Blog/src/components/Webmentions.astro

---
import { Send } from '@lucide/astro';
import { getWebmentionEndpoint } from '@/lib/webmentions';
import { siteConfig } from '@/site.config';

interface Props {
  target?: string;
}

const { target = new URL(Astro.url.pathname, siteConfig.site.url).href } = Astro.props;
const config = siteConfig.webmentions;
const endpoint = config.endpoint.trim();
const receiveEndpoint = endpoint ? getWebmentionEndpoint(endpoint, 'receive') : '';
const getEndpoint = endpoint ? getWebmentionEndpoint(endpoint, 'get') : '';
---

{config.enabled && endpoint && <section
  class="webmentions-shell"
  id="webmentions"
  aria-labelledby="webmentions-title"
  data-webmentions-root
  data-get-endpoint={getEndpoint}
  data-receive-endpoint={receiveEndpoint}
  data-target={target}
  data-pagefind-ignore="all"
>
  <h2 id="webmentions-title">WebMention</h2>

  <div class="webmentions-loading" data-webmentions-loading role="status" aria-label="正在读取 WebMention">
    <svg class="webmentions-loading-spinner" viewBox="25 25 50 50" aria-hidden="true">
      <circle class="webmentions-loading-path" cx="50" cy="50" r="20" fill="none"></circle>
    </svg>
    <span>Loading...</span>
  </div>
  <p class="webmentions-status" data-webmentions-status role="status" hidden></p>

  <div class="webmentions-reactions" data-webmentions-reactions hidden>
    <div data-webmentions-reaction-group="like" hidden>
      <h3><span data-webmentions-like-count>0</span> 人喜欢</h3>
      <div class="webmentions-reaction-list" data-webmentions-like-list></div>
    </div>
    <div data-webmentions-reaction-group="repost" hidden>
      <h3><span data-webmentions-repost-count>0</span> 次转发</h3>
      <div class="webmentions-reaction-list" data-webmentions-repost-list></div>
    </div>
  </div>

  <div class="webmentions-discussion" data-webmentions-discussion hidden>
    <h3><span data-webmentions-discussion-count>0</span> 条回应与提及</h3>
    <ol data-webmentions-list></ol>
  </div>

  {config.form && <form class="webmention-form" action={receiveEndpoint} method="post" data-webmention-form>
    <label for="webmention-source">发送 WebMention</label>
    <div class="webmention-form-row">
      <input id="webmention-source" name="source" type="url" inputmode="url" autocomplete="url" placeholder="https://example.com/your-post" required />
      <input name="target" type="hidden" value={target} />
      <button type="submit">
        <Send size={16} stroke-width={1.8} aria-hidden="true" />
        <span>发送</span>
      </button>
    </div>
    <p class="webmention-form-status" data-webmention-form-status role="status" aria-live="polite"></p>
  </form>}
</section>}

<style>
  .webmentions-shell {
    width: min(100%, var(--article-content-width));
    margin: 4.375rem auto 0;
  }

  .webmentions-shell > h2 {
    margin: 0 0 1.5rem;
    padding-top: 1.375rem;
    border-top: 1px solid var(--color-border);
    color: var(--color-accent-strong);
    font-family: var(--reading-font-family);
    font-size: 1.5625rem;
    font-weight: 500;
  }

  .webmentions-status,
  .webmention-form-status {
    color: var(--color-muted);
    font-size: .86rem;
  }

  .webmentions-loading {
    display: flex;
    min-height: 5rem;
    align-items: center;
    justify-content: center;
    gap: .625rem;
    color: var(--color-muted);
    font-size: .86rem;
  }

  .webmentions-loading[hidden] {
    display: none;
  }

  .webmentions-loading-spinner {
    width: 2.625rem;
    height: 2.625rem;
    animation: webmentions-loading-rotate 2s linear infinite;
  }

  .webmentions-loading-path {
    animation: webmentions-loading-dash 1.5s ease-in-out infinite;
    stroke: var(--color-accent);
    stroke-dasharray: 90, 150;
    stroke-dashoffset: 0;
    stroke-linecap: round;
    stroke-width: 2;
  }

  .webmentions-status {
    margin: 0;
    padding-block: .25rem 1rem;
  }

  @keyframes webmentions-loading-rotate {
    to { transform: rotate(360deg); }
  }

  @keyframes webmentions-loading-dash {
    0% { stroke-dasharray: 1, 200; stroke-dashoffset: 0; }
    50% { stroke-dasharray: 90, 150; stroke-dashoffset: -40px; }
    100% { stroke-dasharray: 90, 150; stroke-dashoffset: -120px; }
  }

  @media (prefers-reduced-motion: reduce) {
    .webmentions-loading-spinner,
    .webmentions-loading-path {
      animation-duration: 3s;
    }
  }

