// <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
// bubbling/composed CustomEvents (`repo:select`, `repo:contextmenu`) — no shared
// globals. Search + filter state is per-viewer view state kept in localStorage
// (§4); filtering is client-side over the already-fetched list.

const FILTER_KEY = 'gitmanager.repolist.filters';

class RepoList extends HTMLElement {
  #refreshMs = 15000;
  #timer = null;
  #controller = null;
  #repos = [];
  #selected = null;
  #filters = { q: '', dirty: false, aheadBehind: false };

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

  connectedCallback() {
    this.#loadFilters();
    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.#repos = (await res.json()) || [];
      this.#apply();
    } catch (err) {
      if (err.name !== 'AbortError') this.#renderError(err);
    }
  }

  #select(repo) {
    this.#selected = repo.path;
    this.#apply(); // reflect selection highlight
    // Cross-component communication is via events only (AGENT.md §1.1).
    this.dispatchEvent(new CustomEvent('repo:select', {
      detail: repo, bubbles: true, composed: true,
    }));
    // Selecting a repo makes it the active project (a user action, §8.2). Fire
    // and forget — the SSE feed reflects the change; failure just skips it.
    fetch('/api/active-project', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ path: repo.path }),
    }).catch(() => {});
  }

  #loadFilters() {
    try {
      const saved = JSON.parse(localStorage.getItem(FILTER_KEY) || '{}');
      this.#filters = { q: '', dirty: false, aheadBehind: false, ...saved };
    } catch { /* ignore — use defaults */ }
  }

  #saveFilters() {
    try { localStorage.setItem(FILTER_KEY, JSON.stringify(this.#filters)); } catch { /* ignore */ }
  }

  // #apply computes the filtered set and renders the body + count.
  #apply() {
    const body = this.shadowRoot.getElementById('body');
    const count = this.shadowRoot.getElementById('count');
    const { q, dirty, aheadBehind } = this.#filters;
    const ql = q.trim().toLowerCase();
    const filtered = this.#repos.filter((r) => {
      if (ql && !(String(r.name).toLowerCase().includes(ql) || String(r.path).toLowerCase().includes(ql))) return false;
      if (dirty && !r.dirty) return false;
      if (aheadBehind && !((r.ahead || 0) > 0 || (r.behind || 0) > 0)) return false;
      return true;
    });

    count.textContent = this.#repos.length ? `${filtered.length} of ${this.#repos.length}` : '';

    if (this.#repos.length === 0) {
      body.innerHTML = `<p class="empty">No repositories found. Check GIT_REPO_ROOTS.</p>`;
      return;
    }
    if (filtered.length === 0) {
      body.innerHTML = `<p class="empty">No repositories match your search.</p>`;
      return;
    }
    this.#renderList(filtered, body);
  }

  #renderList(repos, body) {
    const ul = document.createElement('ul');
    for (const r of repos) {
      const li = document.createElement('li');
      if (r.path === this.#selected) li.classList.add('selected');
      // Right-click opens the command menu (§6) for this repo — via an event,
      // so <repo-menu> stays decoupled from this component (§1.1).
      li.addEventListener('contextmenu', (e) => {
        e.preventDefault();
        this.dispatchEvent(new CustomEvent('repo:contextmenu', {
          detail: { repo: r, x: e.clientX, y: e.clientY },
          bubbles: true, composed: true,
        }));
      });
      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);
  }

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

  #renderShell() {
    this.shadowRoot.innerHTML = `
      <style>
        :host { display: block; }
        .controls { display: grid; gap: 8px; margin-bottom: 10px; }
        #search {
          width: 100%; box-sizing: border-box; font: inherit;
          background: var(--surface-1); color: var(--color-fg);
          border: 1px solid var(--border); border-radius: var(--radius);
          padding: 7px 10px;
        }
        #search:focus { outline: none; border-color: var(--fill-accent); }
        .chips { display: flex; align-items: center; gap: 6px; }
        .chip {
          font: inherit; font-size: 12px; cursor: pointer; padding: 3px 10px;
          border-radius: 999px; border: 1px solid var(--border-strong);
          background: transparent; color: var(--color-fg-muted);
        }
        .chip.active { border-color: var(--fill-accent); color: var(--fill-accent);
                       background: var(--surface-2); }
        .count { margin-left: auto; color: var(--color-fg-muted); font-size: 12px; }
        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); }
        li.selected { border-color: var(--fill-accent); background: var(--surface-2); }
        .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 class="controls">
        <input id="search" type="search" placeholder="Search repositories…" autocomplete="off" />
        <div class="chips">
          <button id="f-dirty" class="chip" type="button">Dirty</button>
          <button id="f-ab" class="chip" type="button">Ahead/behind</button>
          <span id="count" class="count"></span>
        </div>
      </div>
      <div id="body"><p class="empty">Loading repositories…</p></div>
    `;

    const search = this.shadowRoot.getElementById('search');
    const dirtyBtn = this.shadowRoot.getElementById('f-dirty');
    const abBtn = this.shadowRoot.getElementById('f-ab');
    // Reflect persisted state.
    search.value = this.#filters.q;
    dirtyBtn.classList.toggle('active', this.#filters.dirty);
    abBtn.classList.toggle('active', this.#filters.aheadBehind);

    search.addEventListener('input', () => {
      this.#filters.q = search.value;
      this.#saveFilters();
      this.#apply();
    });
    dirtyBtn.addEventListener('click', () => {
      this.#filters.dirty = !this.#filters.dirty;
      dirtyBtn.classList.toggle('active', this.#filters.dirty);
      this.#saveFilters();
      this.#apply();
    });
    abBtn.addEventListener('click', () => {
      this.#filters.aheadBehind = !this.#filters.aheadBehind;
      abBtn.classList.toggle('active', this.#filters.aheadBehind);
      this.#saveFilters();
      this.#apply();
    });
  }

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

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