// Shared poster-tile rendering - used by the home carousels, the library
// grid, and the artist page, so they all stay visually/behaviorally
// identical instead of drifting.
import './tiles.css';
import type { ItemDto } from './types';

export function escapeHtml(str: string): string {
  const div = document.createElement('div');
  div.textContent = str;
  return div.innerHTML;
}

/** "m:ss" (or "h:mm:ss" past an hour) - shared by the album track list and
 *  the music player, so a track's listed duration and its playing position
 *  always read the same way. */
export function formatDuration(totalSeconds: number): string {
  const s = Math.max(0, Math.round(totalSeconds || 0));
  const h = Math.floor(s / 3600);
  const m = Math.floor((s % 3600) / 60);
  const sec = s % 60;
  const pad = (n: number) => String(n).padStart(2, '0');
  return h > 0 ? `${h}:${pad(m)}:${pad(sec)}` : `${m}:${pad(sec)}`;
}

// Small deterministic palette so the same person always gets the same
// avatar color across a session, without needing the server to assign one
// - shared by the video player's presence overlay and the music player's
// listener list, so the same person reads as the same color in either.
const AVATAR_COLORS = ['#52b54b', '#4c8bf5', '#f5a623', '#e05d5d', '#9b59b6', '#1abc9c', '#e67e22', '#3498db'];

export function colorForName(name: string): string {
  let hash = 0;
  for (let i = 0; i < name.length; i++) hash = (hash * 31 + name.charCodeAt(i)) >>> 0;
  return AVATAR_COLORS[hash % AVATAR_COLORS.length] as string;
}

export function initialsFor(name: string): string {
  return (name || '').trim().slice(0, 2).toUpperCase() || '?';
}

// Drill-down targets: a tile for a type with no direct playback (Series,
// MusicArtist, MusicAlbum) links into its own browsing page instead of
// getting a "start a party" button - canWatchParty is already false for
// all three server-side (see WATCH_PARTY_TYPES in CatalogService).
const DRILL_DOWN: Record<string, { route: string; label: string }> = {
  Series: { route: 'series', label: 'Voir les épisodes' },
  MusicArtist: { route: 'artist', label: 'Voir les albums' },
  MusicAlbum: { route: 'album', label: 'Voir les morceaux' },
  Playlist: { route: 'playlist', label: 'Voir la playlist' }
};

export function tileHtml(item: ItemDto): string {
  const drill = item.type ? DRILL_DOWN[item.type] : undefined;
  const drillHref = drill ? `#/${drill.route}/${item.id}` : null;
  const partyLabel = item.type === 'Audio' ? 'Écouter ensemble' : 'Lancer une watch party';
  return `
    <div class="tile">
      ${drillHref ? `<a href="${drillHref}" class="tileLink" aria-label="${escapeHtml(item.name)}"></a>` : ''}
      <img src="${item.imageUrl}" alt="" loading="lazy" onerror="this.classList.add('noImage')" />
      <div class="tileOverlay">
        ${item.canWatchParty ? `<button class="tileBtn startPartyBtn" data-item-id="${item.id}">${partyLabel}</button>` : ''}
        ${drillHref ? `<a class="tileBtn" href="${drillHref}">${drill!.label}</a>` : ''}
        <a class="tileBtn tileBtnLink" href="${item.embyUrl}" target="_blank" rel="noopener">Voir sur Emby</a>
      </div>
      <span class="tileLabel">${escapeHtml(item.name)}${item.year ? ` (${item.year})` : ''}</span>
    </div>`;
}

/**
 * Wires up every "Lancer une watch party" button inside `container`, now
 * and for any tile added to it later. `onStart(itemId)` does the actual
 * work (create the party + navigate) - kept as a caller-supplied callback
 * so this module doesn't need to depend on api/party.ts/router.ts itself.
 *
 * One delegated listener on `container` itself, not one per button - a
 * plain per-button `addEventListener` loop only ever catches whatever's
 * already in the DOM at call time, which renderTilesInChunks (below)
 * deliberately isn't: its later chunks land after this runs, and a
 * direct-bound listener would silently never cover them.
 */
export function wireTileButtons(container: ParentNode, onStart: (itemId: string) => Promise<void>): void {
  container.addEventListener('click', async (e) => {
    const btn = (e.target as HTMLElement).closest<HTMLButtonElement>('.startPartyBtn');
    if (!btn || btn.disabled) return;
    e.preventDefault();
    btn.disabled = true;
    btn.textContent = 'Démarrage...';
    try {
      await onStart(btn.dataset.itemId as string);
    } catch (err) {
      alert((err as Error).message);
      btn.disabled = false;
      btn.textContent = 'Lancer une watch party';
    }
  });
}

/**
 * Renders `items` into `container` a chunk at a time, across animation
 * frames, instead of one `innerHTML` write for the whole list - a library
 * grid can hand back up to 300 tiles at once (CatalogService.getLibraryItems/
 * getArtists), and building + inserting/laying out ~300 posters in a
 * single synchronous task is exactly what a "the page freezes while it
 * loads" report looks like on a slower device. Splitting the same HTML
 * across a few chunks keeps every individual task well under a frame's
 * budget, so the tab stays responsive (and the loading spinner keeps
 * animating) while it works through the rest.
 *
 * Uses `insertAdjacentHTML`, not repeated `innerHTML +=` (which would
 * re-parse and re-render everything already inserted on every chunk).
 * Safe to pair with wireTileButtons/wireSearchFilter called once right
 * after this returns - both already tolerate tiles that land later (see
 * their own comments).
 */
export function renderTilesInChunks(container: HTMLElement, items: ItemDto[], chunkSize = 40): void {
  container.innerHTML = '';
  let i = 0;
  function renderNextChunk(): void {
    const chunk = items.slice(i, i + chunkSize);
    if (!chunk.length) return;
    container.insertAdjacentHTML('beforeend', chunk.map(tileHtml).join(''));
    i += chunkSize;
    if (i < items.length) requestAnimationFrame(renderNextChunk);
  }
  renderNextChunk();
}

/**
 * Wires a search <input> to show/hide `itemSelector` elements by name,
 * live as you type - client-side only, filtering whatever's already
 * rendered rather than a server round trip per keystroke. Deliberately
 * simple for that reason: a library page tops out at a few hundred items
 * (see getLibraryItems's own Limit), well within "just filter the DOM"
 * territory - shared by views/library, views/artist, views/album so the
 * three catalog pages that asked for this all behave identically instead
 * of drifting into three slightly different implementations.
 *
 * `scope` should be wide enough to contain both the items themselves AND
 * a `.searchEmpty` notice element - typically the view's own `root`, not
 * just the immediate grid/list wrapper (which is usually a sibling of
 * `.searchEmpty`, not an ancestor of it).
 */
export function wireSearchFilter(input: HTMLInputElement, scope: ParentNode, itemSelector: string): void {
  input.addEventListener('input', () => {
    const q = input.value.trim().toLowerCase();
    let anyVisible = false;
    scope.querySelectorAll<HTMLElement>(itemSelector).forEach((el) => {
      const matches = !q || (el.textContent || '').toLowerCase().includes(q);
      el.classList.toggle('hide', !matches);
      if (matches) anyVisible = true;
    });
    const emptyNotice = scope.querySelector<HTMLElement>('.searchEmpty');
    if (emptyNotice) emptyNotice.classList.toggle('hide', anyVisible || !q);
  });
}