  .webmentions-reactions {
    display: flex;
    flex-wrap: wrap;
    gap: 1.25rem 2.5rem;
    margin-bottom: 2rem;
  }

  .webmentions-reactions h3,
  .webmentions-discussion h3 {
    margin: 0 0 .75rem;
    color: var(--color-text);
    font-family: var(--reading-font-family);
    font-size: .9375rem;
    font-weight: 500;
  }

  .webmentions-reaction-list {
    display: flex;
    flex-wrap: wrap;
    gap: .45rem;
  }

  :global(.webmention-reaction) {
    display: grid;
    width: 2.25rem;
    height: 2.25rem;
    place-items: center;
    overflow: hidden;
    border: 1px solid var(--color-border);
    border-radius: 50%;
    background: var(--color-code);
    color: var(--color-muted);
    font-family: var(--mirages-font-ui);
    font-size: .75rem;
    font-weight: 600;
    text-decoration: none;
  }

  :global(.webmention-reaction:hover) {
    border-color: var(--color-accent);
    color: var(--color-accent-strong);
  }

  .webmentions-discussion ol {
    margin: 0;
    padding: 0;
    list-style: none;
  }

  :global(.webmention-item) {
    display: grid;
    grid-template-columns: 2.25rem minmax(0, 1fr);
    gap: .75rem;
    padding: 1.25rem 0;
    border-top: 1px solid var(--color-border);
  }

  :global(.webmention-avatar) {
    display: grid;
    width: 2.25rem;
    height: 2.25rem;
    place-items: center;
    border-radius: 50%;
    background: var(--color-code);
    color: var(--color-muted);
    font-family: var(--mirages-font-ui);
    font-size: .75rem;
    font-weight: 600;
  }

  :global(.webmention-meta) {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: .25rem .65rem;
    min-width: 0;
  }

  :global(.webmention-author) {
    color: var(--color-text);
    font-size: .875rem;
    font-weight: 500;
    overflow-wrap: anywhere;
  }

  :global(.webmention-date),
  :global(.webmention-kind) {
    color: var(--color-muted);
    font-size: .75rem;
  }

  :global(.webmention-content) {
    margin: .5rem 0 0;
    color: var(--color-text);
    font-size: .9375rem;
    line-height: 1.65;
    overflow-wrap: anywhere;
    white-space: pre-wrap;
  }

  :global(.webmention-source-link) {
    display: inline-block;
    margin-top: .45rem;
    color: var(--color-accent);
    font-size: .78rem;
  }

  .webmention-form {
    margin-top: 2rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--color-border);
  }

  .webmention-form > label {
    display: block;
    margin-bottom: .5rem;
    color: var(--color-muted);
    font-size: .8rem;
  }

  .webmention-form-row {
    display: flex;
    gap: .625rem;
  }

  .webmention-form input[type='url'] {
    min-width: 0;
    flex: 1 1 auto;
    height: 2.5rem;
    padding: .5rem .75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    color: var(--color-text);
  }

  .webmention-form input[type='url']:focus {
    border-color: var(--color-accent);
    outline: none;
  }

  .webmention-form button {
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    gap: .4rem;
    min-height: 2.5rem;
    padding: .45rem .85rem;
    border: 1px solid var(--color-accent-strong);
    border-radius: var(--radius-sm);
    background: var(--color-accent);
    color: var(--color-accent-contrast);
    cursor: pointer;
    font-weight: 600;
  }

  .webmention-form button:disabled {
    cursor: wait;
    opacity: .6;
  }

  .webmention-form-status {
    min-height: 1.5em;
    margin: .4rem 0 0;
  }

  @media (max-width: 37.5rem) {
    .webmentions-shell {
      width: 100%;
      margin-top: 3.25rem;
    }

    .webmention-form-row {
      align-items: stretch;
      flex-direction: column;
    }

    .webmention-form button {
      align-self: flex-end;
    }
  }
</style>

<script>
  type WebmentionRecord = {
    id: string;
    source: string;
    createdAt: string;
    title: string;
    content: string;
    author: string;
    type: string;
  };

  type WebmentionClientState = {
    bound?: boolean;
    controller?: AbortController;
    observer?: IntersectionObserver;
  };

  declare global {
    interface Window {
      __miragesWebmentions?: WebmentionClientState;
    }
  }

  const state = window.__miragesWebmentions ??= {};

  const getString = (record: Record<string, unknown>, key: string) => {
    const value = record[key];
    return typeof value === 'string' ? value.trim() : '';
  };

  const safeSource = (value: string) => {
    try {
      const url = new URL(value);
      return url.protocol === 'http:' || url.protocol === 'https:' ? url : null;
    } catch {
      return null;
    }
  };

