---
// Feed subscribe button. Signed in: toggle the feed in the user's saved-feeds preferences
// (agent.addSavedFeeds / removeSavedFeeds, which safely read-modify-write the whole prefs
// blob on the PDS). Signed out — or if the write fails for any reason (missing scope, old
// session, unsupported PDS) — fall back to opening the feed on mu.social. Never errors.
---

<script>
  import { ensureWriteScope } from '../lib/auth-step-up';

  const SELECTOR = '.feed-subscribe-btn';

  function buttons(): HTMLElement[] {
    return Array.from(document.querySelectorAll(SELECTOR));
  }

  function setState(b: HTMLElement, subscribed: boolean) {
    b.textContent = subscribed ? b.dataset.labelDone ?? 'Subscribed' : b.dataset.labelSub ?? 'Subscribe';
    b.classList.toggle('subscribed', subscribed);
    b.setAttribute('aria-pressed', String(subscribed));
  }

  function openFeed(b: HTMLElement) {
    if (b.dataset.url) window.open(b.dataset.url, '_blank', 'noopener');
  }

  // On sign-in, reflect whether the viewer already saved this feed (so the button toggles).
  async function refresh() {
    const atn = (window as any).atn;
    const btns = buttons();
    if (!btns.length || !atn?.agent) return;
    try {
      const prefs = await atn.agent.getPreferences();
      for (const b of btns) {
        const saved = prefs.savedFeeds?.find((f: any) => f.value === b.dataset.feed);
        if (saved) b.dataset.savedId = saved.id;
        else delete b.dataset.savedId;
        setState(b, Boolean(saved));
      }
    } catch {
      /* leave buttons in the default "subscribe" state; click falls back to the deeplink */
    }
  }

  document.addEventListener('click', async (e) => {
    const btn = (e.target as HTMLElement)?.closest(SELECTOR) as HTMLElement | null;
    if (!btn) return;
    const atn = (window as any).atn;
    if (!atn?.agent) {
      openFeed(btn);
      return;
    }
    // Subscribing writes saved-feeds prefs, which needs the activity scope. Ask once; if the
    // member declines, fall back to the deeplink (a confirmed grant redirects away before here).
    if (!(await ensureWriteScope('subscribe to this feed'))) {
      openFeed(btn);
      return;
    }
    const agent = atn.agent;
    const feed = btn.dataset.feed as string;
    btn.setAttribute('disabled', '');
    try {
      if (btn.dataset.savedId) {
        await agent.removeSavedFeeds([btn.dataset.savedId]);
        delete btn.dataset.savedId;
        setState(btn, false);
      } else {
        const [created] = await agent.addSavedFeeds([{ type: 'feed', value: feed, pinned: true }]);
        if (created?.id) btn.dataset.savedId = created.id;
        setState(btn, true);
      }
    } catch {
      // Any failure (scope not granted, old session, PDS quirk): fall back to the deeplink.
      openFeed(btn);
    } finally {
      btn.removeAttribute('disabled');
    }
  });

  document.addEventListener('atn:signedin', refresh);
  document.addEventListener('atn:signedout', refresh);
  if ((window as any).atn) refresh();
</script>