import { state }        from './state.js';
import * as pinchZoom   from './handlers/pinch-zoom.js';
import * as selection    from './handlers/selection.js';
import * as dragDrop     from './handlers/drag-drop.js';
import * as hoverPreview from './handlers/image-preview.js';

let _cardObserver = null;

// ── DOM ──────────────────────────────────────────────
const grid          = document.getElementById('grid');
const emptyState    = document.getElementById('empty-state');
const btnOpen       = document.getElementById('btn-open');
const btnSortName   = document.getElementById('btn-sort-name');
const btnSortDate   = document.getElementById('btn-sort-date');
const btnRename     = document.getElementById('btn-rename');
const btnReveal     = document.getElementById('btn-reveal');
const inputPrefix   = document.getElementById('input-prefix');
const inputDigits   = document.getElementById('input-digits');
const previewName   = document.getElementById('preview-name');
const fileCount     = document.getElementById('file-count');
const selCount      = document.getElementById('sel-count');
const dirPath       = document.getElementById('dir-path');
const statusDot     = document.getElementById('status-dot');
const statusText    = document.getElementById('status-text');
const loading       = document.getElementById('loading');
const loadingText   = document.getElementById('loading-text');
const toast         = document.getElementById('toast');
const rubberBand    = document.getElementById('rubber-band');
const gridContainer = document.getElementById('grid-container');
const dragGhostEl   = document.getElementById('drag-ghost');
const thumbSizeHint = document.getElementById('thumb-size-hint');

// ── 핸들러 초기화 ─────────────────────────────────
const callbacks = {
  refreshCardSelection,
  updateSelCount,
  updateNumberBadges,
  updateNewNameLabels,
};

pinchZoom.init({ gridContainer, thumbSizeHint });
selection.init({ gridContainer, rubberBand, grid, state, callbacks });
dragDrop.init({ grid, gridContainer, dragGhostEl, state, callbacks });
hoverPreview.init();

window.api.onFullscreenChange((isFullscreen) => {
  document.body.classList.toggle('fullscreen', isFullscreen);
});

// ── 버튼 이벤트 ──────────────────────────────────
inputPrefix.addEventListener('input', updatePreview);
inputDigits.addEventListener('input', updatePreview);
btnOpen.addEventListener('click', openFolder);

document.addEventListener('keydown', (e) => {
  if (e.target.tagName === 'INPUT') return;
  if (e.code === 'KeyO') btnOpen.click();
  if (e.code === 'KeyS' && !btnRename.disabled) btnRename.click();
});
btnSortName.addEventListener('click', () => sortFiles('name'));
btnSortDate.addEventListener('click', () => sortFiles('date'));
btnRename.addEventListener('click', doRename);
btnReveal.addEventListener('click', () => {
  if (state.currentFolder) window.api.revealFolder(state.currentFolder);
});

// ── 폴더 열기 ────────────────────────────────────
async function openFolder() {
  const folder = await window.api.selectFolder();
  if (!folder) return;
  state.currentFolder = folder;
  dirPath.textContent = folder;
  showLoading('이미지 목록 불러오는 중...');
  const list = await window.api.listImages(folder);
  hideLoading();
  if (!list.length) {
    setStatus('이미지 파일 없음', false);
    showToast('⚠️ 이미지 파일이 없습니다', '#f76a6a', '#0a0a0a');
    return;
  }
  state.files.length = 0;
  state.files.push(...list);
  state.selectedIdxs.clear();
  state.sortMode = 'name';
  updateSortButtons();
  setStatus(`${state.files.length}개 파일 로드됨`, true);

  const folderName = folder.replace(/\\/g, '/').split('/').pop();
  if (folderName) inputPrefix.value = folderName;

  renderGrid();
  updatePreview();
  btnRename.disabled = false;
  btnReveal.disabled = false;
}

// ── 그리드 렌더링 ────────────────────────────────
function renderGrid() {
  if (_cardObserver) { _cardObserver.disconnect(); _cardObserver = null; }

  grid.innerHTML = '';
  emptyState.style.display = 'none';
  grid.style.display = 'grid';
  fileCount.textContent = `${state.files.length}개 파일`;
  updateSelCount();

  // 카드 껍데기만 즉시 생성 (이미지 없음)
  state.files.forEach((file, idx) => grid.appendChild(createCard(file, idx)));

  // 뷰포트 ±400px 범위에 들어온 카드만 이미지 로딩
  const observer = new IntersectionObserver((entries) => {
    entries.forEach(async (entry) => {
      if (!entry.isIntersecting) return;
      observer.unobserve(entry.target);
      const img = entry.target.querySelector('img.card-thumb');
      if (!img || img.src) return;
      const dataUrl = await window.api.readImage(entry.target.dataset.filepath);
      if (dataUrl) img.src = dataUrl;
    });
  }, { root: gridContainer, rootMargin: '400px 0px', threshold: 0 });

  Array.from(grid.children).forEach(card => observer.observe(card));
  _cardObserver = observer;

  refreshCardSelection();
  updateNumberBadges();
  updateNewNameLabels();
}

// ── 카드 생성 ────────────────────────────────────
function createCard(file, idx) {
  const card = document.createElement('div');
  card.className = 'card';
  card.dataset.idx = idx;
  card.dataset.filepath = file.path;
  card.draggable = true;

  const numBadge = document.createElement('div');
  numBadge.className = 'card-num';
  numBadge.textContent = `#${idx + 1}`;

  const checkBadge = document.createElement('div');
  checkBadge.className = 'card-check';
  checkBadge.textContent = '✓';

