// <activity-feed> — shows the active project and a live feed of what happened
// (user AND Claude actions). A self-contained control (AGENT.md §1.1): shadow
// DOM, fetches its own initial data, subscribes to the /events SSE stream, and
// cleans up on disconnect. It reflects the coordination state that Claude reads
// over MCP (§8.2), so the user can see the two staying in sync.

class ActivityFeed extends HTMLElement {
  #es = null;
  #controller = null;
  #events = [];

  constructor() {
    super();
    this.attachShadow({ mode: 'open' });
  }

  connectedCallback() {
    this.#renderShell();
    this.#loadInitial();
    // Live updates. EventSource auto-reconnects if the stream drops.
    this.#es = new EventSource('/events');
    this.#es.addEventListener('activity', (e) => {
      try { this.#onEvent(JSON.parse(e.data)); } catch { /* ignore malformed */ }
    });
  }

  disconnectedCallback() {
    this.#es?.close();
    this.#controller?.abort();
  }

  async #loadInitial() {
    this.#controller?.abort();
    this.#controller = new AbortController();
    try {
      const [apRes, actRes] = await Promise.all([
        fetch('/api/active-project', { signal: this.#controller.signal }),
        fetch('/api/activity', { signal: this.#controller.signal }),
      ]);
      const ap = await apRes.json();
      const events = await actRes.json();
      this.#events = Array.isArray(events) ? events : [];
      this.#renderActive(ap.path || '');
      this.#renderFeed();
    } catch (err) {
      if (err.name !== 'AbortError') this.#renderError(err);
    }
  }

  #onEvent(ev) {
    this.#events.push(ev);
    if (this.#events.length > 200) this.#events = this.#events.slice(-200);
    if (ev.kind === 'active-project-changed') this.#renderActive(ev.repo || '');
    this.#renderFeed();
  }

  #renderActive(path) {
    const el = this.shadowRoot.getElementById('active');
    el.textContent = path ? this.#base(path) : 'none';
    el.title = path;
  }

  #renderFeed() {
    const ul = this.shadowRoot.getElementById('feed');
    // Newest first.
    ul.replaceChildren(...[...this.#events].reverse().map((ev) => {
      const li = document.createElement('li');
      const repo = ev.repo ? this.#base(ev.repo) : '';
      li.innerHTML = `
        <span class="actor ${this.#esc(ev.actor)}">${this.#esc(ev.actor)}</span>
        <span class="kind">${this.#esc(this.#label(ev.kind))}</span>
        ${repo ? `<span class="repo">${this.#esc(repo)}</span>` : ''}
        ${ev.detail ? `<span class="detail">${this.#esc(ev.detail)}</span>` : ''}
        <span class="time">${this.#time(ev.time)}</span>`;
      return li;
    }));
  }

  #renderError(err) {
    this.shadowRoot.getElementById('feed').innerHTML =
      `<li class="error">Could not load activity: ${this.#esc(err.message)}</li>`;
  }

  #renderShell() {
    this.shadowRoot.innerHTML = `
      <style>
        :host { display: block; }
        .box {
          background: var(--surface-1);
          border: 1px solid var(--border);
          border-radius: var(--radius);
          padding: 12px 16px;
        }
        .active { margin-bottom: 8px; color: var(--color-fg-muted); }
        .active strong { color: var(--fill-accent); }
        h3 { font-size: 12px; text-transform: uppercase; letter-spacing: .04em;
             color: var(--color-fg-muted); margin: 8px 0 6px; }
        ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px;
             max-height: 220px; overflow-y: auto; }
        li { display: flex; align-items: baseline; gap: 8px; font-size: 13px; }
        .actor { font-size: 11px; padding: 0 6px; border-radius: var(--radius-sm);
                 border: 1px solid var(--border-strong); text-transform: uppercase; }
        .actor.user { color: var(--git-ahead); border-color: var(--git-ahead); }
        .actor.claude { color: var(--color-success); border-color: var(--color-success); }
        .actor.system { color: var(--color-fg-muted); }
        .repo { font-weight: 600; }
        .detail { color: var(--color-fg-muted); }
        .time { margin-left: auto; color: var(--color-fg-muted); font-size: 11px; white-space: nowrap; }
        .error { color: var(--color-danger); }
        .empty { color: var(--color-fg-muted); }
      </style>
      <div class="box">
        <div class="active">Active project: <strong id="active">none</strong></div>
        <h3>Activity</h3>
        <ul id="feed"><li class="empty">No activity yet.</li></ul>
      </div>`;
  }

  #base(p) {
    return String(p).split(/[/\\]/).filter(Boolean).pop() || p;
  }

  #label(kind) {
    return String(kind || '').replace(/-/g, ' ');
  }

  #time(t) {
    const d = new Date(t);
    return isNaN(d) ? '' : d.toLocaleTimeString();
  }

  #esc(s) {
    return String(s ?? '').replace(/[&<>"']/g, (c) => (
      { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]
    ));
  }
}

customElements.define('activity-feed', ActivityFeed);