import type { Metadata } from "next";
import { cache } from "react";

import { HomePage } from "@/components/home/home-page";
import { JsonLd } from "@/components/seo/json-ld";
import { dramaHref } from "@/components/short-drama/data";
import { getHomeBaseCached } from "@/lib/api/home";
import { getPlayletHomeCached } from "@/lib/api/playlet";
import type { AdvitiseData, ConfigInfo, HomePlayletResponse, PlayletData } from "@/lib/api/types";
import {
  buildWebPageJSONLD,
  getHomeBaseSEOCached,
  mergeSEO,
  resolvePageMetadata,
} from "@/lib/seo";

function summarizeFetchError(error: unknown) {
  if (!(error instanceof Error)) return String(error);
  const cause = (error as Error & { cause?: { code?: string; message?: string } }).cause;
  const code = cause?.code || (error as Error & { code?: string }).code;
  if (code) return `${error.message} (${code})`;
  return error.message;
}

/** 同请求内 metadata + page 共用一次结果 */
const loadHome = cache(async (): Promise<HomePlayletResponse | null> => {
  try {
    return await getPlayletHomeCached();
  } catch (error) {
    console.warn(`[playlet/home] ${summarizeFetchError(error)}; fallback to local mock`);
    return null;
  }
});

const loadHomeBase = cache(async (): Promise<{ advitise?: AdvitiseData; config?: ConfigInfo }> => {
  try {
    const base = await getHomeBaseCached();
    return { advitise: base.advitise, config: base.config };
  } catch (error) {
    console.warn(`[home/base] ${summarizeFetchError(error)}`);
    return {};
  }
});

export async function generateMetadata(): Promise<Metadata> {
  const home = await loadHome();
  // seoInfo → home/base 公共 web* → 代码兜底
  return resolvePageMetadata({
    seoInfo: home?.seoInfo,
    fallbackTitle: "黄果黑料 - 热门短剧在线看",
    fallbackDescription: "黄果黑料汇集热门短剧、最近上新、排行榜与精选专题推荐，支持高清在线播放。",
    fallbackKeywords: ["黄果黑料", "短剧", "在线短剧", "热门短剧"],
    canonical: "/",
  });
}

export default async function Home() {
  const [home, base, siteSeo] = await Promise.all([loadHome(), loadHomeBase(), getHomeBaseSEOCached()]);
  const merged = home
    ? { ...home, advitise: base.advitise ?? home.advitise }
    : base.advitise
      ? { advitise: base.advitise }
      : null;

  const seo = mergeSEO(home?.seoInfo, siteSeo.seo);
  const homeTitle = seo.title || "黄果黑料 - 热门短剧在线看";
  const homeDescription =
    seo.description || "黄果黑料汇集热门短剧、最近上新、排行榜与精选专题推荐，支持高清在线播放。";
  const itemListUrls =
    home?.homeBannerData
      ?.filter((item): item is PlayletData & { id: number } => Boolean(item?.id))
      .slice(0, 12)
      .map((item) => dramaHref(item.id, item.slug)) ?? [];

  return (
    <>
      <JsonLd
        data={buildWebPageJSONLD({
          path: "/",
          title: homeTitle,
          description: homeDescription,
          type: "CollectionPage",
          breadcrumbs: [["首页", "/"]],
          itemListUrls,
          siteName: siteSeo.siteName,
        })}
      />
      <HomePage home={merged} heading={homeTitle} />
    </>
  );
}