  // src 없이 생성 — IntersectionObserver가 뷰포트 진입 시 로딩
  const thumb = document.createElement('img');
  thumb.className = 'card-thumb';
  thumb.alt = file.name;
  thumb.draggable = false;

  const body    = document.createElement('div');
  body.className = 'card-body';
  const nameEl  = document.createElement('div');
  nameEl.className = 'card-name';
  nameEl.title = file.name;
  nameEl.textContent = file.name;
  const newNameEl = document.createElement('div');
  newNameEl.className = 'card-new-name';

  body.appendChild(nameEl);
  body.appendChild(newNameEl);
  card.appendChild(numBadge);
  card.appendChild(checkBadge);
  card.appendChild(thumb);
  card.appendChild(body);

  dragDrop.setupCard(card);
  hoverPreview.setupCard(card);
  card.addEventListener('click', selection.onCardClick);

  return card;
}

// ── 정렬 ─────────────────────────────────────────
async function sortFiles(mode) {
  if (!state.files.length) return;
  if (mode === 'name') state.files.sort((a, b) => a.name.localeCompare(b.name, 'ko'));
  else                 state.files.sort((a, b) => a.mtime - b.mtime);
  state.sortMode = mode;
  state.selectedIdxs.clear();
  updateSortButtons();
  await renderGrid();
  setStatus(`${mode === 'name' ? '이름순' : '날짜순'}으로 정렬됨`, true);
}

function updateSortButtons() {
  btnSortName.classList.toggle('active', state.sortMode === 'name');
  btnSortDate.classList.toggle('active', state.sortMode === 'date');
}

// ── 미리보기 ─────────────────────────────────────
function updatePreview() {
  const prefix = inputPrefix.value.trim() || 'photo';
  const digits = Math.max(1, Math.min(6, parseInt(inputDigits.value) || 3));
  const ext    = state.files.length ? state.files[0].name.split('.').pop().toLowerCase() : 'jpg';
  previewName.textContent = `${prefix}_${'1'.padStart(digits, '0')}.${ext}`;
  updateNewNameLabels();
}

// ── 이름 변경 ────────────────────────────────────
async function doRename() {
  if (!state.files.length || !state.currentFolder) return;
  const prefix = inputPrefix.value.trim() || 'photo';
  const digits = Math.max(1, Math.min(6, parseInt(inputDigits.value) || 3));

  const examples = state.files.slice(0, 3).map((f, i) => {
    const ext = f.name.split('.').pop().toLowerCase();
    return `${f.name}  →  ${prefix}_${String(i + 1).padStart(digits, '0')}.${ext}`;
  }).join('\n');
  const more = state.files.length > 3 ? `\n... 외 ${state.files.length - 3}개` : '';

  if (!confirm(`📂 ${state.files.length}개 파일을 이름 변경합니다:\n\n${examples}${more}\n\n계속하시겠습니까?`)) return;

  showLoading('파일 이름 변경 중...');
  setStatus('이름 변경 중...', false);

  try {
    const result = await window.api.renameFiles({
      folderPath: state.currentFolder,
      files: state.files,
      prefix,
      digits,
    });
    hideLoading();
    if (result.errors.length) {
      alert('일부 오류:\n' + result.errors.join('\n'));
    } else {
      showToast(`✅ ${result.renamed.length}개 파일 이름 변경 완료!`);
      setStatus(`${result.renamed.length}개 파일 이름 변경 완료`, true);
    }
    const newList = await window.api.listImages(state.currentFolder);
    state.files.length = 0;
    state.files.push(...newList);
    state.selectedIdxs.clear();
    renderGrid();
  } catch (e) {
    hideLoading();
    alert('오류 발생: ' + e.message);
  }
}

// ── UI 업데이트 ──────────────────────────────────

function refreshCardSelection() {
  Array.from(grid.children).forEach((card, i) => {
    card.classList.toggle('selected', state.selectedIdxs.has(i));
  });
}

function updateNumberBadges() {
  Array.from(grid.children).forEach((card, i) => {
    const badge = card.querySelector('.card-num');
    if (badge) badge.textContent = `#${i + 1}`;
    card.dataset.idx = i;
  });
}

function updateNewNameLabels() {
  const prefix = inputPrefix.value.trim() || 'photo';
  const digits = Math.max(1, Math.min(6, parseInt(inputDigits.value) || 3));
  Array.from(grid.children).forEach((card, i) => {
    const el   = card.querySelector('.card-new-name');
    const file = state.files[i];
    if (!el || !file) return;
    const ext = file.name.split('.').pop().toLowerCase();
    el.textContent = `→ ${prefix}_${String(i + 1).padStart(digits, '0')}.${ext}`;
  });
}

function updateSelCount() {
  const n = state.selectedIdxs.size;
  if (n > 0) {
    selCount.textContent = `${n}개 선택됨`;
    selCount.classList.add('visible');
  } else {
    selCount.textContent = '';
    selCount.classList.remove('visible');
  }
}

// ── 공통 UI 헬퍼 ─────────────────────────────────

function showLoading(msg = '처리 중...') {
  loadingText.textContent = msg;
  loading.classList.add('show');
}
function hideLoading() {
  loading.classList.remove('show');
}
function setStatus(msg, ready) {
  statusText.textContent = msg;
  statusDot.className = 'status-dot' + (ready ? ' ready' : '');
}
function showToast(msg, bg = '#6af7a0', color = '#0a2a1a') {
  toast.textContent = msg;
  toast.style.background = bg;
  toast.style.color = color;
  toast.classList.add('show');
  setTimeout(() => toast.classList.remove('show'), 3000);
}