// <repo-detail> — detail panel for the repository selected in <repo-list>.
//
// A self-contained control (AGENT.md §1.1): shadow DOM, fetches its own data,
// cleans up on disconnect. It has no reference to <repo-list>; it listens on the
// document for the bubbling/composed `repo:select` event (the sanctioned
// cross-component channel) and fetches `/api/repo?path=…` for the chosen repo.

class RepoDetail extends HTMLElement {
  #controller = null;
  #onSelect = null;

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

  connectedCallback() {
    this.#renderShell();
    this.#renderEmpty();
    this.#onSelect = (e) => this.#load(e.detail?.path);
    document.addEventListener('repo:select', this.#onSelect);
  }

  disconnectedCallback() {
    document.removeEventListener('repo:select', this.#onSelect);
    this.#controller?.abort();
  }

  async #load(path) {
    if (!path) return;
    this.#controller?.abort();
    this.#controller = new AbortController();
    this.#body().innerHTML = `<p class="muted">Loading…</p>`;
    try {
      const res = await fetch(`/api/repo?path=${encodeURIComponent(path)}`, {
        signal: this.#controller.signal,
      });
      if (!res.ok) throw new Error(`HTTP ${res.status}`);
      this.#renderDetail(await res.json());
    } catch (err) {
      if (err.name !== 'AbortError') {
        this.#body().innerHTML = `<p class="error">Could not load details: ${this.#esc(err.message)}</p>`;
      }
    }
  }

  #body() { return this.shadowRoot.getElementById('body'); }

  #renderEmpty() {
    this.#body().innerHTML = `<p class="muted">Select a repository to see its details.</p>`;
  }

  #renderDetail(r) {
    const remotes = (r.remoteDetails || []).map((rm) =>
      `<li><span class="k">${this.#esc(rm.name)}</span> <span class="url">${this.#esc(rm.url)}</span></li>`
    ).join('') || `<li class="muted">none</li>`;

    const branches = (r.branches || []).map((b) =>
      `<li class="${b.current ? 'cur' : ''}">
         ${b.current ? '<span class="dot">●</span>' : ''}${this.#esc(b.name)}
         ${b.upstream ? `<span class="up">→ ${this.#esc(b.upstream)}</span>` : ''}
       </li>`
    ).join('') || `<li class="muted">none</li>`;

    const commits = (r.commits || []).map((c) =>
      `<li>
         <code>${this.#esc(c.short)}</code>
         <span class="subject">${this.#esc(c.subject)}</span>
         <span class="meta">${this.#esc(c.author)} · ${this.#esc(c.date)}</span>
       </li>`
    ).join('') || `<li class="muted">none</li>`;

    this.#body().innerHTML = `
      <div class="head">
        <h2>${this.#esc(r.name)}</h2>
        <span class="badge ${r.dirty ? 'dirty' : 'clean'}">${r.dirty ? 'dirty' : 'clean'}</span>
        ${r.ahead ? `<span class="badge ahead">↑${r.ahead}</span>` : ''}
        ${r.behind ? `<span class="badge behind">↓${r.behind}</span>` : ''}
      </div>
      <p class="path">${this.#esc(r.path)}</p>
      <p class="branch">on <strong>${this.#esc(r.branch || '—')}</strong></p>
      ${r.error ? `<p class="error">${this.#esc(r.error)}</p>` : ''}

      <h3>Remotes</h3>
      <ul class="remotes">${remotes}</ul>

      <h3>Branches</h3>
      <ul class="branches">${branches}</ul>

      <h3>Recent commits</h3>
      <ul class="commits">${commits}</ul>
    `;
  }

  #renderShell() {
    this.shadowRoot.innerHTML = `
      <style>
        :host { display: block; }
        #body {
          background: var(--surface-1);
          border: 1px solid var(--border);
          border-radius: var(--radius);
          padding: 16px 18px;
        }
        .head { display: flex; align-items: center; gap: 10px; }
        h2 { margin: 0; font-size: 16px; }
        h3 { font-size: 12px; text-transform: uppercase; letter-spacing: .04em;
             color: var(--color-fg-muted); margin: 20px 0 6px; }
        .path { color: var(--color-fg-muted); font-size: 12px; margin: 6px 0 0;
                word-break: break-all; }
        .branch { margin: 4px 0 0; }
        ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 4px; }
        li { display: flex; align-items: baseline; gap: 8px; flex-wrap: wrap; }
        code { background: var(--surface-2); padding: 0 5px; border-radius: var(--radius-sm); }
        .k { font-weight: 600; }
        .url, .up, .meta { color: var(--color-fg-muted); font-size: 12px; }
        .subject { flex: 1; }
        .branches .cur { color: var(--git-ahead); font-weight: 600; }
        .dot { color: var(--git-ahead); }
        .muted { color: var(--color-fg-muted); }
        .error { color: var(--color-danger); }
        .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); }
      </style>
      <div id="body"></div>
    `;
  }

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

customElements.define('repo-detail', RepoDetail);