && item.snippet.length > 0 && (
                           <div>
                             <h4 className="flex items-center gap-2 text-xs font-medium text-green-300 mb-1.5">
-                              <MessageSquare size={14} />
-                              匹配内容
+                              <Mic size={14} />
+                              {item.matchedIn.includes("transcript")
+                                ? "语音内容"
+                                : "语音转写"}
                             </h4>
                             <div
                               className="text-xs text-white/70 bg-white/5 rounded-lg p-2 leading-relaxed"
-                              style={{
-                                wordBreak: "break-word",
-                              }}
+                              style={{ wordBreak: "break-word" }}
                             >
-                              {renderSnippet(item.snippet)}
-                            </div>
+                              {renderParts(item.snippet)}
                             </div>
                           </div>
+                        )}
                       </div>
                     </div>
                   </div>
                 );
               })}
             </div>
+
+            {results.length < total && (
+              <div className="mt-8 flex justify-center">
+                <button
+                  type="button"
+                  onClick={loadMore}
+                  disabled={loadingMore}
+                  className="rounded-full border border-white/10 bg-white/5 px-6 py-2.5 text-sm text-white/80 transition-colors hover:border-white/20 hover:text-white disabled:opacity-50"
+                >
+                  {loadingMore
+                    ? "加载中..."
+                    : `加载更多（还有 ${total - results.length} 个）`}
+                </button>
+              </div>
+            )}
           </div>
         )}
       </main>

lib/search.ts

@@ -0,0 +1,172 @@
+// 子串搜索的查询解析与摘要高亮工具。
+// 匹配本身在 Postgres 里用正则匹配 lower() 后的文本完成，这里负责：
+// - 把用户输入拆成关键词（空格分隔，全部需要命中；以 - 开头的词表示排除）
+// - 在原文里找命中位置，截取摘要片段并标出高亮
+
+export type SnippetPart = { text: string; hit: boolean };
+
+export type ParsedQuery = { terms: string[]; excludes: string[] };
+
+const MAX_TERMS = 10;
+const MAX_TERM_LENGTH = 50;
+
+export function parseSearchQuery(raw: string): ParsedQuery {
+  const terms: string[] = [];
+  const excludes: string[] = [];
+  const seen = new Set<string>();
+  for (const token of raw.trim().split(/\s+/)) {
+    if (!token) continue;
+    const isExclude = token.length > 1 && token.startsWith("-");
+    const word = (isExclude ? token.slice(1) : token)
+      .slice(0, MAX_TERM_LENGTH)
+      .toLowerCase();
+    const key = `${isExclude ? "-" : "+"}${word}`;
+    if (!word || seen.has(key)) continue;
+    seen.add(key);
+    (isExclude ? excludes : terms).push(word);
+    if (terms.length + excludes.length >= MAX_TERMS) break;
+  }
+  return { terms, excludes };
+}
+
+type Range = { start: number; end: number; term: string };
+
+function escapeRegExp(s: string) {
+  return s.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+// 纯英文/数字关键词要求「词首」对齐：前面不能紧挨字母数字。
+// 这样 "ai" 不会命中 "said"，但 "用AI做"、"AIGC" 仍能命中；中文关键词是纯子串匹配。
+const ASCII_WORD = /^[a-z0-9]/;
+
+/** 关键词对应的 Postgres 正则（ARE），用于匹配已 lower() 的文本。 */
+export function termToPgPattern(term: string) {
+  const escaped = escapeRegExp(term);
+  return ASCII_WORD.test(term) ? `(^|[^a-z0-9])${escaped}` : escaped;
+}
+
+function termToJsPattern(term: string) {
+  const escaped = escapeRegExp(term);
+  return ASCII_WORD.test(term) ? `(?<![a-z0-9])${escaped}` : escaped;
+}
+
+function findMatches(text: string, terms: string[]): Range[] {
+  if (!text || terms.length === 0) return [];
