// <repo-list> — the dashboard's list of discovered repositories.
//
// A self-contained control in the ActiveX spirit (AGENT.md §1.1): it lives in a
// shadow root, fetches its own data from /api/repos on connect, renders itself,
// and cleans up on disconnect. It talks to the rest of the app only via a
// bubbling/composed `repo:select` CustomEvent — no shared globals.

class RepoList extends HTMLElement {
  #refreshMs = 15000;
  #timer = null;
  #controller = null;

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

  connectedCallback() {
    this.#renderShell();
    this.#load();
    this.#timer = setInterval(() => this.#load(), this.#refreshMs);
  }

  disconnectedCallback() {
    clearInterval(this.#timer);
    this.#controller?.abort();
  }

  async #load() {
    this.#controller?.abort();
    this.#controller = new AbortController();
    try {
      const res = await fetch('/api/repos', { signal: this.#controller.signal });
      if (!res.ok) throw new Error(`HTTP ${res.status}`);
      this.#renderRepos(await res.json());
    } catch (err) {
      if (err.name !== 'AbortError') this.#renderError(err);
    }
  }

  #select(repo) {
    // Cross-component communication is via events only (AGENT.md §1.1).
    this.dispatchEvent(new CustomEvent('repo:select', {
      detail: repo, bubbles: true, composed: true,
    }));
  }

  #renderShell() {
    this.shadowRoot.innerHTML = `
      <style>
        :host { display: block; }
        ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
        li {
          background: var(--surface-1);
          border: 1px solid var(--border);
          border-radius: var(--radius);
          padding: 10px 14px;
          cursor: pointer;
          display: flex; align-items: center; gap: 12px;
        }
        li:hover { border-color: var(--border-strong); }
        .name { font-weight: 600; }
        .branch { color: var(--color-fg-muted); }
        .spacer { margin-left: auto; }
        .badge {
          font-size: 12px; padding: 1px 8px; border-radius: var(--radius-sm);
          border: 1px solid var(--border-strong);
        }
        .dirty { color: var(--git-dirty); border-color: var(--git-dirty); }
        .clean { color: var(--git-clean); border-color: var(--git-clean); }
        .ahead { color: var(--git-ahead); }
        .behind { color: var(--git-behind); }
        .empty, .error { color: var(--color-fg-muted); padding: 12px 0; }
        .error { color: var(--color-danger); }
      </style>
      <div id="body"><p class="empty">Loading repositories…</p></div>
    `;
  }

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

  #renderRepos(repos) {
    const body = this.shadowRoot.getElementById('body');
    if (!repos || repos.length === 0) {
      body.innerHTML = `<p class="empty">No repositories found. Check GIT_REPO_ROOTS.</p>`;
      return;
    }
    const ul = document.createElement('ul');
    for (const r of repos) {
      const li = document.createElement('li');
      li.innerHTML = `
        <span class="name">${this.#esc(r.name)}</span>
        <span class="branch">${this.#esc(r.branch || '—')}</span>
        <span class="spacer"></span>
        ${r.ahead ? `<span class="badge ahead">↑${r.ahead}</span>` : ''}
        ${r.behind ? `<span class="badge behind">↓${r.behind}</span>` : ''}
        <span class="badge ${r.dirty ? 'dirty' : 'clean'}">${r.dirty ? 'dirty' : 'clean'}</span>
      `;
      li.addEventListener('click', () => this.#select(r));
      ul.appendChild(li);
    }
    body.replaceChildren(ul);
  }

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

customElements.define('repo-list', RepoList);