import { state } from '../state';

/**
 * Syncs autoplay checkbox with localStorage on init.
 * Default is enabled (not 'false').
 */
export const setupAutoplayButton = (): void => {
  const btn = document.querySelector('[data-autoplay]') as HTMLInputElement | null;
  if (!btn) return;
  btn.checked = localStorage.getItem('mal:autoplay-enabled') !== 'false';
};

export const isAutoplayEnabled = (): boolean =>
  localStorage.getItem('mal:autoplay-enabled') !== 'false';

/**
 * Updates video overlay text (shown briefly on episode change).
 */
export const updateOverlay = (episode: string, title: string): void => {
  if (!state.videoOverlay) return;
  const p = state.videoOverlay.querySelector('p');
  p && (p.textContent = title ? `Episode ${episode}, ${title}` : `Episode ${episode}`);
};

// helper: get all episode elements from grid and list
const getEpisodeEls = () => {
  const grid = state.episodeGrid;
  const list = state.episodeList;
  return {
    gridEls: grid ? Array.from(grid.querySelectorAll('[data-episode-id]')) : [],
    listEls: list ? Array.from(list.querySelectorAll('[data-episode-id]')) : [],
  };
};

/**
 * Highlights current episode in grid and list.
 * Scrolls to episode into view.
 */
export const updateEpisodeHighlight = (num: number): void => {
  const { gridEls, listEls } = getEpisodeEls();
  // clear old highlights
  [...gridEls, ...listEls].forEach(el =>
    el.classList.remove('ring-2', 'ring-accent', 'bg-accent/20', 'text-accent')
  );

  // apply new highlight
  const gridEl = state.episodeGrid?.querySelector(`[data-episode-id="${num}"]`);
  const listEl = state.episodeList?.querySelector(`[data-episode-id="${num}"]`);
  gridEl?.classList.add('ring-2', 'ring-accent');
  listEl?.classList.add('ring-2', 'ring-accent');
  // scroll into view
  (gridEl ?? listEl)?.scrollIntoView({ behavior: 'smooth', block: 'center' });
};

/**
 * Switches visible episode range in grid.
 * Updates dropdown label and hides/shows episode cards.
 */
export const switchEpisodeRange = (idx: number): void => {
  const dropdown = state.container.querySelector('[data-episode-dropdown]') as HTMLElement | null;
  if (!dropdown) return;
  const btns = Array.from(dropdown.querySelectorAll('.episode-range-btn')) as HTMLButtonElement[];
  const target = btns[idx];
  if (!target) return;

  const start = Number.parseInt(target.dataset.rangeStart ?? '1', 10);
  const end = Number.parseInt(target.dataset.rangeEnd ?? '100', 10);

  // update label (e.g., "01-100")
  const label = dropdown.querySelector('[data-dropdown-label]') as HTMLElement | null;
  if (label)
    label.textContent = `${String(start).padStart(2, '0')}-${String(end).padStart(2, '0')}`;

  // show/hide episodes in range
  state.episodeGrid?.querySelectorAll('[data-episode-id]').forEach(el => {
    const n = Number.parseInt((el as HTMLElement).dataset.episodeId ?? '0', 10);
    el.classList.toggle('hidden', n < start || n > end);
  });
};