// @ts-check

import crel, { fragment } from "../common/crel.js";
import formatBytes from "../common/formatBytes.js";
/** @typedef {import("./nodePath.js").NodePath} NodePath */
/** @typedef {import("../../types/png.d.ts").PngNode} PngNode */

/**
 * @typedef {Function} NodeUiFn
 * @param {PngNode} node
 * @returns {NodeUi}
 */

/**
 * @param {PngNode} rootNode
 * @param {NodeUiFn} getNodeUi
 * @returns {DocumentFragment}
 */
export default (rootNode, getNodeUi) => {
  const [bytesRootEl, treeRootEl] = traverse(rootNode, [], getNodeUi);

  const outerBytesEl = crel("div", { class: "bytes" }, bytesRootEl);
  const outerTreeEl = crel("div", { class: "tree" }, treeRootEl);

  return fragment(outerBytesEl, outerTreeEl);
};

/**
 * @param {PngNode} node
 * @param {NodePath} path
 * @param {NodeUiFn} getNodeUi
 * @returns [HTMLElement, HTMLElement] Each node's bytes and tree elements.
 */
const traverse = (node, path, getNodeUi) => {
  const nodeBytesEl = crel("span", { "data-path": path });

  const isRoot = path.length === 0;
  const { title, description } = getNodeUi(node);
  const nodeTreeEl = crel(
    "details",
    { "data-path": path, ...(isRoot ? { open: "open" } : {}) },
    crel(
      "summary",
      {},
      crel("span", { "class": "title" }, title),
      crel(
        "span",
        { "class": "bytecount" },
        "TODO: X bytes",
      ),
    ),
    description,
  );

  if (node.children) {
    const treeChildrenEl = crel("div", { class: "children" });
    node.children.forEach((child, index) => {
      const [childBytesEl, childTreeEl] = traverse(
        child,
        path.concat(index),
        getNodeUi,
      );
      if (index > 0) nodeBytesEl.append(" ");
      nodeBytesEl.append(childBytesEl);
      treeChildrenEl.append(childTreeEl);
    });
    nodeTreeEl.append(treeChildrenEl);
  } else {
    nodeBytesEl.innerHTML = formatBytes(node.bytes, 256);
  }

  return [nodeBytesEl, nodeTreeEl];
};