  const plainText = (value: string) => {
    if (!value) return '';
    const parsed = new DOMParser().parseFromString(value, 'text/html');
    return (parsed.body.textContent ?? '').replace(/\s+/g, ' ').trim().slice(0, 1200);
  };

  const normalizeMention = (value: unknown): WebmentionRecord | null => {
    if (!value || typeof value !== 'object' || Array.isArray(value)) return null;
    const record = value as Record<string, unknown>;
    const source = safeSource(getString(record, 'source'));
    if (!source) return null;
    return {
      id: getString(record, 'id'),
      source: source.href,
      createdAt: getString(record, 'created_at'),
      title: plainText(getString(record, 'title')),
      content: plainText(getString(record, 'content')),
      author: plainText(getString(record, 'author_name')) || source.hostname,
      type: getString(record, 'type').toLowerCase()
    };
  };

  const kindOf = (mention: WebmentionRecord) => {
    if (mention.type.includes('like')) return 'like';
    if (mention.type.includes('repost') || mention.type.includes('share')) return 'repost';
    if (mention.type.includes('reply')) return 'reply';
    return 'mention';
  };

  const kindLabel = (kind: ReturnType<typeof kindOf>) => ({
    like: '喜欢',
    repost: '转发',
    reply: '回应',
    mention: '提及'
  })[kind];

  const initialFor = (name: string) => Array.from(name.trim())[0]?.toLocaleUpperCase() ?? '@';

  const sourceLink = (mention: WebmentionRecord, className: string) => {
    const link = document.createElement('a');
    link.className = className;
    link.href = mention.source;
    link.target = '_blank';
    link.rel = 'nofollow ugc noopener noreferrer';
    return link;
  };

  const renderReaction = (mention: WebmentionRecord) => {
    const link = sourceLink(mention, 'webmention-reaction');
    link.textContent = initialFor(mention.author);
    link.title = mention.author;
    link.setAttribute('aria-label', `${mention.author}：${kindLabel(kindOf(mention))}`);
    return link;
  };

  const renderDiscussion = (mention: WebmentionRecord) => {
    const kind = kindOf(mention);
    const item = document.createElement('li');
    item.className = 'webmention-item';

    const avatar = document.createElement('span');
    avatar.className = 'webmention-avatar';
    avatar.textContent = initialFor(mention.author);
    avatar.setAttribute('aria-hidden', 'true');

    const body = document.createElement('div');
    const meta = document.createElement('div');
    meta.className = 'webmention-meta';

    const author = sourceLink(mention, 'webmention-author');
    author.textContent = mention.author;
    meta.append(author);

    if (mention.createdAt) {
      const date = new Date(mention.createdAt);
      if (!Number.isNaN(date.getTime())) {
        const time = document.createElement('time');
        time.className = 'webmention-date';
        time.dateTime = date.toISOString();
        time.textContent = new Intl.DateTimeFormat('zh-CN', { dateStyle: 'medium' }).format(date);
        meta.append(time);
      }
    }

    const type = document.createElement('span');
    type.className = 'webmention-kind';
    type.textContent = kindLabel(kind);
    meta.append(type);
    body.append(meta);

    const text = mention.content || mention.title;
    if (text) {
      const content = document.createElement('p');
      content.className = 'webmention-content';
      content.textContent = text;
      body.append(content);
    }

    const source = sourceLink(mention, 'webmention-source-link');
    source.textContent = '查看来源';
    body.append(source);
    item.append(avatar, body);
    return item;
  };

  const renderMentions = (root: HTMLElement, mentions: WebmentionRecord[]) => {
    const loading = root.querySelector<HTMLElement>('[data-webmentions-loading]');
    const status = root.querySelector<HTMLElement>('[data-webmentions-status]');
    const likeGroup = root.querySelector<HTMLElement>('[data-webmentions-reaction-group="like"]');
    const repostGroup = root.querySelector<HTMLElement>('[data-webmentions-reaction-group="repost"]');
    const reactions = root.querySelector<HTMLElement>('[data-webmentions-reactions]');
    const discussion = root.querySelector<HTMLElement>('[data-webmentions-discussion]');
    const likeList = root.querySelector<HTMLElement>('[data-webmentions-like-list]');
    const repostList = root.querySelector<HTMLElement>('[data-webmentions-repost-list]');
    const list = root.querySelector<HTMLOListElement>('[data-webmentions-list]');
    if (!loading || !status || !likeGroup || !repostGroup || !reactions || !discussion || !likeList || !repostList || !list) return;

    const likes = mentions.filter((mention) => kindOf(mention) === 'like');
    const reposts = mentions.filter((mention) => kindOf(mention) === 'repost');
    const discussions = mentions.filter((mention) => !['like', 'repost'].includes(kindOf(mention)));

