import { el, clear, onTeardown } from '../lib/dom.js';
import { loadSnapshot } from '../data/snapshot.js';
import { resolvePokedex, dexRows, prettify } from '../data/pokedex-resolver.js';
import { settings } from '../store/settings.js';
import { selection, stats } from '../store/selection.js';
import { Card } from '../components/Card.js';
import { ProgressRing } from '../components/ProgressRing.js';

const FILTERS = [
  { key: 'all', label: 'All', test: () => true },
  { key: 'caught', label: 'Caught', test: (e) => e.caught },
  { key: 'missing', label: 'Missing', test: (e) => !e.caught },
  { key: 'favorite', label: 'Favorites', test: (e) => e.favorite },
];

const SEARCH_ICON =
  '<svg viewBox="0 0 24 24" width="18" height="18" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"><circle cx="11" cy="11" r="7"/><path d="m20 20-3.5-3.5"/></svg>';

export async function DexGrid() {
  const view = el('section', { class: 'view dexgrid' });
  const snap = await loadSnapshot();

  const grid = el('div', { class: 'grid' });
  let query = '';
  let filterKey = 'all';
  let rows = [];
  let ids = [];

  const ring = ProgressRing();

  const title = el('h1', {});
  const gamePill = el(
    'a',
    { class: 'game-pill', href: '#/games' },
    el('span', {}),
    el('span', { class: 'game-pill__chev', 'aria-hidden': 'true' }, '⌄'),
  );

  const search = el('input', {
    class: 'field-search__input',
    type: 'search',
    placeholder: 'Filter this Pokédex…',
    oninput: (e) => {
      query = e.target.value.trim().toLowerCase();
      paintGrid();
    },
  });

  const filterBar = el('div', { class: 'feed-chips' });
  const chipEls = FILTERS.map((f) => {
    const count = el('span', { class: 'feed-chip__count' });
    const btn = el(
      'button',
      {
        class: 'feed-chip',
        type: 'button',
        onclick: () => {
          filterKey = f.key;
          chipEls.forEach((c, i) => c.btn.classList.toggle('is-active', FILTERS[i].key === f.key));
          paintGrid();
        },
      },
      el('span', {}, f.label),
      count,
    );
    filterBar.append(btn);
    return { btn, count };
  });
  chipEls[0].btn.classList.add('is-active');

  view.append(
    el(
      'header',
      { class: 'feed-head' },
      el(
        'div',
        { class: 'feed-head__top' },
        el('div', { class: 'feed-head__id' }, title, gamePill),
        ring.node,
      ),
      el(
        'div',
        { class: 'field-search' },
        el('span', { class: 'field-search__icon', html: SEARCH_ICON, 'aria-hidden': 'true' }),
        search,
      ),
      filterBar,
    ),
    grid,
  );

  function counts() {
    const p = selection.get().pokemon;
    let caught = 0;
    let favorite = 0;
    for (const id of ids) {
      const e = p[id];
      if (!e) continue;
      if (e.caught) caught++;
      if (e.favorite) favorite++;
    }
    return { all: ids.length, caught, missing: ids.length - caught, favorite };
  }

  function refreshMeta() {
    ring.update(stats(ids));
    const c = counts();
    chipEls.forEach(({ count }, i) => {
      count.textContent = c[FILTERS[i].key];
    });
  }

  function paintGrid() {
    const st = settings.get();
    const pokemonState = selection.get().pokemon;
    // Gen 1–2 game-era sprites have opaque white backgrounds — frame them.
    const boxed =
      st.spriteStyle === 'game' &&
      (snap.versionGroupByKey.get(st.versionGroup)?.generation ?? 9) <= 2;
    const filterTest = FILTERS.find((f) => f.key === filterKey).test;
    const frag = document.createDocumentFragment();
    let shown = 0;

    for (const { species, number } of rows) {
      if (
        query &&
        !species.name.includes(query) &&
        String(number) !== query &&
        String(species.id) !== query
      ) {
        continue;
      }
      const e = pokemonState[species.id] || { seen: false, caught: false, favorite: false };
      if (!filterTest(e)) continue;
      const card = Card(species, number, {
        spriteStyle: st.spriteStyle,
        versionGroup: st.versionGroup,
        boxed,
      });
      if (shown < 30) card.style.setProperty('--i', String(shown));
      frag.append(card);
      shown++;
    }

    clear(grid);
    grid.append(
      shown === 0
        ? el('p', { class: 'grid__empty' }, 'Nothing matches those filters.')
        : frag,
    );
  }

  function rebuild() {
    const st = settings.get();
    const dex = resolvePokedex(snap, st);
    rows = dexRows(snap, dex);
    ids = rows.map((r) => r.species.id);

    title.textContent = prettify(dex.name || dex.key);
    gamePill.firstChild.textContent = prettify(st.versionGroup);
    refreshMeta();
    paintGrid();
  }

  rebuild();

  const offSettings = settings.subscribe(rebuild);
  const offSelection = selection.subscribe(() => {
    refreshMeta();
    if (filterKey !== 'all') paintGrid();
  });
  onTeardown(view, () => {
    offSettings();
    offSelection();
  });

  return view;
}