---
import type { CollectionEntry } from 'astro:content';
import { getCollection } from 'astro:content';
import { postLang } from '../lib/lang';
import { tagCounts, tagLink } from '../lib/tags';
import { categoryLabel } from '../lib/categories';

interface Props {
  posts: CollectionEntry<'posts'>[];
  limit?: number;
  lang?: 'en' | 'zh';
  /**
   * Measured headline per base slug (see lib/portfolio.ts) — rendered as a pill on a
   * portfolio card. Omitted on the home page and tag pages, where a bare list is right.
   */
  metrics?: Record<string, string>;
}

const { posts, limit, lang = 'en', metrics } = Astro.props;
const shown = limit ? posts.slice(0, limit) : posts;
const isZh = lang === 'zh';

const fmt = (d: Date) =>
  d.toLocaleDateString(isZh ? 'zh-CN' : 'en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  });

const updatedLabel = isZh ? '更新于' : 'Updated';

const catHref = (cat: string) => `/${isZh ? 'zh/categories' : 'categories'}/${cat}/`;

const og = (post: CollectionEntry<'posts'>) => post.data.ogImage || '/og-default.jpg';

// Tag pills only link when the tag has its own page (>= TAG_MIN_POSTS in this language).
const counts = tagCounts((await getCollection('posts', ({ data }) => !data.draft))
  .filter((p) => postLang(p.slug) === lang));

// The row thumbnail is displayed at ~398 CSS px wide, so the list used to pull a
// 1200x630 PNG (~45 KB) per row for a 398px slot. Serve 400w/800w WebP derived from
// the same art instead (5.8 KB / 16.1 KB — see scripts/optimize-images.py).
const hasThumb = (post: CollectionEntry<'posts'>) => {
  const p = og(post);
  return p.startsWith('/og/') && p !== '/og-default.png' && p !== '/og-default.jpg';
};
const thumb = (post: CollectionEntry<'posts'>, w: 400 | 800) => {
  // Thumbs are keyed by the base slug, not by the og file: a ZH post's ogImage is
  // /og/zh-<slug>.jpg while the renderer only emits /og/thumb/<slug>-<w>.webp.
  const base = post.slug.replace(/^zh\//, '');
  return `/og/thumb/${base}-${w}.webp`;
};

// A case study is a portfolio artefact, so the row's action says so. The same rule is
// applied in Archive.astro for the /posts/ Featured block.
const ctaLabel = (category: string) => {
  if (category === 'case-studies') return isZh ? '阅读案例复盘' : 'Read case study';
  return isZh ? '阅读文章' : 'Read article';
};
const metricFor = (post: CollectionEntry<'posts'>) =>
  metrics?.[post.slug.replace(/^zh\//, '')];

// A card that lists every tag wraps to two metadata lines on some rows and one on
// others, so the grid loses its rhythm (and the summary/CTA drift). Show four and
// fold the rest into a "+N" chip whose tooltip names them.
const TAG_LIMIT = 4;
---

<ul class="post-list">
  {shown.map((post) => (
    <li class="post-row">
      <a class="thumb" href={`/posts/${post.slug}/`} aria-hidden="true" tabindex="-1">
        <img
          src={hasThumb(post) ? thumb(post, 800) : og(post)}
          srcset={hasThumb(post) ? `${thumb(post, 400)} 400w, ${thumb(post, 800)} 800w` : undefined}
          sizes="(max-width: 640px) 100vw, 398px"
          alt=""
          loading="lazy"
          decoding="async"
          width={hasThumb(post) ? 800 : 1200}
          height={hasThumb(post) ? 420 : 630}
        />
      </a>
      <div class="body">
        <a href={`/posts/${post.slug}/`}><h2>{post.data.title}</h2></a>
        <div class="meta">
          <time datetime={post.data.pubDate.toISOString()}>{fmt(post.data.pubDate)}</time>
          {post.data.updatedDate && (
            <>
              <span class="sep">·</span>
              <span class="updated" title={`${updatedLabel} ${fmt(post.data.updatedDate)}`}>
                {updatedLabel} {fmt(post.data.updatedDate)}
              </span>
            </>
          )}
          <span class="sep">·</span>
          <a class="tag" href={catHref(post.data.category)}>{categoryLabel(post.data.category, lang)}</a>
          {post.data.tags.slice(0, TAG_LIMIT).map((t) => {
            const href = tagLink(t, counts, lang);
            return href ? <a class="tag" href={href}>{t}</a> : <span class="tag">{t}</span>;
          })}
          {post.data.tags.length > TAG_LIMIT && (
            <span class="tag tag-more" title={post.data.tags.slice(TAG_LIMIT).join(', ')}>
              +{post.data.tags.length - TAG_LIMIT}
            </span>
          )}
        </div>
        <p>{post.data.description}</p>
        <div class="row-foot">
          {/* A second visual target for the same destination — deliberately out of the
              tab order so keyboard users get one stop per card, not two. */}
          <a class="row-cta" href={`/posts/${post.slug}/`} tabindex="-1" aria-hidden="true">
            {ctaLabel(post.data.category)} <span aria-hidden="true">→</span>
          </a>
          {metricFor(post) && (
            <span class="row-metric">
              <span class="pulse-dot" aria-hidden="true"></span>{metricFor(post)}
            </span>
          )}
        </div>
      </div>
    </li>
  ))}
</ul>