// fileStore.js
const STORAGE_KEY = "devmate_ide_tree_v2";

/**
 * Tree node structure:
 * {
 *   type: "folder" | "file",
 *   name: "src" or "main.py",
 *   path: "src" or "src/main.py",
 *   children: [ ... ]  // only for folders
 *   content: "..."     // only for files
 * }
 */

const defaultTree = {
  type: "folder",
  name: "root",
  path: "",
  children: [
    {
      type: "file",
      name: "main.py",
      path: "main.py",
      content: "# Python\nprint('Hello from IDE')",
    },
    {
      type: "folder",
      name: "src",
      path: "src",
      children: [
        {
          type: "file",
          name: "script.js",
          path: "src/script.js",
          content: "console.log('Hello from src');",
        },
      ],
    },
  ],
};

// ---------- persistence ----------
export function loadTree() {
  try {
    const raw = localStorage.getItem(STORAGE_KEY);
    return raw ? JSON.parse(raw) : defaultTree;
  } catch (e) {
    console.warn("loadTree failed:", e);
    return defaultTree;
  }
}

export function saveTree(tree) {
  try {
    localStorage.setItem(STORAGE_KEY, JSON.stringify(tree));
  } catch (e) {
    console.warn("saveTree failed:", e);
  }
}

// ---------- traversal helpers ----------
function clone(obj) {
  return JSON.parse(JSON.stringify(obj));
}

// find node and parent by path
export function findNodeAndParent(root, path) {
  if (path === "" || path == null) return { node: root, parent: null };
  const parts = path.split("/").filter(Boolean);
  let node = root;
  let parent = null;
  for (let i = 0; i < parts.length; i++) {
    const part = parts[i];
    parent = node;
    if (!parent.children) return { node: null, parent: null };
    node = parent.children.find((c) => c.name === part);
    if (!node) return { node: null, parent: null };
  }
  return { node, parent };
}

export function getNodeByPath(root, path) {
  const r = findNodeAndParent(root, path);
  return r.node || null;
}

// build child path
function joinPath(parentPath, name) {
  if (!parentPath) return name;
  if (!name) return parentPath;
  return parentPath + "/" + name;
}

// ---------- CRUD operations ----------

// Add file under parentPath (string). If parentPath points to file, use its parent.
export function addFile(tree, filename, parentPath = "") {
  const newTree = clone(tree);
  // find parent
  const { node: parent } = findNodeAndParent(newTree, parentPath);
  const target = parent?.type === "folder" ? parent : newTree;
  // ensure unique name
  let name = filename;
  const exists = (name) =>
    target.children && target.children.some((c) => c.name === name);
  let idx = 1;
  const base = name.includes(".") ? name.slice(0, name.lastIndexOf(".")) : name;
  const ext = name.includes(".") ? name.slice(name.lastIndexOf(".")) : "";
  while (exists(name)) {
    name = `${base}_${idx++}${ext}`;
  }
  const path = joinPath(target.path, name);
  const newNode = { type: "file", name, path, content: `// ${name}\n` };
  target.children = target.children || [];
  target.children.push(newNode);
  return newTree;
}

// Add folder under parentPath
export function addFolder(tree, folderName, parentPath = "") {
  const newTree = clone(tree);
  const { node: parent } = findNodeAndParent(newTree, parentPath);
  const target = parent?.type === "folder" ? parent : newTree;
  let name = folderName;
  const exists = (name) =>
    target.children && target.children.some((c) => c.name === name && c.type === "folder");
  let idx = 1;
  while (exists(name)) {
    name = `${folderName}_${idx++}`;
  }
  const path = joinPath(target.path, name);
  const newNode = { type: "folder", name, path, children: [] };
  target.children = target.children || [];
  target.children.push(newNode);
  return newTree;
}

// Delete node (file or folder) at given path (recursive for folders)
export function deleteNode(tree, path) {
  const newTree = clone(tree);
  if (!path) return newTree; // cannot delete root
  const parts = path.split("/").filter(Boolean);
  const nameToDelete = parts.pop();
  const parentPath = parts.join("/");
  const { node: parent } = findNodeAndParent(newTree, parentPath);
  if (!parent || !parent.children) return newTree;
  parent.children = parent.children.filter((c) => c.name !== nameToDelete);
  return newTree;
}

// Rename node: change name and update paths recursively for children
export function renameNode(tree, path, newName) {
  const newTree = clone(tree);
  const { node, parent } = findNodeAndParent(newTree, path);
  if (!node || !parent) {
    // special case root rename not allowed
    if (node && !parent) return newTree;
    return newTree;
  }
  // ensure no duplicate under parent
  if (parent.children.some((c) => c.name === newName && c.path !== node.path)) {
    // collision: abort
    return newTree;
  }

  const oldPath = node.path;
  node.name = newName;
  const newPath = joinPath(parent.path, newName);
  // update path recursively
  function updatePaths(n, currPath) {
    n.path = currPath;
    if (n.children) {
      for (let child of n.children) {
        const childNewPath = currPath ? currPath + "/" + child.name : child.name;
        updatePaths(child, childNewPath);
      }
    }
  }
  updatePaths(node, newPath);
  return newTree;
}

// Update file content
export function updateFileContent(tree, path, content) {
  const newTree = clone(tree);
  const { node } = findNodeAndParent(newTree, path);
  if (node && node.type === "file") {
    node.content = content;
  }
  return newTree;
}

// Search within files (returns array of {path, file, excerpt})
export function searchTree(node, term, results = []) {
  if (!node) return results;
  if (node.type === "file" && node.content && node.content.includes(term)) {
    results.push({
      path: node.path,
      file: node.name,
      excerpt: node.content
        .split("\n")
        .filter((l) => l.includes(term))
        .slice(0, 5)
        .join("\n"),
    });
  }
  if (node.children) {
    for (const c of node.children) searchTree(c, term, results);
  }
  return results;
}