/**
 * dom-polyfill.ts
 *
 * Sets up (or extends) the global DOM environment required by @maxgraph/core
 * when running in Node.js. Safe to import multiple times — idempotent.
 *
 * The parser (drawio-parser/parser.ts) already sets up a partial DOM polyfill
 * for the basic maxGraph model/serializer classes. This module extends it with
 * the additional globals needed by Graph+GraphView (rendering pipeline):
 *   - location
 *   - SVGElement, MouseEvent, KeyboardEvent, TouchEvent
 *   - requestAnimationFrame / cancelAnimationFrame
 *
 * Must be imported before any maxGraph Graph/GraphView usage.
 */

import { JSDOM } from "jsdom";

// Use the same DOM that may already be set up by parser.ts, or create a new one.
// We detect by checking whether global.document already exists.
let win: Record<string, unknown>;

if ((globalThis as Record<string, unknown>)["document"]) {
  // Parser already set up a DOM — re-use the existing window
  win = (globalThis as Record<string, unknown>)["window"] as Record<string, unknown>;
} else {
  const dom = new JSDOM(
    '<!DOCTYPE html><html><body></body></html>',
    { pretendToBeVisual: true }
  );
  win = dom.window as unknown as Record<string, unknown>;
  (globalThis as Record<string, unknown>)["document"] = win["document"];
  (globalThis as Record<string, unknown>)["window"] = win;
  (globalThis as Record<string, unknown>)["DOMParser"] = win["DOMParser"];
  (globalThis as Record<string, unknown>)["XMLSerializer"] = win["XMLSerializer"];
  (globalThis as Record<string, unknown>)["HTMLElement"] = win["HTMLElement"];
  (globalThis as Record<string, unknown>)["Element"] = win["Element"];
  (globalThis as Record<string, unknown>)["Node"] = win["Node"];
  (globalThis as Record<string, unknown>)["Event"] = win["Event"];
  try {
    Object.defineProperty(globalThis, "navigator", {
      value: win["navigator"],
      writable: true,
      configurable: true,
    });
  } catch { /* already defined */ }
}

// Add/overwrite globals needed specifically for Graph+GraphView rendering
const g = globalThis as Record<string, unknown>;

if (!g["SVGElement"]) g["SVGElement"] = win["SVGElement"] ?? class SVGElement {};
if (!g["MouseEvent"]) g["MouseEvent"] = win["MouseEvent"] ?? class MouseEvent {};
if (!g["KeyboardEvent"]) g["KeyboardEvent"] = win["KeyboardEvent"] ?? class KeyboardEvent {};
if (!g["TouchEvent"]) g["TouchEvent"] = win["TouchEvent"] ?? class TouchEvent {};
if (!g["requestAnimationFrame"]) {
  g["requestAnimationFrame"] = (fn: () => void) => setTimeout(fn, 0);
}
if (!g["cancelAnimationFrame"]) {
  g["cancelAnimationFrame"] = clearTimeout;
}
// location is needed by UrlConverter (used when rendering image shapes)
if (!g["location"]) {
  g["location"] = {
    protocol: "http:",
    host: "localhost",
    href: "http://localhost/",
    pathname: "/",
  };
}

export {};