import { json } from "@/lib/json";
import { getFileUrl } from "@/lib/minio";
import { prisma } from "@/lib/prisma"; // 你的 Prisma 客户端实例
import { NextResponse } from "next/server";

export async function GET(req: Request) {
  const { searchParams } = new URL(req.url);
  const q = (searchParams.get("q") || "").trim();
  const page = Math.max(1, Number(searchParams.get("page") || 1));
  const limit = Math.min(
    50,
    Math.max(1, Number(searchParams.get("limit") || 20)),
  );
  const offset = (page - 1) * limit;

  if (!q) {
    return NextResponse.json({ results: [], total: 0 });
  }

  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 = await prisma.$queryRaw<
      {
        id: string;
        awemeId: string;
        type: "video" | "image";
        rank: number;
        snippet: string;
      }[]
    >`
      WITH tsq AS (
        SELECT websearch_to_tsquery('zhcfg', ${q}) AS query
      )
      -- 视频搜索结果
      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
      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)
      
      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
      FROM "ImagePost" ip, tsq
      WHERE to_tsvector('zhcfg', ip.desc) @@ tsq.query
      
      ORDER BY rank DESC
      OFFSET ${offset}
      LIMIT ${limit};
    `;

    // 查询总数（参数化，避免注入）
    const totalRows = await prisma.$queryRaw<
      {
        count: number;
      }[]
    >`
      WITH tsq AS (
        SELECT websearch_to_tsquery('zhcfg', ${q}) AS query
      )
      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))
        +
        (SELECT COUNT(*)::int FROM "ImagePost" ip
         WHERE to_tsvector('zhcfg', ip.desc) @@ tsq.query)
      ) AS count
      FROM tsq;
    `;

    // 分离视频和图文ID
    const videoIds = rows
      .filter((r) => r.type === "video")
      .map((r) => r.awemeId);
    const imagePostIds = rows
      .filter((r) => r.type === "image")
      .map((r) => r.awemeId);

    // 批量查询视频元信息
    const videos =
      videoIds.length > 0
        ? (
            await prisma.video.findMany({
              where: { aweme_id: { in: videoIds } },
              select: {
                aweme_id: true,
                desc: true,
                cover_url: true,
                video_url: true,
                duration_ms: true,
                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({
              where: { aweme_id: { in: imagePostIds } },
              select: {
                aweme_id: true,
                desc: true,
                author: true,
                images: {
                  orderBy: { order: "asc" },
                  take: 1,
                  select: {
                    url: true,
                    width: true,
                    height: true,
                  },
                },
              },
            })
          ).map((ip) => ({
            ...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,
        video:
          r.type === "video"
            ? videos.find((v) => v.aweme_id === r.awemeId)
            : undefined,
        imagePost:
          r.type === "image"
            ? imagePosts.find((ip) => ip.aweme_id === r.awemeId)
            : undefined,
      })),
      total: totalRows?.[0]?.count ?? 0,
      page,
      limit,
    });
  } catch (err) {
    console.error("Search error:", err);
    return NextResponse.json({ error: "Search failed" }, { status: 500 });
  }
}