    likeList.replaceChildren(...likes.map(renderReaction));
    repostList.replaceChildren(...reposts.map(renderReaction));
    list.replaceChildren(...discussions.map(renderDiscussion));

    const likeCount = root.querySelector<HTMLElement>('[data-webmentions-like-count]');
    const repostCount = root.querySelector<HTMLElement>('[data-webmentions-repost-count]');
    const discussionCount = root.querySelector<HTMLElement>('[data-webmentions-discussion-count]');
    if (likeCount) likeCount.textContent = String(likes.length);
    if (repostCount) repostCount.textContent = String(reposts.length);
    if (discussionCount) discussionCount.textContent = String(discussions.length);

    likeGroup.hidden = likes.length === 0;
    repostGroup.hidden = reposts.length === 0;
    reactions.hidden = likes.length + reposts.length === 0;
    discussion.hidden = discussions.length === 0;
    loading.hidden = true;
    status.textContent = mentions.length ? '' : '暂时还没有站外回应。';
    status.hidden = mentions.length > 0;
  };

  const fetchWebmentions = (root: HTMLElement) => {
    if (root.dataset.webmentionsLoaded) return;
    root.dataset.webmentionsLoaded = 'true';
    const loading = root.querySelector<HTMLElement>('[data-webmentions-loading]');
    const status = root.querySelector<HTMLElement>('[data-webmentions-status]');
    const getEndpoint = root.dataset.getEndpoint;
    const target = root.dataset.target;
    if (!loading || !status || !getEndpoint || !target) return;

    state.controller?.abort();
    const controller = new AbortController();
    state.controller = controller;
    const url = new URL(getEndpoint);
    url.searchParams.set('target', target);

    fetch(url, { headers: { Accept: 'application/json' }, signal: controller.signal })
      .then((response) => {
        if (!response.ok) throw new Error(`HTTP ${response.status}`);
        return response.json();
      })
      .then((data: unknown) => {
        if (!root.isConnected) return;
        const mentions = Array.isArray(data)
          ? data.map(normalizeMention).filter((mention): mention is WebmentionRecord => mention !== null)
          : [];
        renderMentions(root, mentions);
      })
      .catch(() => {
        if (controller.signal.aborted || !root.isConnected) return;
        loading.hidden = true;
        status.textContent = '站外回应暂时无法读取。';
        status.hidden = false;
      });
  };

  const loadCurrentWebmentions = () => {
    const root = document.querySelector<HTMLElement>('[data-webmentions-root]');
    if (!root || root.dataset.webmentionsBound) return;
    root.dataset.webmentionsBound = 'true';

    state.observer?.disconnect();
    if (!('IntersectionObserver' in window)) {
      fetchWebmentions(root);
      return;
    }

    state.observer = new IntersectionObserver((entries, observer) => {
      if (!entries.some((entry) => entry.isIntersecting)) return;
      observer.disconnect();
      fetchWebmentions(root);
    }, { rootMargin: '400px 0px' });
    state.observer.observe(root);
  };

  const submitWebmention = (form: HTMLFormElement) => {
    const status = form.querySelector<HTMLElement>('[data-webmention-form-status]');
    const button = form.querySelector<HTMLButtonElement>('button[type="submit"]');
    if (!status || !button) return;
    button.disabled = true;
    status.textContent = '正在发送...';

    const body = new URLSearchParams();
    for (const [name, value] of new FormData(form)) {
      if (typeof value === 'string') body.append(name, value);
    }

    fetch(form.action, {
      method: 'POST',
      body,
      headers: { Accept: 'application/json' }
    }).then(async (response) => {
      if (!response.ok) {
        const message = plainText(await response.text());
        throw new Error(message || `HTTP ${response.status}`);
      }
      status.textContent = '已收到，验证通过并经审核后会显示在这里。';
      const source = form.elements.namedItem('source');
      if (source instanceof HTMLInputElement) source.value = '';
    }).catch((error: unknown) => {
      const message = error instanceof Error ? error.message : '';
      status.textContent = message ? `发送失败：${message}` : '发送失败，请稍后重试。';
    }).finally(() => {
      button.disabled = false;
    });
  };

  if (!state.bound) {
    state.bound = true;
    document.addEventListener('submit', (event) => {
      const form = event.target;
      if (!(form instanceof HTMLFormElement) || !form.matches('[data-webmention-form]')) return;
      event.preventDefault();
      submitWebmention(form);
    });
    document.addEventListener('astro:page-load', loadCurrentWebmentions);
    document.addEventListener('astro:before-swap', () => {
      state.observer?.disconnect();
      state.controller?.abort();
    });
  }

  loadCurrentWebmentions();
</script>