import type { Metadata } from 'next';
import type { PlazaPost, PlazaUserProfile } from '@/types/plaza';
import { plazaPath, siteOrigin } from '@/lib/site';

const DEFAULT_OG = `${siteOrigin()}/plaza-og.png`;

function postOgImage(post: PlazaPost): string {
  if (post.cover_url) return post.cover_url;
  return `${siteOrigin()}${plazaPath(`p/${post.id}/opengraph-image`)}`;
}

export function homeMetadata(): Metadata {
  const url = `${siteOrigin()}${plazaPath()}`;
  return {
    title: 'Plaza - 发现 AI 创作的精彩内容',
    description: '浏览来自全球用户用 MindSpace 创作的报告、作品和页面',
    openGraph: {
      type: 'website',
      title: 'Plaza - 发现 AI 创作的精彩内容',
      description: '浏览来自全球用户用 MindSpace 创作的报告、作品和页面',
      url,
      siteName: 'MindSpace Plaza',
      images: [{ url: DEFAULT_OG, width: 1200, height: 630 }],
    },
    alternates: { canonical: url },
    robots: { index: true, follow: true },
  };
}

export function categoryMetadata(name: string, slug: string, description?: string): Metadata {
  const url = `${siteOrigin()}${plazaPath(`cat/${slug}`)}`;
  return {
    title: `${name} - Plaza | MindSpace`,
    description: description || `浏览 Plaza「${name}」分类下的 AI 创作内容`,
    openGraph: {
      type: 'website',
      title: `${name} - Plaza`,
      description: description || `Plaza「${name}」分类`,
      url,
      siteName: 'MindSpace Plaza',
      images: [{ url: DEFAULT_OG, width: 1200, height: 630 }],
    },
    alternates: { canonical: url },
    robots: { index: true, follow: true },
  };
}

export function postMetadata(post: PlazaPost): Metadata {
  const url = `${siteOrigin()}${plazaPath(`p/${post.id}`)}`;
  const image = postOgImage(post);
  const description =
    post.summary || `${post.author.display_name} 用 MindSpace 创作的作品`;

  return {
    title: `${post.title} - Plaza | MindSpace`,
    description,
    keywords: post.tags.join(', '),
    openGraph: {
      title: post.title,
      description,
      url,
      siteName: 'MindSpace Plaza',
      images: [{ url: image, width: 1200, height: 630, alt: post.title }],
      type: 'article',
      publishedTime: post.published_at,
      authors: [`${siteOrigin()}/u/${post.author.slug}`],
      tags: post.tags,
    },
    twitter: {
      card: 'summary_large_image',
      title: post.title,
      description,
      images: [image],
      creator: `@${post.author.slug}`,
    },
    alternates: { canonical: url },
    robots: { index: true, follow: true },
  };
}

export function postJsonLd(post: PlazaPost) {
  return {
    '@context': 'https://schema.org',
    '@type': 'Article',
    headline: post.title,
    description: post.summary,
    image: post.cover_url || postOgImage(post),
    datePublished: post.published_at,
    author: {
      '@type': 'Person',
      name: post.author.display_name,
      url: `${siteOrigin()}/u/${post.author.slug}`,
    },
    publisher: {
      '@type': 'Organization',
      name: 'MindSpace',
      logo: {
        '@type': 'ImageObject',
        url: `${siteOrigin()}/logo.png`,
      },
    },
  };
}

export function userMetadata(user: PlazaUserProfile): Metadata {
  const url = `${siteOrigin()}/u/${user.slug}`;
  const description =
    user.bio || `${user.display_name} 在 MindSpace Plaza 发布了 ${user.stats.post_count} 篇作品`;
  const image = user.avatar_url || DEFAULT_OG;

  return {
    title: `${user.display_name} (@${user.slug}) - Plaza | MindSpace`,
    description,
    openGraph: {
      type: 'profile',
      title: user.display_name,
      description,
      url,
      siteName: 'MindSpace Plaza',
      images: user.avatar_url
        ? [{ url: image, width: 400, height: 400, alt: user.display_name }]
        : [{ url: DEFAULT_OG, width: 1200, height: 630 }],
    },
    twitter: {
      card: user.avatar_url ? 'summary' : 'summary_large_image',
      title: user.display_name,
      description,
      images: [image],
    },
    alternates: { canonical: url },
    robots: { index: true, follow: true },
  };
}

export function userJsonLd(user: PlazaUserProfile) {
  return {
    '@context': 'https://schema.org',
    '@type': 'ProfilePage',
    name: user.display_name,
    description: user.bio || `${user.display_name} 的 MindSpace Plaza 主页`,
    url: `${siteOrigin()}/u/${user.slug}`,
    mainEntity: {
      '@type': 'Person',
      name: user.display_name,
      alternateName: user.slug,
      url: `${siteOrigin()}/u/${user.slug}`,
    },
  };
}

export function homeJsonLd() {
  const url = `${siteOrigin()}${plazaPath()}`;
  return {
    '@context': 'https://schema.org',
    '@type': 'WebSite',
    name: 'MindSpace Plaza',
    url,
    description: '浏览来自全球用户用 MindSpace 创作的报告、作品和页面',
    publisher: {
      '@type': 'Organization',
      name: 'MindSpace',
    },
  };
}

export function categoryJsonLd(name: string, slug: string, description?: string) {
  const url = `${siteOrigin()}${plazaPath(`cat/${slug}`)}`;
  return {
    '@context': 'https://schema.org',
    '@type': 'CollectionPage',
    name: `${name} - Plaza`,
    description: description || `Plaza「${name}」分类下的 AI 创作内容`,
    url,
    isPartOf: {
      '@type': 'WebSite',
      name: 'MindSpace Plaza',
      url: `${siteOrigin()}${plazaPath()}`,
    },
  };
}