// MarkLite — Sidebar Module: file tree, independent files, resize handle
(function () {
  'use strict';
  var ML = window.MarkLite;

  var expandedDirs = new Set();
  var lastTreeData = null;

  // ===== Sidebar Highlight =====
  ML.updateSidebarHighlight = function () {
    var tab = ML.getActiveTab();
    var activePath = tab ? tab.filePath : null;
    if (!ML.currentRootPath) {
      ML.sidebarTree.innerHTML = '';
      var indep = renderIndependentFiles();
      if (indep) ML.sidebarTree.appendChild(indep);
      return;
    }
    var oldSection = ML.sidebarTree.querySelector('.independent-files-section');
    var newSection = renderIndependentFiles();
    if (oldSection) oldSection.remove();
    if (newSection) ML.sidebarTree.insertBefore(newSection, ML.sidebarTree.firstChild);
    var treeItems = ML.sidebarTree.querySelectorAll('.tree-item:not(.independent-file-item)');
    treeItems.forEach(function (item) {
      var itemPath = item.dataset.path;
      if (itemPath) item.classList.toggle('active', itemPath === activePath);
    });
  };

  // ===== Independent Files =====
  function getIndependentFiles() {
    if (!ML.tabs.length) return [];
    return ML.tabs.filter(function (t) {
      if (!t.filePath) return false;
      if (!ML.currentRootPath) return true;
      return !t.filePath.startsWith(ML.currentRootPath);
    });
  }

  function renderIndependentFiles() {
    var files = getIndependentFiles();
    if (files.length === 0) return null;
    var section = document.createElement('div');
    section.className = 'independent-files-section';
    var header = document.createElement('div');
    header.className = 'independent-files-header';
    header.textContent = '已打开的文件';
    section.appendChild(header);
    files.forEach(function (tab) {
      var item = document.createElement('div');
      item.className = 'tree-item independent-file-item';
      item.style.paddingLeft = '8px';
      item.dataset.path = tab.filePath;
      var icon = document.createElement('span');
      icon.className = 'tree-icon';
      icon.innerHTML = '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path><polyline points="14 2 14 8 20 8"></polyline></svg>';
      item.appendChild(icon);
      var name = document.createElement('span');
      name.className = 'tree-name';
      name.textContent = ML.getFileName(tab.filePath);
      item.appendChild(name);
      if (tab.isModified) {
        var dot = document.createElement('span');
        dot.className = 'independent-modified-dot';
        dot.textContent = ' •';
        item.appendChild(dot);
      }
      if (tab.id === ML.activeTabId) item.classList.add('active');
      item.addEventListener('click', function (e) { e.stopPropagation(); ML.switchToTab(tab.id); });
      section.appendChild(item);
    });
    return section;
  }

  // ===== Folder Operations =====
  async function openFolderDialog() {
    if (typeof window.electronAPI !== 'undefined' && window.electronAPI.openFolderDialog) {
      var result = await window.electronAPI.openFolderDialog();
      if (result) loadFolder(result);
    }
  }

  async function loadFolder(dirPath) {
    if (typeof window.electronAPI === 'undefined') return;
    ML.currentRootPath = dirPath;
    var result = await window.electronAPI.readDirTree(dirPath);
    if (result.success) {
      renderTree(result.tree, dirPath);
      ML.sidebar.classList.remove('collapsed');
      window.electronAPI.watchDir(dirPath);
    }
  }

  async function refreshTree() {
    if (!ML.currentRootPath) return;
    var result = await window.electronAPI.readDirTree(ML.currentRootPath);
    if (result.success) renderTree(result.tree, ML.currentRootPath);
  }

  // ===== Tree Rendering =====
  function renderTreeOriginal(tree, rootPath) {
    ML.sidebarTree.innerHTML = '';
    var rootNode = { name: ML.getFileName(rootPath) || rootPath, path: rootPath, type: 'dir', children: tree };
    expandedDirs.add(rootPath);
    var fragment = document.createDocumentFragment();
    buildTreeDOM(fragment, rootNode, 0);
    ML.sidebarTree.appendChild(fragment);
  }

