import { prisma } from "@/lib/prisma";
import BackButton from "@/app/components/BackButton";
import AwemeDetailClient from "./Client";
import type { Metadata } from "next";

function ms(v?: number | null) {
  if (!v) return "";
  const s = Math.round(v / 1000);
  const m = Math.floor(s / 60);
  const r = s % 60;
  return `${m}:${r.toString().padStart(2, "0")}`;
}

export async function generateMetadata({ params }: { params: Promise<{ awemeId: string }> }): Promise<Metadata> {
  const id = (await params).awemeId;

  const [video, post] = await Promise.all([
    prisma.video.findUnique({
      where: { aweme_id: id },
      select: { desc: true, author: { select: { nickname: true } } },
    }),
    prisma.imagePost.findUnique({
      where: { aweme_id: id },
      select: { desc: true, author: { select: { nickname: true } } },
    })
  ]);

  const data = video || post;
  if (!data) {
    return {
      title: "作品不存在",
    };
  }

  const desc = data.desc || "查看作品详情";
  const author = data.author.nickname;
  const title = desc.length > 50 ? `${desc.slice(0, 50)}... - ${author}` : `${desc} - ${author}`;

  return {
    title,
    description: desc,
  };
}

export default async function AwemeDetail({ params }: { params: Promise<{ awemeId: string }> }) {
  const id = (await params).awemeId;

  const [video, post] = await Promise.all([
    prisma.video.findUnique({
      where: { aweme_id: id },
      include: { author: true },
    }),
    prisma.imagePost.findUnique({
      where: { aweme_id: id },
      include: { author: true, images: { orderBy: { order: "asc" } } },
    })
  ]);

  if (!video && !post) return <main className="p-8">找不到该作品</main>;

  const isVideo = !!video;
  
  // 获取评论总数
  const commentsCount = await prisma.comment.count({
    where: isVideo ? { videoId: id } : { imagePostId: id },
  });

  const data = isVideo
    ? {
        type: "video" as const,
        aweme_id: video!.aweme_id,
        desc: video!.desc,
        created_at: video!.created_at,
        duration_ms: video!.duration_ms,
        video_url: video!.video_url,
        width: video!.width ?? null,
        height: video!.height ?? null,
        author: { nickname: video!.author.nickname, avatar_url: video!.author.avatar_url },
        commentsCount,
        likesCount: Number(video!.digg_count),
      }
    : {
        type: "image" as const,
        aweme_id: post!.aweme_id,
        desc: post!.desc,
        created_at: post!.created_at,
        images: post!.images,
        music_url: post!.music_url,
        author: { nickname: post!.author.nickname, avatar_url: post!.author.avatar_url },
        commentsCount,
        likesCount: Number(post!.digg_count),
      };

  // Compute prev/next neighbors by created_at across videos and image posts
  const currentCreatedAt = (isVideo ? video!.created_at : post!.created_at) as unknown as Date;
  const [newerVideo, newerPost, olderVideo, olderPost] = await Promise.all([
    prisma.video.findFirst({ where: { created_at: { gt: currentCreatedAt } }, orderBy: { created_at: "asc" }, select: { aweme_id: true, created_at: true } }),
    prisma.imagePost.findFirst({ where: { created_at: { gt: currentCreatedAt } }, orderBy: { created_at: "asc" }, select: { aweme_id: true, created_at: true } }),
    prisma.video.findFirst({ where: { created_at: { lt: currentCreatedAt } }, orderBy: { created_at: "desc" }, select: { aweme_id: true, created_at: true } }),
    prisma.imagePost.findFirst({ where: { created_at: { lt: currentCreatedAt } }, orderBy: { created_at: "desc" }, select: { aweme_id: true, created_at: true } }),
  ]);
  const pickPrev = (() => {
    const cands: { aweme_id: string; created_at: Date }[] = [];
    if (newerVideo) cands.push({ aweme_id: newerVideo.aweme_id, created_at: newerVideo.created_at as unknown as Date });
    if (newerPost) cands.push({ aweme_id: newerPost.aweme_id, created_at: newerPost.created_at as unknown as Date });
    if (cands.length === 0) return null;
    cands.sort((a, b) => +a.created_at - +b.created_at);
    return { aweme_id: cands[0].aweme_id };
  })();
  const pickNext = (() => {
    const cands: { aweme_id: string; created_at: Date }[] = [];
    if (olderVideo) cands.push({ aweme_id: olderVideo.aweme_id, created_at: olderVideo.created_at as unknown as Date });
    if (olderPost) cands.push({ aweme_id: olderPost.aweme_id, created_at: olderPost.created_at as unknown as Date });
    if (cands.length === 0) return null;
    cands.sort((a, b) => +b.created_at - +a.created_at);
    return { aweme_id: cands[0].aweme_id };
  })();
  const neighbors: { prev: { aweme_id: string } | null; next: { aweme_id: string } | null } = { prev: pickPrev, next: pickNext };

  return (
    <main className="min-h-screen w-full overflow-hidden">
      {/* 顶部条改为悬浮在媒体区域之上，避免 sticky 造成 Y 方向滚动条 */}
      <div className="fixed left-3 top-3 z-30">
        <BackButton
          hrefFallback="/"
          className="inline-flex items-center justify-center w-9 h-9 rounded-full bg-white/15 text-white border border-white/20 backdrop-blur hover:bg-white/25"
        />
      </div>
      <AwemeDetailClient data={data as any} neighbors={neighbors as any} />
    </main>
  );
}

export const dynamic = "force-dynamic";