import { state }           from './state.js';
import { showLoading, hideLoading, setStatus, showToast } from './ui.js';
import * as history from './history.js';
import {
  renderGrid, updateSelCount, updateNumberBadges,
  updateNewNameLabels, refreshCardSelection, showEmptyGrid,
} from './grid.js';
import { doRename }         from './rename.js';
import { handleFolderDrop } from './move.js';
import { initModalControls } from './modal.js';
import * as deleteHandler   from './delete.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';
import * as fileExplorer    from './handlers/file-explorer.js';

let _homeDir = null;

// ── DOM ──────────────────────────────────────────────
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 inputPrefix      = document.getElementById('input-prefix');
const inputDigits      = document.getElementById('input-digits');
const previewName      = document.getElementById('preview-name');
const dirPath          = document.getElementById('dir-path');
const rubberBand       = document.getElementById('rubber-band');
const grid             = document.getElementById('grid');
const gridContainer    = document.getElementById('grid-container');
const dragGhostEl      = document.getElementById('drag-ghost');
const thumbSizeHint    = document.getElementById('thumb-size-hint');
const btnPreviewToggle = document.getElementById('btn-preview-toggle');
const btnUndo          = document.getElementById('btn-undo');
const btnRedo          = document.getElementById('btn-redo');
const fileExplorerContainer = document.querySelector('.file-explorer');

// ── 핸들러 초기화 ─────────────────────────────────
history.setOnUpdate(updateHistoryButtons);
initModalControls();

const callbacks = {
  refreshCardSelection, updateSelCount, updateNumberBadges, updateNewNameLabels,
  pushHistory: (affectedPaths) => history.pushReorder(state.files, affectedPaths),
};

pinchZoom.init({ gridContainer, thumbSizeHint });
selection.init({ gridContainer, rubberBand, grid, state, callbacks });
dragDrop.init({ grid, gridContainer, dragGhostEl, state, callbacks, fileExplorerEl: fileExplorerContainer, onFolderDrop: handleFolderDrop });
hoverPreview.init();
deleteHandler.init(grid);
fileExplorer.init(fileExplorerContainer, loadFolder);

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

// ── 앱 시작 ───────────────────────────────────────
(async () => {
  const [lastFolder, homeDir, previewOn] = await Promise.all([
    window.api.getLastFolder(),
    window.api.getHomeDir(),
    window.api.getPreviewOn(),
  ]);
  _homeDir = homeDir;

  btnPreviewToggle.classList.toggle('active', previewOn);
  hoverPreview.setEnabled(previewOn);

  const target = lastFolder || homeDir;
  await fileExplorer.loadTree(homeDir, target);
  await loadFolder(target);
})();

// ── 버튼 / 키보드 이벤트 ─────────────────────────
inputPrefix.addEventListener('input', updatePreview);
inputDigits.addEventListener('input', updatePreview);
btnOpen.addEventListener('click', openFolder);
btnSortName.addEventListener('click', () => sortFiles('name'));
btnSortDate.addEventListener('click', () => sortFiles('date'));
btnRename.addEventListener('click', doRename);
btnUndo.addEventListener('click', performUndo);
btnRedo.addEventListener('click', performRedo);
btnPreviewToggle.addEventListener('click', () => {
  const on = btnPreviewToggle.classList.toggle('active');
  hoverPreview.setEnabled(on);
  window.api.setPreviewOn(on);
});

document.addEventListener('keydown', (e) => {
  if (e.target.tagName === 'INPUT') return;
  if (e.code === 'KeyO') btnOpen.click();
  if (e.code === 'KeyS' && !btnRename.disabled) btnRename.click();
  if (e.code === 'KeyA') {
    state.files.forEach((_, i) => state.selectedIdxs.add(i));
    refreshCardSelection();
    updateSelCount();
  }
  if (e.metaKey && !e.shiftKey && e.code === 'KeyZ') { e.preventDefault(); performUndo(); }
  if (e.metaKey && e.shiftKey && e.code === 'KeyZ') { e.preventDefault(); performRedo(); }
  if (e.code === 'KeyP') btnPreviewToggle.click();
  if (e.code === 'Backspace' || e.code === 'Delete') deleteHandler.deleteSelected();
});