  function renderTree(tree, rootPath) {
    lastTreeData = tree;
    renderTreeOriginal(tree, rootPath);
    var folderHeader = document.createElement('div');
    folderHeader.className = 'sidebar-section-header';
    folderHeader.textContent = '文件夹目录树';
    ML.sidebarTree.insertBefore(folderHeader, ML.sidebarTree.firstChild);
    var indepSection = renderIndependentFiles();
    if (indepSection) ML.sidebarTree.insertBefore(indepSection, ML.sidebarTree.firstChild);
  }

  function buildTreeDOM(parent, node, depth) {
    var item = document.createElement('div');
    item.className = 'tree-item';
    item.style.paddingLeft = (8 + depth * 16) + 'px';
    if (node.type === 'dir') {
      var isExpanded = expandedDirs.has(node.path);
      var arrow = document.createElement('span');
      arrow.className = 'tree-arrow' + (isExpanded ? ' expanded' : '');
      arrow.innerHTML = '<svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5"><polyline points="9 18 15 12 9 6"></polyline></svg>';
      item.appendChild(arrow);
      var icon = document.createElement('span');
      icon.className = 'tree-icon';
      icon.innerHTML = '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z"></path></svg>';
      item.appendChild(icon);
      var name = document.createElement('span');
      name.className = 'tree-name';
      name.textContent = node.name;
      item.appendChild(name);
      parent.appendChild(item);
      if (isExpanded && node.children) {
        node.children.forEach(function (child) { buildTreeDOM(parent, child, depth + 1); });
      }
      item.addEventListener('click', function (e) {
        e.stopPropagation();
        if (expandedDirs.has(node.path)) expandedDirs.delete(node.path);
        else expandedDirs.add(node.path);
        renderTree(lastTreeData || [], ML.currentRootPath);
      });
    } else {
      var spacer = document.createElement('span');
      spacer.style.width = '16px';
      spacer.style.flexShrink = '0';
      item.appendChild(spacer);
      var fileIcon = document.createElement('span');
      fileIcon.className = 'tree-icon';
      fileIcon.innerHTML = '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"></path><polyline points="14 2 14 8 20 8"></polyline></svg>';
      item.appendChild(fileIcon);
      var fileName = document.createElement('span');
      fileName.className = 'tree-name';
      fileName.textContent = node.name;
      item.appendChild(fileName);
      var tab = ML.getActiveTab();
      if (tab && tab.filePath === node.path) item.classList.add('active');
      item.dataset.path = node.path;
      parent.appendChild(item);
      item.addEventListener('click', async function (e) {
        e.stopPropagation();
        var existing = ML.tabs.find(function (t) { return t.filePath === node.path; });
        if (existing) { ML.switchToTab(existing.id); }
        else if (typeof window.electronAPI !== 'undefined') {
          var result = await window.electronAPI.readFile(node.path);
          if (result.success) ML.createNewTab(node.path, result.content);
        }
      });
    }
  }

  // ===== Init =====
  ML.initSidebar = function () {
    var settings = ML.loadSettings();
    if (settings.sidebarCollapsed) ML.sidebar.classList.add('collapsed');
    if (settings.sidebarWidth) ML.sidebar.style.width = settings.sidebarWidth + 'px';

    // Resize handle
    var handle = document.createElement('div');
    handle.className = 'sidebar-resize-handle';
    ML.sidebar.appendChild(handle);
    var isResizing = false;
    handle.addEventListener('mousedown', function (e) { isResizing = true; document.body.style.cursor = 'col-resize'; document.body.style.userSelect = 'none'; e.preventDefault(); });
    document.addEventListener('mousemove', function (e) {
      if (!isResizing) return;
      var newWidth = Math.max(180, Math.min(500, e.clientX));
      ML.sidebar.style.width = newWidth + 'px';
      ML.saveSetting('sidebarWidth', newWidth);
    });
    document.addEventListener('mouseup', function () { if (isResizing) { isResizing = false; document.body.style.cursor = ''; document.body.style.userSelect = ''; } });

    ML.btnOpenFolder.addEventListener('click', function () { if (typeof window.electronAPI !== 'undefined') openFolderDialog(); });
    if (typeof window.electronAPI !== 'undefined') {
      var dirRefreshTimer = null;
      window.electronAPI.onDirChanged(function () {
        if (!ML.currentRootPath) return;
        if (dirRefreshTimer) clearTimeout(dirRefreshTimer);
        dirRefreshTimer = setTimeout(function () { refreshTree(); }, 300);
      });
    }
  };
})();