+  // 长词优先，避免 "老百姓" 被 "百姓" 抢先匹配成更短的高亮
+  const sorted = [...terms].sort((a, b) => b.length - a.length);
+  const re = new RegExp(sorted.map(termToJsPattern).join("|"), "giu");
+  const ranges: Range[] = [];
+  for (const m of text.matchAll(re)) {
+    const start = m.index ?? 0;
+    ranges.push({
+      start,
+      end: start + m[0].length,
+      term: m[0].toLowerCase(),
+    });
+  }
+  return ranges;
+}
+
+// 不要把 UTF-16 代理对（emoji 等）切成两半
+function safeStart(text: string, i: number) {
+  const c = text.charCodeAt(i);
+  return c >= 0xdc00 && c <= 0xdfff ? i - 1 : i;
+}
+function safeEnd(text: string, i: number) {
+  const c = text.charCodeAt(i);
+  return c >= 0xdc00 && c <= 0xdfff ? i + 1 : i;
+}
+
+function highlightRange(
+  text: string,
+  from: number,
+  to: number,
+  matches: Range[],
+): SnippetPart[] {
+  const parts: SnippetPart[] = [];
+  let cursor = from;
+  for (const m of matches) {
+    if (m.end <= from || m.start >= to) continue;
+    const s = Math.max(m.start, from);
+    const e = Math.min(m.end, to);
+    if (s < cursor) continue;
+    if (s > cursor) parts.push({ text: text.slice(cursor, s), hit: false });
+    parts.push({ text: text.slice(s, e), hit: true });
+    cursor = e;
+  }
+  if (cursor < to) parts.push({ text: text.slice(cursor, to), hit: false });
+  return parts;
+}
+
+function normalizeWhitespace(parts: SnippetPart[]): SnippetPart[] {
+  return parts
+    .map((p) => ({ ...p, text: p.text.replace(/\s*\n\s*/g, " ") }))
+    .filter((p) => p.text.length > 0);
+}
+
+/** 整段文字全部返回，只标出命中位置（用于描述）。 */
+export function highlightAll(text: string, terms: string[]): SnippetPart[] {
+  if (!text) return [];
+  return normalizeWhitespace(
+    highlightRange(text, 0, text.length, findMatches(text, terms)),
+  );
+}
+
+/**
+ * 截取命中位置附近的片段（用于语音转写这类长文本）。
+ * 尽量让不同片段覆盖不同的关键词；片段会对齐到换行（转写的句子边界）。
+ */
+export function buildSnippet(
+  text: string,
+  terms: string[],
+  { before = 24, after = 60, maxFragments = 2 } = {},
+): SnippetPart[] {
+  if (!text) return [];
+  const matches = findMatches(text, terms);
+  if (matches.length === 0) {
+    const end = safeEnd(text, Math.min(text.length, before + after));
+    const parts = normalizeWhitespace([
+      { text: text.slice(0, end), hit: false },
+    ]);
+    if (end < text.length) parts.push({ text: "…", hit: false });
+    return parts;
+  }
+
+  const windows: { start: number; end: number }[] = [];
+  const covered = new Set<string>();
+  const pickNext = () =>
+    matches.find(
+      (m) =>
+        !covered.has(m.term) &&
+        windows.every((w) => m.start >= w.end || m.end <= w.start),
+    ) ??
+    matches.find((m) =>
+      windows.every((w) => m.start >= w.end || m.end <= w.start),
+    );
+
+  while (windows.length < maxFragments) {
+    const m = pickNext();
+    if (!m) break;
+    let start = Math.max(0, m.start - before);
+    let end = Math.min(text.length, m.end + after);
+    const nlBefore = text.lastIndexOf("\n", m.start - 1);
+    if (nlBefore >= start) start = nlBefore + 1;
+    const nlAfter = text.indexOf("\n", m.end);
+    if (nlAfter !== -1 && nlAfter < end) end = nlAfter;
+    windows.push({ start: safeStart(text, start), end: safeEnd(text, end) });
+    for (const other of matches) {
+      if (other.start >= start && other.end <= end) covered.add(other.term);
+    }
+  }
+
+  windows.sort((a, b) => a.start - b.start);
+  const parts: SnippetPart[] = [];
+  windows.forEach((w, i) => {
+    if (i === 0 ? w.start > 0 : true) parts.push({ text: "…", hit: false });
+    parts.push(...highlightRange(text, w.start, w.end, matches));
+  });
+  if (windows[windows.length - 1].end < text.length) {
+    parts.push({ text: "…", hit: false });
+  }
+  return normalizeWhitespace(parts);
+}