// ── 폴더 열기 (다이얼로그) ───────────────────────
async function openFolder() {
  const folder = await window.api.selectFolder();
  if (!folder) return;
  const homeDir = _homeDir;
  if (folder.startsWith(homeDir)) {
    await fileExplorer.loadTree(homeDir, folder);
  } else {
    await fileExplorer.loadTree(folder, folder);
  }
  await loadFolder(folder);
}

// ── 폴더 로드 (트리 클릭 또는 다이얼로그 공통) ──
async function loadFolder(folder) {
  if (!folder) return;
  state.currentFolder = folder;
  dirPath.textContent = folder;
  await window.api.setLastFolder(folder);
  await fileExplorer.setSelectedPath(folder);

  showLoading('이미지 목록 불러오는 중...');
  const list = await window.api.listImages(folder);
  hideLoading();

  if (!list.length) {
    state.files.length = 0;
    state.selectedIdxs.clear();
    showEmptyGrid();
    btnRename.disabled = true;
    setStatus('이미지 파일 없음', false);
    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;
  history.reset();
  history.pushReorder(state.files);
}

// ── 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);
  history.pushReorder(state.files);
}

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

// ── Undo / Redo ───────────────────────────────────
let _historyBusy = false;

function updateHistoryButtons() {
  btnUndo.disabled = !history.canUndo();
  btnRedo.disabled = !history.canRedo();
}

async function performUndo() {
  if (_historyBusy || !history.canUndo()) {
    if (!history.canUndo()) showToast('더 이상 되돌릴 수 없습니다');
    return;
  }
  _historyBusy = true;
  try {
    const { entry, targetFiles } = history.undo();
    if (entry.type === 'delete') {
      const { restored, errors } = await window.api.restoreStagedFiles(entry.deletedEntries);
      if (errors.length) showToast('일부 파일 복원 실패: ' + errors[0]);
      _applyHistorySnapshot(targetFiles, new Set(restored));
      if (restored.length) setStatus(`${restored.length}개 파일 복원됨`, true);
    } else {
      _applyHistorySnapshot(targetFiles, entry.affectedPaths);
    }
  } finally {
    _historyBusy = false;
  }
}

async function performRedo() {
  if (_historyBusy || !history.canRedo()) {
    if (!history.canRedo()) showToast('마지막 작업 상태입니다');
    return;
  }
  _historyBusy = true;
  try {
    const nextEntry = history.peekRedo();
    if (nextEntry.type === 'delete') {
      const pathsToRedo = nextEntry.deletedEntries.map(e => e.originalPath);
      const { staged, errors } = await window.api.stageDeleteFiles(pathsToRedo);
      if (errors.length) showToast('일부 파일 삭제 실패: ' + errors[0]);
      const stagedByPath = new Map(staged.map(s => [s.originalPath, s.stagingPath]));
      nextEntry.deletedEntries.forEach(e => {
        if (stagedByPath.has(e.originalPath)) e.stagingPath = stagedByPath.get(e.originalPath);
      });
      const { targetFiles } = history.redo();
      _applyHistorySnapshot(targetFiles, null);
      if (staged.length) setStatus(`${staged.length}개 파일 삭제됨`, true);
    } else {
      const { entry, targetFiles } = history.redo();
      _applyHistorySnapshot(targetFiles, entry.affectedPaths);
    }
  } finally {
    _historyBusy = false;
  }
}

function _applyHistorySnapshot(targetFiles, affectedPaths = null) {
  state.files.length = 0;
  state.files.push(...targetFiles);
  state.selectedIdxs.clear();

  if (affectedPaths && affectedPaths.size > 0) {
    const pathToIdx = new Map(state.files.map((f, i) => [f.path, i]));
    affectedPaths.forEach(p => {
      const idx = pathToIdx.get(p);
      if (idx !== undefined) state.selectedIdxs.add(idx);
    });
  }

  state.sortMode = null;
  updateSortButtons();
  if (!state.files.length) {
    showEmptyGrid();
    btnRename.disabled = true;
  } else {
    renderGrid();
    btnRename.disabled = false;
  }
  updateHistoryButtons();
}

// ── 포맷 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();
}